Investments - Debt Securities by Contractual Maturity Periods (Details) $ in Millions	Dec. 31, 2022 USD ($)
Amortized Cost
Due in one year or less	$ 681
Due after one year through five years	3,817
Due after five years through ten years	3,457
Due after ten years	2,497
Mortgage and other asset-backed securities	390
Total	10,842
Fair Value
Due in one year or less	674
Due after one year through five years	3,583
Due after five years through ten years	3,052
Due after ten years	2,215
Mortgage and other asset-backed securities	348
Total	$ 9,872