Derivative Financial Instruments - Total Notional or Contractual Amounts, Fair Value, Collateral and Net Exposure of Derivative Financial Instruments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Derivative [Line Items]
Fair Value, Derivative Assets	$ 288	$ 285
Fair Value, Derivative Liabilities	238	237
Total Derivative Assets, Fair Value	565	488
Total Derivative Liabilities, Fair Value	238	237
Interest rate swaps
Derivative [Line Items]
Fair Value, Derivative Assets	18	0
Fair Value, Derivative Liabilities	0	0
Foreign exchange forwards
Derivative [Line Items]
Fair Value, Derivative Assets	162	215
Fair Value, Derivative Liabilities	128	208
Client foreign currency options
Derivative [Line Items]
Fair Value, Derivative Assets	9	2
Fair Value, Derivative Liabilities	9	2
Client interest rate derivatives
Derivative [Line Items]
Fair Value, Derivative Assets	99	68
Fair Value, Derivative Liabilities	101	27
Derivatives designated as hedging instruments | Interest rate swaps | Other assets
Derivative [Line Items]
Derivative Assets, Notional or Contractual Amount	10,700	0
Fair Value, Derivative Assets	18	0
Increase (decrease) of variation margin treated as settlement of the related derivative fair values as required by central clearing houses	(112)
Derivatives designated as hedging instruments | Interest rate swaps | Other liability
Derivative [Line Items]
Derivative Liabilities, Notional or Contractual Amount	0	0
Fair Value, Derivative Liabilities	0	0
Derivatives not designated as hedging instruments
Derivative [Line Items]
Fair Value, Derivative Assets	547	488
Fair Value, Derivative Liabilities	238	237
Derivatives not designated as hedging instruments | Foreign exchange forwards | Other assets
Derivative [Line Items]
Derivative Assets, Notional or Contractual Amount	701	68
Fair Value, Derivative Assets	16	0
Derivatives not designated as hedging instruments | Foreign exchange forwards | Other liability
Derivative [Line Items]
Derivative Liabilities, Notional or Contractual Amount	62	567
Fair Value, Derivative Liabilities	2	20
Derivatives not designated as hedging instruments | Equity warrant assets | Other assets
Derivative [Line Items]
Derivative Assets, Notional or Contractual Amount	322	253
Fair Value, Derivative Assets	277	203
Derivatives not designated as hedging instruments | Client foreign exchange forwards | Other assets
Derivative [Line Items]
Derivative Assets, Notional or Contractual Amount	8,245	8,026
Fair Value, Derivative Assets	146	215
Derivatives not designated as hedging instruments | Client foreign exchange forwards | Other liability
Derivative [Line Items]
Derivative Liabilities, Notional or Contractual Amount	7,764	7,491
Fair Value, Derivative Liabilities	126	188
Derivatives not designated as hedging instruments | Client foreign currency options | Other assets
Derivative [Line Items]
Derivative Assets, Notional or Contractual Amount	688	98
Fair Value, Derivative Assets	9	2
Derivatives not designated as hedging instruments | Client foreign currency options | Other liability
Derivative [Line Items]
Derivative Liabilities, Notional or Contractual Amount	688	98
Fair Value, Derivative Liabilities	9	2
Derivatives not designated as hedging instruments | Client interest rate derivatives | Other assets
Derivative [Line Items]
Derivative Assets, Notional or Contractual Amount	2,178	1,082
Fair Value, Derivative Assets	99	68
Derivatives not designated as hedging instruments | Client interest rate derivatives | Other liability
Derivative [Line Items]
Derivative Liabilities, Notional or Contractual Amount	2,315	1,251
Fair Value, Derivative Liabilities	$ 101	27
Increase (decrease) of variation margin treated as settlement of the related derivative fair values as required by central clearing houses		$ (45)