Derivatives (Credit Derivatives) (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Credit Derivatives [Line Items]
Estimated Fair Value of Credit Default Swaps	$ (4)	$ 38
Maximum Amount of Future Payments under Credit Default Swaps	$ 1,869	$ 1,724
Weighted Average Years to Maturity (2)	4 years 1 month 6 days	4 years 1 month 6 days
Credit default swaps | Aaa/Aa/A
Credit Derivatives [Line Items]
Estimated Fair Value of Credit Default Swaps	$ 5	$ 12
Maximum Amount of Future Payments under Credit Default Swaps	$ 664	$ 589
Weighted Average Years to Maturity (2)	2 years 1 month 6 days	2 years 4 months 24 days
Credit default swaps | Baa
Credit Derivatives [Line Items]
Estimated Fair Value of Credit Default Swaps	$ (8)	$ 27
Maximum Amount of Future Payments under Credit Default Swaps	$ 1,177	$ 1,131
Weighted Average Years to Maturity (2)	5 years 2 months 12 days	5 years
Credit default swaps | Ba
Credit Derivatives [Line Items]
Estimated Fair Value of Credit Default Swaps	$ 1	$ 0
Maximum Amount of Future Payments under Credit Default Swaps	$ 24	$ 0
Weighted Average Years to Maturity (2)	4 years 2 months 12 days	0 years
Credit default swaps | Caa and Lower
Credit Derivatives [Line Items]
Estimated Fair Value of Credit Default Swaps	$ (2)	$ (1)
Maximum Amount of Future Payments under Credit Default Swaps	$ 4	$ 4
Weighted Average Years to Maturity (2)	3 years 2 months 12 days	4 years