Derivative Instruments (Cash Flow Hedges) (Details) - Cash Flow Hedging [Member] - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Derivatives Deferred In OCI	$ (4)	$ (125)	$ (10)	$ (211)
Investment Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Derivative Gains Losses Reclassified Into Income From AOCI	(18)	(14)	(36)	(22)
Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Derivative Gains Losses Reclassified Into Income From AOCI	(2)	(3)	(4)	(6)
Interest Rate Swaps
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Derivatives Deferred In OCI	(64)	(33)	(52)	(90)
Interest Rate Swaps | Investment Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Derivative Gains Losses Reclassified Into Income From AOCI	(1)	(3)	(2)	(6)
Interest Rate Swaps | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Derivative Gains Losses Reclassified Into Income From AOCI	(2)	(3)	(4)	(6)
Currency Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Derivatives Deferred In OCI	(60)	(92)	(42)	(121)
Currency Swap [Member] | Investment Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Derivative Gains Losses Reclassified Into Income From AOCI	(17)	(11)	(34)	(16)
Currency Swap [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Derivative Gains Losses Reclassified Into Income From AOCI	$ 0	$ 0	$ 0	$ 0