Derivatives - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Derivative Instruments, Gain (Loss) [Line Items]
Collateral cash payables	$ 533		$ 533		$ 489
Total trading revenues	31	$ 22	75	$ 49
Hedged amount of foreign currency denominated loans	9		9		17
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	3		3		12
Net fair value of derivative liabilities with adjustable posting thresholds	227		227		188
Collateral received	80		80		95
Securities posted collateral	105		105		83
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	4		4		12
Net fair value of derivative liabilities with adjustable posting thresholds	227		227		188
Collateral received	81		81		95
Securities posted collateral	105		105		83
Credit Risk Contract
Derivative Instruments, Gain (Loss) [Line Items]
Derivative asset, notional amount	368		368		351
Derivative liability, notional amount	894		894		874
Visa Class B Shares
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities related to sale	18		18		23
Derivative valuation adjustment					15
Counterparties
Derivative Instruments, Gain (Loss) [Line Items]
Collateral cash receivables	648		648		406
Collateral cash payables	$ 22		$ 22		$ 33