Derivatives and Hedging Activities (Economic Derivatives) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives Not Designated as Hedging Instruments, Gain (Loss), Net	$ (51)	$ 8	$ (41)
Interest Rate Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives Not Designated as Hedging Instruments, Gain (Loss), Net	(69)	44	45
Forward Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives Not Designated as Hedging Instruments, Gain (Loss), Net	(4)	1	2
Net Interest Settlements [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives Not Designated as Hedging Instruments, Gain (Loss), Net	17	(37)	(52)
Derivatives Not Designated As Hedging Before Price Alignment
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives Not Designated as Hedging Instruments, Gain (Loss), Net	(52)	6	(9)
Price Alignment Amount
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives Not Designated as Hedging Instruments, Gain (Loss), Net	1	2	(32)
Mortgage Receivable [Member] | Forward Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives Not Designated as Hedging Instruments, Gain (Loss), Net	$ 4	$ (2)	$ (4)