Derivatives - Narrative (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Nov. 30, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Oct. 31, 2020
Derivative Instruments, Gain (Loss) [Line Items]
Collateral cash payables		$ 184	$ 347
Total trading revenues		360	371	$ 228
Term borrowings		1,590	1,670
Hedged amount of foreign currency denominated loans		7	12
Derivative asset		323	765
Derivative liabilities, other		103	125
Visa Class B Shares
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities related to sale		23	13
Derivative valuation adjustment		19
Additional Derivative Agreements | Derivative Instruments With Adjustable Collateral Posting Thresholds
Derivative Instruments, Gain (Loss) [Line Items]
Net fair value of derivative assets with adjustable posting thresholds		67	200
Net fair value of derivative liabilities with adjustable posting thresholds		26	5
Collateral received		205	320
Securities posted collateral		14	34
Additional Derivative Agreements | Derivative Instruments With Accelerated Termination Provisions
Derivative Instruments, Gain (Loss) [Line Items]
Net fair value of derivative assets with adjustable posting thresholds		74	216
Net fair value of derivative liabilities with adjustable posting thresholds		30	17
Collateral received		213	343
Securities posted collateral		18	53
Interest Rate Contract
Derivative Instruments, Gain (Loss) [Line Items]
Collateral cash payables		181	327
Derivative asset		311	702
Derivative liabilities, other		93	60
Credit Risk Contract
Derivative Instruments, Gain (Loss) [Line Items]
Derivative asset, notional amount		257	233
Derivative liability, notional amount		500	464
Embedded Derivative Financial Instruments
Derivative Instruments, Gain (Loss) [Line Items]
Derivative asset		1	1
Derivative liabilities, other		1	1
Counterparties
Derivative Instruments, Gain (Loss) [Line Items]
Collateral cash receivables		181	280
Collateral cash payables		$ 102	$ 166
Senior Subordinated Notes | Senior Debt Maturing In December 2020 | Long Term Debt Hedged With Fair Value Interest Rate Derivatives Using Long Haul Method
Derivative Instruments, Gain (Loss) [Line Items]
Term borrowings					$ 500
Debt redeemed	$ 500