Variable Interest Entities and Securitization Activities - Proceeds from New Securitization Transactions (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2026	Mar. 31, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Variable Interest Entities and Securitization Activities [Abstract]
New transactions	$ 14,775		$ 12,136	$ 26,740	$ 26,446
Retained interests	$ 159		2,461	$ 290	5,240
Interests in securitization transactions sold		$ 3,400	$ 91		$ 180

Cash Flows Between Transferor and Transferee, Receipts on Transferor's Interest in Transferred Financial Assets, Interests In Securitization Transactions Sold

No definition available.

+ Details

Name:	ms_CashFlowsBetweenTransferorAndTransfereeReceiptsOnTransferorsInterestInTransferredFinancialAssetsInterestsInSecuritizationTransactionsSold
Namespace Prefix:	ms_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- References

No definition available.

+ Details

Name:	ms_VariableInterestEntitiesAndSecuritizationActivitiesAbstract
Namespace Prefix:	ms_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Cash Flows between a transferor and a transferee attributable to newly transferred assets related to either a securitization, asset-backed financing arrangement, or similar transfer in which the transferor has continuing involvement with the transferred financial assets underlying the transaction (including, but not limited to, servicing, recourse, and restrictions on transferor's interests in the transferred financial assets).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (d)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481326/860-20-50-3

+ Details

Name:	us-gaap_CashFlowsBetweenTransfereeAndTransferorProceedsFromNewTransfers
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Cash flows between transferor and a transferee attributable to the transferor's interests related to a securitization, asset-backed financing arrangement, or similar transfer in which the transferor will have continuing involvement with the transferred financial assets underlying the transaction (including, but not limited to, servicing, recourse, and restrictions on transferor's interests in the transferred financial assets).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (d)(5)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481326/860-20-50-3

+ Details

Name:	us-gaap_CashFlowsBetweenTransfereeAndTransferorReceiptsOnInterestsThatContinueToBeHeldOther
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration