Investments (Amortized Cost and Fair Value of Fixed Maturity Holdings by Industry Type) (Details) - USD ($) $ in Millions	Mar. 31, 2024		Dec. 31, 2023
Corporate Securities by Investment Sector And Credit Rating [Line Items]
Amortized Cost	$ 70,790		$ 64,977
Fixed maturity securities, available-for-sale	65,827	[1]	60,467	[2]
Corporate Debt Securities [Member]
Corporate Securities by Investment Sector And Credit Rating [Line Items]
Amortized Cost	44,575		42,014
Fixed maturity securities, available-for-sale	$ 41,048	[1]	$ 38,755	[2]
% of Total	100.00%		100.00%
Corporate Debt Securities [Member] | Finance
Corporate Securities by Investment Sector And Credit Rating [Line Items]
Amortized Cost	$ 15,788		$ 15,052
Fixed maturity securities, available-for-sale	$ 14,526		$ 13,789
% of Total	35.40%		35.60%
Corporate Debt Securities [Member] | Industrial
Corporate Securities by Investment Sector And Credit Rating [Line Items]
Amortized Cost	$ 22,606		$ 21,413
Fixed maturity securities, available-for-sale	$ 20,946		$ 19,935
% of Total	51.00%		51.40%
Corporate Debt Securities [Member] | Utility
Corporate Securities by Investment Sector And Credit Rating [Line Items]
Amortized Cost	$ 6,181		$ 5,549
Fixed maturity securities, available-for-sale	$ 5,576		$ 5,031
% of Total	13.60%		13.00%

[1] Excludes limited partnerships that are measured at estimated fair value using the NAV per share (or its equivalent) as a practical expedient. As of March 31, 2024, the fair value of such investments was $893 million.

[2] Excludes limited partnerships that are measured at estimated fair value using the NAV per share (or its equivalent) as a practical expedient. As of December 31, 2023, the fair value of such investments was $856 million