Investments (Amortized Cost and Fair Value of Fixed Maturity Holdings by Industry Type) (Details) - USD ($) $ in Millions	Dec. 31, 2022		Dec. 31, 2021
Corporate Secturities by Investment Sector And Credit Rating [Line Items]
Available for Sale at Fair value - Amortized cost	$ 59,663		$ 55,873
Fixed maturity securities available-for-sale at fair value (amortized cost of $59,663 and $55,873; allowance for credit losses of $37 and $31)	52,901	[1]	60,749	[2]
Corporate Debt Securities [Member]
Corporate Secturities by Investment Sector And Credit Rating [Line Items]
Available for Sale at Fair value - Amortized cost	38,963		35,239
Fixed maturity securities available-for-sale at fair value (amortized cost of $59,663 and $55,873; allowance for credit losses of $37 and $31)	$ 33,969	[1]	$ 38,103	[2]
Percentage Of Total Available For Sales Securities	100.00%		100.00%
Financial Services Sector [Member] | Corporate Debt Securities [Member]
Corporate Secturities by Investment Sector And Credit Rating [Line Items]
Available for Sale at Fair value - Amortized cost	$ 14,551		$ 13,101
Fixed maturity securities available-for-sale at fair value (amortized cost of $59,663 and $55,873; allowance for credit losses of $37 and $31)	$ 12,680		$ 14,045
Percentage Of Total Available For Sales Securities	37.30%		36.90%
Commercial and Industrial Sector [Member] | Corporate Debt Securities [Member]
Corporate Secturities by Investment Sector And Credit Rating [Line Items]
Available for Sale at Fair value - Amortized cost	$ 19,624		$ 17,857
Fixed maturity securities available-for-sale at fair value (amortized cost of $59,663 and $55,873; allowance for credit losses of $37 and $31)	$ 17,257		$ 19,375
Percentage Of Total Available For Sales Securities	50.80%		50.80%
Utility Industry [Member] | Corporate Debt Securities [Member]
Corporate Secturities by Investment Sector And Credit Rating [Line Items]
Available for Sale at Fair value - Amortized cost	$ 4,788		$ 4,281
Fixed maturity securities available-for-sale at fair value (amortized cost of $59,663 and $55,873; allowance for credit losses of $37 and $31)	$ 4,032		$ 4,683
Percentage Of Total Available For Sales Securities	11.90%		12.30%

[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 December 31, 2022, the fair value of such investments was $683 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, 2021, the fair value of such investments was $581 million.