Investments (Maturities of Fixed Maturity Securities) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Amortized cost, due in one year or less	$ 937
Amortized cost, due after one year through five years	9,895
Amortized cost, due after five years through ten years	16,691
Amortized cost, due after ten years	30,781
Amortized cost, Structured Securities	19,983
Fixed maturity securities, amortized cost	78,287	$ 69,483
Estimated fair value, due in one year or less	951
Estimated fair value, due after one year through five years	10,276
Estimated fair value, due after five years through ten years	17,642
Estimated fair value, due after ten years	36,970
Estimated fair value, Structured Securities	20,688
Fixed maturity securities, estimated fair value	$ 86,527	$ 81,299