Derivatives - Gains/(Losses) on Derivatives Associated with Interest Rate Risk Management Activities (Details) - Customer Interest Rate Contracts Hedging  - Hedging Instruments and Hedged Items:  - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Customer interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gains (Losses)	$ (21)	$ 111
Offsetting upstream interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gains (Losses)	$ 21	$ (111)