Investments (Maturities of Fixed Maturity Securities) (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Available-for-sale Securities, Debt Maturities [Abstract]
Amortized Cost, Due in one year or less	$ 10,447
Amortized Cost, Due after one year through five years	48,816
Amortized Cost, Due after five years through ten years	52,088
Amortized Cost, Due after ten years	127,103
Amortized Cost, Structured Securities	62,056
Amortized Cost, net of ACL	300,510
Estimated Fair Value, Due in one year or less	10,498
Estimated Fair Value, Due after one year through five years	48,055
Estimated Fair Value, Due after five years through ten years	50,283
Estimated Fair Value, Due after ten years	111,325
Estimated Fair Value, Structured Securities	58,248
Estimated Fair Value of Fixed Maturity Securities AFS	$ 278,409	$ 281,412