Fair Value - Fair Value Inputs, Assets and Liabilities, Quantitative Information (Details) - Pricing Methods with Significant Unobservable Market Inputs (Level 3) $ in Millions	Jun. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)
Volatility | Option model | Derivative instruments, liabilities | Minimum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Derivative liability, measurement input	0.060
Volatility | Option model | Derivative instruments, liabilities | Maximum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Derivative liability, measurement input	0.153
Volatility | Option model | Derivative instruments, liabilities | Weighted-Average
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Derivative liability, measurement input	0.075	0.098
Volatility | Option model | Total derivative instruments | Minimum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Derivative asset, measurement input	0.056
Volatility | Option model | Total derivative instruments | Maximum
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Derivative asset, measurement input	0.184
Volatility | Option model | Total derivative instruments | Weighted-Average
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Derivative asset, measurement input	0.091	0.114
Significant unobservable inputs readily available to State Street:
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Total	$ 7	$ 4
Total liabilities carried at fair value	4	2
Significant unobservable inputs readily available to State Street: | Derivative instruments, liabilities
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Derivative instruments, foreign exchange contracts	4	2
Significant unobservable inputs readily available to State Street: | Total derivative instruments
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Derivative Instruments, foreign exchange contracts	$ 7	$ 4