Derivative Financial Instruments - Total Notional or Contractual Amounts, Fair Value, Collateral and Net Exposure of Derivative Financial Instruments (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Derivative [Line Items]
Derivative Assets	$ 377	$ 288
Derivative Liabilities	424	238
Derivative Assets, Total	705	565
Derivative Liabilities, Total	424	238
Reduction in derivative liabilities due to rules of clearing houses	400	112
Interest rate swaps
Derivative [Line Items]
Derivative Assets		18
Foreign exchange contracts
Derivative [Line Items]
Derivative Assets	272	162
Derivative Liabilities	263	128
Client foreign currency options
Derivative [Line Items]
Derivative Assets	8	9
Derivative Liabilities	8	9
Client interest rate derivatives
Derivative [Line Items]
Derivative Assets	70	99
Derivative Liabilities	153	101
Total return swaps
Derivative [Line Items]
Derivative Assets	27
Derivatives designated as hedging instruments | Interest rate swaps | Other assets
Derivative [Line Items]
Derivative Asset, Notional or Contractual Amount	5,900	10,700
Derivative Assets	0	18
Derivatives not designated as hedging instruments
Derivative [Line Items]
Derivative Assets	705	547
Derivative Liabilities	424	238
Derivatives not designated as hedging instruments | Foreign exchange contracts | Other assets
Derivative [Line Items]
Derivative Asset, Notional or Contractual Amount	543	701
Derivative Assets	23	16
Derivatives not designated as hedging instruments | Foreign exchange contracts | Other liabilities
Derivative [Line Items]
Derivative Liabilities, Notional or Contractual Amount	186	62
Derivative Liabilities	9	2
Derivatives not designated as hedging instruments | Equity warrant assets | Other assets
Derivative [Line Items]
Derivative Asset, Notional or Contractual Amount	335	322
Derivative Assets	322	277
Derivatives not designated as hedging instruments | Contingent conversion rights | Other assets
Derivative [Line Items]
Derivative Asset, Notional or Contractual Amount	50
Derivative Assets	6
Derivatives not designated as hedging instruments | Client foreign exchange contracts | Other assets
Derivative [Line Items]
Derivative Asset, Notional or Contractual Amount	9,469	8,245
Derivative Assets	249	146
Derivatives not designated as hedging instruments | Client foreign exchange contracts | Other liabilities
Derivative [Line Items]
Derivative Liabilities, Notional or Contractual Amount	8,940	7,764
Derivative Liabilities	254	126
Derivatives not designated as hedging instruments | Client foreign currency options | Other assets
Derivative [Line Items]
Derivative Asset, Notional or Contractual Amount	298	688
Derivative Assets	8	9
Derivatives not designated as hedging instruments | Client foreign currency options | Other liabilities
Derivative [Line Items]
Derivative Liabilities, Notional or Contractual Amount	298	688
Derivative Liabilities	8	9
Derivatives not designated as hedging instruments | Client interest rate derivatives | Other assets
Derivative [Line Items]
Derivative Asset, Notional or Contractual Amount	2,167	2,178
Derivative Assets	70	99
Derivatives not designated as hedging instruments | Client interest rate derivatives | Other liabilities
Derivative [Line Items]
Derivative Liabilities, Notional or Contractual Amount	2,369	2,315
Derivative Liabilities	153	101
Derivatives not designated as hedging instruments | Total return swaps | Other assets
Derivative [Line Items]
Derivative Assets	27	0
Derivatives not designated as hedging instruments | Total return swaps | Other liabilities
Derivative [Line Items]
Derivative Liabilities, Notional or Contractual Amount	$ 80	$ 0