Segment, Geographic and Revenue Information - Investment Management Asset Management Revenues - Reduction of Fees due to Fee Waivers (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Segment Reporting [Abstract]
Fee waivers	$ 124	$ 94

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