Investments - Scheduled maturities for fixed Income securities (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Amortized cost, net
Due in one year or less	$ 2,870	$ 1,105
Due after one year through five years	26,546	21,039
Due after five years through ten years	11,035	13,808
Due after ten years	3,731	4,281
Subtotal	44,182	40,233
ABS	1,188	1,143
Amortized cost, net	45,370	41,376
Fair value
Due in one year or less	2,836	1,111
Due after one year through five years	25,217	21,291
Due after five years through ten years	9,870	14,079
Due after ten years	3,405	4,500
Subtotal	41,328	40,981
ABS	1,157	1,155
Fair value	$ 42,485	$ 42,136