Derivatives - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Derivative Instruments, Gain (Loss) [Line Items]
Collateral cash payables	$ 334		$ 440
Total trading revenues	36	$ 45
Hedged amount of foreign currency denominated loans	10		16
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	9		5
Net fair value of derivative liabilities with adjustable posting thresholds	138		187
Collateral received	67		82
Securities posted collateral	81		96
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	9		6
Net fair value of derivative liabilities with adjustable posting thresholds	138		187
Collateral received	67		82
Securities posted collateral	81		96
Credit Risk Contract
Derivative Instruments, Gain (Loss) [Line Items]
Derivative asset, notional amount	224		268
Derivative liability, notional amount	884		916
Visa Class B Shares
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities related to sale	18		15
Derivative valuation adjustment	5		15
Counterparties
Derivative Instruments, Gain (Loss) [Line Items]
Collateral cash receivables	404		541
Collateral cash payables	$ 17		$ 25