Segment, Geographic and Revenue Information - Investment Management Asset Management Revenues - Reduction of Fees due to Fee Waivers (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Segment Reporting [Abstract]
Fee waivers	$ 41	$ 131	$ 165	$ 225

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