Investments (Amortized Cost and Fair Value of Fixed Maturity Holdings by Industry Type) (Details) - USD ($) $ in Millions	Mar. 31, 2023		Dec. 31, 2022
Corporate Securities by Investment Sector And Credit Rating [Line Items]
Amortized Cost	$ 61,494		$ 59,663
Fixed maturity securities, available-for-sale	56,085	[1]	52,901	[2]
Corporate Debt Securities [Member]
Corporate Securities by Investment Sector And Credit Rating [Line Items]
Amortized Cost	39,621		38,963
Fixed maturity securities, available-for-sale	$ 35,477	[1]	$ 33,969	[2]
% of Total	100.00%		100.00%
Corporate Debt Securities [Member] | Finance
Corporate Securities by Investment Sector And Credit Rating [Line Items]
Amortized Cost	$ 14,732		$ 14,551
Fixed maturity securities, available-for-sale	$ 13,043		$ 12,680
% of Total	36.80%		37.30%
Corporate Debt Securities [Member] | Industrial
Corporate Securities by Investment Sector And Credit Rating [Line Items]
Amortized Cost	$ 19,945		$ 19,624
Fixed maturity securities, available-for-sale	$ 18,108		$ 17,257
% of Total	51.00%		50.80%
Corporate Debt Securities [Member] | Utility
Corporate Securities by Investment Sector And Credit Rating [Line Items]
Amortized Cost	$ 4,944		$ 4,788
Fixed maturity securities, available-for-sale	$ 4,326		$ 4,032
% of Total	12.20%		11.90%

[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, 2023, the fair value of such investments was $726 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, 2022, the fair value of such investments was $683 million