Investments - Available-for-sale Fixed Maturity Securities by Contractual Maturity (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Cost or Amortized Cost
Cost or Amortized Cost	$ 41,899	$ 41,102
Estimated Fair Value
Estimated Fair Value	39,349	37,697
Available-for-sale Fixed Maturities
Cost or Amortized Cost
Due in one year or less	1,009	1,012
Due after one year through five years	10,486	9,880
Due after five years through ten years	13,763	13,788
Due after ten years	16,388	16,352
Cost or Amortized Cost	41,646	41,032
Estimated Fair Value
Due in one year or less	989	1,001
Due after one year through five years	10,035	9,399
Due after five years through ten years	12,702	12,453
Due after ten years	15,367	14,774
Estimated Fair Value	$ 39,093	$ 37,627