Investments - Debt Securities by Contractual Maturity Periods (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Amortized Cost
Due in one year or less	$ 638
Due after one year through five years	3,972
Due after five years through ten years	3,227
Due after ten years	2,450
Mortgage and other asset-backed securities	381
Total	10,668	$ 10,842
Fair Value
Due in one year or less	630
Due after one year through five years	3,752
Due after five years through ten years	2,915
Due after ten years	2,268
Mortgage and other asset-backed securities	344
Total	$ 9,909	$ 9,872