Investments - Schedule of Maturities for Fixed Income Securities (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Amortized cost, net
Due in one year or less	$ 3,536	$ 2,870
Due after one year through five years	24,560	26,546
Due after five years through ten years	13,038	11,035
Due after ten years	7,742	3,731
Subtotal	48,876	44,182
ABS	1,103	1,188
Amortized cost, net	49,979	45,370
Fair value
Due in one year or less	3,476	2,836
Due after one year through five years	23,246	25,217
Due after five years through ten years	11,919	9,870
Due after ten years	7,029	3,405
Subtotal	45,670	41,328
ABS	1,101	1,157
Total	$ 46,771	$ 42,485