Investments - Schedule of Contractual Maturities of Investments (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Amortized cost
Due in one year or less	$ 728
Due after one year through five years	4,139
Due after five years through ten years	3,583
Due after ten years	4,912
Total	13,362	$ 12,979
Fair value
Due in one year or less	725
Due after one year through five years	4,003
Due after five years through ten years	3,447
Due after ten years	4,503
Total	$ 12,678	$ 12,132
% of fair value
Due in one year or less	5.70%
Due after one year through five years	31.60%
Due after five years through ten years	27.20%
Due after ten years	35.50%
Total	100.00%