Segment, Geographic and Revenue Information - Investment Management Asset Management Revenues - Reduction of Fees due to Fee Waivers (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting [Abstract]
Fee waivers	$ 516	$ 135	$ 43

Amount of fee waived by investment company to comply with regulatory requirements.

No definition available.

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