Commitments and Guarantees - Contractual Amounts of Credit-Related Off-Balance Sheet Financial Instruments (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Unfunded credit facilities	$ 34,149	$ 31,208
Indemnified securities financing	269,180	348,924
Standby letters of credit	$ 1,527	$ 2,125

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