Investments (Maturities of Fixed Maturity Securities) (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Amortized cost, due in one year or less	$ 916
Amortized cost, due after one year through five years	11,564
Amortized cost, due after five years through ten years	16,844
Amortized cost, due after ten years	30,524
Amortized cost, Structured Securities	20,399
Fixed maturity securities, amortized cost	80,247	$ 78,287
Estimated fair value, due in one year or less	921
Estimated fair value, due after one year through five years	11,478
Estimated fair value, due after five years through ten years	16,493
Estimated fair value, due after ten years	32,520
Estimated fair value, Structured Securities	20,090
Fixed maturity securities, estimated fair value	$ 81,502	$ 86,527