false2020FYMORGAN STANLEY0000895421--12-31truefalseus-gaap:OtherAssetsus-gaap:AccruedLiabilitiesAndOtherLiabilitiesus-gaap:OtherAssetsus-gaap:OtherAssetsus-gaap:AccruedLiabilitiesAndOtherLiabilitiesus-gaap:AccruedLiabilitiesAndOtherLiabilitiesP1YP3YQuarterly Results (Unaudited) >
2020 Quarter
$ in millions, except per share dataFirstSecondThird
Fourth1, 2
Total non-interest revenues$8,131 $11,814 $10,171 $11,769 
Net interest1,356 1,600 1,486 1,871 
Net revenues9,487 13,414 11,657 13,640 
Total non-interest expenses7,341 9,059 8,170 9,210 
Income from continuing operations before income taxes
2,146 4,355 3,487 4,430 
Provision for income taxes366 1,119 736 1,018 
Net income1,780 3,236 2,751 3,412 
Net income applicable to noncontrolling interests
82 40 34 27 
Net income applicable to Morgan Stanley
$1,698 $3,196 $2,717 $3,385 
Preferred stock dividends and other
108 149 120 119 
Earnings applicable to Morgan Stanley common shareholders
$1,590 $3,047 $2,597 $3,266 
Earnings (loss) per common share4:
Basic$1.02 $1.98 $1.68 $1.84 
Diluted$1.01 $1.96 $1.66 $1.81 
Dividends declared per common share
$0.35 $0.35 $0.35 $0.35 
Book value per common share$49.09 $49.57 $50.67 $51.13 
 2019 Quarter
$ in millions, except per share dataFirstSecondThird
Fourth1, 2,3
Total non-interest revenues$9,272 $9,215 $8,814 $9,424 
Net interest1,014 1,029 1,218 1,433 
Net revenues10,286 10,244 10,032 10,857 
Total non-interest expenses7,331 7,341 7,322 8,124 
Income from continuing operations before income taxes
2,955 2,903 2,710 2,733 
Provision for income taxes487 657 492 428 
Net income2,468 2,246 2,218 2,305 
Net income applicable to noncontrolling interests
39 45 45 66 
Net income applicable to Morgan Stanley
$2,429 $2,201 $2,173 $2,239 
Preferred stock dividends and other93 170 113 154 
Earnings applicable to Morgan Stanley common shareholders
$2,336 $2,031 $2,060 $2,085 
Earnings (loss) per common share4:
Basic$1.41 $1.24 $1.28 $1.33 
Diluted$1.39 $1.23 $1.27 $1.30 
Dividends declared per common share
$0.30 $0.30 $0.35 $0.35 
Book value per common share$42.83 $44.13 $45.49 $45.82 

1.The fourth quarters of 2020 and 2019 included intermittent net discrete tax benefits of [$18 million] and $158 million, respectively, [primarily associated with remeasurement of reserves and related interest as a result of new information pertaining to the resolution of multi-jurisdiction tax examinations.]
2.Total non-interest revenues includes impairments of the Investment Management business segment’s interests in two distinct equity method investments in third-party asset managers of [$0 million] in 2020 and $41 million in 2019.
3.The fourth quarter of 2019 included specific severance-related costs of approximately $172 million, which are included in Compensation and benefits expenses in the Income statement. These costs were recorded in the business segments approximately as follows: Institutional Securities $124 million, Wealth Management $37 million and Investment Management $11 million.
4.The sum of the quarters’ earnings per common share may not equal the annual amounts due to the averaging effect of the number of shares and share equivalents throughout the year.
2020 Quarter
$ in millions, except per share dataFirstSecondThird
Fourth1, 2
Total non-interest revenues$8,131 $11,814 $10,171 $11,769 
Net interest1,356 1,600 1,486 1,871 
Net revenues9,487 13,414 11,657 13,640 
Total non-interest expenses7,341 9,059 8,170 9,210 
Income from continuing operations before income taxes
2,146 4,355 3,487 4,430 
Provision for income taxes366 1,119 736 1,018 
Net income1,780 3,236 2,751 3,412 
Net income applicable to noncontrolling interests
82 40 34 27 
Net income applicable to Morgan Stanley
$1,698 $3,196 $2,717 $3,385 
Preferred stock dividends and other
108 149 120 119 
Earnings applicable to Morgan Stanley common shareholders
$1,590 $3,047 $2,597 $3,266 
Earnings (loss) per common share4:
Basic$1.02 $1.98 $1.68 $1.84 
Diluted$1.01 $1.96 $1.66 $1.81 
Dividends declared per common share
$0.35 $0.35 $0.35 $0.35 
Book value per common share$49.09 $49.57 $50.67 $51.13 
 2019 Quarter
$ in millions, except per share dataFirstSecondThird
Fourth1, 2,3
Total non-interest revenues$9,272 $9,215 $8,814 $9,424 
Net interest1,014 1,029 1,218 1,433 
Net revenues10,286 10,244 10,032 10,857 
Total non-interest expenses7,331 7,341 7,322 8,124 
Income from continuing operations before income taxes
2,955 2,903 2,710 2,733 
Provision for income taxes487 657 492 428 
Net income2,468 2,246 2,218 2,305 
Net income applicable to noncontrolling interests
39 45 45 66 
Net income applicable to Morgan Stanley
$2,429 $2,201 $2,173 $2,239 
Preferred stock dividends and other93 170 113 154 
Earnings applicable to Morgan Stanley common shareholders
$2,336 $2,031 $2,060 $2,085 
Earnings (loss) per common share4:
Basic$1.41 $1.24 $1.28 $1.33 
Diluted$1.39 $1.23 $1.27 $1.30 
Dividends declared per common share
$0.30 $0.30 $0.35 $0.35 
Book value per common share$42.83 $44.13 $45.49 $45.82 

1.The fourth quarters of 2020 and 2019 included intermittent net discrete tax benefits of [$18 million] and $158 million, respectively, [primarily associated with remeasurement of reserves and related interest as a result of new information pertaining to the resolution of multi-jurisdiction tax examinations.]
2.Total non-interest revenues includes impairments of the Investment Management business segment’s interests in two distinct equity method investments in third-party asset managers of [$0 million] in 2020 and $41 million in 2019.
3.The fourth quarter of 2019 included specific severance-related costs of approximately $172 million, which are included in Compensation and benefits expenses in the Income statement. These costs were recorded in the business segments approximately as follows: Institutional Securities $124 million, Wealth Management $37 million and Investment Management $11 million.
4.The sum of the quarters’ earnings per common share may not equal the annual amounts due to the averaging effect of the number of shares and share equivalents throughout the year.
8,13111,81410,17111,7691,3561,6001,4861,8719,48713,41411,65713,6407,3419,0598,1709,2102,1464,3553,4874,4303661,1197361,0181,7803,2362,7513,412824034271,6983,1962,7173,3851081491201191,5903,0472,5973,2661.021.981.681.841.011.961.661.810.350.350.350.3549.0949.5750.6751.139,2729,2158,8149,4241,0141,0291,2181,43310,28610,24410,03210,8577,3317,3417,3228,1242,9552,9032,7102,7334876574924282,4682,2462,2182,305394545662,4292,2012,1732,239931701131542,3362,0312,0602,0851.411.241.281.331.391.231.271.300.300.300.350.3542.8344.1345.4945.8218158041172124371100008954212020-01-012020-12-310000895421us-gaap:CommonClassAMember2020-01-012020-12-310000895421us-gaap:SeriesAPreferredStockMember2020-01-012020-12-310000895421us-gaap:SeriesEPreferredStockMember2020-01-012020-12-310000895421us-gaap:SeriesFPreferredStockMember2020-01-012020-12-310000895421ms:SeriesIPreferredStockMember2020-01-012020-12-310000895421ms:SeriesKPreferredStockMember2020-01-012020-12-310000895421ms:SeriesLPreferredStockMember2020-01-012020-12-310000895421ms:GlobalMediumTermNotesSeriesAFixedRateStepUpSeniorNotesDue2026ofMorganStanleyFinanceLLCMember2020-01-012020-12-310000895421ms:MorganStanleyCushingMLPHighIncomeIndexETNsdueMarch212031Member2020-01-012020-12-31iso4217:USD00008954212020-06-30xbrli:shares00008954212021-01-2900008954212019-01-012019-12-3100008954212018-01-012018-12-31iso4217:USDxbrli:shares00008954212020-12-3100008954212019-12-310000895421us-gaap:PreferredStockMember2019-12-310000895421us-gaap:PreferredStockMember2018-12-310000895421us-gaap:PreferredStockMember2017-12-310000895421us-gaap:PreferredStockMember2020-01-012020-12-310000895421us-gaap:PreferredStockMember2019-01-012019-12-310000895421us-gaap:PreferredStockMember2018-01-012018-12-310000895421us-gaap:PreferredStockMember2020-12-310000895421us-gaap:CommonStockMember2020-12-310000895421us-gaap:CommonStockMember2019-12-310000895421us-gaap:CommonStockMember2018-12-310000895421us-gaap:AdditionalPaidInCapitalMember2019-12-310000895421us-gaap:AdditionalPaidInCapitalMember2018-12-310000895421us-gaap:AdditionalPaidInCapitalMember2017-12-310000895421us-gaap:AdditionalPaidInCapitalMember2020-01-012020-12-310000895421us-gaap:AdditionalPaidInCapitalMember2019-01-012019-12-310000895421us-gaap:AdditionalPaidInCapitalMember2018-01-012018-12-310000895421us-gaap:AdditionalPaidInCapitalMember2020-12-310000895421us-gaap:RetainedEarningsMember2019-12-310000895421us-gaap:RetainedEarningsMember2018-12-310000895421us-gaap:RetainedEarningsMember2017-12-310000895421us-gaap:RetainedEarningsMembersrt:CumulativeEffectPeriodOfAdoptionAdjustmentMember2019-12-310000895421us-gaap:RetainedEarningsMembersrt:CumulativeEffectPeriodOfAdoptionAdjustmentMember2018-12-310000895421us-gaap:RetainedEarningsMembersrt:CumulativeEffectPeriodOfAdoptionAdjustmentMember2017-12-310000895421us-gaap:RetainedEarningsMember2020-01-012020-12-310000895421us-gaap:RetainedEarningsMember2019-01-012019-12-310000895421us-gaap:RetainedEarningsMember2018-01-012018-12-310000895421us-gaap:RetainedEarningsMember2020-12-310000895421us-gaap:TrustForBenefitOfEmployeesMember2019-12-310000895421us-gaap:TrustForBenefitOfEmployeesMember2018-12-310000895421us-gaap:TrustForBenefitOfEmployeesMember2017-12-310000895421us-gaap:TrustForBenefitOfEmployeesMember2020-01-012020-12-310000895421us-gaap:TrustForBenefitOfEmployeesMember2019-01-012019-12-310000895421us-gaap:TrustForBenefitOfEmployeesMember2018-01-012018-12-310000895421us-gaap:TrustForBenefitOfEmployeesMember2020-12-310000895421us-gaap:AccumulatedOtherComprehensiveIncomeMember2019-12-310000895421us-gaap:AccumulatedOtherComprehensiveIncomeMember2018-12-310000895421us-gaap:AccumulatedOtherComprehensiveIncomeMember2017-12-310000895421srt:CumulativeEffectPeriodOfAdoptionAdjustmentMemberus-gaap:AccumulatedOtherComprehensiveIncomeMember2019-12-310000895421srt:CumulativeEffectPeriodOfAdoptionAdjustmentMemberus-gaap:AccumulatedOtherComprehensiveIncomeMember2018-12-310000895421srt:CumulativeEffectPeriodOfAdoptionAdjustmentMemberus-gaap:AccumulatedOtherComprehensiveIncomeMember2017-12-310000895421us-gaap:AccumulatedOtherComprehensiveIncomeMember2020-01-012020-12-310000895421us-gaap:AccumulatedOtherComprehensiveIncomeMember2019-01-012019-12-310000895421us-gaap:AccumulatedOtherComprehensiveIncomeMember2018-01-012018-12-310000895421us-gaap:AccumulatedOtherComprehensiveIncomeMember2020-12-310000895421us-gaap:TreasuryStockMember2019-12-310000895421us-gaap:TreasuryStockMember2018-12-310000895421us-gaap:TreasuryStockMember2017-12-310000895421us-gaap:TreasuryStockMember2020-01-012020-12-310000895421us-gaap:TreasuryStockMember2019-01-012019-12-310000895421us-gaap:TreasuryStockMember2018-01-012018-12-310000895421us-gaap:TreasuryStockMember2020-12-310000895421ms:CommonStockIssuedToEmployeeTrustMember2019-12-310000895421ms:CommonStockIssuedToEmployeeTrustMember2018-12-310000895421ms:CommonStockIssuedToEmployeeTrustMember2017-12-310000895421ms:CommonStockIssuedToEmployeeTrustMember2020-01-012020-12-310000895421ms:CommonStockIssuedToEmployeeTrustMember2019-01-012019-12-310000895421ms:CommonStockIssuedToEmployeeTrustMember2018-01-012018-12-310000895421ms:CommonStockIssuedToEmployeeTrustMember2020-12-310000895421us-gaap:NoncontrollingInterestMember2019-12-310000895421us-gaap:NoncontrollingInterestMember2018-12-310000895421us-gaap:NoncontrollingInterestMember2017-12-310000895421us-gaap:NoncontrollingInterestMember2020-01-012020-12-310000895421us-gaap:NoncontrollingInterestMember2019-01-012019-12-310000895421us-gaap:NoncontrollingInterestMember2018-01-012018-12-310000895421us-gaap:NoncontrollingInterestMember2020-12-3100008954212018-12-3100008954212017-12-31xbrli:pure0000895421srt:MinimumMember2020-01-012020-12-310000895421srt:MaximumMember2020-01-012020-12-310000895421us-gaap:BuildingMember2020-01-012020-12-310000895421ms:LeaseholdImprovementsBuildingMembersrt:MaximumMember2020-01-012020-12-310000895421srt:MaximumMemberms:LeaseholdImprovementsOtherAssetsMember2020-01-012020-12-310000895421us-gaap:FurnitureAndFixturesMember2020-01-012020-12-310000895421us-gaap:EquipmentMembersrt:MinimumMember2020-01-012020-12-310000895421srt:MaximumMemberus-gaap:EquipmentMember2020-01-012020-12-310000895421us-gaap:ElectricityGenerationPlantNonNuclearMembersrt:MinimumMember2020-01-012020-12-310000895421srt:MaximumMemberus-gaap:ElectricityGenerationPlantNonNuclearMember2020-01-012020-12-310000895421us-gaap:ComputerSoftwareIntangibleAssetMembersrt:MinimumMember2020-01-012020-12-310000895421srt:MaximumMemberus-gaap:ComputerSoftwareIntangibleAssetMember2020-01-012020-12-310000895421ms:AllowanceforCreditLossesMembersrt:CumulativeEffectPeriodOfAdoptionAdjustmentMemberus-gaap:AccountingStandardsUpdate201613Member2019-12-310000895421us-gaap:RetainedEarningsMembersrt:CumulativeEffectPeriodOfAdoptionAdjustmentMemberus-gaap:AccountingStandardsUpdate201613Member2019-12-310000895421srt:CumulativeEffectPeriodOfAdoptionAdjustmentMemberms:AllowanceforCreditLossesonEmployeeLoansMemberus-gaap:AccountingStandardsUpdate201613Member2019-12-310000895421us-gaap:RetainedEarningsMembersrt:CumulativeEffectPeriodOfAdoptionAdjustmentMemberus-gaap:AccountingStandardsUpdate201811Member2018-12-310000895421srt:CumulativeEffectPeriodOfAdoptionAdjustmentMember2019-01-0100008954212019-01-010000895421ms:ETRADEFinancialCorporationMember2020-10-020000895421ms:ETRADEFinancialCorporationMember2020-10-022020-10-020000895421us-gaap:CommonClassAMemberms:ETRADEFinancialCorporationMember2020-10-022020-10-020000895421ms:SeriesMPreferredStockandSeriesNPreferredStockMemberms:ETRADEFinancialCorporationMember2020-10-022020-10-020000895421ms:ETRADEFinancialCorporationMemberus-gaap:CustomerRelationshipsMember2020-10-020000895421ms:ETRADEFinancialCorporationMemberus-gaap:CustomerRelationshipsMember2020-10-022020-10-020000895421ms:ETRADEFinancialCorporationMember2020-10-022020-12-310000895421ms:ETRADEFinancialCorporationMember2020-01-012020-12-310000895421ms:ETRADEFinancialCorporationMember2019-01-012019-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasuryAndGovernmentMemberus-gaap:FairValueInputsLevel1Member2020-12-310000895421us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasuryAndGovernmentMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasuryAndGovernmentMember2020-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Memberus-gaap:USTreasuryAndGovernmentMember2020-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:ForeignGovernmentDebtSecuritiesMember2020-12-310000895421us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ForeignGovernmentDebtSecuritiesMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ForeignGovernmentDebtSecuritiesMember2020-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Memberus-gaap:ForeignGovernmentDebtSecuritiesMember2020-12-310000895421us-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Member2020-12-310000895421us-gaap:FairValueInputsLevel2Memberus-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421us-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Member2020-12-310000895421ms:MortgageAndAssetBackedSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Member2020-12-310000895421ms:MortgageAndAssetBackedSecuritiesMemberus-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberms:MortgageAndAssetBackedSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421ms:MortgageAndAssetBackedSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Member2020-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Member2020-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Member2020-12-310000895421ms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Member2020-12-310000895421us-gaap:FairValueInputsLevel2Memberms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421ms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Member2020-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberms:CorporateEquitiesMemberus-gaap:FairValueInputsLevel1Member2020-12-310000895421us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberms:CorporateEquitiesMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberms:CorporateEquitiesMember2020-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberms:CorporateEquitiesMemberus-gaap:FairValueInputsLevel12And3Member2020-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:InterestRateContractMember2020-12-310000895421us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:InterestRateContractMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:InterestRateContractMember2020-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Memberus-gaap:InterestRateContractMember2020-12-310000895421us-gaap:CreditRiskContractMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Member2020-12-310000895421us-gaap:FairValueInputsLevel2Memberus-gaap:CreditRiskContractMemberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:CreditRiskContractMemberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421us-gaap:CreditRiskContractMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Member2020-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:ForeignExchangeContractMember2020-12-310000895421us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ForeignExchangeContractMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ForeignExchangeContractMember2020-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Memberus-gaap:ForeignExchangeContractMember2020-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:EquityContractMember2020-12-310000895421us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:EquityContractMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:EquityContractMember2020-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Memberus-gaap:EquityContractMember2020-12-310000895421ms:CommodityAndOtherContractsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Member2020-12-310000895421ms:CommodityAndOtherContractsMemberus-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421ms:CommodityAndOtherContractsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421ms:CommodityAndOtherContractsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Member2020-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Member2020-12-310000895421us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421us-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Member2020-12-310000895421us-gaap:USTreasuryAndGovernmentMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Member2020-12-310000895421us-gaap:USTreasuryAndGovernmentMemberus-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:USTreasuryAndGovernmentMemberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421us-gaap:USTreasuryAndGovernmentMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Member2020-12-310000895421us-gaap:ForeignGovernmentDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Member2020-12-310000895421us-gaap:ForeignGovernmentDebtSecuritiesMemberus-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421us-gaap:ForeignGovernmentDebtSecuritiesMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421us-gaap:ForeignGovernmentDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Member2020-12-310000895421ms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Member2020-12-310000895421ms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421ms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421ms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Member2020-12-310000895421ms:CorporateEquitiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Member2020-12-310000895421ms:CorporateEquitiesMemberus-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberms:CorporateEquitiesMemberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421ms:CorporateEquitiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Member2020-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasuryAndGovernmentMemberus-gaap:FairValueInputsLevel1Member2019-12-310000895421us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasuryAndGovernmentMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasuryAndGovernmentMember2019-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Memberus-gaap:USTreasuryAndGovernmentMember2019-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:ForeignGovernmentDebtSecuritiesMember2019-12-310000895421us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ForeignGovernmentDebtSecuritiesMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ForeignGovernmentDebtSecuritiesMember2019-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Memberus-gaap:ForeignGovernmentDebtSecuritiesMember2019-12-310000895421us-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Member2019-12-310000895421us-gaap:FairValueInputsLevel2Memberus-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421us-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Member2019-12-310000895421ms:MortgageAndAssetBackedSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Member2019-12-310000895421ms:MortgageAndAssetBackedSecuritiesMemberus-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberms:MortgageAndAssetBackedSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421ms:MortgageAndAssetBackedSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Member2019-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Member2019-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Member2019-12-310000895421ms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Member2019-12-310000895421us-gaap:FairValueInputsLevel2Memberms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421ms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Member2019-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberms:CorporateEquitiesMemberus-gaap:FairValueInputsLevel1Member2019-12-310000895421us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberms:CorporateEquitiesMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberms:CorporateEquitiesMember2019-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberms:CorporateEquitiesMemberus-gaap:FairValueInputsLevel12And3Member2019-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:InterestRateContractMember2019-12-310000895421us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:InterestRateContractMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:InterestRateContractMember2019-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Memberus-gaap:InterestRateContractMember2019-12-310000895421us-gaap:CreditRiskContractMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Member2019-12-310000895421us-gaap:FairValueInputsLevel2Memberus-gaap:CreditRiskContractMemberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:CreditRiskContractMemberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421us-gaap:CreditRiskContractMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Member2019-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:ForeignExchangeContractMember2019-12-310000895421us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ForeignExchangeContractMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ForeignExchangeContractMember2019-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Memberus-gaap:ForeignExchangeContractMember2019-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:EquityContractMember2019-12-310000895421us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:EquityContractMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:EquityContractMember2019-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Memberus-gaap:EquityContractMember2019-12-310000895421ms:CommodityAndOtherContractsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Member2019-12-310000895421ms:CommodityAndOtherContractsMemberus-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421ms:CommodityAndOtherContractsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421ms:CommodityAndOtherContractsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Member2019-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Member2019-12-310000895421us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421us-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Member2019-12-310000895421us-gaap:USTreasuryAndGovernmentMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Member2019-12-310000895421us-gaap:USTreasuryAndGovernmentMemberus-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:USTreasuryAndGovernmentMemberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421us-gaap:USTreasuryAndGovernmentMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Member2019-12-310000895421us-gaap:ForeignGovernmentDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Member2019-12-310000895421us-gaap:ForeignGovernmentDebtSecuritiesMemberus-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421us-gaap:ForeignGovernmentDebtSecuritiesMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421us-gaap:ForeignGovernmentDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Member2019-12-310000895421ms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Member2019-12-310000895421ms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421ms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421ms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Member2019-12-310000895421ms:CorporateEquitiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Member2019-12-310000895421ms:CorporateEquitiesMemberus-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberms:CorporateEquitiesMemberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421ms:CorporateEquitiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Member2019-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CommercialPortfolioSegmentMember2020-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CommercialPortfolioSegmentMember2019-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:FairValueMeasurementsRecurringMemberms:SecuredLendingFacilitiesMember2020-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:FairValueMeasurementsRecurringMemberms:SecuredLendingFacilitiesMember2019-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CommercialRealEstatePortfolioSegmentMember2020-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CommercialRealEstatePortfolioSegmentMember2019-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:ResidentialPortfolioSegmentMemberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:ResidentialPortfolioSegmentMemberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421ms:SecuritiesBasedLendingandOtherLoansMemberus-gaap:SeniorDebtObligationsMemberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421ms:SecuritiesBasedLendingandOtherLoansMemberus-gaap:SeniorDebtObligationsMemberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421ms:AccountsReceivableAndOtherReceivablesNetMemberus-gaap:FutureMemberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421ms:AccountsReceivableAndOtherReceivablesNetMemberus-gaap:FutureMemberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasuryAndGovernmentMember2018-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasuryAndGovernmentMember2017-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasuryAndGovernmentMember2020-01-012020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasuryAndGovernmentMember2019-01-012019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasuryAndGovernmentMember2018-01-012018-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ForeignGovernmentDebtSecuritiesMember2018-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ForeignGovernmentDebtSecuritiesMember2017-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ForeignGovernmentDebtSecuritiesMember2020-01-012020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ForeignGovernmentDebtSecuritiesMember2019-01-012019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ForeignGovernmentDebtSecuritiesMember2018-01-012018-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:FairValueMeasurementsRecurringMember2018-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:FairValueMeasurementsRecurringMember2017-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:FairValueMeasurementsRecurringMember2020-01-012020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:FairValueMeasurementsRecurringMember2019-01-012019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:FairValueMeasurementsRecurringMember2018-01-012018-12-310000895421us-gaap:FairValueInputsLevel3Memberms:MortgageAndAssetBackedSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMember2018-12-310000895421us-gaap:FairValueInputsLevel3Memberms:MortgageAndAssetBackedSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMember2017-12-310000895421us-gaap:FairValueInputsLevel3Memberms:MortgageAndAssetBackedSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMember2020-01-012020-12-310000895421us-gaap:FairValueInputsLevel3Memberms:MortgageAndAssetBackedSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMember2019-01-012019-12-310000895421us-gaap:FairValueInputsLevel3Memberms:MortgageAndAssetBackedSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMember2018-01-012018-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2018-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2017-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2020-01-012020-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2019-01-012019-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2018-01-012018-12-310000895421us-gaap:FairValueInputsLevel3Memberms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMember2018-12-310000895421us-gaap:FairValueInputsLevel3Memberms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMember2017-12-310000895421us-gaap:FairValueInputsLevel3Memberms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMember2020-01-012020-12-310000895421us-gaap:FairValueInputsLevel3Memberms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMember2019-01-012019-12-310000895421us-gaap:FairValueInputsLevel3Memberms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMember2018-01-012018-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberms:CorporateEquitiesMember2018-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberms:CorporateEquitiesMember2017-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberms:CorporateEquitiesMember2020-01-012020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberms:CorporateEquitiesMember2019-01-012019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberms:CorporateEquitiesMember2018-01-012018-12-310000895421us-gaap:InvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421us-gaap:InvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2018-12-310000895421us-gaap:InvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2017-12-310000895421us-gaap:InvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2020-01-012020-12-310000895421us-gaap:InvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2019-01-012019-12-310000895421us-gaap:InvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2018-01-012018-12-310000895421us-gaap:InvestmentsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421us-gaap:AvailableforsaleSecuritiesMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421us-gaap:AvailableforsaleSecuritiesMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2018-12-310000895421us-gaap:AvailableforsaleSecuritiesMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2017-12-310000895421us-gaap:AvailableforsaleSecuritiesMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2020-01-012020-12-310000895421us-gaap:AvailableforsaleSecuritiesMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2019-01-012019-12-310000895421us-gaap:AvailableforsaleSecuritiesMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2018-01-012018-12-310000895421us-gaap:AvailableforsaleSecuritiesMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FederalFundsSoldAndSecuritiesBorrowedOrPurchasedUnderAgreementsToResellMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FederalFundsSoldAndSecuritiesBorrowedOrPurchasedUnderAgreementsToResellMember2018-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FederalFundsSoldAndSecuritiesBorrowedOrPurchasedUnderAgreementsToResellMember2017-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FederalFundsSoldAndSecuritiesBorrowedOrPurchasedUnderAgreementsToResellMember2020-01-012020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FederalFundsSoldAndSecuritiesBorrowedOrPurchasedUnderAgreementsToResellMember2019-01-012019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FederalFundsSoldAndSecuritiesBorrowedOrPurchasedUnderAgreementsToResellMember2018-01-012018-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:FederalFundsSoldAndSecuritiesBorrowedOrPurchasedUnderAgreementsToResellMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:InterestRateContractMember2018-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:InterestRateContractMember2017-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:InterestRateContractMember2020-01-012020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:InterestRateContractMember2019-01-012019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:InterestRateContractMember2018-01-012018-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:CreditRiskContractMemberus-gaap:FairValueMeasurementsRecurringMember2018-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:CreditRiskContractMemberus-gaap:FairValueMeasurementsRecurringMember2017-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:CreditRiskContractMemberus-gaap:FairValueMeasurementsRecurringMember2020-01-012020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:CreditRiskContractMemberus-gaap:FairValueMeasurementsRecurringMember2019-01-012019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:CreditRiskContractMemberus-gaap:FairValueMeasurementsRecurringMember2018-01-012018-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ForeignExchangeContractMember2018-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ForeignExchangeContractMember2017-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ForeignExchangeContractMember2020-01-012020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ForeignExchangeContractMember2019-01-012019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ForeignExchangeContractMember2018-01-012018-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:EquityContractMember2018-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:EquityContractMember2017-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:EquityContractMember2020-01-012020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:EquityContractMember2019-01-012019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:EquityContractMember2018-01-012018-12-310000895421ms:CommodityAndOtherContractsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2018-12-310000895421ms:CommodityAndOtherContractsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2017-12-310000895421ms:CommodityAndOtherContractsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2020-01-012020-12-310000895421ms:CommodityAndOtherContractsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2019-01-012019-12-310000895421ms:CommodityAndOtherContractsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2018-01-012018-12-310000895421us-gaap:DepositsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421us-gaap:DepositsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2018-12-310000895421us-gaap:DepositsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2017-12-310000895421us-gaap:DepositsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2020-01-012020-12-310000895421us-gaap:DepositsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2019-01-012019-12-310000895421us-gaap:DepositsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2018-01-012018-12-310000895421us-gaap:DepositsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421ms:NonderivativeTradingLiabilitiesMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421ms:NonderivativeTradingLiabilitiesMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2018-12-310000895421ms:NonderivativeTradingLiabilitiesMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2017-12-310000895421ms:NonderivativeTradingLiabilitiesMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2020-01-012020-12-310000895421ms:NonderivativeTradingLiabilitiesMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2019-01-012019-12-310000895421ms:NonderivativeTradingLiabilitiesMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2018-01-012018-12-310000895421ms:NonderivativeTradingLiabilitiesMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:SecuritiesLoanedOrSoldUnderAgreementsToRepurchaseMemberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:SecuritiesLoanedOrSoldUnderAgreementsToRepurchaseMemberus-gaap:FairValueMeasurementsRecurringMember2018-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:SecuritiesLoanedOrSoldUnderAgreementsToRepurchaseMemberus-gaap:FairValueMeasurementsRecurringMember2017-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:SecuritiesLoanedOrSoldUnderAgreementsToRepurchaseMemberus-gaap:FairValueMeasurementsRecurringMember2020-01-012020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:SecuritiesLoanedOrSoldUnderAgreementsToRepurchaseMemberus-gaap:FairValueMeasurementsRecurringMember2019-01-012019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:SecuritiesLoanedOrSoldUnderAgreementsToRepurchaseMemberus-gaap:FairValueMeasurementsRecurringMember2018-01-012018-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:SecuritiesLoanedOrSoldUnderAgreementsToRepurchaseMemberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421ms:OtherSecuredFinancingsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421ms:OtherSecuredFinancingsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2018-12-310000895421ms:OtherSecuredFinancingsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2017-12-310000895421ms:OtherSecuredFinancingsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2020-01-012020-12-310000895421ms:OtherSecuredFinancingsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2019-01-012019-12-310000895421ms:OtherSecuredFinancingsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2018-01-012018-12-310000895421ms:OtherSecuredFinancingsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:BorrowingsMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:BorrowingsMember2018-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:BorrowingsMember2017-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:BorrowingsMember2020-01-012020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:BorrowingsMember2019-01-012019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:BorrowingsMember2018-01-012018-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:BorrowingsMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2020-01-012020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2019-01-012019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2018-01-012018-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberus-gaap:EquityContractMember2018-01-012018-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMemberms:MeasurementInputBondPriceMemberus-gaap:ForeignGovernmentDebtSecuritiesMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberms:MortgageAndAssetBackedSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMembersrt:MinimumMemberms:MeasurementInputBondPriceMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberms:MortgageAndAssetBackedSecuritiesMembersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMemberms:MeasurementInputBondPriceMember2020-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberms:MortgageAndAssetBackedSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMemberms:MeasurementInputBondPriceMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberms:MortgageAndAssetBackedSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMembersrt:MinimumMemberms:MeasurementInputBondPriceMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberms:MortgageAndAssetBackedSecuritiesMembersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMemberms:MeasurementInputBondPriceMember2019-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberms:MortgageAndAssetBackedSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMemberms:MeasurementInputBondPriceMember2019-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:MeasurementInputDiscountRateMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMembersrt:MinimumMemberms:ValuationTechniqueMarginLoanMember2019-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:MeasurementInputDiscountRateMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueMarginLoanMember2019-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:MeasurementInputDiscountRateMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueMarginLoanMember2019-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:FairValueInputsLevel3Memberms:MeasurementInputVolatilitySkewMemberus-gaap:FairValueMeasurementsRecurringMembersrt:MinimumMemberms:ValuationTechniqueMarginLoanMember2019-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberms:MeasurementInputVolatilitySkewMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueMarginLoanMember2019-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberms:MeasurementInputVolatilitySkewMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueMarginLoanMember2019-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MeasurementInputCreditSpreadMembersrt:MinimumMemberms:ValuationTechniqueMarginLoanMember2019-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MeasurementInputCreditSpreadMemberms:ValuationTechniqueMarginLoanMember2019-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MeasurementInputCreditSpreadMemberms:ValuationTechniqueMarginLoanMember2019-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberms:MeasurementInputMarginLoanMembersrt:MinimumMemberms:ValuationTechniqueMarginLoanMember2020-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberms:MeasurementInputMarginLoanMemberms:ValuationTechniqueMarginLoanMember2020-12-310000895421us-gaap:SeniorDebtObligationsMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberms:MeasurementInputMarginLoanMemberms:ValuationTechniqueMarginLoanMember2020-12-310000895421ms:MeasurementInputLoanPriceMemberus-gaap:SeniorDebtObligationsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMembersrt:MinimumMember2020-12-310000895421ms:MeasurementInputLoanPriceMemberus-gaap:SeniorDebtObligationsMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMember2020-12-310000895421ms:MeasurementInputLoanPriceMemberus-gaap:SeniorDebtObligationsMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMember2020-12-310000895421ms:MeasurementInputLoanPriceMemberus-gaap:SeniorDebtObligationsMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMembersrt:MinimumMember2019-12-310000895421ms:MeasurementInputLoanPriceMemberus-gaap:SeniorDebtObligationsMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMember2019-12-310000895421ms:MeasurementInputLoanPriceMemberus-gaap:SeniorDebtObligationsMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMembersrt:MinimumMemberms:MeasurementInputBondPriceMember2020-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MaximumMemberms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMemberms:MeasurementInputBondPriceMember2020-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMemberms:MeasurementInputBondPriceMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMembersrt:MinimumMemberms:MeasurementInputBondPriceMember2019-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MaximumMemberms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMemberms:MeasurementInputBondPriceMember2019-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMemberms:MeasurementInputBondPriceMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueDiscountedCashFlowMembersrt:MinimumMemberms:MeasurementInputRecoveryRateMember2020-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MaximumMemberms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueDiscountedCashFlowMemberms:MeasurementInputRecoveryRateMember2020-12-310000895421srt:ArithmeticAverageMemberus-gaap:FairValueInputsLevel3Memberms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueDiscountedCashFlowMemberms:MeasurementInputRecoveryRateMember2020-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MedianMemberms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueDiscountedCashFlowMemberms:MeasurementInputRecoveryRateMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueDiscountedCashFlowMemberms:MeasurementInputRecoveryRateMember2019-12-310000895421ms:MeasurementInputEquityVolatilityMemberus-gaap:FairValueInputsLevel3Memberms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMembersrt:MinimumMember2020-12-310000895421ms:MeasurementInputEquityVolatilityMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMember2020-12-310000895421ms:MeasurementInputEquityVolatilityMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMember2020-12-310000895421ms:MeasurementInputEquityVolatilityMemberus-gaap:FairValueInputsLevel3Memberms:CorporateandOtherDebtSecuritiesMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputSharePriceMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputSharePriceMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberms:MeasurementInputWeightedAverageCostOfCapitalMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueDiscountedCashFlowMembersrt:MinimumMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberms:MeasurementInputWeightedAverageCostOfCapitalMembersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueDiscountedCashFlowMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberms:MeasurementInputWeightedAverageCostOfCapitalMembersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueDiscountedCashFlowMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberms:MeasurementInputWeightedAverageCostOfCapitalMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueDiscountedCashFlowMembersrt:MinimumMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberms:MeasurementInputWeightedAverageCostOfCapitalMembersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueDiscountedCashFlowMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberms:MeasurementInputWeightedAverageCostOfCapitalMembersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueDiscountedCashFlowMember2019-12-310000895421ms:MeasurementInputExitMultipleMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueDiscountedCashFlowMembersrt:MinimumMember2020-12-310000895421ms:MeasurementInputExitMultipleMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueDiscountedCashFlowMember2020-12-310000895421ms:MeasurementInputExitMultipleMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueDiscountedCashFlowMember2020-12-310000895421ms:MeasurementInputExitMultipleMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueDiscountedCashFlowMembersrt:MinimumMember2019-12-310000895421ms:MeasurementInputExitMultipleMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueDiscountedCashFlowMember2019-12-310000895421ms:MeasurementInputExitMultipleMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueDiscountedCashFlowMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:MarketApproachValuationTechniqueMemberus-gaap:FairValueMeasurementsRecurringMembersrt:MinimumMemberus-gaap:MeasurementInputEbitdaMultipleMember2020-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:MarketApproachValuationTechniqueMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MeasurementInputEbitdaMultipleMember2020-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:MarketApproachValuationTechniqueMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MeasurementInputEbitdaMultipleMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:MarketApproachValuationTechniqueMemberus-gaap:FairValueMeasurementsRecurringMembersrt:MinimumMemberus-gaap:MeasurementInputEbitdaMultipleMember2019-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:MarketApproachValuationTechniqueMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MeasurementInputEbitdaMultipleMember2019-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:MarketApproachValuationTechniqueMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MeasurementInputEbitdaMultipleMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputSharePriceMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMembersrt:MinimumMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputSharePriceMembersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMember2020-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:MeasurementInputSharePriceMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputSharePriceMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMembersrt:MinimumMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputSharePriceMembersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMember2019-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:MeasurementInputSharePriceMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:InterestRateContractMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:InterestRateContractMember2019-12-310000895421ms:MeasurementInputInterestRateVolatilitySkewMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMembersrt:MinimumMember2020-12-310000895421ms:MeasurementInputInterestRateVolatilitySkewMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMember2020-12-310000895421ms:MeasurementInputInterestRateVolatilitySkewMembersrt:ArithmeticAverageMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMember2020-12-310000895421ms:MeasurementInputInterestRateVolatilitySkewMemberus-gaap:FairValueInputsLevel3Membersrt:MedianMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMember2020-12-310000895421ms:MeasurementInputInterestRateVolatilitySkewMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMembersrt:MinimumMember2019-12-310000895421ms:MeasurementInputInterestRateVolatilitySkewMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMember2019-12-310000895421ms:MeasurementInputInterestRateVolatilitySkewMembersrt:ArithmeticAverageMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMember2019-12-310000895421ms:MeasurementInputInterestRateVolatilitySkewMemberus-gaap:FairValueInputsLevel3Membersrt:MedianMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMembersrt:MinimumMemberms:MeasurementInputInterestRateCurveCorrelationMember2020-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMemberms:MeasurementInputInterestRateCurveCorrelationMember2020-12-310000895421srt:ArithmeticAverageMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMemberms:MeasurementInputInterestRateCurveCorrelationMember2020-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MedianMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMemberms:MeasurementInputInterestRateCurveCorrelationMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMembersrt:MinimumMemberms:MeasurementInputInterestRateCurveCorrelationMember2019-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMemberms:MeasurementInputInterestRateCurveCorrelationMember2019-12-310000895421srt:ArithmeticAverageMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMemberms:MeasurementInputInterestRateCurveCorrelationMember2019-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MedianMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMemberms:MeasurementInputInterestRateCurveCorrelationMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberms:MeasurementInputBondVolatilityMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMembersrt:MinimumMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberms:MeasurementInputBondVolatilityMembersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMember2020-12-310000895421srt:ArithmeticAverageMemberus-gaap:FairValueInputsLevel3Memberms:MeasurementInputBondVolatilityMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberms:MeasurementInputBondVolatilityMembersrt:MedianMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberms:MeasurementInputBondVolatilityMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMembersrt:MinimumMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberms:MeasurementInputBondVolatilityMembersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMember2019-12-310000895421srt:ArithmeticAverageMemberus-gaap:FairValueInputsLevel3Memberms:MeasurementInputBondVolatilityMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberms:MeasurementInputBondVolatilityMembersrt:MedianMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberms:MeasurementInputInflationVolatilityMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMembersrt:MinimumMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberms:MeasurementInputInflationVolatilityMembersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMember2020-12-310000895421srt:ArithmeticAverageMemberus-gaap:FairValueInputsLevel3Memberms:MeasurementInputInflationVolatilityMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberms:MeasurementInputInflationVolatilityMembersrt:MedianMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberms:MeasurementInputInflationVolatilityMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMembersrt:MinimumMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberms:MeasurementInputInflationVolatilityMembersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMember2019-12-310000895421srt:ArithmeticAverageMemberus-gaap:FairValueInputsLevel3Memberms:MeasurementInputInflationVolatilityMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberms:MeasurementInputInflationVolatilityMembersrt:MedianMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMember2019-12-310000895421ms:MeasurementInputInterestRateCurveMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMember2020-12-310000895421ms:MeasurementInputInterestRateCurveMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:InterestRateContractMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CreditRiskContractMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CreditRiskContractMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberms:MeasurementInputCashSyntheticBasisMemberus-gaap:FairValueMeasurementsRecurringMemberms:CreditDefaultSwapModelMemberus-gaap:CreditRiskContractMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberms:MeasurementInputCashSyntheticBasisMemberus-gaap:FairValueMeasurementsRecurringMemberms:CreditDefaultSwapModelMemberus-gaap:CreditRiskContractMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberms:CreditDefaultSwapModelMembersrt:MinimumMemberus-gaap:CreditRiskContractMemberms:MeasurementInputBondPriceMember2020-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberms:CreditDefaultSwapModelMemberus-gaap:CreditRiskContractMemberms:MeasurementInputBondPriceMember2020-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberms:CreditDefaultSwapModelMemberus-gaap:CreditRiskContractMemberms:MeasurementInputBondPriceMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberms:CreditDefaultSwapModelMembersrt:MinimumMemberus-gaap:CreditRiskContractMemberms:MeasurementInputBondPriceMember2019-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberms:CreditDefaultSwapModelMemberus-gaap:CreditRiskContractMemberms:MeasurementInputBondPriceMember2019-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberms:CreditDefaultSwapModelMemberus-gaap:CreditRiskContractMemberms:MeasurementInputBondPriceMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberms:CreditDefaultSwapModelMemberus-gaap:MeasurementInputCreditSpreadMembersrt:MinimumMemberus-gaap:CreditRiskContractMember2020-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberms:CreditDefaultSwapModelMemberus-gaap:MeasurementInputCreditSpreadMemberus-gaap:CreditRiskContractMember2020-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberms:CreditDefaultSwapModelMemberus-gaap:MeasurementInputCreditSpreadMemberus-gaap:CreditRiskContractMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberms:CreditDefaultSwapModelMemberus-gaap:MeasurementInputCreditSpreadMembersrt:MinimumMemberus-gaap:CreditRiskContractMember2019-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberms:CreditDefaultSwapModelMemberus-gaap:MeasurementInputCreditSpreadMemberus-gaap:CreditRiskContractMember2019-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberms:CreditDefaultSwapModelMemberus-gaap:MeasurementInputCreditSpreadMemberus-gaap:CreditRiskContractMember2019-12-310000895421ms:MeasurementInputFundingSpreadMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberms:CreditDefaultSwapModelMembersrt:MinimumMemberus-gaap:CreditRiskContractMember2020-12-310000895421ms:MeasurementInputFundingSpreadMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberms:CreditDefaultSwapModelMemberus-gaap:CreditRiskContractMember2020-12-310000895421ms:MeasurementInputFundingSpreadMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberms:CreditDefaultSwapModelMemberus-gaap:CreditRiskContractMember2020-12-310000895421ms:MeasurementInputFundingSpreadMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberms:CreditDefaultSwapModelMembersrt:MinimumMemberus-gaap:CreditRiskContractMember2019-12-310000895421ms:MeasurementInputFundingSpreadMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberms:CreditDefaultSwapModelMemberus-gaap:CreditRiskContractMember2019-12-310000895421ms:MeasurementInputFundingSpreadMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberms:CreditDefaultSwapModelMemberus-gaap:CreditRiskContractMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberms:MeasurementInputCreditCorrelationMembersrt:MinimumMemberus-gaap:CreditRiskContractMemberms:ValuationTechniqueCorrelationModelMember2020-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberms:MeasurementInputCreditCorrelationMemberus-gaap:CreditRiskContractMemberms:ValuationTechniqueCorrelationModelMember2020-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberms:MeasurementInputCreditCorrelationMemberus-gaap:CreditRiskContractMemberms:ValuationTechniqueCorrelationModelMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberms:MeasurementInputCreditCorrelationMembersrt:MinimumMemberus-gaap:CreditRiskContractMemberms:ValuationTechniqueCorrelationModelMember2019-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberms:MeasurementInputCreditCorrelationMemberus-gaap:CreditRiskContractMemberms:ValuationTechniqueCorrelationModelMember2019-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberms:MeasurementInputCreditCorrelationMemberus-gaap:CreditRiskContractMemberms:ValuationTechniqueCorrelationModelMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ForeignExchangeContractMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ForeignExchangeContractMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMembersrt:MinimumMemberms:MeasurementInputInterestRateForeignExchangeCorrelationMemberus-gaap:ForeignExchangeContractMember2020-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputInterestRateForeignExchangeCorrelationMemberus-gaap:ForeignExchangeContractMember2020-12-310000895421srt:ArithmeticAverageMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputInterestRateForeignExchangeCorrelationMemberus-gaap:ForeignExchangeContractMember2020-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MedianMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputInterestRateForeignExchangeCorrelationMemberus-gaap:ForeignExchangeContractMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMembersrt:MinimumMemberms:MeasurementInputInterestRateForeignExchangeCorrelationMemberus-gaap:ForeignExchangeContractMember2019-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputInterestRateForeignExchangeCorrelationMemberus-gaap:ForeignExchangeContractMember2019-12-310000895421srt:ArithmeticAverageMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputInterestRateForeignExchangeCorrelationMemberus-gaap:ForeignExchangeContractMember2019-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MedianMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputInterestRateForeignExchangeCorrelationMemberus-gaap:ForeignExchangeContractMember2019-12-310000895421ms:MeasurementInputInterestRateVolatilitySkewMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMembersrt:MinimumMemberus-gaap:ForeignExchangeContractMember2020-12-310000895421ms:MeasurementInputInterestRateVolatilitySkewMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:ForeignExchangeContractMember2020-12-310000895421ms:MeasurementInputInterestRateVolatilitySkewMembersrt:ArithmeticAverageMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:ForeignExchangeContractMember2020-12-310000895421ms:MeasurementInputInterestRateVolatilitySkewMemberus-gaap:FairValueInputsLevel3Membersrt:MedianMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:ForeignExchangeContractMember2020-12-310000895421ms:MeasurementInputInterestRateVolatilitySkewMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMembersrt:MinimumMemberus-gaap:ForeignExchangeContractMember2019-12-310000895421ms:MeasurementInputInterestRateVolatilitySkewMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:ForeignExchangeContractMember2019-12-310000895421ms:MeasurementInputInterestRateVolatilitySkewMembersrt:ArithmeticAverageMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:ForeignExchangeContractMember2019-12-310000895421ms:MeasurementInputInterestRateVolatilitySkewMemberus-gaap:FairValueInputsLevel3Membersrt:MedianMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:ForeignExchangeContractMember2019-12-310000895421ms:MeasurementInputInterestRateCurveMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMembersrt:MinimumMemberus-gaap:ForeignExchangeContractMember2020-12-310000895421ms:MeasurementInputInterestRateCurveMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:ForeignExchangeContractMember2020-12-310000895421srt:ArithmeticAverageMemberms:MeasurementInputInterestRateCurveMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:ForeignExchangeContractMember2020-12-310000895421ms:MeasurementInputInterestRateCurveMemberus-gaap:FairValueInputsLevel3Membersrt:MedianMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:ForeignExchangeContractMember2020-12-310000895421ms:MeasurementInputInterestRateCurveMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMembersrt:MinimumMemberus-gaap:ForeignExchangeContractMember2019-12-310000895421ms:MeasurementInputInterestRateCurveMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:ForeignExchangeContractMember2019-12-310000895421srt:ArithmeticAverageMemberms:MeasurementInputInterestRateCurveMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:ForeignExchangeContractMember2019-12-310000895421ms:MeasurementInputInterestRateCurveMemberus-gaap:FairValueInputsLevel3Membersrt:MedianMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:ForeignExchangeContractMember2019-12-310000895421ms:MeasurementInputForeignExchangeVolatilitySkewMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMembersrt:MinimumMemberus-gaap:ForeignExchangeContractMember2020-12-310000895421ms:MeasurementInputForeignExchangeVolatilitySkewMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:ForeignExchangeContractMember2020-12-310000895421ms:MeasurementInputForeignExchangeVolatilitySkewMembersrt:ArithmeticAverageMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:ForeignExchangeContractMember2020-12-310000895421ms:MeasurementInputForeignExchangeVolatilitySkewMemberus-gaap:FairValueInputsLevel3Membersrt:MedianMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:ForeignExchangeContractMember2020-12-310000895421ms:MeasurementInputContingencyProbabilityMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMembersrt:MinimumMemberus-gaap:ForeignExchangeContractMember2020-12-310000895421ms:MeasurementInputContingencyProbabilityMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:ForeignExchangeContractMember2020-12-310000895421ms:MeasurementInputContingencyProbabilityMembersrt:ArithmeticAverageMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:ForeignExchangeContractMember2020-12-310000895421ms:MeasurementInputContingencyProbabilityMemberus-gaap:FairValueInputsLevel3Membersrt:MedianMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:ForeignExchangeContractMember2020-12-310000895421ms:MeasurementInputContingencyProbabilityMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMembersrt:MinimumMemberus-gaap:ForeignExchangeContractMember2019-12-310000895421ms:MeasurementInputContingencyProbabilityMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:ForeignExchangeContractMember2019-12-310000895421ms:MeasurementInputContingencyProbabilityMembersrt:ArithmeticAverageMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:ForeignExchangeContractMember2019-12-310000895421ms:MeasurementInputContingencyProbabilityMemberus-gaap:FairValueInputsLevel3Membersrt:MedianMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:ForeignExchangeContractMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:EquityContractMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:EquityContractMember2019-12-310000895421ms:MeasurementInputEquityVolatilityMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMembersrt:MinimumMemberus-gaap:EquityContractMember2020-12-310000895421ms:MeasurementInputEquityVolatilityMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:EquityContractMember2020-12-310000895421ms:MeasurementInputEquityVolatilityMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:EquityContractMember2020-12-310000895421ms:MeasurementInputEquityVolatilityMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMembersrt:MinimumMemberus-gaap:EquityContractMember2019-12-310000895421ms:MeasurementInputEquityVolatilityMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:EquityContractMember2019-12-310000895421ms:MeasurementInputEquityVolatilityMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:EquityContractMember2019-12-310000895421ms:MeasurementInputEquityVolatilitySkewMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMembersrt:MinimumMemberus-gaap:EquityContractMember2020-12-310000895421ms:MeasurementInputEquityVolatilitySkewMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:EquityContractMember2020-12-310000895421ms:MeasurementInputEquityVolatilitySkewMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:EquityContractMember2020-12-310000895421ms:MeasurementInputEquityVolatilitySkewMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMembersrt:MinimumMemberus-gaap:EquityContractMember2019-12-310000895421ms:MeasurementInputEquityVolatilitySkewMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:EquityContractMember2019-12-310000895421ms:MeasurementInputEquityVolatilitySkewMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:EquityContractMember2019-12-310000895421ms:MeasurementInputEquityCorrelationMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMembersrt:MinimumMemberus-gaap:EquityContractMember2020-12-310000895421ms:MeasurementInputEquityCorrelationMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:EquityContractMember2020-12-310000895421ms:MeasurementInputEquityCorrelationMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:EquityContractMember2020-12-310000895421ms:MeasurementInputEquityCorrelationMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMembersrt:MinimumMemberus-gaap:EquityContractMember2019-12-310000895421ms:MeasurementInputEquityCorrelationMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:EquityContractMember2019-12-310000895421ms:MeasurementInputEquityCorrelationMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberus-gaap:EquityContractMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputForeignExchangeCorrelationMembersrt:MinimumMemberus-gaap:EquityContractMember2020-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputForeignExchangeCorrelationMemberus-gaap:EquityContractMember2020-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputForeignExchangeCorrelationMemberus-gaap:EquityContractMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputForeignExchangeCorrelationMembersrt:MinimumMemberus-gaap:EquityContractMember2019-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputForeignExchangeCorrelationMemberus-gaap:EquityContractMember2019-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputForeignExchangeCorrelationMemberus-gaap:EquityContractMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputInterestRateCorrelationMembersrt:MinimumMemberus-gaap:EquityContractMember2020-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputInterestRateCorrelationMemberus-gaap:EquityContractMember2020-12-310000895421srt:ArithmeticAverageMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputInterestRateCorrelationMemberus-gaap:EquityContractMember2020-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MedianMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputInterestRateCorrelationMemberus-gaap:EquityContractMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputInterestRateCorrelationMembersrt:MinimumMemberus-gaap:EquityContractMember2019-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputInterestRateCorrelationMemberus-gaap:EquityContractMember2019-12-310000895421srt:ArithmeticAverageMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputInterestRateCorrelationMemberus-gaap:EquityContractMember2019-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MedianMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputInterestRateCorrelationMemberus-gaap:EquityContractMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberms:CommodityAndOtherContractsMemberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberms:CommodityAndOtherContractsMemberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421ms:MeasurementInputForwardPowerPriceMemberus-gaap:FairValueInputsLevel3Memberms:CommodityAndOtherContractsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMembersrt:MinimumMember2020-12-310000895421ms:MeasurementInputForwardPowerPriceMemberus-gaap:FairValueInputsLevel3Memberms:CommodityAndOtherContractsMembersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMember2020-12-310000895421ms:MeasurementInputForwardPowerPriceMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberms:CommodityAndOtherContractsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMember2020-12-310000895421ms:MeasurementInputForwardPowerPriceMemberus-gaap:FairValueInputsLevel3Memberms:CommodityAndOtherContractsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMembersrt:MinimumMember2019-12-310000895421ms:MeasurementInputForwardPowerPriceMemberus-gaap:FairValueInputsLevel3Memberms:CommodityAndOtherContractsMembersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMember2019-12-310000895421ms:MeasurementInputForwardPowerPriceMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberms:CommodityAndOtherContractsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberms:CommodityAndOtherContractsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputCommodityVolatilityMembersrt:MinimumMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberms:CommodityAndOtherContractsMembersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputCommodityVolatilityMember2020-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberms:CommodityAndOtherContractsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputCommodityVolatilityMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberms:CommodityAndOtherContractsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputCommodityVolatilityMembersrt:MinimumMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberms:CommodityAndOtherContractsMembersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputCommodityVolatilityMember2019-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberms:CommodityAndOtherContractsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputCommodityVolatilityMember2019-12-310000895421ms:MeasurementInputCrossCommodityCorrelationMemberus-gaap:FairValueInputsLevel3Memberms:CommodityAndOtherContractsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMembersrt:MinimumMember2020-12-310000895421ms:MeasurementInputCrossCommodityCorrelationMemberus-gaap:FairValueInputsLevel3Memberms:CommodityAndOtherContractsMembersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMember2020-12-310000895421ms:MeasurementInputCrossCommodityCorrelationMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberms:CommodityAndOtherContractsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMember2020-12-310000895421ms:MeasurementInputCrossCommodityCorrelationMemberus-gaap:FairValueInputsLevel3Memberms:CommodityAndOtherContractsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMembersrt:MinimumMember2019-12-310000895421ms:MeasurementInputCrossCommodityCorrelationMemberus-gaap:FairValueInputsLevel3Memberms:CommodityAndOtherContractsMembersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMember2019-12-310000895421ms:MeasurementInputCrossCommodityCorrelationMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberms:CommodityAndOtherContractsMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMember2019-12-310000895421ms:MeasurementInputEquityVolatilityMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMembersrt:MinimumMember2020-12-310000895421ms:MeasurementInputEquityVolatilityMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMember2020-12-310000895421ms:MeasurementInputEquityVolatilityMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMember2020-12-310000895421ms:MeasurementInputEquityVolatilityMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMembersrt:MinimumMember2019-12-310000895421ms:MeasurementInputEquityVolatilityMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMember2019-12-310000895421ms:MeasurementInputEquityVolatilityMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputSharePriceMemberms:CorporateEquitiesMembersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:MeasurementInputSharePriceMemberms:CorporateEquitiesMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMembersrt:MinimumMember2020-12-310000895421ms:MeasurementInputFundingSpreadMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueDiscountedCashFlowMembersrt:MinimumMember2020-12-310000895421ms:MeasurementInputFundingSpreadMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueDiscountedCashFlowMember2020-12-310000895421ms:MeasurementInputFundingSpreadMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueDiscountedCashFlowMember2020-12-310000895421ms:MeasurementInputFundingSpreadMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueDiscountedCashFlowMembersrt:MinimumMember2019-12-310000895421ms:MeasurementInputFundingSpreadMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueDiscountedCashFlowMember2019-12-310000895421ms:MeasurementInputFundingSpreadMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueDiscountedCashFlowMember2019-12-310000895421ms:MeasurementInputLoanPriceMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMembersrt:MinimumMember2020-12-310000895421ms:MeasurementInputLoanPriceMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMember2020-12-310000895421ms:MeasurementInputLoanPriceMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberms:ValuationTechniqueComparablePricingMember2020-12-310000895421ms:MeasurementInputEquityVolatilitySkewMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMembersrt:MinimumMember2020-12-310000895421ms:MeasurementInputEquityVolatilitySkewMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMember2020-12-310000895421ms:MeasurementInputEquityVolatilitySkewMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMember2020-12-310000895421ms:MeasurementInputEquityVolatilitySkewMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMembersrt:MinimumMember2019-12-310000895421ms:MeasurementInputEquityVolatilitySkewMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMember2019-12-310000895421ms:MeasurementInputEquityVolatilitySkewMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMember2019-12-310000895421ms:MeasurementInputEquityCorrelationMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMembersrt:MinimumMember2020-12-310000895421ms:MeasurementInputEquityCorrelationMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMember2020-12-310000895421ms:MeasurementInputEquityCorrelationMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMember2020-12-310000895421ms:MeasurementInputEquityCorrelationMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMembersrt:MinimumMember2019-12-310000895421ms:MeasurementInputEquityCorrelationMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMember2019-12-310000895421ms:MeasurementInputEquityCorrelationMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMembersrt:MinimumMemberms:MeasurementInputEquityForeignExchangeCorrelationMember2020-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputEquityForeignExchangeCorrelationMember2020-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputEquityForeignExchangeCorrelationMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMembersrt:MinimumMemberms:MeasurementInputEquityForeignExchangeCorrelationMember2019-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputEquityForeignExchangeCorrelationMember2019-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputEquityForeignExchangeCorrelationMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMembersrt:MinimumMemberms:MeasurementInputInterestRateForeignExchangeCorrelationMember2020-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputInterestRateForeignExchangeCorrelationMember2020-12-310000895421srt:ArithmeticAverageMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputInterestRateForeignExchangeCorrelationMember2020-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MedianMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputInterestRateForeignExchangeCorrelationMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMembersrt:MinimumMemberms:MeasurementInputInterestRateForeignExchangeCorrelationMember2019-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputInterestRateForeignExchangeCorrelationMember2019-12-310000895421srt:ArithmeticAverageMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputInterestRateForeignExchangeCorrelationMember2019-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MedianMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:ValuationTechniqueOptionPricingModelMemberms:MeasurementInputInterestRateForeignExchangeCorrelationMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsNonrecurringMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsNonrecurringMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberms:ValuationTechniqueCorporateLoanModelMemberus-gaap:FairValueMeasurementsNonrecurringMemberus-gaap:MeasurementInputCreditSpreadMembersrt:MinimumMember2020-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MaximumMemberms:ValuationTechniqueCorporateLoanModelMemberus-gaap:FairValueMeasurementsNonrecurringMemberus-gaap:MeasurementInputCreditSpreadMember2020-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberms:ValuationTechniqueCorporateLoanModelMemberus-gaap:FairValueMeasurementsNonrecurringMemberus-gaap:MeasurementInputCreditSpreadMember2020-12-310000895421us-gaap:FairValueInputsLevel3Memberms:ValuationTechniqueCorporateLoanModelMemberus-gaap:FairValueMeasurementsNonrecurringMemberus-gaap:MeasurementInputCreditSpreadMembersrt:MinimumMember2019-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MaximumMemberms:ValuationTechniqueCorporateLoanModelMemberus-gaap:FairValueMeasurementsNonrecurringMemberus-gaap:MeasurementInputCreditSpreadMember2019-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberms:ValuationTechniqueCorporateLoanModelMemberus-gaap:FairValueMeasurementsNonrecurringMemberus-gaap:MeasurementInputCreditSpreadMember2019-12-310000895421ms:ValuationTechniqueWarehouseModelMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsNonrecurringMemberus-gaap:MeasurementInputCreditSpreadMembersrt:MinimumMember2020-12-310000895421ms:ValuationTechniqueWarehouseModelMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsNonrecurringMemberus-gaap:MeasurementInputCreditSpreadMember2020-12-310000895421ms:ValuationTechniqueWarehouseModelMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsNonrecurringMemberus-gaap:MeasurementInputCreditSpreadMember2020-12-310000895421ms:ValuationTechniqueWarehouseModelMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsNonrecurringMemberus-gaap:MeasurementInputCreditSpreadMembersrt:MinimumMember2019-12-310000895421ms:ValuationTechniqueWarehouseModelMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:FairValueMeasurementsNonrecurringMemberus-gaap:MeasurementInputCreditSpreadMember2019-12-310000895421ms:ValuationTechniqueWarehouseModelMemberus-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberus-gaap:FairValueMeasurementsNonrecurringMemberus-gaap:MeasurementInputCreditSpreadMember2019-12-310000895421us-gaap:FairValueInputsLevel3Memberms:ValuationTechniqueComparablePricingMemberus-gaap:FairValueMeasurementsNonrecurringMembersrt:MinimumMemberms:MeasurementInputBondPriceMember2020-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:MaximumMemberms:ValuationTechniqueComparablePricingMemberus-gaap:FairValueMeasurementsNonrecurringMemberms:MeasurementInputBondPriceMember2020-12-310000895421us-gaap:FairValueInputsLevel3Membersrt:WeightedAverageMemberms:ValuationTechniqueComparablePricingMemberus-gaap:FairValueMeasurementsNonrecurringMemberms:MeasurementInputBondPriceMember2020-12-310000895421us-gaap:PrivateEquityFundsMember2020-12-310000895421us-gaap:PrivateEquityFundsMember2019-12-310000895421us-gaap:RealEstateFundsMember2020-12-310000895421us-gaap:RealEstateFundsMember2019-12-310000895421us-gaap:HedgeFundsMember2020-12-310000895421us-gaap:HedgeFundsMember2019-12-310000895421us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsNonrecurringMember2020-12-310000895421us-gaap:FairValueMeasurementsNonrecurringMember2020-12-310000895421us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsNonrecurringMember2019-12-310000895421us-gaap:FairValueMeasurementsNonrecurringMember2019-12-310000895421ms:LendingCommitmentMemberus-gaap:FairValueMeasurementsNonrecurringMember2020-01-012020-12-310000895421ms:LendingCommitmentMemberus-gaap:FairValueMeasurementsNonrecurringMember2019-01-012019-12-310000895421ms:LendingCommitmentMemberus-gaap:FairValueMeasurementsNonrecurringMember2018-01-012018-12-310000895421ms:IntangibleAssetsMemberus-gaap:FairValueMeasurementsNonrecurringMember2020-01-012020-12-310000895421ms:IntangibleAssetsMemberus-gaap:FairValueMeasurementsNonrecurringMember2019-01-012019-12-310000895421ms:IntangibleAssetsMemberus-gaap:FairValueMeasurementsNonrecurringMember2018-01-012018-12-310000895421us-gaap:OtherInvestmentsMemberus-gaap:FairValueMeasurementsNonrecurringMember2020-01-012020-12-310000895421us-gaap:OtherInvestmentsMemberus-gaap:FairValueMeasurementsNonrecurringMember2019-01-012019-12-310000895421us-gaap:OtherInvestmentsMemberus-gaap:FairValueMeasurementsNonrecurringMember2018-01-012018-12-310000895421ms:PropertyPlantAndEquipmentAndCapitalizedSoftwareCostsMemberus-gaap:FairValueMeasurementsNonrecurringMember2020-01-012020-12-310000895421ms:PropertyPlantAndEquipmentAndCapitalizedSoftwareCostsMemberus-gaap:FairValueMeasurementsNonrecurringMember2019-01-012019-12-310000895421ms:PropertyPlantAndEquipmentAndCapitalizedSoftwareCostsMemberus-gaap:FairValueMeasurementsNonrecurringMember2018-01-012018-12-310000895421ms:RightOfUseAssetsMemberus-gaap:FairValueMeasurementsNonrecurringMember2020-01-012020-12-310000895421ms:RightOfUseAssetsMemberus-gaap:FairValueMeasurementsNonrecurringMember2019-01-012019-12-310000895421ms:RightOfUseAssetsMemberus-gaap:FairValueMeasurementsNonrecurringMember2018-01-012018-12-310000895421us-gaap:AssetsMemberus-gaap:FairValueMeasurementsNonrecurringMember2020-01-012020-12-310000895421us-gaap:AssetsMemberus-gaap:FairValueMeasurementsNonrecurringMember2019-01-012019-12-310000895421us-gaap:AssetsMemberus-gaap:FairValueMeasurementsNonrecurringMember2018-01-012018-12-310000895421us-gaap:OtherLiabilitiesMemberus-gaap:FairValueMeasurementsNonrecurringMember2020-01-012020-12-310000895421us-gaap:OtherLiabilitiesMemberus-gaap:FairValueMeasurementsNonrecurringMember2019-01-012019-12-310000895421us-gaap:OtherLiabilitiesMemberus-gaap:FairValueMeasurementsNonrecurringMember2018-01-012018-12-310000895421us-gaap:FairValueMeasurementsNonrecurringMemberus-gaap:LiabilityMember2020-01-012020-12-310000895421us-gaap:FairValueMeasurementsNonrecurringMemberus-gaap:LiabilityMember2019-01-012019-12-310000895421us-gaap:FairValueMeasurementsNonrecurringMemberus-gaap:LiabilityMember2018-01-012018-12-310000895421us-gaap:PortionAtOtherThanFairValueFairValueDisclosureMember2020-12-310000895421us-gaap:EstimateOfFairValueFairValueDisclosureMemberus-gaap:FairValueInputsLevel1Member2020-12-310000895421us-gaap:EstimateOfFairValueFairValueDisclosureMemberus-gaap:FairValueInputsLevel2Member2020-12-310000895421us-gaap:EstimateOfFairValueFairValueDisclosureMemberus-gaap:FairValueInputsLevel3Member2020-12-310000895421us-gaap:EstimateOfFairValueFairValueDisclosureMember2020-12-310000895421us-gaap:PortionAtOtherThanFairValueFairValueDisclosureMember2019-12-310000895421us-gaap:EstimateOfFairValueFairValueDisclosureMemberus-gaap:FairValueInputsLevel1Member2019-12-310000895421us-gaap:EstimateOfFairValueFairValueDisclosureMemberus-gaap:FairValueInputsLevel2Member2019-12-310000895421us-gaap:EstimateOfFairValueFairValueDisclosureMemberus-gaap:FairValueInputsLevel3Member2019-12-310000895421us-gaap:EstimateOfFairValueFairValueDisclosureMember2019-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberus-gaap:EquityContractMember2020-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberus-gaap:EquityContractMember2019-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberus-gaap:InterestRateContractMember2020-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberus-gaap:InterestRateContractMember2019-12-310000895421ms:CommodityAndOtherContractsMemberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421ms:CommodityAndOtherContractsMemberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421us-gaap:CreditRiskContractMemberus-gaap:FairValueMeasurementsRecurringMember2020-12-310000895421us-gaap:CreditRiskContractMemberus-gaap:FairValueMeasurementsRecurringMember2019-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberus-gaap:ForeignExchangeContractMember2020-12-310000895421us-gaap:FairValueMeasurementsRecurringMemberus-gaap:ForeignExchangeContractMember2019-12-310000895421us-gaap:DebtMemberus-gaap:TradingRevenueMember2020-01-012020-12-310000895421us-gaap:DebtMemberus-gaap:TradingRevenueMember2019-01-012019-12-310000895421us-gaap:DebtMemberus-gaap:TradingRevenueMember2018-01-012018-12-310000895421us-gaap:InterestExpenseMemberus-gaap:DebtMember2020-01-012020-12-310000895421us-gaap:InterestExpenseMemberus-gaap:DebtMember2019-01-012019-12-310000895421us-gaap:InterestExpenseMemberus-gaap:DebtMember2018-01-012018-12-310000895421us-gaap:DebtMember2020-01-012020-12-310000895421us-gaap:DebtMember2019-01-012019-12-310000895421us-gaap:DebtMember2018-01-012018-12-310000895421ms:LoansAndOtherDebtMemberus-gaap:TradingRevenueMember2020-01-012020-12-310000895421ms:LoansAndOtherDebtMemberus-gaap:OtherComprehensiveIncomeMember2020-01-012020-12-310000895421us-gaap:WrittenLoanCommitmentFairValueOptionMemberus-gaap:TradingRevenueMember2020-01-012020-12-310000895421us-gaap:WrittenLoanCommitmentFairValueOptionMemberus-gaap:OtherComprehensiveIncomeMember2020-01-012020-12-310000895421us-gaap:DepositsMemberus-gaap:TradingRevenueMember2020-01-012020-12-310000895421us-gaap:OtherComprehensiveIncomeMemberus-gaap:DepositsMember2020-01-012020-12-310000895421us-gaap:OtherComprehensiveIncomeMemberus-gaap:DebtMember2020-01-012020-12-310000895421ms:LoansAndOtherDebtMemberus-gaap:TradingRevenueMember2019-01-012019-12-310000895421ms:LoansAndOtherDebtMemberus-gaap:OtherComprehensiveIncomeMember2019-01-012019-12-310000895421us-gaap:WrittenLoanCommitmentFairValueOptionMemberus-gaap:TradingRevenueMember2019-01-012019-12-310000895421us-gaap:WrittenLoanCommitmentFairValueOptionMemberus-gaap:OtherComprehensiveIncomeMember2019-01-012019-12-310000895421us-gaap:DepositsMemberus-gaap:TradingRevenueMember2019-01-012019-12-310000895421us-gaap:OtherComprehensiveIncomeMemberus-gaap:DepositsMember2019-01-012019-12-310000895421us-gaap:OtherComprehensiveIncomeMemberus-gaap:DebtMember2019-01-012019-12-310000895421ms:LoansAndOtherDebtMemberus-gaap:TradingRevenueMember2018-01-012018-12-310000895421ms:LoansAndOtherDebtMemberus-gaap:OtherComprehensiveIncomeMember2018-01-012018-12-310000895421us-gaap:WrittenLoanCommitmentFairValueOptionMemberus-gaap:TradingRevenueMember2018-01-012018-12-310000895421us-gaap:WrittenLoanCommitmentFairValueOptionMemberus-gaap:OtherComprehensiveIncomeMember2018-01-012018-12-310000895421us-gaap:DepositsMemberus-gaap:TradingRevenueMember2018-01-012018-12-310000895421us-gaap:OtherComprehensiveIncomeMemberus-gaap:DepositsMember2018-01-012018-12-310000895421us-gaap:OtherComprehensiveIncomeMemberus-gaap:DebtMember2018-01-012018-12-310000895421us-gaap:OtherDebtSecuritiesMemberus-gaap:TradingRevenueMember2018-01-012018-12-310000895421us-gaap:OtherDebtSecuritiesMemberus-gaap:OtherComprehensiveIncomeMember2018-01-012018-12-310000895421us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:OverTheCounterMemberus-gaap:InterestRateContractMember2020-12-310000895421us-gaap:ExchangeClearedMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InterestRateContractMember2020-12-310000895421us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InterestRateContractMemberus-gaap:ExchangeTradedMember2020-12-310000895421us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InterestRateContractMember2020-12-310000895421us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:OverTheCounterMemberus-gaap:ForeignExchangeContractMember2020-12-310000895421us-gaap:ExchangeClearedMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:ForeignExchangeContractMember2020-12-310000895421us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:ForeignExchangeContractMemberus-gaap:ExchangeTradedMember2020-12-310000895421us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:ForeignExchangeContractMember2020-12-310000895421us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:OverTheCounterMember2020-12-310000895421us-gaap:ExchangeClearedMemberus-gaap:DesignatedAsHedgingInstrumentMember2020-12-310000895421us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:ExchangeTradedMember2020-12-310000895421us-gaap:DesignatedAsHedgingInstrumentMember2020-12-310000895421us-gaap:OverTheCounterMemberus-gaap:NondesignatedMemberus-gaap:InterestRateContractMember2020-12-310000895421us-gaap:ExchangeClearedMemberus-gaap:NondesignatedMemberus-gaap:InterestRateContractMember2020-12-310000895421us-gaap:NondesignatedMemberus-gaap:InterestRateContractMemberus-gaap:ExchangeTradedMember2020-12-310000895421us-gaap:NondesignatedMemberus-gaap:InterestRateContractMember2020-12-310000895421us-gaap:CreditRiskContractMemberus-gaap:OverTheCounterMemberus-gaap:NondesignatedMember2020-12-310000895421us-gaap:ExchangeClearedMemberus-gaap:CreditRiskContractMemberus-gaap:NondesignatedMember2020-12-310000895421us-gaap:CreditRiskContractMemberus-gaap:NondesignatedMemberus-gaap:ExchangeTradedMember2020-12-310000895421us-gaap:CreditRiskContractMemberus-gaap:NondesignatedMember2020-12-310000895421us-gaap:OverTheCounterMemberus-gaap:ForeignExchangeContractMemberus-gaap:NondesignatedMember2020-12-310000895421us-gaap:ExchangeClearedMemberus-gaap:ForeignExchangeContractMemberus-gaap:NondesignatedMember2020-12-310000895421us-gaap:ForeignExchangeContractMemberus-gaap:NondesignatedMemberus-gaap:ExchangeTradedMember2020-12-310000895421us-gaap:ForeignExchangeContractMemberus-gaap:NondesignatedMember2020-12-310000895421us-gaap:OverTheCounterMemberus-gaap:NondesignatedMemberus-gaap:EquityContractMember2020-12-310000895421us-gaap:ExchangeClearedMemberus-gaap:NondesignatedMemberus-gaap:EquityContractMember2020-12-310000895421us-gaap:NondesignatedMemberus-gaap:EquityContractMemberus-gaap:ExchangeTradedMember2020-12-310000895421us-gaap:NondesignatedMemberus-gaap:EquityContractMember2020-12-310000895421ms:CommodityAndOtherContractsMemberus-gaap:OverTheCounterMemberus-gaap:NondesignatedMember2020-12-310000895421ms:CommodityAndOtherContractsMemberus-gaap:ExchangeClearedMemberus-gaap:NondesignatedMember2020-12-310000895421ms:CommodityAndOtherContractsMemberus-gaap:NondesignatedMemberus-gaap:ExchangeTradedMember2020-12-310000895421ms:CommodityAndOtherContractsMemberus-gaap:NondesignatedMember2020-12-310000895421us-gaap:OverTheCounterMemberus-gaap:NondesignatedMember2020-12-310000895421us-gaap:ExchangeClearedMemberus-gaap:NondesignatedMember2020-12-310000895421us-gaap:NondesignatedMemberus-gaap:ExchangeTradedMember2020-12-310000895421us-gaap:NondesignatedMember2020-12-310000895421us-gaap:OverTheCounterMember2020-12-310000895421us-gaap:ExchangeClearedMember2020-12-310000895421us-gaap:ExchangeTradedMember2020-12-310000895421us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:OverTheCounterMemberus-gaap:InterestRateContractMember2019-12-310000895421us-gaap:ExchangeClearedMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InterestRateContractMember2019-12-310000895421us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InterestRateContractMemberus-gaap:ExchangeTradedMember2019-12-310000895421us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InterestRateContractMember2019-12-310000895421us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:OverTheCounterMemberus-gaap:ForeignExchangeContractMember2019-12-310000895421us-gaap:ExchangeClearedMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:ForeignExchangeContractMember2019-12-310000895421us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:ForeignExchangeContractMemberus-gaap:ExchangeTradedMember2019-12-310000895421us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:ForeignExchangeContractMember2019-12-310000895421us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:OverTheCounterMember2019-12-310000895421us-gaap:ExchangeClearedMemberus-gaap:DesignatedAsHedgingInstrumentMember2019-12-310000895421us-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:ExchangeTradedMember2019-12-310000895421us-gaap:DesignatedAsHedgingInstrumentMember2019-12-310000895421us-gaap:OverTheCounterMemberus-gaap:NondesignatedMemberus-gaap:InterestRateContractMember2019-12-310000895421us-gaap:ExchangeClearedMemberus-gaap:NondesignatedMemberus-gaap:InterestRateContractMember2019-12-310000895421us-gaap:NondesignatedMemberus-gaap:InterestRateContractMemberus-gaap:ExchangeTradedMember2019-12-310000895421us-gaap:NondesignatedMemberus-gaap:InterestRateContractMember2019-12-310000895421us-gaap:CreditRiskContractMemberus-gaap:OverTheCounterMemberus-gaap:NondesignatedMember2019-12-310000895421us-gaap:ExchangeClearedMemberus-gaap:CreditRiskContractMemberus-gaap:NondesignatedMember2019-12-310000895421us-gaap:CreditRiskContractMemberus-gaap:NondesignatedMemberus-gaap:ExchangeTradedMember2019-12-310000895421us-gaap:CreditRiskContractMemberus-gaap:NondesignatedMember2019-12-310000895421us-gaap:OverTheCounterMemberus-gaap:ForeignExchangeContractMemberus-gaap:NondesignatedMember2019-12-310000895421us-gaap:ExchangeClearedMemberus-gaap:ForeignExchangeContractMemberus-gaap:NondesignatedMember2019-12-310000895421us-gaap:ForeignExchangeContractMemberus-gaap:NondesignatedMemberus-gaap:ExchangeTradedMember2019-12-310000895421us-gaap:ForeignExchangeContractMemberus-gaap:NondesignatedMember2019-12-310000895421us-gaap:OverTheCounterMemberus-gaap:NondesignatedMemberus-gaap:EquityContractMember2019-12-310000895421us-gaap:ExchangeClearedMemberus-gaap:NondesignatedMemberus-gaap:EquityContractMember2019-12-310000895421us-gaap:NondesignatedMemberus-gaap:EquityContractMemberus-gaap:ExchangeTradedMember2019-12-310000895421us-gaap:NondesignatedMemberus-gaap:EquityContractMember2019-12-310000895421ms:CommodityAndOtherContractsMemberus-gaap:OverTheCounterMemberus-gaap:NondesignatedMember2019-12-310000895421ms:CommodityAndOtherContractsMemberus-gaap:ExchangeClearedMemberus-gaap:NondesignatedMember2019-12-310000895421ms:CommodityAndOtherContractsMemberus-gaap:NondesignatedMemberus-gaap:ExchangeTradedMember2019-12-310000895421ms:CommodityAndOtherContractsMemberus-gaap:NondesignatedMember2019-12-310000895421us-gaap:OverTheCounterMemberus-gaap:NondesignatedMember2019-12-310000895421us-gaap:ExchangeClearedMemberus-gaap:NondesignatedMember2019-12-310000895421us-gaap:NondesignatedMemberus-gaap:ExchangeTradedMember2019-12-310000895421us-gaap:NondesignatedMember2019-12-310000895421us-gaap:OverTheCounterMember2019-12-310000895421us-gaap:ExchangeClearedMember2019-12-310000895421us-gaap:ExchangeTradedMember2019-12-310000895421us-gaap:InterestIncomeMemberus-gaap:FairValueHedgingMemberus-gaap:InterestRateContractMember2020-01-012020-12-310000895421us-gaap:InterestIncomeMemberus-gaap:FairValueHedgingMemberus-gaap:InterestRateContractMember2019-01-012019-12-310000895421us-gaap:InterestIncomeMemberus-gaap:FairValueHedgingMemberus-gaap:InterestRateContractMember2018-01-012018-12-310000895421us-gaap:InterestIncomeMemberus-gaap:FairValueHedgingMemberus-gaap:AvailableforsaleSecuritiesMember2020-01-012020-12-310000895421us-gaap:InterestIncomeMemberus-gaap:FairValueHedgingMemberus-gaap:AvailableforsaleSecuritiesMember2019-01-012019-12-310000895421us-gaap:InterestIncomeMemberus-gaap:FairValueHedgingMemberus-gaap:AvailableforsaleSecuritiesMember2018-01-012018-12-310000895421us-gaap:InterestExpenseMemberus-gaap:FairValueHedgingMemberus-gaap:InterestRateContractMember2020-01-012020-12-310000895421us-gaap:InterestExpenseMemberus-gaap:FairValueHedgingMemberus-gaap:InterestRateContractMember2019-01-012019-12-310000895421us-gaap:InterestExpenseMemberus-gaap:FairValueHedgingMemberus-gaap:InterestRateContractMember2018-01-012018-12-310000895421us-gaap:InterestExpenseMemberus-gaap:FairValueHedgingMemberus-gaap:DepositsMember2020-01-012020-12-310000895421us-gaap:InterestExpenseMemberus-gaap:FairValueHedgingMemberus-gaap:DepositsMember2019-01-012019-12-310000895421us-gaap:InterestExpenseMemberus-gaap:FairValueHedgingMemberus-gaap:DepositsMember2018-01-012018-12-310000895421us-gaap:InterestExpenseMemberus-gaap:BorrowingsMemberus-gaap:FairValueHedgingMember2020-01-012020-12-310000895421us-gaap:InterestExpenseMemberus-gaap:BorrowingsMemberus-gaap:FairValueHedgingMember2019-01-012019-12-310000895421us-gaap:InterestExpenseMemberus-gaap:BorrowingsMemberus-gaap:FairValueHedgingMember2018-01-012018-12-310000895421us-gaap:NetInvestmentHedgingMemberus-gaap:ForeignExchangeContractMember2020-01-012020-12-310000895421us-gaap:NetInvestmentHedgingMemberus-gaap:ForeignExchangeContractMember2019-01-012019-12-310000895421us-gaap:NetInvestmentHedgingMemberus-gaap:ForeignExchangeContractMember2018-01-012018-12-310000895421us-gaap:AvailableforsaleSecuritiesMember2020-12-310000895421us-gaap:AvailableforsaleSecuritiesMember2019-12-310000895421us-gaap:DepositsMember2020-12-310000895421us-gaap:DepositsMember2019-12-310000895421us-gaap:BorrowingsMember2020-12-310000895421us-gaap:BorrowingsMember2019-12-310000895421ms:DerivativeCreditRiskRelatedContingentFeaturesTriggeringCircumstancesOneNotchCreditRatingDowngradeMember2020-12-310000895421ms:DerivativeCreditRiskRelatedContingentFeaturestriggeringCircumstancesTwoNotchCreditRatingDowngradeMember2020-12-310000895421us-gaap:CollaborativeArrangementMember2020-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:LessThanTwelveMonthsFromBalanceSheetDateMemberus-gaap:InternalInvestmentGradeMemberms:SingleNameCreditDefaultSwapMember2020-12-310000895421ms:CreditDerivativesSellingProtectionMemberus-gaap:InternalInvestmentGradeMemberms:SingleNameCreditDefaultSwapMemberms:MoreThanOneAndWithinThreeYearsFromBalanceSheetDateMember2020-12-310000895421ms:CreditDerivativesSellingProtectionMemberus-gaap:InternalInvestmentGradeMemberms:MoreThanThreeAndWithinFiveYearsFromBalanceSheetDateMemberms:SingleNameCreditDefaultSwapMember2020-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:MoreThanFiveYearsFromBalanceSheetDateMemberus-gaap:InternalInvestmentGradeMemberms:SingleNameCreditDefaultSwapMember2020-12-310000895421ms:CreditDerivativesSellingProtectionMemberus-gaap:InternalInvestmentGradeMemberms:SingleNameCreditDefaultSwapMember2020-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:LessThanTwelveMonthsFromBalanceSheetDateMemberus-gaap:InternalNoninvestmentGradeMemberms:SingleNameCreditDefaultSwapMember2020-12-310000895421ms:CreditDerivativesSellingProtectionMemberus-gaap:InternalNoninvestmentGradeMemberms:SingleNameCreditDefaultSwapMemberms:MoreThanOneAndWithinThreeYearsFromBalanceSheetDateMember2020-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:MoreThanThreeAndWithinFiveYearsFromBalanceSheetDateMemberus-gaap:InternalNoninvestmentGradeMemberms:SingleNameCreditDefaultSwapMember2020-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:MoreThanFiveYearsFromBalanceSheetDateMemberus-gaap:InternalNoninvestmentGradeMemberms:SingleNameCreditDefaultSwapMember2020-12-310000895421ms:CreditDerivativesSellingProtectionMemberus-gaap:InternalNoninvestmentGradeMemberms:SingleNameCreditDefaultSwapMember2020-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:LessThanTwelveMonthsFromBalanceSheetDateMemberms:SingleNameCreditDefaultSwapMember2020-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:SingleNameCreditDefaultSwapMemberms:MoreThanOneAndWithinThreeYearsFromBalanceSheetDateMember2020-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:MoreThanThreeAndWithinFiveYearsFromBalanceSheetDateMemberms:SingleNameCreditDefaultSwapMember2020-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:MoreThanFiveYearsFromBalanceSheetDateMemberms:SingleNameCreditDefaultSwapMember2020-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:SingleNameCreditDefaultSwapMember2020-12-310000895421ms:TotalIndexAndBasketCreditDefaultSwapsMemberms:CreditDerivativesSellingProtectionMemberms:LessThanTwelveMonthsFromBalanceSheetDateMemberus-gaap:InternalInvestmentGradeMember2020-12-310000895421ms:TotalIndexAndBasketCreditDefaultSwapsMemberms:CreditDerivativesSellingProtectionMemberus-gaap:InternalInvestmentGradeMemberms:MoreThanOneAndWithinThreeYearsFromBalanceSheetDateMember2020-12-310000895421ms:TotalIndexAndBasketCreditDefaultSwapsMemberms:CreditDerivativesSellingProtectionMemberus-gaap:InternalInvestmentGradeMemberms:MoreThanThreeAndWithinFiveYearsFromBalanceSheetDateMember2020-12-310000895421ms:TotalIndexAndBasketCreditDefaultSwapsMemberms:CreditDerivativesSellingProtectionMemberms:MoreThanFiveYearsFromBalanceSheetDateMemberus-gaap:InternalInvestmentGradeMember2020-12-310000895421ms:TotalIndexAndBasketCreditDefaultSwapsMemberms:CreditDerivativesSellingProtectionMemberus-gaap:InternalInvestmentGradeMember2020-12-310000895421ms:TotalIndexAndBasketCreditDefaultSwapsMemberms:CreditDerivativesSellingProtectionMemberms:LessThanTwelveMonthsFromBalanceSheetDateMemberus-gaap:InternalNoninvestmentGradeMember2020-12-310000895421ms:TotalIndexAndBasketCreditDefaultSwapsMemberms:CreditDerivativesSellingProtectionMemberus-gaap:InternalNoninvestmentGradeMemberms:MoreThanOneAndWithinThreeYearsFromBalanceSheetDateMember2020-12-310000895421ms:TotalIndexAndBasketCreditDefaultSwapsMemberms:CreditDerivativesSellingProtectionMemberms:MoreThanThreeAndWithinFiveYearsFromBalanceSheetDateMemberus-gaap:InternalNoninvestmentGradeMember2020-12-310000895421ms:TotalIndexAndBasketCreditDefaultSwapsMemberms:CreditDerivativesSellingProtectionMemberms:MoreThanFiveYearsFromBalanceSheetDateMemberus-gaap:InternalNoninvestmentGradeMember2020-12-310000895421ms:TotalIndexAndBasketCreditDefaultSwapsMemberms:CreditDerivativesSellingProtectionMemberus-gaap:InternalNoninvestmentGradeMember2020-12-310000895421ms:TotalIndexAndBasketCreditDefaultSwapsMemberms:CreditDerivativesSellingProtectionMemberms:LessThanTwelveMonthsFromBalanceSheetDateMember2020-12-310000895421ms:TotalIndexAndBasketCreditDefaultSwapsMemberms:CreditDerivativesSellingProtectionMemberms:MoreThanOneAndWithinThreeYearsFromBalanceSheetDateMember2020-12-310000895421ms:TotalIndexAndBasketCreditDefaultSwapsMemberms:CreditDerivativesSellingProtectionMemberms:MoreThanThreeAndWithinFiveYearsFromBalanceSheetDateMember2020-12-310000895421ms:TotalIndexAndBasketCreditDefaultSwapsMemberms:CreditDerivativesSellingProtectionMemberms:MoreThanFiveYearsFromBalanceSheetDateMember2020-12-310000895421ms:TotalIndexAndBasketCreditDefaultSwapsMemberms:CreditDerivativesSellingProtectionMember2020-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:LessThanTwelveMonthsFromBalanceSheetDateMemberus-gaap:CreditDefaultSwapMember2020-12-310000895421ms:CreditDerivativesSellingProtectionMemberus-gaap:CreditDefaultSwapMemberms:MoreThanOneAndWithinThreeYearsFromBalanceSheetDateMember2020-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:MoreThanThreeAndWithinFiveYearsFromBalanceSheetDateMemberus-gaap:CreditDefaultSwapMember2020-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:MoreThanFiveYearsFromBalanceSheetDateMemberus-gaap:CreditDefaultSwapMember2020-12-310000895421ms:CreditDerivativesSellingProtectionMemberus-gaap:CreditDefaultSwapMember2020-12-310000895421us-gaap:OtherCreditDerivativesMemberms:CreditDerivativesSellingProtectionMemberms:LessThanTwelveMonthsFromBalanceSheetDateMember2020-12-310000895421us-gaap:OtherCreditDerivativesMemberms:CreditDerivativesSellingProtectionMemberms:MoreThanOneAndWithinThreeYearsFromBalanceSheetDateMember2020-12-310000895421us-gaap:OtherCreditDerivativesMemberms:CreditDerivativesSellingProtectionMemberms:MoreThanThreeAndWithinFiveYearsFromBalanceSheetDateMember2020-12-310000895421us-gaap:OtherCreditDerivativesMemberms:CreditDerivativesSellingProtectionMemberms:MoreThanFiveYearsFromBalanceSheetDateMember2020-12-310000895421us-gaap:OtherCreditDerivativesMemberms:CreditDerivativesSellingProtectionMember2020-12-310000895421ms:LessThanTwelveMonthsFromBalanceSheetDateMemberms:CreditDerivativesSellingProtectionMember2020-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:MoreThanOneAndWithinThreeYearsFromBalanceSheetDateMember2020-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:MoreThanThreeAndWithinFiveYearsFromBalanceSheetDateMember2020-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:MoreThanFiveYearsFromBalanceSheetDateMember2020-12-310000895421ms:CreditDerivativesSellingProtectionMember2020-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:LessThanTwelveMonthsFromBalanceSheetDateMemberus-gaap:InternalInvestmentGradeMemberms:SingleNameCreditDefaultSwapMember2019-12-310000895421ms:CreditDerivativesSellingProtectionMemberus-gaap:InternalInvestmentGradeMemberms:SingleNameCreditDefaultSwapMemberms:MoreThanOneAndWithinThreeYearsFromBalanceSheetDateMember2019-12-310000895421ms:CreditDerivativesSellingProtectionMemberus-gaap:InternalInvestmentGradeMemberms:MoreThanThreeAndWithinFiveYearsFromBalanceSheetDateMemberms:SingleNameCreditDefaultSwapMember2019-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:MoreThanFiveYearsFromBalanceSheetDateMemberus-gaap:InternalInvestmentGradeMemberms:SingleNameCreditDefaultSwapMember2019-12-310000895421ms:CreditDerivativesSellingProtectionMemberus-gaap:InternalInvestmentGradeMemberms:SingleNameCreditDefaultSwapMember2019-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:LessThanTwelveMonthsFromBalanceSheetDateMemberus-gaap:InternalNoninvestmentGradeMemberms:SingleNameCreditDefaultSwapMember2019-12-310000895421ms:CreditDerivativesSellingProtectionMemberus-gaap:InternalNoninvestmentGradeMemberms:SingleNameCreditDefaultSwapMemberms:MoreThanOneAndWithinThreeYearsFromBalanceSheetDateMember2019-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:MoreThanThreeAndWithinFiveYearsFromBalanceSheetDateMemberus-gaap:InternalNoninvestmentGradeMemberms:SingleNameCreditDefaultSwapMember2019-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:MoreThanFiveYearsFromBalanceSheetDateMemberus-gaap:InternalNoninvestmentGradeMemberms:SingleNameCreditDefaultSwapMember2019-12-310000895421ms:CreditDerivativesSellingProtectionMemberus-gaap:InternalNoninvestmentGradeMemberms:SingleNameCreditDefaultSwapMember2019-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:LessThanTwelveMonthsFromBalanceSheetDateMemberms:SingleNameCreditDefaultSwapMember2019-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:SingleNameCreditDefaultSwapMemberms:MoreThanOneAndWithinThreeYearsFromBalanceSheetDateMember2019-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:MoreThanThreeAndWithinFiveYearsFromBalanceSheetDateMemberms:SingleNameCreditDefaultSwapMember2019-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:MoreThanFiveYearsFromBalanceSheetDateMemberms:SingleNameCreditDefaultSwapMember2019-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:SingleNameCreditDefaultSwapMember2019-12-310000895421ms:TotalIndexAndBasketCreditDefaultSwapsMemberms:CreditDerivativesSellingProtectionMemberms:LessThanTwelveMonthsFromBalanceSheetDateMemberus-gaap:InternalInvestmentGradeMember2019-12-310000895421ms:TotalIndexAndBasketCreditDefaultSwapsMemberms:CreditDerivativesSellingProtectionMemberus-gaap:InternalInvestmentGradeMemberms:MoreThanOneAndWithinThreeYearsFromBalanceSheetDateMember2019-12-310000895421ms:TotalIndexAndBasketCreditDefaultSwapsMemberms:CreditDerivativesSellingProtectionMemberus-gaap:InternalInvestmentGradeMemberms:MoreThanThreeAndWithinFiveYearsFromBalanceSheetDateMember2019-12-310000895421ms:TotalIndexAndBasketCreditDefaultSwapsMemberms:CreditDerivativesSellingProtectionMemberms:MoreThanFiveYearsFromBalanceSheetDateMemberus-gaap:InternalInvestmentGradeMember2019-12-310000895421ms:TotalIndexAndBasketCreditDefaultSwapsMemberms:CreditDerivativesSellingProtectionMemberus-gaap:InternalInvestmentGradeMember2019-12-310000895421ms:TotalIndexAndBasketCreditDefaultSwapsMemberms:CreditDerivativesSellingProtectionMemberms:LessThanTwelveMonthsFromBalanceSheetDateMemberus-gaap:InternalNoninvestmentGradeMember2019-12-310000895421ms:TotalIndexAndBasketCreditDefaultSwapsMemberms:CreditDerivativesSellingProtectionMemberus-gaap:InternalNoninvestmentGradeMemberms:MoreThanOneAndWithinThreeYearsFromBalanceSheetDateMember2019-12-310000895421ms:TotalIndexAndBasketCreditDefaultSwapsMemberms:CreditDerivativesSellingProtectionMemberms:MoreThanThreeAndWithinFiveYearsFromBalanceSheetDateMemberus-gaap:InternalNoninvestmentGradeMember2019-12-310000895421ms:TotalIndexAndBasketCreditDefaultSwapsMemberms:CreditDerivativesSellingProtectionMemberms:MoreThanFiveYearsFromBalanceSheetDateMemberus-gaap:InternalNoninvestmentGradeMember2019-12-310000895421ms:TotalIndexAndBasketCreditDefaultSwapsMemberms:CreditDerivativesSellingProtectionMemberus-gaap:InternalNoninvestmentGradeMember2019-12-310000895421ms:TotalIndexAndBasketCreditDefaultSwapsMemberms:CreditDerivativesSellingProtectionMemberms:LessThanTwelveMonthsFromBalanceSheetDateMember2019-12-310000895421ms:TotalIndexAndBasketCreditDefaultSwapsMemberms:CreditDerivativesSellingProtectionMemberms:MoreThanOneAndWithinThreeYearsFromBalanceSheetDateMember2019-12-310000895421ms:TotalIndexAndBasketCreditDefaultSwapsMemberms:CreditDerivativesSellingProtectionMemberms:MoreThanThreeAndWithinFiveYearsFromBalanceSheetDateMember2019-12-310000895421ms:TotalIndexAndBasketCreditDefaultSwapsMemberms:CreditDerivativesSellingProtectionMemberms:MoreThanFiveYearsFromBalanceSheetDateMember2019-12-310000895421ms:TotalIndexAndBasketCreditDefaultSwapsMemberms:CreditDerivativesSellingProtectionMember2019-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:LessThanTwelveMonthsFromBalanceSheetDateMemberus-gaap:CreditDefaultSwapMember2019-12-310000895421ms:CreditDerivativesSellingProtectionMemberus-gaap:CreditDefaultSwapMemberms:MoreThanOneAndWithinThreeYearsFromBalanceSheetDateMember2019-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:MoreThanThreeAndWithinFiveYearsFromBalanceSheetDateMemberus-gaap:CreditDefaultSwapMember2019-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:MoreThanFiveYearsFromBalanceSheetDateMemberus-gaap:CreditDefaultSwapMember2019-12-310000895421ms:CreditDerivativesSellingProtectionMemberus-gaap:CreditDefaultSwapMember2019-12-310000895421us-gaap:OtherCreditDerivativesMemberms:CreditDerivativesSellingProtectionMemberms:LessThanTwelveMonthsFromBalanceSheetDateMember2019-12-310000895421us-gaap:OtherCreditDerivativesMemberms:CreditDerivativesSellingProtectionMemberms:MoreThanOneAndWithinThreeYearsFromBalanceSheetDateMember2019-12-310000895421us-gaap:OtherCreditDerivativesMemberms:CreditDerivativesSellingProtectionMemberms:MoreThanThreeAndWithinFiveYearsFromBalanceSheetDateMember2019-12-310000895421us-gaap:OtherCreditDerivativesMemberms:CreditDerivativesSellingProtectionMemberms:MoreThanFiveYearsFromBalanceSheetDateMember2019-12-310000895421us-gaap:OtherCreditDerivativesMemberms:CreditDerivativesSellingProtectionMember2019-12-310000895421ms:LessThanTwelveMonthsFromBalanceSheetDateMemberms:CreditDerivativesSellingProtectionMember2019-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:MoreThanOneAndWithinThreeYearsFromBalanceSheetDateMember2019-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:MoreThanThreeAndWithinFiveYearsFromBalanceSheetDateMember2019-12-310000895421ms:CreditDerivativesSellingProtectionMemberms:MoreThanFiveYearsFromBalanceSheetDateMember2019-12-310000895421ms:CreditDerivativesSellingProtectionMember2019-12-310000895421us-gaap:CreditDefaultSwapBuyingProtectionMemberms:SingleNameCreditDefaultSwapMember2020-12-310000895421us-gaap:CreditDefaultSwapBuyingProtectionMemberms:SingleNameCreditDefaultSwapMember2019-12-310000895421ms:IndexAndBasketCreditDefaultSwapMemberus-gaap:CreditDefaultSwapBuyingProtectionMember2020-12-310000895421ms:IndexAndBasketCreditDefaultSwapMemberus-gaap:CreditDefaultSwapBuyingProtectionMember2019-12-310000895421us-gaap:CreditDefaultSwapBuyingProtectionMemberms:TranchedIndexAndBasketCreditDefaultSwapMember2020-12-310000895421us-gaap:CreditDefaultSwapBuyingProtectionMemberms:TranchedIndexAndBasketCreditDefaultSwapMember2019-12-310000895421us-gaap:CreditDefaultSwapBuyingProtectionMemberus-gaap:CreditDefaultSwapMember2020-12-310000895421us-gaap:CreditDefaultSwapBuyingProtectionMemberus-gaap:CreditDefaultSwapMember2019-12-310000895421us-gaap:USTreasurySecuritiesMember2020-12-310000895421us-gaap:USGovernmentAgenciesDebtSecuritiesMember2020-12-310000895421us-gaap:USTreasuryAndGovernmentMember2020-12-310000895421us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember2020-12-310000895421us-gaap:CorporateBondSecuritiesMember2020-12-310000895421us-gaap:USStatesAndPoliticalSubdivisionsMember2020-12-310000895421ms:AssetBackedSecuritiesFederalFamilyEducationLoanProgramMember2020-12-310000895421ms:AssetBackedSecuritiesOtherMember2020-12-310000895421ms:CorporateandOtherDebtSecuritiesMember2020-12-310000895421us-gaap:MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember2020-12-310000895421us-gaap:USTreasurySecuritiesMember2019-12-310000895421us-gaap:USGovernmentAgenciesDebtSecuritiesMember2019-12-310000895421us-gaap:USTreasuryAndGovernmentMember2019-12-310000895421us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember2019-12-310000895421us-gaap:CorporateBondSecuritiesMember2019-12-310000895421us-gaap:USStatesAndPoliticalSubdivisionsMember2019-12-310000895421ms:AssetBackedSecuritiesFederalFamilyEducationLoanProgramMember2019-12-310000895421ms:CorporateandOtherDebtSecuritiesMember2019-12-310000895421us-gaap:MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember2019-12-3100008954212020-01-012020-03-31ms:security0000895421us-gaap:USTreasurySecuritiesMember2020-01-012020-12-310000895421us-gaap:USGovernmentAgenciesDebtSecuritiesMember2020-01-012020-12-310000895421us-gaap:USTreasuryAndGovernmentMember2020-01-012020-12-310000895421us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember2020-01-012020-12-310000895421us-gaap:CorporateBondSecuritiesMember2020-01-012020-12-310000895421us-gaap:USStatesAndPoliticalSubdivisionsMember2020-01-012020-12-310000895421ms:AssetBackedSecuritiesFederalFamilyEducationLoanProgramMember2020-01-012020-12-310000895421ms:AssetBackedSecuritiesOtherMember2020-01-012020-12-310000895421ms:CorporateandOtherDebtSecuritiesMember2020-01-012020-12-310000895421us-gaap:MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember2020-01-012020-12-310000895421us-gaap:MaturityOvernightMember2020-12-310000895421us-gaap:MaturityUpTo30DaysMember2020-12-310000895421us-gaap:Maturity30To90DaysMember2020-12-310000895421us-gaap:MaturityOver90DaysMember2020-12-310000895421us-gaap:MaturityOvernightMember2019-12-310000895421us-gaap:MaturityUpTo30DaysMember2019-12-310000895421us-gaap:Maturity30To90DaysMember2019-12-310000895421us-gaap:MaturityOver90DaysMember2019-12-310000895421us-gaap:USTreasuryAndGovernmentMember2020-12-310000895421us-gaap:USTreasuryAndGovernmentMember2019-12-310000895421us-gaap:USStatesAndPoliticalSubdivisionsMember2020-12-310000895421us-gaap:USStatesAndPoliticalSubdivisionsMember2019-12-310000895421us-gaap:ForeignGovernmentDebtSecuritiesMember2020-12-310000895421us-gaap:ForeignGovernmentDebtSecuritiesMember2019-12-310000895421us-gaap:AssetBackedSecuritiesMember2020-12-310000895421us-gaap:AssetBackedSecuritiesMember2019-12-310000895421ms:CorporateandOtherDebtSecuritiesMember2020-12-310000895421ms:CorporateandOtherDebtSecuritiesMember2019-12-310000895421ms:CorporateEquitiesMember2020-12-310000895421ms:CorporateEquitiesMember2019-12-310000895421us-gaap:CollateralizedSecuritiesOtherMember2020-12-310000895421us-gaap:CollateralizedSecuritiesOtherMember2019-12-310000895421ms:UsTreasuryAndGovernmentAndForeignGovernmentDebtSecuritiesMemberms:TradingAssetsToTotalAssetsRatioMember2020-01-012020-12-310000895421ms:UsTreasuryAndGovernmentAndForeignGovernmentDebtSecuritiesMemberms:TradingAssetsToTotalAssetsRatioMember2019-01-012019-12-310000895421ms:UsTreasuryAndGovernmentAndForeignGovernmentDebtSecuritiesMemberms:CollateralReceivedToTotalAssetsRatioMember2020-01-012020-12-310000895421ms:UsTreasuryAndGovernmentAndForeignGovernmentDebtSecuritiesMemberms:CollateralReceivedToTotalAssetsRatioMember2019-01-012019-12-310000895421us-gaap:CommercialPortfolioSegmentMember2020-12-310000895421ms:SecuredLendingFacilitiesMember2020-12-310000895421us-gaap:CommercialRealEstatePortfolioSegmentMember2020-12-310000895421us-gaap:ResidentialPortfolioSegmentMember2020-12-310000895421ms:SecuritiesBasedLendingandOtherLoansMember2020-12-310000895421us-gaap:CommercialPortfolioSegmentMember2019-12-310000895421ms:SecuredLendingFacilitiesMember2019-12-310000895421us-gaap:CommercialRealEstatePortfolioSegmentMember2019-12-310000895421us-gaap:ResidentialPortfolioSegmentMember2019-12-310000895421ms:SecuritiesBasedLendingandOtherLoansMember2019-12-310000895421ms:InvestmentGradeMemberus-gaap:CommercialPortfolioSegmentMember2020-12-310000895421ms:NoninvestmentGradeMemberus-gaap:CommercialPortfolioSegmentMember2020-12-310000895421ms:InvestmentGradeMemberms:SecuredLendingFacilitiesMember2020-12-310000895421ms:NoninvestmentGradeMemberms:SecuredLendingFacilitiesMember2020-12-310000895421ms:InvestmentGradeMemberus-gaap:CommercialRealEstatePortfolioSegmentMember2020-12-310000895421ms:NoninvestmentGradeMemberus-gaap:CommercialRealEstatePortfolioSegmentMember2020-12-310000895421us-gaap:ResidentialPortfolioSegmentMemberms:FICOScoreGreaterthanorEqualto740Member2020-12-310000895421ms:FICOScoreBetween680and739Memberus-gaap:ResidentialPortfolioSegmentMember2020-12-310000895421ms:FICOScoreLessthan680Memberus-gaap:ResidentialPortfolioSegmentMember2020-12-310000895421us-gaap:ResidentialPortfolioSegmentMemberms:DebttoValueRatioLessthanorEqualto80PercentMember2020-12-310000895421us-gaap:ResidentialPortfolioSegmentMemberms:DebttoValueRatioGreaterthan80PercentMember2020-12-310000895421ms:SecuritiesBasedLendingMember2020-12-310000895421ms:OtherLoansMemberms:InvestmentGradeMember2020-12-310000895421ms:OtherLoansMemberms:NoninvestmentGradeMember2020-12-310000895421us-gaap:CommercialPortfolioSegmentMemberus-gaap:FinancingReceivables1To29DaysPastDueMember2020-12-310000895421ms:FinancialAssetPastDueMinusCurrentMemberus-gaap:CommercialPortfolioSegmentMember2020-12-310000895421us-gaap:CommercialPortfolioSegmentMemberms:FinancialAssetPastDueMember2020-12-310000895421ms:SecuredLendingFacilitiesMemberus-gaap:FinancingReceivables1To29DaysPastDueMember2020-12-310000895421ms:FinancialAssetPastDueMinusCurrentMemberms:SecuredLendingFacilitiesMember2020-12-310000895421ms:SecuredLendingFacilitiesMemberms:FinancialAssetPastDueMember2020-12-310000895421us-gaap:CommercialRealEstatePortfolioSegmentMemberus-gaap:FinancingReceivables1To29DaysPastDueMember2020-12-310000895421ms:FinancialAssetPastDueMinusCurrentMemberus-gaap:CommercialRealEstatePortfolioSegmentMember2020-12-310000895421ms:FinancialAssetPastDueMemberus-gaap:CommercialRealEstatePortfolioSegmentMember2020-12-310000895421us-gaap:ResidentialPortfolioSegmentMemberus-gaap:FinancingReceivables1To29DaysPastDueMember2020-12-310000895421us-gaap:ResidentialPortfolioSegmentMemberms:FinancialAssetPastDueMinusCurrentMember2020-12-310000895421us-gaap:ResidentialPortfolioSegmentMemberms:FinancialAssetPastDueMember2020-12-310000895421ms:SecuritiesBasedLendingandOtherLoansMemberus-gaap:FinancingReceivables1To29DaysPastDueMember2020-12-310000895421ms:SecuritiesBasedLendingandOtherLoansMemberms:FinancialAssetPastDueMinusCurrentMember2020-12-310000895421ms:SecuritiesBasedLendingandOtherLoansMemberms:FinancialAssetPastDueMember2020-12-310000895421us-gaap:FinancingReceivables1To29DaysPastDueMember2020-12-310000895421ms:FinancialAssetPastDueMinusCurrentMember2020-12-310000895421ms:FinancialAssetPastDueMember2020-12-310000895421us-gaap:CommercialPortfolioSegmentMember2020-01-012020-12-310000895421ms:SecuredLendingFacilitiesMember2020-01-012020-12-310000895421us-gaap:CommercialRealEstatePortfolioSegmentMember2020-01-012020-12-310000895421us-gaap:ResidentialPortfolioSegmentMember2020-01-012020-12-310000895421ms:SecuritiesBasedLendingandOtherLoansMember2020-01-012020-12-310000895421us-gaap:CommercialPortfolioSegmentMember2018-12-310000895421ms:SecuredLendingFacilitiesMember2018-12-310000895421us-gaap:CommercialRealEstatePortfolioSegmentMember2018-12-310000895421us-gaap:ResidentialPortfolioSegmentMember2018-12-310000895421ms:SecuritiesBasedLendingandOtherLoansMember2018-12-310000895421us-gaap:CommercialPortfolioSegmentMember2019-01-012019-12-310000895421ms:SecuredLendingFacilitiesMember2019-01-012019-12-310000895421us-gaap:CommercialRealEstatePortfolioSegmentMember2019-01-012019-12-310000895421us-gaap:ResidentialPortfolioSegmentMember2019-01-012019-12-310000895421ms:SecuritiesBasedLendingandOtherLoansMember2019-01-012019-12-310000895421us-gaap:CommercialPortfolioSegmentMember2017-12-310000895421ms:SecuredLendingFacilitiesMember2017-12-310000895421us-gaap:CommercialRealEstatePortfolioSegmentMember2017-12-310000895421us-gaap:ResidentialPortfolioSegmentMember2017-12-310000895421ms:SecuritiesBasedLendingandOtherLoansMember2017-12-310000895421us-gaap:CommercialPortfolioSegmentMember2018-01-012018-12-310000895421ms:SecuredLendingFacilitiesMember2018-01-012018-12-310000895421us-gaap:CommercialRealEstatePortfolioSegmentMember2018-01-012018-12-310000895421us-gaap:ResidentialPortfolioSegmentMember2018-01-012018-12-310000895421ms:SecuritiesBasedLendingandOtherLoansMember2018-01-012018-12-310000895421ms:CurrentlyEmployedbytheFirmMember2020-12-310000895421ms:NoLongerEmployedbytheFirmMember2020-12-310000895421ms:InstitutionalSecuritiesSegmentMember2018-12-310000895421ms:GlobalWealthManagementGroupMember2018-12-310000895421ms:AssetManagementSegmentMember2018-12-310000895421ms:InstitutionalSecuritiesSegmentMember2019-01-012019-12-310000895421ms:GlobalWealthManagementGroupMember2019-01-012019-12-310000895421ms:AssetManagementSegmentMember2019-01-012019-12-310000895421ms:InstitutionalSecuritiesSegmentMember2019-12-310000895421ms:GlobalWealthManagementGroupMember2019-12-310000895421ms:AssetManagementSegmentMember2019-12-310000895421ms:InstitutionalSecuritiesSegmentMember2020-01-012020-12-310000895421ms:GlobalWealthManagementGroupMember2020-01-012020-12-310000895421ms:AssetManagementSegmentMember2020-01-012020-12-310000895421ms:InstitutionalSecuritiesSegmentMember2020-12-310000895421ms:GlobalWealthManagementGroupMember2020-12-310000895421ms:AssetManagementSegmentMember2020-12-310000895421us-gaap:TradeNamesMember2020-12-310000895421us-gaap:TradeNamesMember2019-12-310000895421us-gaap:CustomerRelationshipsMember2020-12-310000895421us-gaap:CustomerRelationshipsMember2019-12-310000895421us-gaap:EmploymentContractsMember2020-12-310000895421us-gaap:EmploymentContractsMember2019-12-310000895421us-gaap:OtherIntangibleAssetsMember2020-12-310000895421us-gaap:OtherIntangibleAssetsMember2019-12-310000895421ms:InvestmentManagementSegmentMember2020-12-310000895421ms:InvestmentManagementSegmentMember2019-12-310000895421ms:InvestmentManagementSegmentMember2020-01-012020-12-310000895421ms:InvestmentManagementSegmentMember2019-01-012019-12-310000895421ms:InvestmentManagementSegmentMember2018-01-012018-12-310000895421ms:InvestmentManagementSegmentMember2019-10-012019-12-310000895421ms:InvestmentManagementSegmentMember2018-10-012018-12-310000895421ms:MitsubishiUfjMorganStanleySecuritiesCoLtdMember2020-01-012020-12-310000895421ms:MitsubishiUfjMorganStanleySecuritiesCoLtdMember2019-01-012019-12-310000895421ms:MitsubishiUfjMorganStanleySecuritiesCoLtdMember2018-01-012018-12-310000895421ms:MorganStanleyMufgSecuritiesCoLtdMember2020-12-310000895421ms:MorganStanleyMufgSecuritiesCoLtdMemberms:MitsubishiUfjFinancialGroupIncMember2020-12-310000895421ms:MitsubishiUfjMorganStanleySecuritiesCoLtdMember2020-12-310000895421ms:MorganStanleyMufgSecuritiesCoLtdMemberms:InstitutionalSecuritiesSegmentMember2020-12-310000895421ms:LongTermDebtFixedRateMembersrt:ParentCompanyMember2020-12-310000895421ms:LongTermDebtVariableRateMembersrt:ParentCompanyMember2020-12-310000895421srt:SubsidiariesMemberms:LongTermDebtFixedRateMember2020-12-310000895421srt:SubsidiariesMemberms:LongTermDebtVariableRateMember2020-12-310000895421us-gaap:SeniorNotesMember2020-12-310000895421us-gaap:SeniorNotesMember2019-12-310000895421us-gaap:SubordinatedDebtMember2020-01-012020-12-310000895421us-gaap:SubordinatedDebtMember2019-01-012019-12-310000895421ms:FixedRateDebtMemberus-gaap:SecuredDebtMember2020-12-310000895421ms:VariableRateMemberus-gaap:SecuredDebtMember2020-12-310000895421us-gaap:SecuredDebtMember2020-12-310000895421us-gaap:SecuredDebtMember2019-12-310000895421us-gaap:CommercialLoanMember2020-12-310000895421ms:SecuredLendingFacilitiesMember2020-12-310000895421us-gaap:RealEstateMember2020-12-310000895421ms:SecuritiesBasedLendingandOtherLoansMember2020-12-310000895421ms:CommitmentsForwardStartingReverseRepurchaseAgreementsMember2020-12-310000895421ms:CentralCounterpartyCommitmentMember2020-12-310000895421ms:FirmCommitmentContractMember2020-12-310000895421ms:CommitmentsInvestmentActivitiesMember2020-12-310000895421ms:CommitmentsLettersOfCreditAndOtherFinancialGuaranteesObtainedToSatisfyCollateralRequirementsMember2020-12-310000895421ms:LessThanTwelveMonthsFromBalanceSheetDateMemberus-gaap:CreditRiskContractMember2020-12-310000895421us-gaap:CreditRiskContractMemberms:MoreThanOneAndWithinThreeYearsFromBalanceSheetDateMember2020-12-310000895421ms:MoreThanThreeAndWithinFiveYearsFromBalanceSheetDateMemberus-gaap:CreditRiskContractMember2020-12-310000895421ms:MoreThanFiveYearsFromBalanceSheetDateMemberus-gaap:CreditRiskContractMember2020-12-310000895421us-gaap:CreditRiskContractMember2020-12-310000895421us-gaap:OtherCreditDerivativesMemberms:LessThanTwelveMonthsFromBalanceSheetDateMember2020-12-310000895421us-gaap:OtherCreditDerivativesMemberms:MoreThanOneAndWithinThreeYearsFromBalanceSheetDateMember2020-12-310000895421us-gaap:OtherCreditDerivativesMemberms:MoreThanThreeAndWithinFiveYearsFromBalanceSheetDateMember2020-12-310000895421us-gaap:OtherCreditDerivativesMemberms:MoreThanFiveYearsFromBalanceSheetDateMember2020-12-310000895421us-gaap:OtherCreditDerivativesMember2020-12-310000895421ms:LessThanTwelveMonthsFromBalanceSheetDateMemberus-gaap:DerivativeMember2020-12-310000895421us-gaap:DerivativeMemberms:MoreThanOneAndWithinThreeYearsFromBalanceSheetDateMember2020-12-310000895421us-gaap:DerivativeMemberms:MoreThanThreeAndWithinFiveYearsFromBalanceSheetDateMember2020-12-310000895421us-gaap:DerivativeMemberms:MoreThanFiveYearsFromBalanceSheetDateMember2020-12-310000895421us-gaap:DerivativeMember2020-12-310000895421us-gaap:StandbyLettersOfCreditMemberms:LessThanTwelveMonthsFromBalanceSheetDateMember2020-12-310000895421us-gaap:StandbyLettersOfCreditMemberms:MoreThanOneAndWithinThreeYearsFromBalanceSheetDateMember2020-12-310000895421us-gaap:StandbyLettersOfCreditMemberms:MoreThanThreeAndWithinFiveYearsFromBalanceSheetDateMember2020-12-310000895421us-gaap:StandbyLettersOfCreditMemberms:MoreThanFiveYearsFromBalanceSheetDateMember2020-12-310000895421us-gaap:StandbyLettersOfCreditMember2020-12-310000895421ms:LessThanTwelveMonthsFromBalanceSheetDateMemberus-gaap:MarketValueGuaranteeMember2020-12-310000895421us-gaap:MarketValueGuaranteeMemberms:MoreThanOneAndWithinThreeYearsFromBalanceSheetDateMember2020-12-310000895421ms:MoreThanThreeAndWithinFiveYearsFromBalanceSheetDateMemberus-gaap:MarketValueGuaranteeMember2020-12-310000895421ms:MoreThanFiveYearsFromBalanceSheetDateMemberus-gaap:MarketValueGuaranteeMember2020-12-310000895421us-gaap:MarketValueGuaranteeMember2020-12-310000895421ms:LiquidityFacilitiesGuaranteeMemberms:LessThanTwelveMonthsFromBalanceSheetDateMember