Deferred Compensation Plans and Carried Interest Compensation - Carried Interest Compensation Expense (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Compensation Related Costs [Abstract]
Carried interest compensation expense	$ 346	$ 215	$ 534

Deferred Compensation Arrangement with Individual, Return on Referenced Investments, Carried Interest

No definition available.

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