Segment, Geographic and Revenue Information - Revenue Recognized from Prior Services (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2026	Mar. 31, 2025
Segment Reporting [Abstract]
Non-interest revenues	$ 924	$ 595

Revenue recognized in the reporting period from performance obligations satisfied (or partially satisfied) in previous periods.

No definition available.

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