Derivative Instruments (Fair Value Hedge Attributable to Foreign Currency) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Foreign Exchange Contract | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	$ 0	$ 0	$ 0	$ 0
Gain (Loss) on Fair Value Hedge Ineffectiveness, Net	0	0	0	0
Foreign Exchange Contract | Insurance Claims [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	0	0	0	0
Gain (Loss) on Fair Value Hedge Ineffectiveness, Net	0	0	0	0
Foreign Exchange Contract | Investment Income (Expense)
Derivative Instruments, Gain (Loss) [Line Items]
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	3	0	2	(3)
Gain (Loss) on Fair Value Hedge Ineffectiveness, Net	(4)	0	(4)	2
Interest Rate Contract | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	(3)	0	(5)	0
Gain (Loss) on Fair Value Hedge Ineffectiveness, Net	1	0	2	0
Interest Rate Contract | Insurance Claims [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	0	0	0	0
Gain (Loss) on Fair Value Hedge Ineffectiveness, Net	0	0	0	0
Interest Rate Contract | Investment Income (Expense)
Derivative Instruments, Gain (Loss) [Line Items]
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	0	0	0	0
Gain (Loss) on Fair Value Hedge Ineffectiveness, Net	0	$ 0	0	$ 0
Financial Futures | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	0		0
Gain (Loss) on Fair Value Hedge Ineffectiveness, Net	0		0
Financial Futures | Insurance Claims [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	(4)		(4)
Gain (Loss) on Fair Value Hedge Ineffectiveness, Net	2		2
Financial Futures | Investment Income (Expense)
Derivative Instruments, Gain (Loss) [Line Items]
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	0		0
Gain (Loss) on Fair Value Hedge Ineffectiveness, Net	$ 0		$ 0