Commitments and Guarantees - Contractual Amounts of Credit-Related Off-Balance Sheet Financial Instruments (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Unfunded credit facilities	$ 34,191	$ 34,197
Indemnified securities financing	310,814	279,916
Standby letters of credit	$ 908	$ 1,510

Aggregate Fair Value Of Indemnified Securities On Loan

No definition available.

Name:	stt_AggregateFairValueOfIndemnifiedSecuritiesOnLoan
Namespace Prefix:	stt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant