Investments - Schedule of Maturities for Fixed Income Securities (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Amortized cost, net
Due in one year or less	$ 3,374	$ 3,422
Due after one year through five years	23,324	23,218
Due after five years through ten years	14,894	12,553
Due after ten years	8,406	8,717
Subtotal	49,998	47,910
ABS	1,839	1,739
Amortized cost, net	51,837	49,649
Fair value
Due in one year or less	3,333	3,374
Due after one year through five years	22,678	22,614
Due after five years through ten years	14,560	12,273
Due after ten years	8,360	8,859
Subtotal	48,931	47,120
ABS	1,846	1,745
Total	$ 50,777	$ 48,865