Investments (Maturities of Fixed Maturity Securities) (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Amortized cost, due in one year or less	$ 3,788
Amortized cost, due after one year through five years	18,698
Amortized cost, due after five years through ten years	14,088
Amortized cost, due after ten years	29,459
Amortized cost, Structured Securities	22,143
Fixed maturity securities, amortized cost	88,176	$ 87,131
Estimated fair value, due in one year or less	3,746
Estimated fair value, due after one year through five years	18,050
Estimated fair value, due after five years through ten years	12,715
Estimated fair value, due after ten years	25,431
Estimated fair value, Structured Securities	20,639
Fixed maturity securities, estimated fair value	$ 80,581	$ 80,991