Investments (Maturities of Fixed Maturity Securities) (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Amortized cost, due in one year or less	$ 1,010
Amortized cost, due after one year through five years	13,547
Amortized cost, due after five years through ten years	16,818
Amortized cost, due after ten years	30,750
Amortized cost, Structured Securities	21,270
Fixed maturity securities, amortized cost	83,395	$ 78,287
Estimated fair value, due in one year or less	996
Estimated fair value, due after one year through five years	12,836
Estimated fair value, due after five years through ten years	14,853
Estimated fair value, due after ten years	26,689
Estimated fair value, Structured Securities	19,383
Fixed maturity securities, estimated fair value	$ 74,757	$ 86,527