Other Assets - Net Benefits Attributable to Tax Equity Investments under the Proportional Amortization Method (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2024	Mar. 31, 2023
Equity Method Investments and Joint Ventures [Abstract]
Income tax credits and other income tax benefits	$ 75	$ 71
Proportional amortization	(60)	(49)
Net benefits	$ 15	$ 22

Amount, after amortization expense, of income tax credit and other income tax benefit generated by investment under tax credit program elected to be accounted for using proportional amortization method. Includes, but is not limited to, investment under tax credit program not meeting condition for accounting under proportional amortization method.

No definition available.

Name:	ms_InvestmentProgramProportionalAmortizationMethodElectedIncomeTaxCreditAndOtherIncomeTaxBenefitAfterAmortizationExpense
Namespace Prefix:	ms_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration