Derivative Instruments (Exposure from Credit Derivatives by Rating of the Underlying Credits) (Details) - USD ($) $ in Millions		3 Months Ended	6 Months Ended
		Mar. 31, 2024	Jun. 30, 2024	Dec. 31, 2023
Credit Derivatives [Line Items]
Credit Derivative Current Fair Value	[1]		$ 1	$ 4
Maximum Potential Future Exposure on Credit Risk Derivatives	[1],[2]		$ 2,373	1,475
Derivative Average Remaining Maturity	[1],[3]	8 years 6 months	6 years 4 months 24 days
Standard Poors AAA To A Minus Ratings [Member] | Single Name Credit Default Swaps [Member]
Credit Derivatives [Line Items]
Credit Derivative Current Fair Value	[1]		$ (2)	2
Maximum Potential Future Exposure on Credit Risk Derivatives	[1],[2]		$ 410	420
Derivative Average Remaining Maturity	[1],[3]	18 years 1 month 6 days	18 years
Standard Poors BBB Rating [Member] | Single Name Credit Default Swaps [Member]
Credit Derivatives [Line Items]
Credit Derivative Current Fair Value	[1]		$ 4	4
Maximum Potential Future Exposure on Credit Risk Derivatives	[1],[2]		$ 145	165
Derivative Average Remaining Maturity	[1],[3]	2 years 9 months 18 days	2 years 7 months 6 days
Standard Poors BBB Rating [Member] | Credit Default Swaps Referencing Indices [Member]
Credit Derivatives [Line Items]
Credit Derivative Current Fair Value	[1]		$ (1)	(1)
Maximum Potential Future Exposure on Credit Risk Derivatives	[1],[2]		$ 1,803	880
Derivative Average Remaining Maturity	[1],[3]	5 years	4 years 2 months 12 days
Standard Poors BBB Rating [Member] | Credit Default Subtotal [Member]
Credit Derivatives [Line Items]
Credit Derivative Current Fair Value	[1]		$ 3	3
Maximum Potential Future Exposure on Credit Risk Derivatives	[1],[2]		$ 1,948	1,045
Derivative Average Remaining Maturity	[1],[3]	4 years 8 months 12 days	4 years
Standard & Poor's, BB Rating [Member]
Credit Derivatives [Line Items]
Derivative Average Remaining Maturity	[1],[2]	2 years 2 months 12 days	2 years
Standard & Poor's, BB Rating [Member] | Single Name Credit Default Swaps [Member]
Credit Derivatives [Line Items]
Credit Derivative Current Fair Value	[1]		$ 0	(1)
Maximum Potential Future Exposure on Credit Risk Derivatives	[1],[2]		$ 5	10
Standard & Poor's, B Rating
Credit Derivatives [Line Items]
Derivative Average Remaining Maturity	[3]	0 years	1 year 8 months 12 days
Standard & Poor's, B Rating | Single Name Credit Default Swaps [Member]
Credit Derivatives [Line Items]
Credit Derivative Current Fair Value	[1]		$ 0	0
Maximum Potential Future Exposure on Credit Risk Derivatives	[2]		$ 10	$ 0

[1] The rating agency designations are based on ratings from Standard and Poor’s (“S&P”).

[2] Assumes the value of the referenced credit obligations is zero.

[3] The weighted average years to maturity of the credit default swaps is calculated based on weighted average notional amounts.