Derivative Instruments (Cash Flow Hedges) (Details) - Cash Flow Hedging [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Derivatives Deferred In OCI	$ 115	$ 167	$ 125	$ 44
Investment Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Derivative Gains Losses Reclassified Into Income From AOCI	(18)	(20)	(54)	(42)
Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Derivative Gains Losses Reclassified Into Income From AOCI	(2)	(3)	(6)	(9)
Interest Rate Swaps
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Derivatives Deferred In OCI	12	57	40	33
Interest Rate Swaps | Investment Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Derivative Gains Losses Reclassified Into Income From AOCI	(1)	(3)	(3)	(9)
Interest Rate Swaps | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Derivative Gains Losses Reclassified Into Income From AOCI	(2)	(3)	(6)	(9)
Currency Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Derivatives Deferred In OCI	127	110	85	11
Currency Swap [Member] | Investment Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Derivative Gains Losses Reclassified Into Income From AOCI	(17)	(17)	(51)	(33)
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