Investments (Maturities of Fixed Maturity Securities) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Amortized cost, due in one year or less	$ 2,725
Amortized cost, due after one year through five years	17,064
Amortized cost, due after five years through ten years	15,000
Amortized cost, due after ten years	29,764
Amortized cost, Structured Securities	21,576
Fixed maturity securities, amortized cost	86,129	$ 83,395
Estimated fair value, due in one year or less	2,691
Estimated fair value, due after one year through five years	16,611
Estimated fair value, due after five years through ten years	13,764
Estimated fair value, due after ten years	26,913
Estimated fair value, Structured Securities	20,106
Fixed maturity securities available-for-sale, at estimated fair value (amortized cost: $73,144 and $71,285, respectively; allowance for credit losses of $20 and $4, respectively)	$ 80,085	$ 74,757