Investments - Schedule of Contractual Maturities of Investments (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Amortized cost
Due in one year or less	$ 772
Due after one year through five years	4,348
Due after five years through ten years	3,508
Due after ten years	5,080
Total	13,708	$ 12,979
Fair value
Due in one year or less	766
Due after one year through five years	4,179
Due after five years through ten years	3,312
Due after ten years	4,613
Total	$ 12,870	$ 12,132
% of fair value
Due in one year or less	6.00%
Due after one year through five years	32.50%
Due after five years through ten years	25.70%
Due after ten years	35.80%
Total	100.00%