Derivatives (Credit Derivatives) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Credit Derivatives [Line Items]
Estimated Fair Value of Credit Default Swaps	$ 228	$ 105
Maximum Amount of Future Payments under Credit Default Swaps	$ 12,468	$ 11,512
Weighted Average Years to Maturity	4 years 6 months	4 years 8 months 12 days
Aaa/Aa/A
Credit Derivatives [Line Items]
Estimated Fair Value of Credit Default Swaps	$ 82	$ 82
Maximum Amount of Future Payments under Credit Default Swaps	$ 3,980	$ 4,409
Weighted Average Years to Maturity	2 years 7 months 6 days	3 years 4 months 24 days
Aaa/Aa/A | Single name credit default swaps (3)
Credit Derivatives [Line Items]
Estimated Fair Value of Credit Default Swaps	$ 2	$ 3
Maximum Amount of Future Payments under Credit Default Swaps	$ 150	$ 158
Weighted Average Years to Maturity	1 year 7 months 6 days	2 years 2 months 12 days
Aaa/Aa/A | Credit default swaps referencing indices
Credit Derivatives [Line Items]
Estimated Fair Value of Credit Default Swaps	$ 80	$ 79
Maximum Amount of Future Payments under Credit Default Swaps	$ 3,830	$ 4,251
Weighted Average Years to Maturity	2 years 8 months 12 days	3 years 4 months 24 days
Baa
Credit Derivatives [Line Items]
Estimated Fair Value of Credit Default Swaps	$ 146	$ 29
Maximum Amount of Future Payments under Credit Default Swaps	$ 8,287	$ 6,856
Weighted Average Years to Maturity	5 years 3 months 18 days	5 years 6 months
Baa | Single name credit default swaps (3)
Credit Derivatives [Line Items]
Estimated Fair Value of Credit Default Swaps	$ 1	$ 1
Maximum Amount of Future Payments under Credit Default Swaps	$ 99	$ 81
Weighted Average Years to Maturity	2 years 1 month 6 days	2 years 6 months
Baa | Credit default swaps referencing indices
Credit Derivatives [Line Items]
Estimated Fair Value of Credit Default Swaps	$ 145	$ 28
Maximum Amount of Future Payments under Credit Default Swaps	$ 8,188	$ 6,775
Weighted Average Years to Maturity	5 years 4 months 24 days	5 years 7 months 6 days
Ba
Credit Derivatives [Line Items]
Estimated Fair Value of Credit Default Swaps	$ 2	$ 2
Maximum Amount of Future Payments under Credit Default Swaps	$ 42	$ 87
Weighted Average Years to Maturity	2 years 7 months 6 days	2 years 1 month 6 days
Ba | Single name credit default swaps (3)
Credit Derivatives [Line Items]
Estimated Fair Value of Credit Default Swaps	$ 0	$ 0
Maximum Amount of Future Payments under Credit Default Swaps	$ 17	$ 62
Weighted Average Years to Maturity	2 years 1 month 6 days	1 year 3 months 18 days
Ba | Credit default swaps referencing indices
Credit Derivatives [Line Items]
Estimated Fair Value of Credit Default Swaps	$ 2	$ 2
Maximum Amount of Future Payments under Credit Default Swaps	$ 25	$ 25
Weighted Average Years to Maturity	3 years	4 years
B [Member]
Credit Derivatives [Line Items]
Estimated Fair Value of Credit Default Swaps	$ 2	$ 2
Maximum Amount of Future Payments under Credit Default Swaps	$ 129	$ 130
Weighted Average Years to Maturity	5 years	4 years 8 months 12 days
B [Member] | Credit default swaps referencing indices
Credit Derivatives [Line Items]
Estimated Fair Value of Credit Default Swaps	$ 2	$ 2
Maximum Amount of Future Payments under Credit Default Swaps	$ 129	$ 130
Weighted Average Years to Maturity	5 years	4 years 8 months 12 days
Caa
Credit Derivatives [Line Items]
Estimated Fair Value of Credit Default Swaps	$ (4)	$ (10)
Maximum Amount of Future Payments under Credit Default Swaps	$ 30
Weighted Average Years to Maturity	2 years 6 months	3 years 6 months
Caa | Credit default swaps referencing indices
Credit Derivatives [Line Items]
Estimated Fair Value of Credit Default Swaps	$ (4)	$ (10)
Maximum Amount of Future Payments under Credit Default Swaps	$ 30	$ 30
Weighted Average Years to Maturity	2 years 6 months	3 years 6 months