Investments (Details) - Contractual Maturities - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Investments [Abstract]
Fixed maturities, due in one year or less, amortized cost	$ 7,357
Fixed maturities, due after 1 year through 5 years, amortized cost	23,640
Fixed maturities, due after 5 years through 10 years, amortized cost	22,647
Fixed maturities, due after 10 years, amortized cost	21,745
Fixed maturities excluding mortgage-backed securities, collateralized mortgage obligations and pass-through securities, amortized cost	75,389
Mortgage-backed securities, collateralized mortgage obligations and pass-through securities, amortized cost	12,888
Fixed maturities, amortized cost	88,277	$ 81,781
Fixed maturities, due in one year or less, fair value	7,328
Fixed maturities, due after 1 year through 5 years, fair value	22,965
Fixed maturities, due after 5 years through 10 years, fair value	20,897
Fixed maturities, due after 10 years, fair value	19,871
Fixed maturities excluding mortgage-backed securities, collateralized mortgage obligations and pass-through securities, fair value	71,061
Mortgage-backed securities, collateralized mortgage obligations and pass-through securities, fair value	12,605
Fixed maturities, at fair value	$ 83,666	$ 77,807