Derivative Instruments (Fair Value Hedge Cumulative) (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Interest Rate Contract
Derivative Instruments, Gain (Loss) [Line Items]
Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease)	$ (16)	$ (11)
Hedged Liability, Discontinued Fair Value Hedge, Cumulative Increase (Decrease)	1	0
Fair Value Hedge Liabilities	(510)	(1,111)
Other Contract
Derivative Instruments, Gain (Loss) [Line Items]
Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease)	(8)	(7)
Hedged Liability, Discontinued Fair Value Hedge, Cumulative Increase (Decrease)	(3)	0
Fair Value Hedge Liabilities	$ (564)	$ (508)