Variable Interest Entities and Securitization Activities - Transferred Assets with Continuing Involvement (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Variable Interest Entity
Derivative assets	$ 66,250	$ 38,154
Derivative liabilities	48,262	34,568
SPE
Variable Interest Entity
Interests purchased in the secondary market	348	264
Derivative assets	1,259	891
Derivative liabilities	282	284
SPE \| Investment grade
Variable Interest Entity
Interests purchased in the secondary market	259	169
SPE \| Non-investment grade
Variable Interest Entity
Interests purchased in the secondary market	89	95
SPE \| RML
Variable Interest Entity
SPE assets (UPB)	9,395	6,802
Retained interests	135	91
Interests purchased in the secondary market	76	56
Derivative assets	0	0
Derivative liabilities	0	0
SPE \| RML \| Investment grade
Variable Interest Entity
Retained interests	111	72
Interests purchased in the secondary market	33	18
SPE \| RML \| Non-investment grade
Variable Interest Entity
Retained interests	24	19
Interests purchased in the secondary market	43	38
SPE \| CML
Variable Interest Entity
SPE assets (UPB)	92,284	94,276
Retained interests	1,434	1,224
Interests purchased in the secondary market	227	171
Derivative assets	0	0
Derivative liabilities	0	0
SPE \| CML \| Investment grade
Variable Interest Entity
Retained interests	930	638
Interests purchased in the secondary market	181	118
SPE \| CML \| Non-investment grade
Variable Interest Entity
Retained interests	504	586
Interests purchased in the secondary market	46	53
SPE \| U.S. Agency CMO
Variable Interest Entity
SPE assets (UPB)	17,854	28,697
Retained interests	290	465
Interests purchased in the secondary market	45	33
Derivative assets	0	0
Derivative liabilities	0	0
SPE \| U.S. Agency CMO \| Investment grade
Variable Interest Entity
Retained interests	279	465
Interests purchased in the secondary market	45	33
SPE \| U.S. Agency CMO \| Non-investment grade
Variable Interest Entity
Retained interests	11	0
Interests purchased in the secondary market	0	0
SPE \| CLN and Other
Variable Interest Entity
SPE assets (UPB)	10,775	13,121
Retained interests	45	69
Interests purchased in the secondary market	0	4
Derivative assets	1,259	891
Derivative liabilities	282	284
SPE \| CLN and Other \| Investment grade
Variable Interest Entity
Retained interests	0	0
Interests purchased in the secondary market	0	0
SPE \| CLN and Other \| Non-investment grade
Variable Interest Entity
Retained interests	45	69
Interests purchased in the secondary market	$ 0	$ 4

Fair value of interests purchased in the secondary market

No definition available.

Name:	ms_InterestsPurchasedInSecondaryMarketFairValue
Namespace Prefix:	ms_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The carrying value of an interest continued to be held by the transferor in a securitized financial instrument.

+ References

No definition available.

+ Details

Name:	ms_RetainedInterest
Namespace Prefix:	ms_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Principal amount of transferred financial assets in which the transferor has continuing involvement with the assets underlying the transaction. Continuing involvement includes, but is not limited to, servicing, recourse, and restrictions on transferor's interests in transferred financial assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)(1)
-URI https://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719

+ Details

Name:	us-gaap_ContinuingInvolvementWithTransferredFinancialAssetsPrincipalAmountOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 10
-URI https://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 22
-URI https://asc.fasb.org/extlink&oid=99393222&loc=SL20226052-175313

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI https://asc.fasb.org/extlink&oid=123594938&loc=d3e13433-108611

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

+ Details

Name:	us-gaap_DerivativeAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 10
-URI https://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI https://asc.fasb.org/extlink&oid=123594938&loc=d3e13433-108611

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 22
-URI https://asc.fasb.org/extlink&oid=99393222&loc=SL20226052-175313

+ Details

Name:	us-gaap_DerivativeLiabilities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_VariableInterestEntityLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	ms_QualifyingSpecialPurposeEntityClassificationAxis=ms_SpecialPurposeEntitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_InternalInvestmentGradeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_InternalNoninvestmentGradeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_ResidentialMortgageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CommercialMortgageBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=ms_CreditLinkedNotesAndOtherMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: