Investments - Schedule of Contractual Maturities of Investments (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Amortized cost
Due in one year or less	$ 686
Due after one year through five years	3,636
Due after five years through ten years	3,460
Due after ten years	4,548
Total	12,330	$ 12,230
Fair value
Due in one year or less	690
Due after one year through five years	3,690
Due after five years through ten years	3,525
Due after ten years	4,471
Total	$ 12,376	$ 13,022
% of fair value
Due in one year or less	5.60%
Due after one year through five years	29.80%
Due after five years through ten years	28.50%
Due after ten years	36.10%
Total	100.00%