20-F 1 d245977d20f.htm ANNUAL REPORT Annual Report
falseFY0.002490.001390.00240.003480.012830.001620.002550.0094P1YP1DP1D0.004120.006960.002960.00770.004120.006960001163653http://fasb.org/us-gaap/2021-01-31#PropertyPlantAndEquipmentNethttp://fasb.org/us-gaap/2021-01-31#PropertyPlantAndEquipmentNethttp://fasb.org/us-gaap/2021-01-31#OperatingLeaseLiabilityPrimarily includes a reduction of ¥59,330 million of valuation allowances of certain foreign subsidiaries mainly by expiration of loss carryforwards, an increase of ¥11,462 million of valuation allowances mainly due to a decrease of valuation of financial instruments, and a reduction of ¥8,637 million related to Japanese subsidiaries and the Company mainly by utilization of loss carryforwards. In total, ¥56,505 million of allowances decreased for the year ended March 31, 2020.Primarily includes an increase of ¥51,706 million of valuation allowances of certain foreign subsidiaries mainly due to an increase in operating loss carryforwards, and a reduction of ¥13,575 million of valuation allowances related to Japanese subsidiaries and the Company mainly due to a decrease of operating loss carryforwards. In total, ¥38,131 million of allowances increased for the year ended March 31, 2022.Primarily includes an increase of ¥48,883 million of valuation allowances of certain foreign subsidiaries mainly due to an increase in valuation allowances related to operating loss carryforwards, a reduction of ¥5,871 million of valuation allowances mainly due to an increase in valuation of financial instruments, and a reduction of ¥3,409 million of valuation allowances related to Japanese subsidiaries and the Company mainly due to an increase of valuation of financial instruments and a decrease of accrued pension and severance costs. In total, ¥39,603 million of allowances increased for the year ended March 31, 2021.Contract liabilities primarily rise from investment advisory services and are recognized over the term of the contract based on time elapsed.Include all recognized balances irrespective of whether they are transacted under a master netting agreement or whether Nomura has obtained sufficient evidence of enforceability of the master netting agreement. Amounts include transactions carried at fair value through election of the fair value option. As of March 31, 2021, the gross balance of reverse repurchase agreements and repurchase agreements which were not transacted under master netting agreements or are documented under master netting agreements for which Nomura has not yet obtained sufficient evidence of enforceability amounted to ¥480 billion and ¥2,653 billion, respectively. As of March 31, 2021, the gross balance of securities borrowing transactions and securities lending transactions which were not transacted under master netting agreements or are documented under master netting agreements for which Nomura has not yet obtained sufficient evidence of enforceability amounted to ¥1,947 billion and ¥213 billion, respectively. As of March 31, 2022, the gross balance of reverse repurchase agreements and repurchase agreements which were not transacted under master netting agreements or are documented under master netting agreements for which Nomura has not yet obtained sufficient evidence of enforceability amounted to ¥793 billion and ¥2,453 billion, respectively. As of March 31, 2022, the gross balance of securities borrowing transactions and securities lending transactions which were not transacted under master netting agreements or are documented under master netting agreements for which Nomura has not yet obtained sufficient evidence of enforceability amounted to ¥1,511 billion and ¥158 billion, respectively.Represent amounts offset through counterparty netting under master netting or similar agreements for which Nomura has obtained sufficient evidence of enforceability in accordance with ASC 210-20. Amounts offset include transactions carried at fair value through election of the fair value option.Reverse repurchase agreements and securities borrowing transactions are reported within Collateralized agreements—Securities purchased under agreements to resell and Collateralized agreements—Securities borrowed in the consolidated balance sheets, respectively. Repurchase agreements and securities lending transactions are reported within Collateralized financing—Securities sold under agreements to repurchase and Collateralized financing—Securities loaned in the consolidated balance sheets, respectively. Amounts reported under securities lending transactions also include transactions where Nomura lends securities and receives securities that can be sold or pledged as collateral. Nomura recognizes the securities received at fair value and a liability for the same amount, representing the obligation to return those securities. The liability is reported within Other liabilities in the consolidated balance sheets.Represent amounts which are not permitted to be offset on the face of the balance sheet in accordance with ASC 210-20 but which provide Nomura with the right of offset in the event of counterparty default. Amounts relating to agreements where Nomura has not yet obtained sufficient evidence of enforceability of such offsetting rights are excluded.Includes marketable and non-marketable equity securities held for other than trading or operating purposes. These investments comprise of listed equity securities and unlisted equity securities of ¥30,912 million and ¥239,334 million respectively, as of March 31, 2021, and ¥13,572 million and ¥235,877 million respectively, as of March 31, 2022. In principle, these securities are carried at fair value, with changes in fair value recognized and reported within Revenue—Other in the consolidated statements of income. It also includes equity securities without a readily determinable fair value of ¥65,365 million as of March 31, 2021 and 2022 respectively.Includes a liability of ¥62,889 million and ¥76,866 million as of March 31, 2021 and 2022 respectively, in respect of outstanding and unsettled investigations, lawsuits and other legal proceedings where loss is considered probable and the amount of such loss can be reasonably estimated. See Note 20 “Commitments, contingencies and guarantees” for further information.Operating lease liabilities are presented through Other liabilities—Other. See Note 8 “Leases” for further information.Includes trading balances of secured borrowings.Finance Act 2021, enacted on June 10, 2021, increases the headline U.K. corporation tax rate from 19% to 25% on April 1, 2023. Deferred tax assets and liabilities as of the balance sheet date are calculated by reference to the most appropriate enacted rates as of March 31, 2022. As a result of the change in closing deferred tax rate, Nomura recognized a movement in Effect of changes in foreign tax laws of ¥36 billion (which decreased Nomura’s effective tax rate by 16.0%), which was offset by a movement in Changes in deferred tax valuation allowances of ¥36 billion (which increased Nomura’s effective tax rate by 16.0%) during the year ended March 31, 2022.Non-taxable income during the year ended March 31, 2020 includes approximately ¥53 billion of the tax effect from non-taxable dividend income from affiliated Nomura companies, including deemed dividend (which decreased Nomura’s effective tax rate by 21.2%).Represents the adjustments to initially apply Accounting Standards Update ASU 2016-02, “Leases” for the year ended March 31, 2020 and ASU 2016-13, “Measurement of Credit Losses on Financial Instruments” for the year ended March 31, 2021.Includes gains and losses reported primarily within Net gain on trading, Gain on private equity and debt investments, and also within Gain (loss) on investments in equity securities, Revenue—Other and Non-interest expenses—Other, Interest and dividends and Interest expense in the consolidated statements of income.Amounts reported in Purchases / issues include increases in trading liabilities while Sales / redemptions include decreases in trading liabilities.Amounts of gains and losses on these transfers which were recognized in the period when the Transfers into Level 3 occurred were not significant for the year ended March 31, 2021 and March 31, 2022.Transfers into Level 3 indicate certain valuation inputs of a financial instrument become unobservable or significant. Transfers out of Level 3 indicate certain valuation inputs of a financial instrument become observable or insignificant. See Quantitative and qualitative information regarding significant unobservable inputs above for the valuation inputs of each financial instruments.Derivatives which contain multiple types of risk are classified based on the primary risk type of the instrumentSee Note 13 “Employee benefit plans” for further information.See Note 2 “Fair value measurements” for further information.Includes equity investments that would have been accounted for under the equity method had Nomura not chosen to elect the fair value option.Certain investments that are measured at fair value using net asset value per share as a practical expedient have not been classified in the fair value hierarchy. As of March 31, 2021 and March 31, 2022, the fair values of these investments which are included in Trading assets and private equity and debt investments were ¥24 billion and ¥45 billion, respectively. As of March 31, 2021 and March 31, 2022, the fair values of these investments which are included in Other assets—Others were ¥4 billion and ¥3 billion, respectively.Represents the amount offset under counterparty netting of derivative assets and liabilities as well as cash collateral netting against net derivatives.Private equity and debt investments include private non-traded financial instruments including minority private equity and venture capital equity investments and other junior debt investments such as mezzanine debt held for non-trading purposes, and post-IPO investments. Also include minority equity investments that would have been accounted for under the equity method had Nomura not chosen to elect the fair value option to these investments as permitted under ASC 825.Includes collateralized loan obligations (“CLOs”) and asset-backed securities (“ABS”) such as those secured on credit card loans, auto loans and student loans.Derivatives which contain multiple types of risk are classified based on the primary risk type of the instrument.Includes loan commitments for which the fair value option has been elected.Includes liabilities recognized from secured financing transactions that are accounted for as financings rather than sales. Nomura elected the fair value option for these liabilities.Includes deposits received at banks and structured notes for which the fair value option has been elected.Includes embedded derivatives bifurcated from issued structured notes. If unrealized gains are greater than unrealized losses, borrowings are reduced by the excess amount.Includes collateralized agreements or collateralized financing for which the fair value option has been elected.Includes embedded derivatives bifurcated from deposits received at banks. If unrealized gains are greater than unrealized losses, deposits are reduced by the excess amount.Includes equity investments which comprise listed and unlisted equity securities held for operating purposes in the amounts of ¥93,230 million and ¥33,419 million, respectively, as of March 31, 2021 and ¥101,503 million and ¥32,394 million, respectively, as of March 31, 2022.Includes loans and receivables for which the fair value option has been elected.Includes gains and losses reported within Net gain on trading, Gain on private equity and debt investments, and also within Gain on investments in equity securities, Revenue—Other and Non-interest expenses—Other, Interest and dividends and Interest expense in the consolidated statements of income.Range information is provided in percentages, coefficients and multiples and represents the highest and lowest level significant unobservable valuation input used to value that type of financial instrument. A wide dispersion in the range does not necessarily reflect increased uncertainty or subjectivity in the valuation input and is typically just a consequence of the different characteristics of the financial instruments themselves.Weighted average information for non-derivatives is calculated by weighting each valuation input by the fair value of the financial instrument.Nomura has not provided weighted average information for derivatives as unlike cash products the risk on such products is distinct from the balance sheet value and is subject to netting.The range in notice period required to be provided before redemption is possible.The contractual amount of any unfunded commitments Nomura is required to make to the entities in which the investment is held.The range in frequency with which Nomura is permitted to redeem investments.Includes changes in unrealized gains and losses in Other comprehensive income (loss) for recurring Level 3 fair value measurements held at the end of the reporting period. They were ¥0 billion and ¥5 billion for the years ended March 31, 2021 and 2022.The above table only considers the impact of an increase in each significant unobservable valuation input on the fair value measurement of the financial instrument. However, a decrease in the significant unobservable valuation input would have the opposite effect on the fair value measurement of the financial instrument. For example, if an increase in a significant unobservable valuation input would result in a lower fair value measurement, a decrease in the significant unobservable valuation input would result in a higher fair value measurement.The impact of an increase in the significant unobservable valuation input on the fair value measurement for a derivative assumes Nomura is long risk to the input e.g., long volatility. Where Nomura is short such risk, the impact of an increase would have a converse effect on the fair value measurement of the derivative.Includes gains and losses reported primarily within Revenue—Net gain on trading and Revenue—Other in the consolidated statements of income.Includes financial instruments which are carried at fair value on a recurring basis.Carrying values are shown after deducting relevant allowances for credit losses.Includes loans receivable and loan commitments carried at fair value through election of the fair value option.Includes corporate type equity investments.The earliest year in which Nomura remains subject to examination for transfer pricing issues is 2016.ROU assets and operating lease liabilities are included by ¥20,793 million and ¥23,899 million as of March 31, 2021 and 2022 respectively.Includes primarily debt investment funds. Hedge funds and real estate funds are also included.Certain assets that are measured at fair value using net asset value per share as a practical expedient have not been classified in the fair value hierarchy. As of March 31, 2021 and 2022, the fair values of these assets were ¥10,823 million and ¥26,865 million, respectively.Consideration of the interrelationships between significant unobservable valuation inputs is only relevant where more than one unobservable valuation input is used to determine the fair value measurement of the financial instrument.Valuation techniques and unobservable valuation inputs in respect of equity securities reported within Other assets in the consolidated balance sheets.Includes amounts recognized against collateralized agreements, customer contract assets and receivables and other receivables.Following default by a U.S. client in connection with the U.S. Prime Brokerage Event in March 2021, a provision for losses of ¥41,561 million was recognized. During year ending March 2022, an additional provision for losses of ¥9,289 million was recognized during the quarter ended June 30, 2021, which was subsequently partially offset by a release in the allowance of ¥2,535 million during the quarter ended March 31, 2022. See Note 23 “U.S. Prime Brokerage Event” for further information on this event.Primarily includes the effect of foreign exchange movements and recoveries collected.Closing balance recognized on March 31, 2020 as determined using legacy U.S. GAAP guidance in effect prior to the adoption of ASC 326.The adjusted opening balance recognized on April 1, 2020 on adoption of the CECL impairment model under ASC 326.Following default by a U.S. client in connection with the U.S. Prime Brokerage Event in March 2021, an allowance for current expected credit losses of ¥41,561 million was recognized. During year ending March 2022, an additional allowance for current expected credit losses of ¥9,289 million was recognized during the quarter ended June 30, 2021, which was subsequently partially offset by a release in the allowance of ¥2,535 million during the quarter ended March 31, 2022. See Note 23 “U.S. Prime Brokerage Event” for further information on this event.Includes reverse repurchase and repurchase agreements.Includes structured notes and other financial liabilities.Includes secured financing transactions arising from transfers of financial assets which did not meet the criteria for sales accounting.Includes unfunded written loan commitments.Other than above, there were ¥299 billion and ¥331 billion of government, agency and municipal securities reported within Other assets—Non-trading debt securities in the consolidated balance sheets as of March 31, 2021 and 2022, respectively. These securities are primarily Japanese government, agency and municipal securities.Includes the amount of embedded derivatives bifurcated in accordance with ASC 815.As of March 31, 2021 and 2022, the amounts reported include derivatives used for non-trading purposes other than those designated as fair value or net investment accounting hedges. These amounts have not been separately presented since such amounts were not significant.Includes all gross derivative asset and liability balances irrespective of whether they are transacted under a master netting agreement or whether Nomura has obtained sufficient evidence of enforceability of the master netting agreement. As of March 31, 2021, the gross balance of derivative assets and derivative liabilities which are not documented under master netting agreements or are documented under master netting agreements for which Nomura has not yet obtained sufficient evidence of enforceability was ¥392 billion and ¥589 billion, respectively. As of March 31, 2022, the gross balance of such derivative assets and derivative liabilities was ¥458 billion and ¥671 billion, respectively.Represents amounts offset through counterparty offsetting of derivative assets and liabilities as well as cash collateral offsetting against net derivatives under master netting and similar agreements for which Nomura has obtained sufficient evidence of enforceability in accordance with ASC 815. As of March 31, 2021, Nomura offset a total of ¥1,594 billion of cash collateral receivables against net derivative liabilities and ¥1,683 billion of cash collateral payables against net derivative assets. As of March 31, 2022, Nomura offset a total of ¥1,431 billion of cash collateral receivables against net derivative liabilities and ¥1,960 billion of cash collateral payables against net derivative assets.Net derivative assets and net derivative liabilities are generally reported within Trading assets and private equity and debt investments—Trading assets and Trading liabilities, respectively in the consolidated balance sheet. Bifurcated embedded derivatives are reported within Short-term borrowings or Long-term borrowings depending on the maturity of the underlying host contract.Represents amounts which are not permitted to be offset on the consolidated balance sheets in accordance with ASC 210-20 and ASC 815 but which provide Nomura with a legally enforceable right of offset in the event of counterparty default. Amounts relating to derivative and collateral agreements where Nomura has not yet obtained sufficient evidence of enforceability of such offsetting rights are excluded. As of March 31, 2021, a total of ¥283 billion of cash collateral receivables and ¥572 billion of cash collateral payables, including amounts reported in the table, have not been offset against net derivatives. As of March 31, 2022, a total of ¥359 billion of cash collateral receivables and ¥652 billion of cash collateral payables, including amounts reported in the table, have not been offset against net derivatives.Includes net gains (losses) on derivatives used for non-trading purposes which are not designated as fair value or net investment hedges. For the year ended March 31, 2020, these amounts were not significant. For the year ended March 31, 2021, net losses for these non-trading derivatives were ¥3 billion. For the year ended March 31, 2022, these amounts were not significant.Non-trading debt securities are primarily Japanese municipal securities. Investments in and advances to affiliated companies primarily comprise shares in NRI.Relate to collateralized exposures where a specified ratio of LTV is maintained.Repurchase agreements and securities lending transactions are reported within Collateralized financing—Securities sold under agreements to repurchase and Collateralized financing—Securities loaned in the consolidated balance sheets, respectively. Amounts reported for securities lending transactions also include transactions where Nomura lends securities and receives securities that can be sold or pledged as collateral. Nomura recognizes the securities received at fair value and a liability for the same amount, representing the obligation to return those securities. The liability is reported within Other liabilities in the consolidated balance sheets. The total gross recognized liabilities reported for repurchase agreements and securities lending transactions are consistent with the total gross balances reported in the offsetting disclosures above. Open transactions do not have an explicit contractual maturity date and are terminable on demand by Nomura or the counterparty. Other includes credit derivatives where the credit rating of the underlying reference asset is below investment grade or where a credit rating is unavailable.Carrying value amounts are shown on a gross basis prior to cash collateral or counterparty offsetting. Asset balances represent positive fair value amounts caused by tightening of credit spreads of underlyings since inception of the credit derivatives.Includes ¥2,170 billion of U.S. government sponsored agency mortgage pass through securities and collateralized mortgage obligations as of March 31, 2021. Includes ¥1,404 billion of U.S. government sponsored agency mortgage pass through securities and collateralized mortgage obligations as of March 31, 2022.Includes CLOs and ABS such as those secured on credit card loans, auto loans and student loans. Includes loans of ¥197,859 million to a U.S. client in connection with the U.S. Prime Brokerage Event. See Note. 23 “U.S. Prime Brokerage Event” for further information on this event.Includes loans of ¥57,524 million to a U.S. client in connection with the U.S. Prime Brokerage Event. See Note. 23 “U.S. Prime Brokerage Event” for further information on this event.Cost, accumulated depreciation and net carrying amounts include amounts relating to real estate utilized by Nomura. For the year ended March 31, 2021, Nomura recognized goodwill as a result of acquiring 100% of the ownership interests in Greentech Capital, LLC which has been allocated in its entirety to the Wholesale division for segmental reporting and reporting unit purposes. See Note 9 “Business Combination” for further information.Includes currency translation adjustments.Includes secured borrowings of ¥55,569 million as of March 31, 2021 and ¥92,580 million as of March 31, 2022.Includes secured borrowings of ¥118,106 million as of March 31, 2021 and ¥79,843 million as of March 31, 2022.Includes secured borrowings of ¥788,618 million as of March 31, 2021 and ¥761,620 million as of March 31, 2022.Weighted-average price of the Company’s common stock used to determine number of awards granted.Weighted-average price of the Company’s common stock used to determine the final cash settlement amount of the awards.The price of the Company’s common stock used to remeasure the fair value of the remaining outstanding unvested awards as of March 31, 2022.Credit derivatives are disclosed in Note 3 “Derivative instruments and hedging activities” and are excluded from above.Derivative contracts primarily consist of equity, interest rate and foreign exchange contracts.Primarily related to a certain sponsored repo program where Nomura guarantees to a third party clearing house in relation to its clients’ payment obligations. Our credit exposures under this guarantee is minimized by obtaining collateral from clients at amount approximately the maximum potential payout under the guarantee.Non-interest revenue and Non-interest expense for the year ended March 31, 2021 and March 31, 2022 include losses arising from the U.S. Prime Brokerage Event. See Note 23 “U.S. Prime Brokerage Event” Includes an impairment loss of ¥47,661 million recognized in respect of Nomura’s investment in Nomura Real Estate holdings, Inc. during the year ended March 31, 2021. Based on the period and extent to which the share price of the investee (and therefore its estimated fair value) was below the carrying value of the investment, Nomura determined the impairment was other-than-temporary and an impairment loss was recognized through earnings. The loss was reported within Non-interest expenses—Other in the consolidated statements of income. Income before income taxes for the year ended March 31, 2022 includes a loss of approximately ¥62.0 billion related to legacy transactions in the U.S. from before the global financial crisis (2007 – 2008) that was recognized including legal expenses as well as certain transactions intended to mitigate future losses.Includes the impact of Nomura’s own creditworthiness.Loss before income taxes for the year ended March 31, 2021 includes a gain of ¥ 71,075 million which represents the difference between the fair value of the assets acquired and the carrying value of the assets transferred by Nomura as a result of the rights conversion of the Tokyo Nihonbashi district redevelopment project.Income before income taxes for the year ended March 31, 2022 includes a gain of approximately ¥79.0 billion from the partial sale of Nomura’s investment in the ordinary shares of Nomura Research Institute, Ltd.Income before income taxes for the year ended March 31, 2020 includes a gain of ¥73,293 million from the partial sale of Nomura’s investment in the ordinary shares of Nomura Research Institute, Ltd.There is no revenue derived from transactions with a single major external customer.Includes losses arising from the U.S. Prime Brokerage Event. See Note 23 “U.S. Prime Brokerage Event.”During the fiscal year ended March 31, 2021, as a result of the rights conversion of the Tokyo Nihonbashi district redevelopment project, the estimate of future cash flows for the ARO associated with our properties has been changed.Tax benefit recognized on the outside basis differences for investment in subsidiaries and affiliates during the year ended March 31, 2021 of approximately ¥21 billion (which decreased Nomura’s effective tax rate by 9.1%) arises from the recognition of deferred tax assets from the decision and commitment of Nomura management to liquidate a certain wholly-owned subsidiary within Nomura in the foreseeable future. The valuation allowances of ¥3 billion have been recognized against these deferred tax assets, the impact of which are reported in Changes in deferred tax valuation allowances for the same period. 0001163653 2021-04-01 2022-03-31 0001163653 2021-03-31 0001163653 2022-03-31 0001163653 2020-04-01 2021-03-31 0001163653 2019-04-01 2020-03-31 0001163653 2020-03-31 0001163653 2022-06-24 0001163653 2022-01-01 2022-03-31 0001163653 2019-03-31 0001163653 nmr:ListedEquityMember 2021-03-31 0001163653 nmr:UnlistedEquityMember 2021-03-31 0001163653 us-gaap:NondesignatedMember us-gaap:InterestRateContractMember 2021-03-31 0001163653 us-gaap:NondesignatedMember us-gaap:CreditRiskContractMember 2021-03-31 0001163653 us-gaap:NondesignatedMember us-gaap:EquityContractMember 2021-03-31 0001163653 us-gaap:NondesignatedMember us-gaap:ForeignExchangeContractMember 2021-03-31 0001163653 us-gaap:NondesignatedMember us-gaap:CommodityContractMember 2021-03-31 0001163653 us-gaap:NondesignatedMember 2021-03-31 0001163653 us-gaap:DesignatedAsHedgingInstrumentMember us-gaap:InterestRateContractMember 2021-03-31 0001163653 us-gaap:DesignatedAsHedgingInstrumentMember us-gaap:ForeignExchangeContractMember 2021-03-31 0001163653 us-gaap:DesignatedAsHedgingInstrumentMember 2021-03-31 0001163653 us-gaap:VariableInterestEntityPrimaryBeneficiaryMember 2021-03-31 0001163653 nmr:TransferredToSPEsMember 2021-03-31 0001163653 us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember us-gaap:EquitySecuritiesMember 2021-03-31 0001163653 us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember us-gaap:DebtSecuritiesMember 2021-03-31 0001163653 us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember us-gaap:MortgageBackedSecuritiesMember 2021-03-31 0001163653 us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember nmr:InvestmentTrustFundsAndOtherMember 2021-03-31 0001163653 us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember nmr:PrivateEquityAndDebtInvestmentsMember 2021-03-31 0001163653 us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember us-gaap:LoansReceivableMember 2021-03-31 0001163653 us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember nmr:OtherAssetMember 2021-03-31 0001163653 us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember 2021-03-31 0001163653 us-gaap:CommitmentsToExtendCreditMember us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:EquitySecuritiesMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:PrivateEquityAndDebtInvestmentsMember 2021-03-31 0001163653 nmr:CollateralizedAgreementsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:LoansReceivableMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:ForeignExchangeContractMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:ForeignGovernmentDebtSecuritiesMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:BankAndCorporateDebtSecuritiesAndLoansForTradingPurposeMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:CommercialMortgageBackedSecuritiesMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:ResidentialMortgageBackedSecuritiesMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:RealEstateBackedSecuritiesMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:CollateralizedDebtObligationsMember 2021-03-31 0001163653 us-gaap:EquityContractMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:InterestRateContractMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:CreditRiskContractMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember 2021-03-31 0001163653 us-gaap:FairValueInputsLevel2Member nmr:GovernmentAgencyAndMunicipalSecuritiesMember 2021-03-31 0001163653 nmr:GovernmentAgencyAndMunicipalSecuritiesMember 2021-03-31 0001163653 us-gaap:ExternalCreditRatingInvestmentGradeMember nmr:GovernmentAgencyAndMunicipalSecuritiesMember 2021-03-31 0001163653 us-gaap:FairValueInputsLevel3Member us-gaap:MortgageBackedSecuritiesMember 2021-03-31 0001163653 us-gaap:MortgageBackedSecuritiesMember 2021-03-31 0001163653 us-gaap:ExternalCreditRatingInvestmentGradeMember us-gaap:MortgageBackedSecuritiesMember 2021-03-31 0001163653 us-gaap:ExternalCreditRatingNonInvestmentGradeMember us-gaap:MortgageBackedSecuritiesMember 2021-03-31 0001163653 us-gaap:FairValueInputsLevel2Member 2021-03-31 0001163653 us-gaap:FairValueInputsLevel3Member 2021-03-31 0001163653 us-gaap:ExternalCreditRatingInvestmentGradeMember 2021-03-31 0001163653 us-gaap:ExternalCreditRatingNonInvestmentGradeMember 2021-03-31 0001163653 us-gaap:FairValueInputsLevel1Member nmr:GovernmentAgencyAndMunicipalSecuritiesMember 2021-03-31 0001163653 us-gaap:FairValueInputsLevel3Member nmr:GovernmentAgencyAndMunicipalSecuritiesMember 2021-03-31 0001163653 us-gaap:ExternalCreditRatingNonInvestmentGradeMember nmr:GovernmentAgencyAndMunicipalSecuritiesMember 2021-03-31 0001163653 us-gaap:FairValueInputsLevel1Member us-gaap:CorporateDebtSecuritiesMember 2021-03-31 0001163653 us-gaap:FairValueInputsLevel2Member us-gaap:CorporateDebtSecuritiesMember 2021-03-31 0001163653 us-gaap:FairValueInputsLevel3Member us-gaap:CorporateDebtSecuritiesMember 2021-03-31 0001163653 us-gaap:CorporateDebtSecuritiesMember 2021-03-31 0001163653 us-gaap:ExternalCreditRatingInvestmentGradeMember us-gaap:CorporateDebtSecuritiesMember 2021-03-31 0001163653 us-gaap:ExternalCreditRatingNonInvestmentGradeMember us-gaap:CorporateDebtSecuritiesMember 2021-03-31 0001163653 us-gaap:FairValueInputsLevel1Member us-gaap:MortgageBackedSecuritiesMember 2021-03-31 0001163653 us-gaap:FairValueInputsLevel2Member us-gaap:MortgageBackedSecuritiesMember 2021-03-31 0001163653 us-gaap:FairValueInputsLevel1Member 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2021-03-31 0001163653 us-gaap:EquitySecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2021-03-31 0001163653 us-gaap:EquitySecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:EquitySecuritiesMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember us-gaap:EquitySecuritiesMember 2021-03-31 0001163653 us-gaap:EquitySecuritiesMember us-gaap:FairValueMeasurementsRecurringMember 2021-03-31 0001163653 nmr:PrivateEquityAndDebtInvestmentsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2021-03-31 0001163653 nmr:PrivateEquityAndDebtInvestmentsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2021-03-31 0001163653 nmr:PrivateEquityAndDebtInvestmentsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember nmr:PrivateEquityAndDebtInvestmentsMember 2021-03-31 0001163653 nmr:PrivateEquityAndDebtInvestmentsMember us-gaap:FairValueMeasurementsRecurringMember 2021-03-31 0001163653 nmr:JapaneseGovernmentDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2021-03-31 0001163653 nmr:JapaneseGovernmentDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2021-03-31 0001163653 nmr:JapaneseGovernmentDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2021-03-31 0001163653 nmr:JapaneseGovernmentDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember 2021-03-31 0001163653 nmr:JapaneseGovernmentDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember 2021-03-31 0001163653 nmr:JapaneseAgencyAndMunicipalDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2021-03-31 0001163653 nmr:JapaneseAgencyAndMunicipalDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2021-03-31 0001163653 nmr:JapaneseAgencyAndMunicipalDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2021-03-31 0001163653 nmr:JapaneseAgencyAndMunicipalDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember 2021-03-31 0001163653 nmr:JapaneseAgencyAndMunicipalDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember 2021-03-31 0001163653 us-gaap:ForeignGovernmentDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2021-03-31 0001163653 us-gaap:ForeignGovernmentDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2021-03-31 0001163653 us-gaap:ForeignGovernmentDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2021-03-31 0001163653 nmr:CounterpartyCashCollateralNettingMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:ForeignGovernmentDebtSecuritiesMember 2021-03-31 0001163653 us-gaap:ForeignGovernmentDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember 2021-03-31 0001163653 nmr:BankAndCorporateDebtSecuritiesAndLoansForTradingPurposeMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2021-03-31 0001163653 nmr:BankAndCorporateDebtSecuritiesAndLoansForTradingPurposeMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2021-03-31 0001163653 nmr:BankAndCorporateDebtSecuritiesAndLoansForTradingPurposeMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2021-03-31 0001163653 nmr:BankAndCorporateDebtSecuritiesAndLoansForTradingPurposeMember us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember nmr:BankAndCorporateDebtSecuritiesAndLoansForTradingPurposeMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommercialMortgageBackedSecuritiesMember us-gaap:FairValueInputsLevel1Member 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommercialMortgageBackedSecuritiesMember us-gaap:FairValueInputsLevel2Member 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommercialMortgageBackedSecuritiesMember us-gaap:FairValueInputsLevel3Member 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommercialMortgageBackedSecuritiesMember nmr:CounterpartyCashCollateralNettingMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommercialMortgageBackedSecuritiesMember 2021-03-31 0001163653 us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2021-03-31 0001163653 us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2021-03-31 0001163653 us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2021-03-31 0001163653 us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember 2021-03-31 0001163653 us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember 2021-03-31 0001163653 us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member nmr:IssuedGuaranteedByGovernmentSponsoredEntityMember 2021-03-31 0001163653 us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member nmr:IssuedGuaranteedByGovernmentSponsoredEntityMember 2021-03-31 0001163653 us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:IssuedGuaranteedByGovernmentSponsoredEntityMember 2021-03-31 0001163653 us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember nmr:IssuedGuaranteedByGovernmentSponsoredEntityMember 2021-03-31 0001163653 us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember nmr:IssuedGuaranteedByGovernmentSponsoredEntityMember 2021-03-31 0001163653 us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member nmr:OtherResidentialMortgagebackedSecuritiesMember 2021-03-31 0001163653 nmr:OtherResidentialMortgagebackedSecuritiesMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:ResidentialMortgageBackedSecuritiesMember 2021-03-31 0001163653 us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:OtherResidentialMortgagebackedSecuritiesMember 2021-03-31 0001163653 us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember nmr:OtherResidentialMortgagebackedSecuritiesMember 2021-03-31 0001163653 us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember nmr:OtherResidentialMortgagebackedSecuritiesMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember nmr:RealEstateBackedSecuritiesMember us-gaap:FairValueInputsLevel1Member 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember nmr:RealEstateBackedSecuritiesMember us-gaap:FairValueInputsLevel2Member 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:RealEstateBackedSecuritiesMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember nmr:RealEstateBackedSecuritiesMember nmr:CounterpartyCashCollateralNettingMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember nmr:RealEstateBackedSecuritiesMember 2021-03-31 0001163653 us-gaap:CollateralizedDebtObligationsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2021-03-31 0001163653 us-gaap:CollateralizedDebtObligationsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2021-03-31 0001163653 us-gaap:CollateralizedDebtObligationsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2021-03-31 0001163653 us-gaap:CollateralizedDebtObligationsMember us-gaap:FairValueMeasurementsRecurringMember 2021-03-31 0001163653 nmr:InvestmentTrustFundsAndOtherMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2021-03-31 0001163653 nmr:InvestmentTrustFundsAndOtherMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2021-03-31 0001163653 nmr:InvestmentTrustFundsAndOtherMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2021-03-31 0001163653 nmr:CounterpartyCashCollateralNettingMember us-gaap:FairValueMeasurementsRecurringMember nmr:InvestmentTrustFundsAndOtherMember 2021-03-31 0001163653 nmr:InvestmentTrustFundsAndOtherMember us-gaap:FairValueMeasurementsRecurringMember 2021-03-31 0001163653 us-gaap:CollateralizedDebtObligationsMember us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember us-gaap:CorporateDebtSecuritiesMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:CorporateDebtSecuritiesMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member us-gaap:CorporateDebtSecuritiesMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member us-gaap:CorporateDebtSecuritiesMember 2021-03-31 0001163653 us-gaap:CarryingReportedAmountFairValueDisclosureMember 2021-03-31 0001163653 us-gaap:EstimateOfFairValueFairValueDisclosureMember 2021-03-31 0001163653 nmr:DerivativeContractsMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember nmr:NetAssetValueValuationTechniqueMember 2021-03-31 0001163653 us-gaap:ShortTermDebtMember 2021-03-31 0001163653 us-gaap:LandAndBuildingMember 2021-03-31 0001163653 us-gaap:AirTransportationEquipmentMember 2021-03-31 0001163653 nmr:MaturityGreaterThan1YearMember 2021-03-31 0001163653 nmr:Maturity90DaysTo1YearMember 2021-03-31 0001163653 us-gaap:Maturity30To90DaysMember 2021-03-31 0001163653 us-gaap:MaturityUpTo30DaysMember 2021-03-31 0001163653 us-gaap:MaturityOvernightAndOnDemandMember 2021-03-31 0001163653 us-gaap:CustomerRelationshipsMember 2021-03-31 0001163653 us-gaap:OtherIntangibleAssetsMember 2021-03-31 0001163653 nmr:EquitiesAndConvertibleBondsMember 2021-03-31 0001163653 nmr:GovernmentAndGovernmentAgencySecuritiesMember 2021-03-31 0001163653 us-gaap:ResidentialMortgageBackedSecuritiesMember 2021-03-31 0001163653 us-gaap:CollateralizedDebtObligationsMember 2021-03-31 0001163653 nmr:InvestmentTrustFundsAndOtherMember 2021-03-31 0001163653 us-gaap:ForeignGovernmentDebtSecuritiesMember 2021-03-31 0001163653 us-gaap:CommercialMortgageBackedSecuritiesMember 2021-03-31 0001163653 us-gaap:OverTheCounterMember us-gaap:EquityContractMember 2021-03-31 0001163653 us-gaap:ExchangeTradedMember us-gaap:EquityContractMember 2021-03-31 0001163653 us-gaap:OverTheCounterMember us-gaap:InterestRateContractMember 2021-03-31 0001163653 us-gaap:ExchangeClearedMember us-gaap:InterestRateContractMember 2021-03-31 0001163653 us-gaap:ExchangeTradedMember us-gaap:InterestRateContractMember 2021-03-31 0001163653 us-gaap:OverTheCounterMember us-gaap:CreditRiskContractMember 2021-03-31 0001163653 us-gaap:ExchangeClearedMember us-gaap:CreditRiskContractMember 2021-03-31 0001163653 us-gaap:ExchangeTradedMember us-gaap:CreditRiskContractMember 2021-03-31 0001163653 us-gaap:OverTheCounterMember us-gaap:ForeignExchangeContractMember 2021-03-31 0001163653 us-gaap:CommodityContractMember us-gaap:OverTheCounterMember 2021-03-31 0001163653 us-gaap:ExchangeTradedMember us-gaap:CommodityContractMember 2021-03-31 0001163653 nmr:AffiliatedCompaniesAndOtherEquityMethodInvesteesMember 2021-03-31 0001163653 country:JP nmr:GovernmentAgencyAndMunicipalSecuritiesMember 2021-03-31 0001163653 country:US nmr:GovernmentAgencyAndMunicipalSecuritiesMember 2021-03-31 0001163653 us-gaap:EuropeanUnionMember nmr:GovernmentAgencyAndMunicipalSecuritiesMember 2021-03-31 0001163653 nmr:FairValueConcentrationCreditRiskGeographicalOtherCountriesMember nmr:GovernmentAgencyAndMunicipalSecuritiesMember 2021-03-31 0001163653 nmr:GovernmentAgencyAndMunicipalSecuritiesMember 2021-03-31 0001163653 nmr:UnsecuredCorporateLoansMember nmr:InternallyAssignedGradeTotalMember 2021-03-31 0001163653 nmr:UnsecuredCorporateLoansMember nmr:OthersMember 2021-03-31 0001163653 nmr:UnsecuredCorporateLoansMember nmr:CCDMember 2021-03-31 0001163653 nmr:UnsecuredCorporateLoansMember nmr:BBCCCMember 2021-03-31 0001163653 nmr:UnsecuredCorporateLoansMember nmr:AAABBBMember 2021-03-31 0001163653 nmr:SecuredCorporateLoansMember nmr:InternallyAssignedGradeTotalMember 2021-03-31 0001163653 nmr:SecuredCorporateLoansMember nmr:OthersMember 2021-03-31 0001163653 nmr:SecuredCorporateLoansMember nmr:CCDMember 2021-03-31 0001163653 nmr:InternallyAssignedGradeTotalMember nmr:AdvancesToAffiliatedCompaniesMember 2021-03-31 0001163653 nmr:CCDMember nmr:AdvancesToAffiliatedCompaniesMember 2021-03-31 0001163653 nmr:OthersMember nmr:AdvancesToAffiliatedCompaniesMember 2021-03-31 0001163653 nmr:BBCCCMember nmr:AdvancesToAffiliatedCompaniesMember 2021-03-31 0001163653 nmr:AAABBBMember nmr:AdvancesToAffiliatedCompaniesMember 2021-03-31 0001163653 nmr:SecuredLoansAtBanksMember nmr:InternallyAssignedGradeTotalMember 2021-03-31 0001163653 nmr:SecuredLoansAtBanksMember nmr:OthersMember 2021-03-31 0001163653 nmr:SecuredLoansAtBanksMember nmr:CCDMember 2021-03-31 0001163653 nmr:SecuredLoansAtBanksMember nmr:BBCCCMember 2021-03-31 0001163653 nmr:SecuredLoansAtBanksMember nmr:AAABBBMember 2021-03-31 0001163653 nmr:UnsecuredLoansAtBanksMember nmr:AAABBBMember 2021-03-31 0001163653 nmr:SecuredCorporateLoansMember nmr:BBCCCMember 2021-03-31 0001163653 nmr:SecuredCorporateLoansMember nmr:AAABBBMember 2021-03-31 0001163653 nmr:UnsecuredInterBankMoneyMarketLoansMember nmr:InternallyAssignedGradeTotalMember 2021-03-31 0001163653 nmr:OthersMember nmr:UnsecuredInterBankMoneyMarketLoansMember 2021-03-31 0001163653 nmr:UnsecuredInterBankMoneyMarketLoansMember nmr:CCDMember 2021-03-31 0001163653 nmr:UnsecuredInterBankMoneyMarketLoansMember nmr:BBCCCMember 2021-03-31 0001163653 nmr:UnsecuredInterBankMoneyMarketLoansMember nmr:AAABBBMember 2021-03-31 0001163653 nmr:ShortTermSecuredMarginLoansMember nmr:InternallyAssignedGradeTotalMember 2021-03-31 0001163653 nmr:ShortTermSecuredMarginLoansMember nmr:OthersMember 2021-03-31 0001163653 nmr:ShortTermSecuredMarginLoansMember nmr:CCDMember 2021-03-31 0001163653 nmr:ShortTermSecuredMarginLoansMember nmr:BBCCCMember 2021-03-31 0001163653 nmr:ShortTermSecuredMarginLoansMember nmr:AAABBBMember 2021-03-31 0001163653 nmr:UnsecuredLoansAtBanksMember nmr:InternallyAssignedGradeTotalMember 2021-03-31 0001163653 nmr:OthersMember nmr:UnsecuredLoansAtBanksMember 2021-03-31 0001163653 nmr:UnsecuredLoansAtBanksMember nmr:CCDMember 2021-03-31 0001163653 nmr:UnsecuredLoansAtBanksMember nmr:BBCCCMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:TradingLiabilitiesMember us-gaap:CorporateDebtSecuritiesMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:ShortTermDebtMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:LongTermDebtMember 2021-03-31 0001163653 us-gaap:CommodityContractMember us-gaap:FairValueMeasurementsRecurringMember 2021-03-31 0001163653 us-gaap:CommodityContractMember us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember 2021-03-31 0001163653 us-gaap:CommodityContractMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2021-03-31 0001163653 us-gaap:CommodityContractMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2021-03-31 0001163653 us-gaap:CommodityContractMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2021-03-31 0001163653 us-gaap:ForeignExchangeContractMember us-gaap:FairValueMeasurementsRecurringMember 2021-03-31 0001163653 us-gaap:ForeignExchangeContractMember us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember 2021-03-31 0001163653 us-gaap:ForeignExchangeContractMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2021-03-31 0001163653 us-gaap:ForeignExchangeContractMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2021-03-31 0001163653 us-gaap:ForeignExchangeContractMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2021-03-31 0001163653 us-gaap:CreditRiskContractMember us-gaap:FairValueMeasurementsRecurringMember 2021-03-31 0001163653 us-gaap:CreditRiskContractMember us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember 2021-03-31 0001163653 us-gaap:CreditRiskContractMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2021-03-31 0001163653 us-gaap:CreditRiskContractMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2021-03-31 0001163653 us-gaap:CreditRiskContractMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2021-03-31 0001163653 us-gaap:InterestRateContractMember us-gaap:FairValueMeasurementsRecurringMember 2021-03-31 0001163653 us-gaap:InterestRateContractMember us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember 2021-03-31 0001163653 us-gaap:InterestRateContractMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2021-03-31 0001163653 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:InterestRateContractMember 2021-03-31 0001163653 us-gaap:InterestRateContractMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2021-03-31 0001163653 us-gaap:EquityContractMember us-gaap:FairValueMeasurementsRecurringMember 2021-03-31 0001163653 us-gaap:EquityContractMember us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember 2021-03-31 0001163653 us-gaap:EquityContractMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2021-03-31 0001163653 us-gaap:EquityContractMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2021-03-31 0001163653 us-gaap:EquityContractMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2021-03-31 0001163653 us-gaap:RealEstateFundsMember 2021-03-31 0001163653 us-gaap:PrivateEquityFundsMember 2021-03-31 0001163653 us-gaap:VentureCapitalFundsMember 2021-03-31 0001163653 us-gaap:HedgeFundsMember 2021-03-31 0001163653 nmr:JapaneseYenDenominatedMember nmr:FixedRateObligationsMember 2021-03-31 0001163653 nmr:NonJapaneseYenDenominatedMember nmr:FixedRateObligationsMember 2021-03-31 0001163653 nmr:JapaneseYenDenominatedMember nmr:FloatingRateObligationsMember 2021-03-31 0001163653 nmr:NonJapaneseYenDenominatedMember nmr:FloatingRateObligationsMember 2021-03-31 0001163653 nmr:JapaneseYenDenominatedMember nmr:IndexOrEquityLinkedObligationsMember 2021-03-31 0001163653 nmr:NonJapaneseYenDenominatedMember nmr:IndexOrEquityLinkedObligationsMember 2021-03-31 0001163653 nmr:InvestmentTrustFundsAndOtherMember us-gaap:FairValueMeasuredAtNetAssetValuePerShareMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember nmr:OtherAssetsAggregateCarryingAmountsMember nmr:NetAssetValueValuationTechniqueMember 2021-03-31 0001163653 us-gaap:FinancialStandbyLetterOfCreditMember 2021-03-31 0001163653 nmr:FixedRateObligationsMember srt:MinimumMember 2021-03-31 0001163653 nmr:FixedRateObligationsMember srt:MaximumMember 2021-03-31 0001163653 nmr:FloatingRateObligationsMember srt:MinimumMember 2021-03-31 0001163653 nmr:FloatingRateObligationsMember srt:MaximumMember 2021-03-31 0001163653 nmr:IndexOrEquityLinkedObligationsMember srt:MinimumMember 2021-03-31 0001163653 nmr:IndexOrEquityLinkedObligationsMember srt:MaximumMember 2021-03-31 0001163653 nmr:OverseasSubsidiariesMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:MarketApproachValuationTechniqueMember nmr:PrivateEquityAndDebtInvestmentsMember nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:MeasurementInputEbitdaMultipleMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:MarketApproachValuationTechniqueMember nmr:PrivateEquityAndDebtInvestmentsMember nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:MeasurementInputEbitdaMultipleMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:MarketApproachValuationTechniqueMember nmr:PrivateEquityAndDebtInvestmentsMember nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:MeasurementInputPriceEarningsRatioMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:MarketApproachValuationTechniqueMember nmr:PrivateEquityAndDebtInvestmentsMember nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:MeasurementInputDiscountRateMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:MarketApproachValuationTechniqueMember nmr:PrivateEquityAndDebtInvestmentsMember nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:MeasurementInputDiscountRateMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:PrivateEquityAndDebtInvestmentsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputWeightedAverageCostCapitalMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:PrivateEquityAndDebtInvestmentsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputWeightedAverageCostCapitalMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:PrivateEquityAndDebtInvestmentsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputLongTermRevenueGrowthRateMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:PrivateEquityAndDebtInvestmentsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputLongTermRevenueGrowthRateMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:PrivateEquityAndDebtInvestmentsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputCreditSpreadMember srt:MinimumMember 2021-03-31 0001163653 srt:MaximumMember us-gaap:MeasurementInputCreditSpreadMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:PrivateEquityAndDebtInvestmentsMember nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:PrivateEquityAndDebtInvestmentsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputDiscountRateMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:PrivateEquityAndDebtInvestmentsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputDiscountRateMember srt:MaximumMember 2021-03-31 0001163653 nmr:MeasurementInputWeightedAverageCostCapitalMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:PrivateEquityAndDebtInvestmentsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember srt:WeightedAverageMember 2021-03-31 0001163653 us-gaap:MeasurementInputLongTermRevenueGrowthRateMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:PrivateEquityAndDebtInvestmentsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember srt:WeightedAverageMember 2021-03-31 0001163653 us-gaap:MeasurementInputCreditSpreadMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:PrivateEquityAndDebtInvestmentsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember srt:WeightedAverageMember 2021-03-31 0001163653 us-gaap:MeasurementInputDiscountRateMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:PrivateEquityAndDebtInvestmentsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember srt:WeightedAverageMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:CollateralizedDebtObligationsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputYieldsMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:CollateralizedDebtObligationsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputYieldsMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:CollateralizedDebtObligationsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputPrepaymentRateMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:CollateralizedDebtObligationsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputDefaultRateMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:CollateralizedDebtObligationsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputLossSeverityMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:CollateralizedDebtObligationsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputLossSeverityMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:CollateralizedDebtObligationsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputYieldsMember srt:WeightedAverageMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:CollateralizedDebtObligationsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputPrepaymentRateMember srt:WeightedAverageMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:CollateralizedDebtObligationsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputDefaultRateMember srt:WeightedAverageMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:CollateralizedDebtObligationsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputLossSeverityMember srt:WeightedAverageMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:RealEstateBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputLossSeverityMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:RealEstateBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputLossSeverityMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputYieldsMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputYieldsMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputPrepaymentRateMember srt:MinimumMember 2021-03-31 0001163653 srt:MaximumMember us-gaap:MeasurementInputPrepaymentRateMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:ResidentialMortgageBackedSecuritiesMember nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputLossSeverityMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputLossSeverityMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputYieldsMember srt:WeightedAverageMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputPrepaymentRateMember srt:WeightedAverageMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputLossSeverityMember srt:WeightedAverageMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:CommercialMortgageBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputYieldsMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:CommercialMortgageBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputYieldsMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:CommercialMortgageBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputLossSeverityMember srt:MinimumMember 2021-03-31 0001163653 srt:MaximumMember us-gaap:MeasurementInputLossSeverityMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:CommercialMortgageBackedSecuritiesMember nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:CommercialMortgageBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputYieldsMember srt:WeightedAverageMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:CommercialMortgageBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputLossSeverityMember srt:WeightedAverageMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:BankAndCorporateDebtSecuritiesAndLoansForTradingPurposeMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputCreditSpreadMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:BankAndCorporateDebtSecuritiesAndLoansForTradingPurposeMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputCreditSpreadMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:BankAndCorporateDebtSecuritiesAndLoansForTradingPurposeMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputRecoveryRateMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:BankAndCorporateDebtSecuritiesAndLoansForTradingPurposeMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputRecoveryRateMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:BankAndCorporateDebtSecuritiesAndLoansForTradingPurposeMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputCreditSpreadMember srt:WeightedAverageMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:BankAndCorporateDebtSecuritiesAndLoansForTradingPurposeMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputRecoveryRateMember srt:WeightedAverageMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:ForeignGovernmentDebtSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputCreditSpreadMember srt:MaximumMember 2021-03-31 0001163653 srt:MinimumMember nmr:MeasurementInputRecoveryRateMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:ForeignGovernmentDebtSecuritiesMember nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2021-03-31 0001163653 nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:MeasurementInputEbitdaMultipleMember srt:WeightedAverageMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:PrivateEquityAndDebtInvestmentsMember us-gaap:MarketApproachValuationTechniqueMember 2021-03-31 0001163653 nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:MeasurementInputPriceEarningsRatioMember srt:WeightedAverageMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:PrivateEquityAndDebtInvestmentsMember us-gaap:MarketApproachValuationTechniqueMember 2021-03-31 0001163653 nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:MeasurementInputDiscountRateMember srt:WeightedAverageMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:PrivateEquityAndDebtInvestmentsMember us-gaap:MarketApproachValuationTechniqueMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:ForeignGovernmentDebtSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputCreditSpreadMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:ForeignGovernmentDebtSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputRecoveryRateMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:ForeignGovernmentDebtSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputCreditSpreadMember srt:WeightedAverageMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:ForeignGovernmentDebtSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputRecoveryRateMember srt:WeightedAverageMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:RealEstateBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputLossSeverityMember srt:WeightedAverageMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:EquitySecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputDiscountRateMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:EquitySecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputDiscountRateMember srt:WeightedAverageMember 2021-03-31 0001163653 srt:AmericasMember 2021-03-31 0001163653 srt:EuropeMember 2021-03-31 0001163653 srt:AsiaPacificMember 2021-03-31 0001163653 nmr:SubtotalMember 2021-03-31 0001163653 country:JP 2021-03-31 0001163653 nmr:NomuraSecuritiesMember 2021-03-31 0001163653 nmr:NomuraFinancialProductsAndServicesIncMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:InterestRateContractMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember us-gaap:MeasurementInputRiskFreeInterestRateMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:InterestRateContractMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember us-gaap:MeasurementInputRiskFreeInterestRateMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:InterestRateContractMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputForeignExchangeVolatilityMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:InterestRateContractMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputForeignExchangeVolatilityMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:InterestRateContractMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputCorrelationMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:InterestRateContractMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputCorrelationMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:EquityContractMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:ValuationTechniqueOptionPricingModelMember us-gaap:MeasurementInputExpectedDividendPaymentMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:EquityContractMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:ValuationTechniqueOptionPricingModelMember us-gaap:MeasurementInputExpectedDividendPaymentMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:EquityContractMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:ValuationTechniqueOptionPricingModelMember srt:MinimumMember nmr:MeasurementInputForeignExchangeVolatilityMember 2021-03-31 0001163653 srt:MaximumMember nmr:MeasurementInputForeignExchangeVolatilityMember us-gaap:ValuationTechniqueOptionPricingModelMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:EquityContractMember 2021-03-31 0001163653 us-gaap:EquityContractMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:ValuationTechniqueOptionPricingModelMember nmr:MeasurementInputCorrelationMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:EquityContractMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:ValuationTechniqueOptionPricingModelMember nmr:MeasurementInputCorrelationMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:CreditRiskContractMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputForeignExchangeVolatilityMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:CreditRiskContractMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputCorrelationMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:CreditRiskContractMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputCorrelationMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:InterestRateContractMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember us-gaap:MeasurementInputPriceVolatilityMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:CreditRiskContractMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember us-gaap:MeasurementInputCreditSpreadMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:CreditRiskContractMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember us-gaap:MeasurementInputCreditSpreadMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:CreditRiskContractMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputRecoveryRateMember srt:MinimumMember 2021-03-31 0001163653 srt:MaximumMember nmr:MeasurementInputRecoveryRateMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember us-gaap:CreditRiskContractMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:CreditRiskContractMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputForeignExchangeVolatilityMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:ForeignExchangeContractMember us-gaap:ValuationTechniqueOptionPricingModelMember us-gaap:MeasurementInputRiskFreeInterestRateMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:ForeignExchangeContractMember us-gaap:ValuationTechniqueOptionPricingModelMember us-gaap:MeasurementInputRiskFreeInterestRateMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:ForeignExchangeContractMember us-gaap:ValuationTechniqueOptionPricingModelMember nmr:MeasurementInputForeignExchangeVolatilityMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:ForeignExchangeContractMember us-gaap:ValuationTechniqueOptionPricingModelMember nmr:MeasurementInputForeignExchangeVolatilityMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:ForeignExchangeContractMember us-gaap:ValuationTechniqueOptionPricingModelMember nmr:MeasurementInputCorrelationMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:ForeignExchangeContractMember us-gaap:ValuationTechniqueOptionPricingModelMember nmr:MeasurementInputCorrelationMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:ForeignExchangeContractMember us-gaap:ValuationTechniqueOptionPricingModelMember us-gaap:MeasurementInputPriceVolatilityMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:ForeignExchangeContractMember us-gaap:ValuationTechniqueOptionPricingModelMember us-gaap:MeasurementInputPriceVolatilityMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:InterestRateContractMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember us-gaap:MeasurementInputPriceVolatilityMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:LoansReceivableMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputCreditSpreadMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:LoansReceivableMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputCreditSpreadMember srt:MaximumMember 2021-03-31 0001163653 srt:MinimumMember nmr:MeasurementInputRecoveryRateMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:LoansReceivableMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:LoansReceivableMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputRecoveryRateMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:LoansReceivableMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputCreditSpreadMember srt:WeightedAverageMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:LoansReceivableMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputRecoveryRateMember srt:WeightedAverageMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:CollateralizedAgreementsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputRepoRateMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:CollateralizedAgreementsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputRepoRateMember srt:MaximumMember 2021-03-31 0001163653 srt:WeightedAverageMember nmr:MeasurementInputRepoRateMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:CollateralizedAgreementsMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2021-03-31 0001163653 nmr:NomuraResearchInstituteLtdMember 2021-03-31 0001163653 nmr:NomuraRealEstateHoldingsIncMember 2021-03-31 0001163653 nmr:NonJapanPlanMember us-gaap:FairValueInputsLevel1Member 2021-03-31 0001163653 nmr:NonJapanPlanMember us-gaap:FairValueInputsLevel2Member 2021-03-31 0001163653 nmr:NonJapanPlanMember us-gaap:FairValueInputsLevel3Member 2021-03-31 0001163653 nmr:NonJapanPlanMember 2021-03-31 0001163653 nmr:AmericanCenturyCompaniesIncMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember nmr:MeasurementInputWeightedAverageCostCapitalMember us-gaap:ValuationTechniqueDiscountedCashFlowMember 2021-03-31 0001163653 us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputLongTermRevenueGrowthRateMember nmr:InvestmentsAndOtherAssetsOtherMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember us-gaap:MeasurementInputDiscountRateMember us-gaap:ValuationTechniqueDiscountedCashFlowMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember us-gaap:MarketApproachValuationTechniqueMember us-gaap:MeasurementInputEbitdaMultipleMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember us-gaap:MarketApproachValuationTechniqueMember us-gaap:MeasurementInputEbitdaMultipleMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember us-gaap:MarketApproachValuationTechniqueMember nmr:MeasurementInputPriceEarningsRatioMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember us-gaap:MarketApproachValuationTechniqueMember nmr:MeasurementInputPriceEarningsRatioMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember us-gaap:MarketApproachValuationTechniqueMember nmr:MeasurementInputPriceBookValueRatioMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember us-gaap:MarketApproachValuationTechniqueMember nmr:MeasurementInputPriceBookValueRatioMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember us-gaap:MarketApproachValuationTechniqueMember us-gaap:MeasurementInputDiscountRateMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember us-gaap:MarketApproachValuationTechniqueMember us-gaap:MeasurementInputDiscountRateMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember srt:WeightedAverageMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputWeightedAverageCostCapitalMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember srt:WeightedAverageMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputLongTermRevenueGrowthRateMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember srt:WeightedAverageMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputDiscountRateMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember srt:WeightedAverageMember us-gaap:MarketApproachValuationTechniqueMember us-gaap:MeasurementInputEbitdaMultipleMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember srt:WeightedAverageMember us-gaap:MarketApproachValuationTechniqueMember nmr:MeasurementInputPriceEarningsRatioMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember srt:WeightedAverageMember us-gaap:MarketApproachValuationTechniqueMember nmr:MeasurementInputPriceBookValueRatioMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember srt:WeightedAverageMember us-gaap:MarketApproachValuationTechniqueMember us-gaap:MeasurementInputDiscountRateMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:TradingLiabilitiesMember us-gaap:CorporateDebtSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputRecoveryRateMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:TradingLiabilitiesMember us-gaap:CorporateDebtSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputRecoveryRateMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:CorporateDebtSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputRecoveryRateMember us-gaap:TradingLiabilitiesMember srt:WeightedAverageMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:ShortTermDebtMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputForeignExchangeVolatilityMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:ShortTermDebtMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputForeignExchangeVolatilityMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:ShortTermDebtMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputCorrelationMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:ShortTermDebtMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputCorrelationMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:EquitySecuritiesMember 2021-03-31 0001163653 us-gaap:OtherAffiliatesMember 2021-03-31 0001163653 nmr:MaintenanceAgreementsMember nmr:OtherCommitmentsMember 2021-03-31 0001163653 us-gaap:CommercialPortfolioSegmentMember 2021-03-31 0001163653 nmr:InterBankMoneyMarketLoansMember 2021-03-31 0001163653 nmr:ShortTermSecuredMarginLoansMember 2021-03-31 0001163653 nmr:LoansAtBanksMember 2021-03-31 0001163653 srt:ParentCompanyMember 2021-03-31 0001163653 srt:AffiliatedEntityMember 2021-03-31 0001163653 nmr:PrivateEquityAndPooledInvestmentsMember us-gaap:FairValueInputsLevel1Member 2021-03-31 0001163653 us-gaap:FairValueInputsLevel2Member nmr:PrivateEquityAndPooledInvestmentsMember 2021-03-31 0001163653 nmr:PrivateEquityAndPooledInvestmentsMember us-gaap:FairValueInputsLevel3Member 2021-03-31 0001163653 nmr:PrivateEquityAndPooledInvestmentsMember us-gaap:FairValueInputsLevel12And3Member 2021-03-31 0001163653 us-gaap:FairValueInputsLevel1Member nmr:JapaneseGovernmentDebtSecuritiesMember 2021-03-31 0001163653 us-gaap:FairValueInputsLevel2Member nmr:JapaneseGovernmentDebtSecuritiesMember 2021-03-31 0001163653 us-gaap:FairValueInputsLevel3Member nmr:JapaneseGovernmentDebtSecuritiesMember 2021-03-31 0001163653 us-gaap:FairValueInputsLevel12And3Member nmr:JapaneseGovernmentDebtSecuritiesMember 2021-03-31 0001163653 nmr:InvestmentTrustFundsAndOtherMember us-gaap:FairValueInputsLevel1Member 2021-03-31 0001163653 nmr:InvestmentTrustFundsAndOtherMember us-gaap:FairValueInputsLevel2Member 2021-03-31 0001163653 nmr:InvestmentTrustFundsAndOtherMember us-gaap:FairValueInputsLevel3Member 2021-03-31 0001163653 nmr:InvestmentTrustFundsAndOtherMember us-gaap:FairValueInputsLevel12And3Member 2021-03-31 0001163653 nmr:LifeInsuranceCompanyGeneralAccountsMember us-gaap:FairValueInputsLevel1Member 2021-03-31 0001163653 nmr:LifeInsuranceCompanyGeneralAccountsMember us-gaap:FairValueInputsLevel2Member 2021-03-31 0001163653 nmr:LifeInsuranceCompanyGeneralAccountsMember us-gaap:FairValueInputsLevel3Member 2021-03-31 0001163653 nmr:LifeInsuranceCompanyGeneralAccountsMember us-gaap:FairValueInputsLevel12And3Member 2021-03-31 0001163653 nmr:OtherPensionPlanAssetsMember us-gaap:FairValueInputsLevel1Member 2021-03-31 0001163653 nmr:OtherPensionPlanAssetsMember us-gaap:FairValueInputsLevel2Member 2021-03-31 0001163653 nmr:OtherPensionPlanAssetsMember us-gaap:FairValueInputsLevel3Member 2021-03-31 0001163653 nmr:OtherPensionPlanAssetsMember us-gaap:FairValueInputsLevel12And3Member 2021-03-31 0001163653 us-gaap:FairValueInputsLevel12And3Member 2021-03-31 0001163653 nmr:InvestmentsInAndAdvancesToAffiliatedCompaniesMember 2021-03-31 0001163653 us-gaap:LoansReceivableMember 2021-03-31 0001163653 nmr:TradingAssetsAndPrivateEquityInvestmentsMember 2021-03-31 0001163653 us-gaap:PropertyPlantAndEquipmentMember 2021-03-31 0001163653 nmr:NonTradingDebtSecuritiesMember 2021-03-31 0001163653 nmr:OtherAssetsAggregateCarryingAmountsMember 2021-03-31 0001163653 nmr:CreditDefaultSwapIndicesMember 2021-03-31 0001163653 nmr:CreditriskRelatedOptionsAndSwaptionsMember 2021-03-31 0001163653 nmr:OtherCreditRiskRelatedPortfolioProductsMember 2021-03-31 0001163653 us-gaap:CreditDefaultSwapMember 2021-03-31 0001163653 nmr:LongTermBorrowingsFromBanksAndFinancialInstitutionsMember 2021-03-31 0001163653 nmr:BondsAndNotesIssuedMember 2021-03-31 0001163653 nmr:AffiliateGroupMember 2021-03-31 0001163653 nmr:OtcDerivativesWithFinancialInstitutionsMember 2021-03-31 0001163653 us-gaap:CreditDefaultSwapMember nmr:LaterThanFiveYearsMember 2021-03-31 0001163653 us-gaap:CreditDefaultSwapMember nmr:LaterThanThreeYearsNotLaterThanFiveYearsMember 2021-03-31 0001163653 us-gaap:CreditDefaultSwapMember nmr:LaterThanOneYearNotLaterThanThreeYearsMember 2021-03-31 0001163653 us-gaap:CreditDefaultSwapMember nmr:NotLaterThanOneYearMember 2021-03-31 0001163653 nmr:OtherCreditRiskRelatedPortfolioProductsMember nmr:LaterThanFiveYearsMember 2021-03-31 0001163653 nmr:OtherCreditRiskRelatedPortfolioProductsMember nmr:LaterThanThreeYearsNotLaterThanFiveYearsMember 2021-03-31 0001163653 nmr:OtherCreditRiskRelatedPortfolioProductsMember nmr:LaterThanOneYearNotLaterThanThreeYearsMember 2021-03-31 0001163653 nmr:OtherCreditRiskRelatedPortfolioProductsMember nmr:NotLaterThanOneYearMember 2021-03-31 0001163653 nmr:CreditDefaultSwapIndicesMember nmr:LaterThanFiveYearsMember 2021-03-31 0001163653 nmr:CreditDefaultSwapIndicesMember nmr:LaterThanThreeYearsNotLaterThanFiveYearsMember 2021-03-31 0001163653 nmr:CreditDefaultSwapIndicesMember nmr:LaterThanOneYearNotLaterThanThreeYearsMember 2021-03-31 0001163653 nmr:CreditDefaultSwapIndicesMember nmr:NotLaterThanOneYearMember 2021-03-31 0001163653 nmr:CreditriskRelatedOptionsAndSwaptionsMember nmr:LaterThanFiveYearsMember 2021-03-31 0001163653 nmr:CreditriskRelatedOptionsAndSwaptionsMember nmr:LaterThanThreeYearsNotLaterThanFiveYearsMember 2021-03-31 0001163653 nmr:CreditriskRelatedOptionsAndSwaptionsMember nmr:LaterThanOneYearNotLaterThanThreeYearsMember 2021-03-31 0001163653 nmr:CreditriskRelatedOptionsAndSwaptionsMember nmr:NotLaterThanOneYearMember 2021-03-31 0001163653 nmr:LaterThanFiveYearsMember 2021-03-31 0001163653 nmr:LaterThanThreeYearsNotLaterThanFiveYearsMember 2021-03-31 0001163653 nmr:LaterThanOneYearNotLaterThanThreeYearsMember 2021-03-31 0001163653 nmr:NotLaterThanOneYearMember 2021-03-31 0001163653 us-gaap:RestrictedStockUnitsRSUMember 2021-03-31 0001163653 nmr:LiquidityFacilitiesToCentralClearingCounterpartiesMember 2021-03-31 0001163653 nmr:OtherCommitmentsToExtendCreditMember 2021-03-31 0001163653 nmr:FixedRateObligationsMember 2021-03-31 0001163653 nmr:FloatingRateObligationsMember 2021-03-31 0001163653 nmr:IndexOrEquityLinkedObligationsMember 2021-03-31 0001163653 nmr:SARPlanBMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:LongTermDebtMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputForeignExchangeVolatilityMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:LongTermDebtMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputForeignExchangeVolatilityMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:LongTermDebtMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputCorrelationMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:LongTermDebtMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputCorrelationMember srt:MaximumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:LongTermDebtMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember us-gaap:MeasurementInputPriceVolatilityMember srt:MinimumMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:LongTermDebtMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember us-gaap:MeasurementInputPriceVolatilityMember srt:MaximumMember 2021-03-31 0001163653 nmr:StandardPoorSOtherRatingMember 2021-03-31 0001163653 srt:StandardPoorsBBRatingMember 2021-03-31 0001163653 srt:StandardPoorsBBBRatingMember 2021-03-31 0001163653 srt:StandardPoorsARatingMember 2021-03-31 0001163653 srt:StandardPoorsAARatingMember 2021-03-31 0001163653 srt:StandardPoorsAAARatingMember 2021-03-31 0001163653 nmr:CreditriskRelatedOptionsAndSwaptionsMember nmr:StandardPoorSOtherRatingMember 2021-03-31 0001163653 nmr:CreditriskRelatedOptionsAndSwaptionsMember srt:StandardPoorsBBRatingMember 2021-03-31 0001163653 nmr:CreditriskRelatedOptionsAndSwaptionsMember srt:StandardPoorsBBBRatingMember 2021-03-31 0001163653 nmr:CreditriskRelatedOptionsAndSwaptionsMember srt:StandardPoorsARatingMember 2021-03-31 0001163653 nmr:CreditriskRelatedOptionsAndSwaptionsMember srt:StandardPoorsAARatingMember 2021-03-31 0001163653 nmr:CreditriskRelatedOptionsAndSwaptionsMember srt:StandardPoorsAAARatingMember 2021-03-31 0001163653 nmr:StandardPoorSOtherRatingMember nmr:OtherCreditRiskRelatedPortfolioProductsMember 2021-03-31 0001163653 nmr:OtherCreditRiskRelatedPortfolioProductsMember srt:StandardPoorsBBRatingMember 2021-03-31 0001163653 nmr:OtherCreditRiskRelatedPortfolioProductsMember srt:StandardPoorsBBBRatingMember 2021-03-31 0001163653 nmr:OtherCreditRiskRelatedPortfolioProductsMember srt:StandardPoorsARatingMember 2021-03-31 0001163653 srt:StandardPoorsAARatingMember nmr:OtherCreditRiskRelatedPortfolioProductsMember 2021-03-31 0001163653 srt:StandardPoorsAAARatingMember nmr:OtherCreditRiskRelatedPortfolioProductsMember 2021-03-31 0001163653 nmr:StandardPoorSOtherRatingMember nmr:CreditDefaultSwapIndicesMember 2021-03-31 0001163653 nmr:CreditDefaultSwapIndicesMember srt:StandardPoorsBBRatingMember 2021-03-31 0001163653 nmr:CreditDefaultSwapIndicesMember srt:StandardPoorsBBBRatingMember 2021-03-31 0001163653 nmr:CreditDefaultSwapIndicesMember srt:StandardPoorsARatingMember 2021-03-31 0001163653 nmr:CreditDefaultSwapIndicesMember srt:StandardPoorsAARatingMember 2021-03-31 0001163653 nmr:CreditDefaultSwapIndicesMember srt:StandardPoorsAAARatingMember 2021-03-31 0001163653 nmr:StandardPoorSOtherRatingMember us-gaap:CreditDefaultSwapMember 2021-03-31 0001163653 us-gaap:CreditDefaultSwapMember srt:StandardPoorsBBRatingMember 2021-03-31 0001163653 us-gaap:CreditDefaultSwapMember srt:StandardPoorsBBBRatingMember 2021-03-31 0001163653 us-gaap:CreditDefaultSwapMember srt:StandardPoorsARatingMember 2021-03-31 0001163653 us-gaap:CreditDefaultSwapMember srt:StandardPoorsAARatingMember 2021-03-31 0001163653 us-gaap:CreditDefaultSwapMember srt:StandardPoorsAAARatingMember 2021-03-31 0001163653 nmr:NSUsMember 2021-03-31 0001163653 nmr:CSUsMember 2021-03-31 0001163653 nmr:LongTermBorrowingsMember 2021-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember nmr:OtherAssetsAggregateCarryingAmountsMember 2021-03-31 0001163653 nmr:OtherAssetsAggregateCarryingAmountsMember us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember 2021-03-31 0001163653 nmr:OtherAssetsAggregateCarryingAmountsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2021-03-31 0001163653 nmr:OtherAssetsAggregateCarryingAmountsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2021-03-31 0001163653 nmr:OtherAssetsAggregateCarryingAmountsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2021-03-31 0001163653 nmr:NonTradingDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember 2021-03-31 0001163653 nmr:NonTradingDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember 2021-03-31 0001163653 nmr:NonTradingDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2021-03-31 0001163653 nmr:NonTradingDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2021-03-31 0001163653 nmr:NonTradingDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2021-03-31 0001163653 us-gaap:AccountingStandardsUpdate201602Member 2021-03-31 0001163653 nmr:CorporateLoanMember 2021-03-31 0001163653 us-gaap:OtherLiabilitiesMember 2021-03-31 0001163653 us-gaap:SaleAndTotalReturnSwapMember 2021-03-31 0001163653 nmr:GreentechCapitalLlcMember 2021-03-31 0001163653 nmr:SubprimeBorkerageMember country:US nmr:LoansWithTheClientMember srt:SubsidiariesMember 2021-03-31 0001163653 nmr:ListedEquityMember 2021-03-31 0001163653 nmr:UnlistedEquityMember 2021-03-31 0001163653 us-gaap:BuildingMember 2021-03-31 0001163653 us-gaap:LandMember 2021-03-31 0001163653 us-gaap:BuildingMember 2021-03-31 0001163653 nmr:EquipmentAndFacilitiesMember 2021-03-31 0001163653 us-gaap:ComputerSoftwareIntangibleAssetMember 2021-03-31 0001163653 us-gaap:ConstructionInProgressMember 2021-03-31 0001163653 nmr:ListedEquityMember 2022-03-31 0001163653 nmr:UnlistedEquityMember 2022-03-31 0001163653 us-gaap:EquityContractMember us-gaap:NondesignatedMember 2022-03-31 0001163653 us-gaap:InterestRateContractMember us-gaap:NondesignatedMember 2022-03-31 0001163653 us-gaap:CreditRiskContractMember us-gaap:NondesignatedMember 2022-03-31 0001163653 us-gaap:ForeignExchangeContractMember us-gaap:NondesignatedMember 2022-03-31 0001163653 us-gaap:CommodityContractMember us-gaap:NondesignatedMember 2022-03-31 0001163653 us-gaap:NondesignatedMember 2022-03-31 0001163653 us-gaap:InterestRateContractMember us-gaap:DesignatedAsHedgingInstrumentMember 2022-03-31 0001163653 us-gaap:ForeignExchangeContractMember us-gaap:DesignatedAsHedgingInstrumentMember 2022-03-31 0001163653 us-gaap:DesignatedAsHedgingInstrumentMember 2022-03-31 0001163653 us-gaap:VariableInterestEntityPrimaryBeneficiaryMember 2022-03-31 0001163653 nmr:TransferredToSPEsMember 2022-03-31 0001163653 us-gaap:EquitySecuritiesMember us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember 2022-03-31 0001163653 us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember us-gaap:DebtSecuritiesMember 2022-03-31 0001163653 us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember us-gaap:MortgageBackedSecuritiesMember 2022-03-31 0001163653 us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember nmr:InvestmentTrustFundsAndOtherMember 2022-03-31 0001163653 us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember nmr:PrivateEquityAndDebtInvestmentsMember 2022-03-31 0001163653 us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember us-gaap:LoansReceivableMember 2022-03-31 0001163653 us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember nmr:OtherAssetMember 2022-03-31 0001163653 us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:EquitySecuritiesMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:PrivateEquityAndDebtInvestmentsMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:ForeignGovernmentDebtSecuritiesMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:BankAndCorporateDebtSecuritiesAndLoansForTradingPurposeMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:CommercialMortgageBackedSecuritiesMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:ResidentialMortgageBackedSecuritiesMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:RealEstateBackedSecuritiesMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:CollateralizedDebtObligationsMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:EquityContractMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:InterestRateContractMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:CreditRiskContractMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:ForeignExchangeContractMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:LoansReceivableMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:CollateralizedAgreementsMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember 2022-03-31 0001163653 us-gaap:FairValueInputsLevel2Member nmr:GovernmentAgencyAndMunicipalSecuritiesMember 2022-03-31 0001163653 nmr:GovernmentAgencyAndMunicipalSecuritiesMember 2022-03-31 0001163653 us-gaap:ExternalCreditRatingInvestmentGradeMember nmr:GovernmentAgencyAndMunicipalSecuritiesMember 2022-03-31 0001163653 us-gaap:FairValueInputsLevel3Member us-gaap:MortgageBackedSecuritiesMember 2022-03-31 0001163653 us-gaap:MortgageBackedSecuritiesMember 2022-03-31 0001163653 us-gaap:ExternalCreditRatingInvestmentGradeMember us-gaap:MortgageBackedSecuritiesMember 2022-03-31 0001163653 us-gaap:ExternalCreditRatingNonInvestmentGradeMember us-gaap:MortgageBackedSecuritiesMember 2022-03-31 0001163653 us-gaap:FairValueInputsLevel2Member 2022-03-31 0001163653 us-gaap:FairValueInputsLevel3Member 2022-03-31 0001163653 us-gaap:ExternalCreditRatingInvestmentGradeMember 2022-03-31 0001163653 us-gaap:ExternalCreditRatingNonInvestmentGradeMember 2022-03-31 0001163653 us-gaap:FairValueInputsLevel1Member nmr:GovernmentAgencyAndMunicipalSecuritiesMember 2022-03-31 0001163653 us-gaap:FairValueInputsLevel3Member nmr:GovernmentAgencyAndMunicipalSecuritiesMember 2022-03-31 0001163653 us-gaap:ExternalCreditRatingNonInvestmentGradeMember nmr:GovernmentAgencyAndMunicipalSecuritiesMember 2022-03-31 0001163653 us-gaap:FairValueInputsLevel1Member us-gaap:CorporateDebtSecuritiesMember 2022-03-31 0001163653 us-gaap:FairValueInputsLevel2Member us-gaap:CorporateDebtSecuritiesMember 2022-03-31 0001163653 us-gaap:FairValueInputsLevel3Member us-gaap:CorporateDebtSecuritiesMember 2022-03-31 0001163653 us-gaap:CorporateDebtSecuritiesMember 2022-03-31 0001163653 us-gaap:ExternalCreditRatingInvestmentGradeMember us-gaap:CorporateDebtSecuritiesMember 2022-03-31 0001163653 us-gaap:ExternalCreditRatingNonInvestmentGradeMember us-gaap:CorporateDebtSecuritiesMember 2022-03-31 0001163653 us-gaap:FairValueInputsLevel1Member us-gaap:MortgageBackedSecuritiesMember 2022-03-31 0001163653 us-gaap:FairValueInputsLevel2Member us-gaap:MortgageBackedSecuritiesMember 2022-03-31 0001163653 us-gaap:FairValueInputsLevel1Member 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember 2022-03-31 0001163653 us-gaap:CollateralizedDebtObligationsMember us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember 2022-03-31 0001163653 us-gaap:CollateralizedDebtObligationsMember us-gaap:FairValueMeasurementsRecurringMember 2022-03-31 0001163653 nmr:InvestmentTrustFundsAndOtherMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2022-03-31 0001163653 nmr:InvestmentTrustFundsAndOtherMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2022-03-31 0001163653 nmr:InvestmentTrustFundsAndOtherMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember nmr:InvestmentTrustFundsAndOtherMember 2022-03-31 0001163653 nmr:InvestmentTrustFundsAndOtherMember us-gaap:FairValueMeasurementsRecurringMember 2022-03-31 0001163653 us-gaap:CollateralizedDebtObligationsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2022-03-31 0001163653 us-gaap:CollateralizedDebtObligationsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2022-03-31 0001163653 us-gaap:CollateralizedDebtObligationsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember nmr:RealEstateBackedSecuritiesMember 2022-03-31 0001163653 nmr:RealEstateBackedSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember nmr:RealEstateBackedSecuritiesMember us-gaap:FairValueInputsLevel3Member 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember nmr:RealEstateBackedSecuritiesMember us-gaap:FairValueInputsLevel2Member 2022-03-31 0001163653 nmr:RealEstateBackedSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2022-03-31 0001163653 us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember nmr:OtherResidentialMortgagebackedSecuritiesMember 2022-03-31 0001163653 nmr:OtherResidentialMortgagebackedSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember us-gaap:ResidentialMortgageBackedSecuritiesMember 2022-03-31 0001163653 us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:OtherResidentialMortgagebackedSecuritiesMember 2022-03-31 0001163653 us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member nmr:OtherResidentialMortgagebackedSecuritiesMember 2022-03-31 0001163653 us-gaap:ResidentialMortgageBackedSecuritiesMember nmr:OtherResidentialMortgagebackedSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2022-03-31 0001163653 us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember nmr:IssuedGuaranteedByGovernmentSponsoredEntityMember 2022-03-31 0001163653 nmr:IssuedGuaranteedByGovernmentSponsoredEntityMember us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember us-gaap:ResidentialMortgageBackedSecuritiesMember 2022-03-31 0001163653 nmr:IssuedGuaranteedByGovernmentSponsoredEntityMember us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2022-03-31 0001163653 us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member nmr:IssuedGuaranteedByGovernmentSponsoredEntityMember 2022-03-31 0001163653 us-gaap:ResidentialMortgageBackedSecuritiesMember nmr:IssuedGuaranteedByGovernmentSponsoredEntityMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2022-03-31 0001163653 us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember 2022-03-31 0001163653 us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember 2022-03-31 0001163653 us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2022-03-31 0001163653 us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2022-03-31 0001163653 us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommercialMortgageBackedSecuritiesMember 2022-03-31 0001163653 us-gaap:CommercialMortgageBackedSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommercialMortgageBackedSecuritiesMember us-gaap:FairValueInputsLevel3Member 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommercialMortgageBackedSecuritiesMember us-gaap:FairValueInputsLevel2Member 2022-03-31 0001163653 us-gaap:CommercialMortgageBackedSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2022-03-31 0001163653 nmr:BankAndCorporateDebtSecuritiesAndLoansForTradingPurposeMember us-gaap:FairValueMeasurementsRecurringMember 2022-03-31 0001163653 nmr:BankAndCorporateDebtSecuritiesAndLoansForTradingPurposeMember us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember 2022-03-31 0001163653 nmr:BankAndCorporateDebtSecuritiesAndLoansForTradingPurposeMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2022-03-31 0001163653 nmr:BankAndCorporateDebtSecuritiesAndLoansForTradingPurposeMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2022-03-31 0001163653 nmr:BankAndCorporateDebtSecuritiesAndLoansForTradingPurposeMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2022-03-31 0001163653 us-gaap:ForeignGovernmentDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember 2022-03-31 0001163653 us-gaap:ForeignGovernmentDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember 2022-03-31 0001163653 us-gaap:ForeignGovernmentDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2022-03-31 0001163653 us-gaap:ForeignGovernmentDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2022-03-31 0001163653 us-gaap:ForeignGovernmentDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember nmr:JapaneseAgencyAndMunicipalDebtSecuritiesMember 2022-03-31 0001163653 nmr:JapaneseAgencyAndMunicipalDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember 2022-03-31 0001163653 nmr:JapaneseAgencyAndMunicipalDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2022-03-31 0001163653 nmr:JapaneseAgencyAndMunicipalDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2022-03-31 0001163653 nmr:JapaneseAgencyAndMunicipalDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2022-03-31 0001163653 nmr:JapaneseGovernmentDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember 2022-03-31 0001163653 nmr:JapaneseGovernmentDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember 2022-03-31 0001163653 nmr:JapaneseGovernmentDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2022-03-31 0001163653 nmr:JapaneseGovernmentDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2022-03-31 0001163653 nmr:JapaneseGovernmentDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2022-03-31 0001163653 nmr:PrivateEquityAndDebtInvestmentsMember us-gaap:FairValueMeasurementsRecurringMember 2022-03-31 0001163653 nmr:PrivateEquityAndDebtInvestmentsMember nmr:CounterpartyCashCollateralNettingMember us-gaap:FairValueMeasurementsRecurringMember 2022-03-31 0001163653 nmr:PrivateEquityAndDebtInvestmentsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2022-03-31 0001163653 nmr:PrivateEquityAndDebtInvestmentsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2022-03-31 0001163653 nmr:PrivateEquityAndDebtInvestmentsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2022-03-31 0001163653 us-gaap:EquitySecuritiesMember us-gaap:FairValueMeasurementsRecurringMember 2022-03-31 0001163653 us-gaap:EquitySecuritiesMember nmr:CounterpartyCashCollateralNettingMember us-gaap:FairValueMeasurementsRecurringMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:EquitySecuritiesMember 2022-03-31 0001163653 us-gaap:EquitySecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2022-03-31 0001163653 us-gaap:EquitySecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member us-gaap:CorporateDebtSecuritiesMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member us-gaap:CorporateDebtSecuritiesMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:CorporateDebtSecuritiesMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember us-gaap:CorporateDebtSecuritiesMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember 2022-03-31 0001163653 us-gaap:CarryingReportedAmountFairValueDisclosureMember 2022-03-31 0001163653 us-gaap:EstimateOfFairValueFairValueDisclosureMember 2022-03-31 0001163653 nmr:DerivativeContractsMember 2022-03-31 0001163653 us-gaap:FinancialStandbyLetterOfCreditMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember nmr:NetAssetValueValuationTechniqueMember 2022-03-31 0001163653 nmr:OtherCommitmentsMember 2022-03-31 0001163653 us-gaap:ShortTermDebtMember 2022-03-31 0001163653 us-gaap:LandAndBuildingMember 2022-03-31 0001163653 us-gaap:AirTransportationEquipmentMember 2022-03-31 0001163653 nmr:MaturityGreaterThan1YearMember 2022-03-31 0001163653 nmr:Maturity90DaysTo1YearMember 2022-03-31 0001163653 us-gaap:Maturity30To90DaysMember 2022-03-31 0001163653 us-gaap:MaturityUpTo30DaysMember 2022-03-31 0001163653 us-gaap:MaturityOvernightAndOnDemandMember 2022-03-31 0001163653 us-gaap:CustomerRelationshipsMember 2022-03-31 0001163653 us-gaap:OtherIntangibleAssetsMember 2022-03-31 0001163653 nmr:EquitiesAndConvertibleBondsMember 2022-03-31 0001163653 nmr:GovernmentAndGovernmentAgencySecuritiesMember 2022-03-31 0001163653 us-gaap:ResidentialMortgageBackedSecuritiesMember 2022-03-31 0001163653 us-gaap:CollateralizedDebtObligationsMember 2022-03-31 0001163653 nmr:InvestmentTrustFundsAndOtherMember 2022-03-31 0001163653 us-gaap:ForeignGovernmentDebtSecuritiesMember 2022-03-31 0001163653 us-gaap:CommercialMortgageBackedSecuritiesMember 2022-03-31 0001163653 us-gaap:OverTheCounterMember us-gaap:EquityContractMember 2022-03-31 0001163653 us-gaap:ExchangeTradedMember us-gaap:EquityContractMember 2022-03-31 0001163653 us-gaap:OverTheCounterMember us-gaap:InterestRateContractMember 2022-03-31 0001163653 us-gaap:ExchangeClearedMember us-gaap:InterestRateContractMember 2022-03-31 0001163653 us-gaap:ExchangeTradedMember us-gaap:InterestRateContractMember 2022-03-31 0001163653 us-gaap:OverTheCounterMember us-gaap:CreditRiskContractMember 2022-03-31 0001163653 us-gaap:ExchangeClearedMember us-gaap:CreditRiskContractMember 2022-03-31 0001163653 us-gaap:CreditRiskContractMember us-gaap:ExchangeTradedMember 2022-03-31 0001163653 us-gaap:OverTheCounterMember us-gaap:ForeignExchangeContractMember 2022-03-31 0001163653 us-gaap:OverTheCounterMember us-gaap:CommodityContractMember 2022-03-31 0001163653 us-gaap:ExchangeTradedMember us-gaap:CommodityContractMember 2022-03-31 0001163653 nmr:AffiliatedCompaniesAndOtherEquityMethodInvesteesMember 2022-03-31 0001163653 country:JP nmr:GovernmentAgencyAndMunicipalSecuritiesMember 2022-03-31 0001163653 country:US nmr:GovernmentAgencyAndMunicipalSecuritiesMember 2022-03-31 0001163653 us-gaap:EuropeanUnionMember nmr:GovernmentAgencyAndMunicipalSecuritiesMember 2022-03-31 0001163653 nmr:FairValueConcentrationCreditRiskGeographicalOtherCountriesMember nmr:GovernmentAgencyAndMunicipalSecuritiesMember 2022-03-31 0001163653 nmr:GovernmentAgencyAndMunicipalSecuritiesMember 2022-03-31 0001163653 nmr:AdvancesToAffiliatedCompaniesMember nmr:InternallyAssignedGradeTotalMember 2022-03-31 0001163653 nmr:OthersMember nmr:AdvancesToAffiliatedCompaniesMember 2022-03-31 0001163653 nmr:CCDMember nmr:AdvancesToAffiliatedCompaniesMember 2022-03-31 0001163653 nmr:BBCCCMember nmr:AdvancesToAffiliatedCompaniesMember 2022-03-31 0001163653 nmr:AdvancesToAffiliatedCompaniesMember nmr:AAABBBMember 2022-03-31 0001163653 nmr:UnsecuredCorporateLoansMember nmr:InternallyAssignedGradeTotalMember 2022-03-31 0001163653 nmr:UnsecuredCorporateLoansMember nmr:OthersMember 2022-03-31 0001163653 nmr:UnsecuredCorporateLoansMember nmr:CCDMember 2022-03-31 0001163653 nmr:UnsecuredCorporateLoansMember nmr:BBCCCMember 2022-03-31 0001163653 nmr:UnsecuredCorporateLoansMember nmr:AAABBBMember 2022-03-31 0001163653 nmr:SecuredCorporateLoansMember nmr:InternallyAssignedGradeTotalMember 2022-03-31 0001163653 nmr:OthersMember nmr:SecuredCorporateLoansMember 2022-03-31 0001163653 nmr:SecuredCorporateLoansMember nmr:CCDMember 2022-03-31 0001163653 nmr:SecuredCorporateLoansMember nmr:BBCCCMember 2022-03-31 0001163653 nmr:SecuredCorporateLoansMember nmr:AAABBBMember 2022-03-31 0001163653 nmr:UnsecuredInterBankMoneyMarketLoansMember nmr:InternallyAssignedGradeTotalMember 2022-03-31 0001163653 nmr:OthersMember nmr:UnsecuredInterBankMoneyMarketLoansMember 2022-03-31 0001163653 nmr:UnsecuredInterBankMoneyMarketLoansMember nmr:CCDMember 2022-03-31 0001163653 nmr:UnsecuredInterBankMoneyMarketLoansMember nmr:BBCCCMember 2022-03-31 0001163653 nmr:UnsecuredInterBankMoneyMarketLoansMember nmr:AAABBBMember 2022-03-31 0001163653 nmr:ShortTermSecuredMarginLoansMember nmr:InternallyAssignedGradeTotalMember 2022-03-31 0001163653 nmr:OthersMember nmr:ShortTermSecuredMarginLoansMember 2022-03-31 0001163653 nmr:ShortTermSecuredMarginLoansMember nmr:CCDMember 2022-03-31 0001163653 nmr:ShortTermSecuredMarginLoansMember nmr:BBCCCMember 2022-03-31 0001163653 nmr:AAABBBMember nmr:ShortTermSecuredMarginLoansMember 2022-03-31 0001163653 nmr:UnsecuredLoansAtBanksMember nmr:InternallyAssignedGradeTotalMember 2022-03-31 0001163653 nmr:OthersMember nmr:UnsecuredLoansAtBanksMember 2022-03-31 0001163653 nmr:UnsecuredLoansAtBanksMember nmr:CCDMember 2022-03-31 0001163653 nmr:UnsecuredLoansAtBanksMember nmr:BBCCCMember 2022-03-31 0001163653 nmr:UnsecuredLoansAtBanksMember nmr:AAABBBMember 2022-03-31 0001163653 nmr:SecuredLoansAtBanksMember nmr:InternallyAssignedGradeTotalMember 2022-03-31 0001163653 nmr:SecuredLoansAtBanksMember nmr:OthersMember 2022-03-31 0001163653 nmr:SecuredLoansAtBanksMember nmr:CCDMember 2022-03-31 0001163653 nmr:SecuredLoansAtBanksMember nmr:BBCCCMember 2022-03-31 0001163653 nmr:SecuredLoansAtBanksMember nmr:AAABBBMember 2022-03-31 0001163653 us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember us-gaap:CommitmentsToExtendCreditMember 2022-03-31 0001163653 srt:MinimumMember 2022-03-31 0001163653 srt:MaximumMember 2022-03-31 0001163653 srt:MinimumMember nmr:LimitedPartnershipMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:TradingLiabilitiesMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:ShortTermDebtMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:PayablesAndDepositsMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:LongTermDebtMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:OtherLiabilitiesOtherMember 2022-03-31 0001163653 us-gaap:EquityContractMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2022-03-31 0001163653 us-gaap:EquityContractMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2022-03-31 0001163653 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquityContractMember 2022-03-31 0001163653 us-gaap:EquityContractMember us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember 2022-03-31 0001163653 us-gaap:EquityContractMember us-gaap:FairValueMeasurementsRecurringMember 2022-03-31 0001163653 us-gaap:InterestRateContractMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2022-03-31 0001163653 us-gaap:InterestRateContractMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2022-03-31 0001163653 us-gaap:InterestRateContractMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2022-03-31 0001163653 us-gaap:InterestRateContractMember us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember 2022-03-31 0001163653 us-gaap:InterestRateContractMember us-gaap:FairValueMeasurementsRecurringMember 2022-03-31 0001163653 us-gaap:CreditRiskContractMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2022-03-31 0001163653 us-gaap:CreditRiskContractMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2022-03-31 0001163653 us-gaap:CreditRiskContractMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2022-03-31 0001163653 us-gaap:CreditRiskContractMember us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember 2022-03-31 0001163653 us-gaap:CreditRiskContractMember us-gaap:FairValueMeasurementsRecurringMember 2022-03-31 0001163653 us-gaap:ForeignExchangeContractMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2022-03-31 0001163653 us-gaap:ForeignExchangeContractMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2022-03-31 0001163653 us-gaap:ForeignExchangeContractMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2022-03-31 0001163653 us-gaap:ForeignExchangeContractMember us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember 2022-03-31 0001163653 us-gaap:ForeignExchangeContractMember us-gaap:FairValueMeasurementsRecurringMember 2022-03-31 0001163653 us-gaap:CommodityContractMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2022-03-31 0001163653 us-gaap:CommodityContractMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2022-03-31 0001163653 us-gaap:CommodityContractMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2022-03-31 0001163653 us-gaap:CommodityContractMember us-gaap:FairValueMeasurementsRecurringMember nmr:CounterpartyCashCollateralNettingMember 2022-03-31 0001163653 us-gaap:CommodityContractMember us-gaap:FairValueMeasurementsRecurringMember 2022-03-31 0001163653 us-gaap:RealEstateFundsMember 2022-03-31 0001163653 us-gaap:PrivateEquityFundsMember 2022-03-31 0001163653 us-gaap:HedgeFundsMember 2022-03-31 0001163653 us-gaap:VentureCapitalFundsMember 2022-03-31 0001163653 nmr:JapaneseYenDenominatedMember nmr:FixedRateObligationsMember 2022-03-31 0001163653 nmr:NonJapaneseYenDenominatedMember nmr:FixedRateObligationsMember 2022-03-31 0001163653 nmr:JapaneseYenDenominatedMember nmr:FloatingRateObligationsMember 2022-03-31 0001163653 nmr:NonJapaneseYenDenominatedMember nmr:FloatingRateObligationsMember 2022-03-31 0001163653 nmr:JapaneseYenDenominatedMember nmr:IndexOrEquityLinkedObligationsMember 2022-03-31 0001163653 nmr:NonJapaneseYenDenominatedMember nmr:IndexOrEquityLinkedObligationsMember 2022-03-31 0001163653 us-gaap:FinancialStandbyLetterOfCreditMember nmr:NotLaterThanOneYearMember 2022-03-31 0001163653 us-gaap:FinancialStandbyLetterOfCreditMember nmr:LaterThanOneYearNotLaterThanThreeYearsMember 2022-03-31 0001163653 us-gaap:FinancialStandbyLetterOfCreditMember nmr:LaterThanThreeYearsNotLaterThanFiveYearsMember 2022-03-31 0001163653 us-gaap:FinancialStandbyLetterOfCreditMember nmr:LaterThanFiveYearsMember 2022-03-31 0001163653 nmr:NotLaterThanOneYearMember nmr:DerivativeContractsMember 2022-03-31 0001163653 nmr:LaterThanOneYearNotLaterThanThreeYearsMember nmr:DerivativeContractsMember 2022-03-31 0001163653 nmr:LaterThanThreeYearsNotLaterThanFiveYearsMember nmr:DerivativeContractsMember 2022-03-31 0001163653 nmr:LaterThanFiveYearsMember nmr:DerivativeContractsMember 2022-03-31 0001163653 nmr:InvestmentTrustFundsAndOtherMember us-gaap:FairValueMeasuredAtNetAssetValuePerShareMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember nmr:OtherAssetsAggregateCarryingAmountsMember nmr:NetAssetValueValuationTechniqueMember 2022-03-31 0001163653 nmr:FloatingRateObligationsMember srt:MinimumMember 2022-03-31 0001163653 nmr:FloatingRateObligationsMember srt:MaximumMember 2022-03-31 0001163653 nmr:IndexOrEquityLinkedObligationsMember srt:MinimumMember 2022-03-31 0001163653 nmr:IndexOrEquityLinkedObligationsMember srt:MaximumMember 2022-03-31 0001163653 nmr:FixedRateObligationsMember srt:MinimumMember 2022-03-31 0001163653 nmr:FixedRateObligationsMember srt:MaximumMember 2022-03-31 0001163653 nmr:OverseasSubsidiariesMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember srt:WeightedAverageMember us-gaap:EquitySecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputDiscountRateMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember srt:WeightedAverageMember nmr:PrivateEquityAndDebtInvestmentsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputWeightedAverageCostCapitalMember 2022-03-31 0001163653 us-gaap:MeasurementInputLongTermRevenueGrowthRateMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:PrivateEquityAndDebtInvestmentsMember srt:WeightedAverageMember nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember srt:WeightedAverageMember nmr:PrivateEquityAndDebtInvestmentsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputDiscountRateMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember srt:WeightedAverageMember us-gaap:MarketApproachValuationTechniqueMember us-gaap:MeasurementInputEbitdaMultipleMember nmr:PrivateEquityAndDebtInvestmentsMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember srt:WeightedAverageMember us-gaap:MarketApproachValuationTechniqueMember nmr:MeasurementInputPriceEarningsRatioMember nmr:PrivateEquityAndDebtInvestmentsMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember srt:WeightedAverageMember us-gaap:MarketApproachValuationTechniqueMember us-gaap:MeasurementInputDiscountRateMember nmr:PrivateEquityAndDebtInvestmentsMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember srt:WeightedAverageMember us-gaap:ForeignGovernmentDebtSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputCreditSpreadMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember srt:WeightedAverageMember us-gaap:ForeignGovernmentDebtSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputRecoveryRateMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember srt:WeightedAverageMember nmr:BankAndCorporateDebtSecuritiesAndLoansForTradingPurposeMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputCreditSpreadMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember srt:WeightedAverageMember nmr:BankAndCorporateDebtSecuritiesAndLoansForTradingPurposeMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputRecoveryRateMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember srt:WeightedAverageMember us-gaap:CommercialMortgageBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputYieldsMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember srt:WeightedAverageMember us-gaap:CommercialMortgageBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputLossSeverityMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember srt:WeightedAverageMember us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputYieldsMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:CollateralizedDebtObligationsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputPrepaymentRateMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:CollateralizedDebtObligationsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputDefaultRateMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:CollateralizedDebtObligationsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputLossSeverityMember srt:MinimumMember 2022-03-31 0001163653 srt:MaximumMember us-gaap:MeasurementInputLossSeverityMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:CollateralizedDebtObligationsMember nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:EquitySecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputDiscountRateMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:PrivateEquityAndDebtInvestmentsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputWeightedAverageCostCapitalMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:PrivateEquityAndDebtInvestmentsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputWeightedAverageCostCapitalMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:PrivateEquityAndDebtInvestmentsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputLongTermRevenueGrowthRateMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:PrivateEquityAndDebtInvestmentsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputLongTermRevenueGrowthRateMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:PrivateEquityAndDebtInvestmentsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputDiscountRateMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:PrivateEquityAndDebtInvestmentsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputDiscountRateMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:MarketApproachValuationTechniqueMember us-gaap:MeasurementInputEbitdaMultipleMember srt:MinimumMember nmr:PrivateEquityAndDebtInvestmentsMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:MarketApproachValuationTechniqueMember us-gaap:MeasurementInputEbitdaMultipleMember srt:MaximumMember nmr:PrivateEquityAndDebtInvestmentsMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:MarketApproachValuationTechniqueMember nmr:MeasurementInputPriceEarningsRatioMember srt:MinimumMember nmr:PrivateEquityAndDebtInvestmentsMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:MarketApproachValuationTechniqueMember nmr:MeasurementInputPriceEarningsRatioMember srt:MaximumMember nmr:PrivateEquityAndDebtInvestmentsMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:MarketApproachValuationTechniqueMember us-gaap:MeasurementInputDiscountRateMember srt:MinimumMember nmr:PrivateEquityAndDebtInvestmentsMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:MarketApproachValuationTechniqueMember us-gaap:MeasurementInputDiscountRateMember srt:MaximumMember nmr:PrivateEquityAndDebtInvestmentsMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:ForeignGovernmentDebtSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputCreditSpreadMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:ForeignGovernmentDebtSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputCreditSpreadMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:ForeignGovernmentDebtSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputRecoveryRateMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:BankAndCorporateDebtSecuritiesAndLoansForTradingPurposeMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputCreditSpreadMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:BankAndCorporateDebtSecuritiesAndLoansForTradingPurposeMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputCreditSpreadMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:BankAndCorporateDebtSecuritiesAndLoansForTradingPurposeMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputRecoveryRateMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:BankAndCorporateDebtSecuritiesAndLoansForTradingPurposeMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputRecoveryRateMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:CommercialMortgageBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputYieldsMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:CommercialMortgageBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputYieldsMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:CommercialMortgageBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputLossSeverityMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:CommercialMortgageBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputLossSeverityMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputYieldsMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputYieldsMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputPrepaymentRateMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputPrepaymentRateMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputLossSeverityMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputLossSeverityMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:RealEstateBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputLossSeverityMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember nmr:RealEstateBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputLossSeverityMember srt:MaximumMember 2022-03-31 0001163653 srt:MinimumMember nmr:MeasurementInputYieldsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:CollateralizedDebtObligationsMember nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:CollateralizedDebtObligationsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputYieldsMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember us-gaap:CollateralizedDebtObligationsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputPrepaymentRateMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember srt:WeightedAverageMember us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputPrepaymentRateMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember srt:WeightedAverageMember us-gaap:ResidentialMortgageBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputLossSeverityMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember srt:WeightedAverageMember nmr:RealEstateBackedSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputLossSeverityMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember srt:WeightedAverageMember us-gaap:CollateralizedDebtObligationsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputYieldsMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember srt:WeightedAverageMember us-gaap:CollateralizedDebtObligationsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputPrepaymentRateMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember srt:WeightedAverageMember us-gaap:CollateralizedDebtObligationsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputDefaultRateMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:TradingAssetsAndPrivateEquityInvestmentsMember srt:WeightedAverageMember us-gaap:CollateralizedDebtObligationsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputLossSeverityMember 2022-03-31 0001163653 srt:AmericasMember 2022-03-31 0001163653 srt:EuropeMember 2022-03-31 0001163653 srt:AsiaPacificMember 2022-03-31 0001163653 nmr:SubtotalMember 2022-03-31 0001163653 country:JP 2022-03-31 0001163653 nmr:NomuraSecuritiesMember 2022-03-31 0001163653 nmr:NomuraFinancialProductsAndServicesIncMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:EquityContractMember us-gaap:ValuationTechniqueOptionPricingModelMember us-gaap:MeasurementInputExpectedDividendPaymentMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:EquityContractMember us-gaap:ValuationTechniqueOptionPricingModelMember us-gaap:MeasurementInputExpectedDividendPaymentMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:ForeignExchangeContractMember us-gaap:ValuationTechniqueOptionPricingModelMember us-gaap:MeasurementInputPriceVolatilityMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:ForeignExchangeContractMember us-gaap:ValuationTechniqueOptionPricingModelMember us-gaap:MeasurementInputPriceVolatilityMember srt:MaximumMember 2022-03-31 0001163653 srt:MinimumMember nmr:MeasurementInputForeignExchangeVolatilityMember us-gaap:ValuationTechniqueOptionPricingModelMember us-gaap:EquityContractMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:EquityContractMember us-gaap:ValuationTechniqueOptionPricingModelMember nmr:MeasurementInputForeignExchangeVolatilityMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:EquityContractMember us-gaap:ValuationTechniqueOptionPricingModelMember nmr:MeasurementInputCorrelationMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:EquityContractMember us-gaap:ValuationTechniqueOptionPricingModelMember nmr:MeasurementInputCorrelationMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:InterestRateContractMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember us-gaap:MeasurementInputRiskFreeInterestRateMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:InterestRateContractMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember us-gaap:MeasurementInputRiskFreeInterestRateMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:InterestRateContractMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputForeignExchangeVolatilityMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:InterestRateContractMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputForeignExchangeVolatilityMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:InterestRateContractMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputCorrelationMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:InterestRateContractMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputCorrelationMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:InterestRateContractMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember us-gaap:MeasurementInputPriceVolatilityMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:InterestRateContractMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember us-gaap:MeasurementInputPriceVolatilityMember srt:MaximumMember 2022-03-31 0001163653 srt:MinimumMember us-gaap:MeasurementInputCreditSpreadMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember us-gaap:CreditRiskContractMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:CreditRiskContractMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember us-gaap:MeasurementInputCreditSpreadMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:CreditRiskContractMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputRecoveryRateMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:CreditRiskContractMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputRecoveryRateMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:CreditRiskContractMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputForeignExchangeVolatilityMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:CreditRiskContractMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputForeignExchangeVolatilityMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:CreditRiskContractMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputCorrelationMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:CreditRiskContractMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputCorrelationMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:ForeignExchangeContractMember us-gaap:ValuationTechniqueOptionPricingModelMember us-gaap:MeasurementInputRiskFreeInterestRateMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:ForeignExchangeContractMember us-gaap:ValuationTechniqueOptionPricingModelMember us-gaap:MeasurementInputRiskFreeInterestRateMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:ForeignExchangeContractMember us-gaap:ValuationTechniqueOptionPricingModelMember nmr:MeasurementInputForeignExchangeVolatilityMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:ForeignExchangeContractMember us-gaap:ValuationTechniqueOptionPricingModelMember nmr:MeasurementInputForeignExchangeVolatilityMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:ForeignExchangeContractMember us-gaap:ValuationTechniqueOptionPricingModelMember nmr:MeasurementInputCorrelationMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:ForeignExchangeContractMember us-gaap:ValuationTechniqueOptionPricingModelMember nmr:MeasurementInputCorrelationMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:LoansReceivableMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputCreditSpreadMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:LoansReceivableMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputCreditSpreadMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:LoansReceivableMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputRecoveryRateMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:LoansReceivableMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputRecoveryRateMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:LoansReceivableMember srt:WeightedAverageMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputCreditSpreadMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:LoansReceivableMember srt:WeightedAverageMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputRecoveryRateMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:CollateralizedAgreementsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputRepoRateMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:CollateralizedAgreementsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputRepoRateMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:CollateralizedAgreementsMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputRepoRateMember srt:WeightedAverageMember 2022-03-31 0001163653 us-gaap:EquitySecuritiesMember 2022-03-31 0001163653 us-gaap:DebtSecuritiesMember 2022-03-31 0001163653 nmr:LifeInsuranceCompanyGeneralAccountsMember 2022-03-31 0001163653 nmr:OtherPensionPlanAssetsMember 2022-03-31 0001163653 nmr:NomuraResearchInstituteLtdMember 2022-03-31 0001163653 nmr:NomuraRealEstateHoldingsIncMember 2022-03-31 0001163653 nmr:SARPlanBMember 2022-03-31 0001163653 nmr:NomuraGlobalFinancialProductsIncMember 2022-03-31 0001163653 nmr:InstinetLLCMember 2022-03-31 0001163653 nmr:NonJapanPlanMember us-gaap:FairValueInputsLevel1Member 2022-03-31 0001163653 nmr:NonJapanPlanMember us-gaap:FairValueInputsLevel2Member 2022-03-31 0001163653 nmr:NonJapanPlanMember us-gaap:FairValueInputsLevel3Member 2022-03-31 0001163653 nmr:NonJapanPlanMember 2022-03-31 0001163653 nmr:AmericanCenturyCompaniesIncMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember srt:WeightedAverageMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputWeightedAverageCostCapitalMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember srt:WeightedAverageMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputLongTermRevenueGrowthRateMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember srt:WeightedAverageMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputDiscountRateMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember srt:WeightedAverageMember us-gaap:MarketApproachValuationTechniqueMember us-gaap:MeasurementInputEbitdaMultipleMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember srt:WeightedAverageMember us-gaap:MarketApproachValuationTechniqueMember nmr:MeasurementInputPriceEarningsRatioMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputWeightedAverageCostCapitalMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputLongTermRevenueGrowthRateMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember us-gaap:ValuationTechniqueDiscountedCashFlowMember us-gaap:MeasurementInputDiscountRateMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember us-gaap:MarketApproachValuationTechniqueMember us-gaap:MeasurementInputEbitdaMultipleMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember us-gaap:MarketApproachValuationTechniqueMember us-gaap:MeasurementInputEbitdaMultipleMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember us-gaap:MarketApproachValuationTechniqueMember nmr:MeasurementInputPriceEarningsRatioMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember us-gaap:MarketApproachValuationTechniqueMember nmr:MeasurementInputPriceEarningsRatioMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember us-gaap:MarketApproachValuationTechniqueMember nmr:MeasurementInputPriceBookValueRatioMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember us-gaap:MarketApproachValuationTechniqueMember nmr:MeasurementInputPriceBookValueRatioMember srt:MaximumMember 2022-03-31 0001163653 srt:MinimumMember us-gaap:MeasurementInputDiscountRateMember us-gaap:MarketApproachValuationTechniqueMember nmr:InvestmentsAndOtherAssetsOtherMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember us-gaap:MarketApproachValuationTechniqueMember us-gaap:MeasurementInputDiscountRateMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember srt:WeightedAverageMember us-gaap:MarketApproachValuationTechniqueMember nmr:MeasurementInputPriceBookValueRatioMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:InvestmentsAndOtherAssetsOtherMember srt:WeightedAverageMember us-gaap:MarketApproachValuationTechniqueMember us-gaap:MeasurementInputDiscountRateMember 2022-03-31 0001163653 nmr:NomuraSecuritiesInternationalIncMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:TradingLiabilitiesMember us-gaap:CorporateDebtSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputRecoveryRateMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:TradingLiabilitiesMember us-gaap:CorporateDebtSecuritiesMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputRecoveryRateMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:TradingLiabilitiesMember us-gaap:CorporateDebtSecuritiesMember srt:WeightedAverageMember us-gaap:ValuationTechniqueDiscountedCashFlowMember nmr:MeasurementInputRecoveryRateMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:ShortTermDebtMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputForeignExchangeVolatilityMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:ShortTermDebtMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputForeignExchangeVolatilityMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:ShortTermDebtMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputCorrelationMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:ShortTermDebtMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputCorrelationMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:EquitySecuritiesMember 2022-03-31 0001163653 us-gaap:OtherAffiliatesMember 2022-03-31 0001163653 nmr:OtherCommitmentsMember nmr:MaintenanceAgreementsMember 2022-03-31 0001163653 nmr:InterBankMoneyMarketLoansMember 2022-03-31 0001163653 nmr:ShortTermSecuredMarginLoansMember 2022-03-31 0001163653 us-gaap:CommercialPortfolioSegmentMember 2022-03-31 0001163653 srt:ParentCompanyMember 2022-03-31 0001163653 srt:AffiliatedEntityMember 2022-03-31 0001163653 nmr:LoansAtBanksMember 2022-03-31 0001163653 us-gaap:FairValueInputsLevel12And3Member 2022-03-31 0001163653 us-gaap:FairValueInputsLevel1Member nmr:PrivateEquityAndPooledInvestmentsMember 2022-03-31 0001163653 nmr:PrivateEquityAndPooledInvestmentsMember us-gaap:FairValueInputsLevel2Member 2022-03-31 0001163653 nmr:PrivateEquityAndPooledInvestmentsMember us-gaap:FairValueInputsLevel3Member 2022-03-31 0001163653 nmr:PrivateEquityAndPooledInvestmentsMember us-gaap:FairValueInputsLevel12And3Member 2022-03-31 0001163653 nmr:JapaneseGovernmentDebtSecuritiesMember us-gaap:FairValueInputsLevel1Member 2022-03-31 0001163653 us-gaap:FairValueInputsLevel2Member nmr:JapaneseGovernmentDebtSecuritiesMember 2022-03-31 0001163653 us-gaap:FairValueInputsLevel3Member nmr:JapaneseGovernmentDebtSecuritiesMember 2022-03-31 0001163653 nmr:JapaneseGovernmentDebtSecuritiesMember us-gaap:FairValueInputsLevel12And3Member 2022-03-31 0001163653 us-gaap:FairValueInputsLevel1Member nmr:InvestmentTrustFundsAndOtherMember 2022-03-31 0001163653 nmr:InvestmentTrustFundsAndOtherMember us-gaap:FairValueInputsLevel2Member 2022-03-31 0001163653 nmr:InvestmentTrustFundsAndOtherMember us-gaap:FairValueInputsLevel3Member 2022-03-31 0001163653 nmr:InvestmentTrustFundsAndOtherMember us-gaap:FairValueInputsLevel12And3Member 2022-03-31 0001163653 us-gaap:FairValueInputsLevel1Member nmr:LifeInsuranceCompanyGeneralAccountsMember 2022-03-31 0001163653 nmr:LifeInsuranceCompanyGeneralAccountsMember us-gaap:FairValueInputsLevel2Member 2022-03-31 0001163653 us-gaap:FairValueInputsLevel3Member nmr:LifeInsuranceCompanyGeneralAccountsMember 2022-03-31 0001163653 nmr:LifeInsuranceCompanyGeneralAccountsMember us-gaap:FairValueInputsLevel12And3Member 2022-03-31 0001163653 us-gaap:FairValueInputsLevel1Member nmr:OtherPensionPlanAssetsMember 2022-03-31 0001163653 nmr:OtherPensionPlanAssetsMember us-gaap:FairValueInputsLevel2Member 2022-03-31 0001163653 us-gaap:FairValueInputsLevel3Member nmr:OtherPensionPlanAssetsMember 2022-03-31 0001163653 nmr:OtherPensionPlanAssetsMember us-gaap:FairValueInputsLevel12And3Member 2022-03-31 0001163653 nmr:InvestmentsInAndAdvancesToAffiliatedCompaniesMember 2022-03-31 0001163653 us-gaap:LoansReceivableMember 2022-03-31 0001163653 nmr:TradingAssetsAndPrivateEquityInvestmentsMember 2022-03-31 0001163653 us-gaap:PropertyPlantAndEquipmentMember 2022-03-31 0001163653 nmr:NonTradingDebtSecuritiesMember 2022-03-31 0001163653 nmr:OtherAssetsAggregateCarryingAmountsMember 2022-03-31 0001163653 nmr:CreditriskRelatedOptionsAndSwaptionsMember 2022-03-31 0001163653 nmr:OtherCreditRiskRelatedPortfolioProductsMember 2022-03-31 0001163653 nmr:CreditDefaultSwapIndicesMember 2022-03-31 0001163653 us-gaap:CreditDefaultSwapMember 2022-03-31 0001163653 nmr:LongTermBorrowingsFromBanksAndFinancialInstitutionsMember 2022-03-31 0001163653 nmr:BondsAndNotesIssuedMember 2022-03-31 0001163653 nmr:AffiliateGroupMember 2022-03-31 0001163653 nmr:OtcDerivativesWithFinancialInstitutionsMember 2022-03-31 0001163653 nmr:LaterThanFiveYearsMember 2022-03-31 0001163653 nmr:LaterThanThreeYearsNotLaterThanFiveYearsMember 2022-03-31 0001163653 nmr:LaterThanOneYearNotLaterThanThreeYearsMember 2022-03-31 0001163653 nmr:NotLaterThanOneYearMember 2022-03-31 0001163653 nmr:CreditriskRelatedOptionsAndSwaptionsMember nmr:LaterThanFiveYearsMember 2022-03-31 0001163653 nmr:CreditriskRelatedOptionsAndSwaptionsMember nmr:LaterThanThreeYearsNotLaterThanFiveYearsMember 2022-03-31 0001163653 nmr:CreditriskRelatedOptionsAndSwaptionsMember nmr:LaterThanOneYearNotLaterThanThreeYearsMember 2022-03-31 0001163653 nmr:CreditriskRelatedOptionsAndSwaptionsMember nmr:NotLaterThanOneYearMember 2022-03-31 0001163653 nmr:OtherCreditRiskRelatedPortfolioProductsMember nmr:LaterThanFiveYearsMember 2022-03-31 0001163653 nmr:OtherCreditRiskRelatedPortfolioProductsMember nmr:LaterThanThreeYearsNotLaterThanFiveYearsMember 2022-03-31 0001163653 nmr:OtherCreditRiskRelatedPortfolioProductsMember nmr:LaterThanOneYearNotLaterThanThreeYearsMember 2022-03-31 0001163653 nmr:OtherCreditRiskRelatedPortfolioProductsMember nmr:NotLaterThanOneYearMember 2022-03-31 0001163653 nmr:CreditDefaultSwapIndicesMember nmr:LaterThanFiveYearsMember 2022-03-31 0001163653 nmr:CreditDefaultSwapIndicesMember nmr:LaterThanThreeYearsNotLaterThanFiveYearsMember 2022-03-31 0001163653 nmr:CreditDefaultSwapIndicesMember nmr:LaterThanOneYearNotLaterThanThreeYearsMember 2022-03-31 0001163653 nmr:CreditDefaultSwapIndicesMember nmr:NotLaterThanOneYearMember 2022-03-31 0001163653 us-gaap:CreditDefaultSwapMember nmr:LaterThanFiveYearsMember 2022-03-31 0001163653 us-gaap:CreditDefaultSwapMember nmr:LaterThanThreeYearsNotLaterThanFiveYearsMember 2022-03-31 0001163653 us-gaap:CreditDefaultSwapMember nmr:LaterThanOneYearNotLaterThanThreeYearsMember 2022-03-31 0001163653 us-gaap:CreditDefaultSwapMember nmr:NotLaterThanOneYearMember 2022-03-31 0001163653 us-gaap:RestrictedStockUnitsRSUMember 2022-03-31 0001163653 nmr:LiquidityFacilitiesToCentralClearingCounterpartiesMember 2022-03-31 0001163653 nmr:OtherCommitmentsToExtendCreditMember 2022-03-31 0001163653 nmr:FixedRateObligationsMember 2022-03-31 0001163653 nmr:FloatingRateObligationsMember 2022-03-31 0001163653 nmr:IndexOrEquityLinkedObligationsMember 2022-03-31 0001163653 nmr:SARPlanBMember 2022-03-31 0001163653 nmr:LiquidityFacilitiesToCentralClearingCounterpartiesMember nmr:NotLaterThanOneYearMember 2022-03-31 0001163653 nmr:LaterThanOneYearNotLaterThanThreeYearsMember nmr:LiquidityFacilitiesToCentralClearingCounterpartiesMember 2022-03-31 0001163653 nmr:LaterThanThreeYearsNotLaterThanFiveYearsMember nmr:LiquidityFacilitiesToCentralClearingCounterpartiesMember 2022-03-31 0001163653 nmr:LaterThanFiveYearsMember nmr:LiquidityFacilitiesToCentralClearingCounterpartiesMember 2022-03-31 0001163653 nmr:OtherCommitmentsToExtendCreditMember nmr:NotLaterThanOneYearMember 2022-03-31 0001163653 nmr:OtherCommitmentsToExtendCreditMember nmr:LaterThanOneYearNotLaterThanThreeYearsMember 2022-03-31 0001163653 nmr:OtherCommitmentsToExtendCreditMember nmr:LaterThanThreeYearsNotLaterThanFiveYearsMember 2022-03-31 0001163653 nmr:OtherCommitmentsToExtendCreditMember nmr:LaterThanFiveYearsMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:PayablesAndDepositsMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember us-gaap:MeasurementInputPriceVolatilityMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:PayablesAndDepositsMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputForeignExchangeVolatilityMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:PayablesAndDepositsMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputForeignExchangeVolatilityMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:PayablesAndDepositsMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputCorrelationMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:PayablesAndDepositsMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputCorrelationMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member nmr:PayablesAndDepositsMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember us-gaap:MeasurementInputPriceVolatilityMember srt:MaximumMember 2022-03-31 0001163653 nmr:CSUsMember 2022-03-31 0001163653 nmr:NSUsMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:LongTermDebtMember us-gaap:MeasurementInputLossSeverityMember us-gaap:ValuationTechniqueDiscountedCashFlowMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:LongTermDebtMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputForeignExchangeVolatilityMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:LongTermDebtMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputForeignExchangeVolatilityMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:LongTermDebtMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputCorrelationMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:LongTermDebtMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember nmr:MeasurementInputCorrelationMember srt:MaximumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:LongTermDebtMember srt:WeightedAverageMember us-gaap:MeasurementInputLossSeverityMember us-gaap:ValuationTechniqueDiscountedCashFlowMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:LongTermDebtMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember us-gaap:MeasurementInputPriceVolatilityMember srt:MinimumMember 2022-03-31 0001163653 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member us-gaap:LongTermDebtMember nmr:DiscountCashFlowsValuationTechniqueAndOptionModelsMember us-gaap:MeasurementInputPriceVolatilityMember srt:MaximumMember 2022-03-31 0001163653 nmr:StandardPoorSOtherRatingMember 2022-03-31 0001163653 srt:StandardPoorsBBRatingMember 2022-03-31 0001163653 srt:StandardPoorsBBBRatingMember 2022-03-31 0001163653 srt:StandardPoorsARatingMember 2022-03-31 0001163653 srt:StandardPoorsAARatingMember 2022-03-31 0001163653 srt:StandardPoorsAAARatingMember 2022-03-31 0001163653 nmr:CreditriskRelatedOptionsAndSwaptionsMember nmr:StandardPoorSOtherRatingMember 2022-03-31 0001163653 nmr:CreditriskRelatedOptionsAndSwaptionsMember srt:StandardPoorsBBRatingMember 2022-03-31 0001163653 nmr:CreditriskRelatedOptionsAndSwaptionsMember srt:StandardPoorsBBBRatingMember 2022-03-31 0001163653 nmr:CreditriskRelatedOptionsAndSwaptionsMember srt:StandardPoorsARatingMember 2022-03-31 0001163653 nmr:CreditriskRelatedOptionsAndSwaptionsMember srt:StandardPoorsAARatingMember 2022-03-31 0001163653 nmr:CreditriskRelatedOptionsAndSwaptionsMember srt:StandardPoorsAAARatingMember 2022-03-31 0001163653 nmr:StandardPoorSOtherRatingMember nmr:OtherCreditRiskRelatedPortfolioProductsMember 2022-03-31 0001163653 nmr:OtherCreditRiskRelatedPortfolioProductsMember srt:StandardPoorsBBRatingMember 2022-03-31 0001163653 nmr:OtherCreditRiskRelatedPortfolioProductsMember srt:StandardPoorsBBBRatingMember 2022-03-31 0001163653 nmr:OtherCreditRiskRelatedPortfolioProductsMember srt:StandardPoorsARatingMember 2022-03-31 0001163653 srt:StandardPoorsAARatingMember nmr:OtherCreditRiskRelatedPortfolioProductsMember 2022-03-31 0001163653 srt:StandardPoorsAAARatingMember nmr:OtherCreditRiskRelatedPortfolioProductsMember 2022-03-31 0001163653 nmr:StandardPoorSOtherRatingMember nmr:CreditDefaultSwapIndicesMember 2022-03-31 0001163653 nmr:CreditDefaultSwapIndicesMember srt:StandardPoorsBBRatingMember 2022-03-31 0001163653 nmr:CreditDefaultSwapIndicesMember srt:StandardPoorsBBBRatingMember 2022-03-31 0001163653 nmr:CreditDefaultSwapIndicesMember srt:StandardPoorsARatingMember 2022-03-31 0001163653 nmr:CreditDefaultSwapIndicesMember srt:StandardPoorsAARatingMember 2022-03-31 0001163653 nmr:CreditDefaultSwapIndicesMember srt:StandardPoorsAAARatingMember 2022-03-31 0001163653 nmr:StandardPoorSOtherRatingMember us-gaap:CreditDefaultSwapMember 2022-03-31 0001163653 us-gaap:CreditDefaultSwapMember srt:StandardPoorsBBRatingMember 2022-03-31 0001163653 us-gaap:CreditDefaultSwapMember srt:StandardPoorsBBBRatingMember 2022-03-31 0001163653 us-gaap:CreditDefaultSwapMember srt:StandardPoorsARatingMember 2022-03-31 0001163653 us-gaap:CreditDefaultSwapMember srt:StandardPoorsAARatingMember 2022-03-31 0001163653 us-gaap:CreditDefaultSwapMember srt:StandardPoorsAAARatingMember 2022-03-31 0001163653 nmr:SARPlanAAndSARPlanBMember 2022-03-31 0001163653 nmr:LongTermBorrowingsMember 2022-03-31 0001163653 nmr:NonTradingDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2022-03-31 0001163653 nmr:NonTradingDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2022-03-31 0001163653 nmr:NonTradingDebtSecuritiesMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2022-03-31 0001163653 nmr:NonTradingDebtSecuritiesMember nmr:CounterpartyCashCollateralNettingMember us-gaap:FairValueMeasurementsRecurringMember 2022-03-31 0001163653 nmr:NonTradingDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember 2022-03-31 0001163653 nmr:OtherAssetsAggregateCarryingAmountsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2022-03-31 0001163653 nmr:OtherAssetsAggregateCarryingAmountsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2022-03-31 0001163653 nmr:OtherAssetsAggregateCarryingAmountsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2022-03-31 0001163653 nmr:OtherAssetsAggregateCarryingAmountsMember nmr:CounterpartyCashCollateralNettingMember us-gaap:FairValueMeasurementsRecurringMember 2022-03-31 0001163653 nmr:OtherAssetsAggregateCarryingAmountsMember us-gaap:FairValueMeasurementsRecurringMember 2022-03-31 0001163653 us-gaap:AccountingStandardsUpdate201602Member 2022-03-31 0001163653 nmr:CorporateLoanMember 2022-03-31 0001163653 us-gaap:OtherLiabilitiesMember 2022-03-31 0001163653 nmr:NomuraHoldingsIncMember us-gaap:NationalTaxAgencyJapanMember 2022-03-31 0001163653 srt:SubsidiariesMember us-gaap:HerMajestysRevenueAndCustomsHMRCMember 2022-03-31 0001163653 us-gaap:InternalRevenueServiceIRSMember srt:SubsidiariesMember 2022-03-31 0001163653 us-gaap:InlandRevenueHongKongMember srt:SubsidiariesMember 2022-03-31 0001163653 srt:SubsidiariesMember us-gaap:ForeignCountryMember 2022-03-31 0001163653 nmr:OperatingLossCarryforwardsIndefinitelyMember 2022-03-31 0001163653 nmr:TwoThousandThirteenThroughTwoThousandTwentyTwoExpirationPeriodMember 2022-03-31 0001163653 nmr:TwoThousandTwentyThreeAndThereafterExpirationPeriodMember 2022-03-31 0001163653 us-gaap:SaleAndTotalReturnSwapMember 2022-03-31 0001163653 nmr:SubprimeBorkerageMember country:US nmr:LoansWithTheClientMember srt:SubsidiariesMember 2022-03-31 0001163653 nmr:ListedEquityMember 2022-03-31 0001163653 nmr:UnlistedEquityMember