Investments - Scheduled maturities for fixed income securities (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Amortized cost, net
Due in one year or less	$ 920
Due after one year through five years	17,788
Due after five years through ten years	13,763
Due after ten years	5,250
Subtotal	37,721
ABS and MBS	1,090
Amortized cost, net	38,811	$ 40,034
Fair value
Due in one year or less	928
Due after one year through five years	18,257
Due after five years through ten years	14,209
Due after ten years	5,491
Subtotal	38,885
ABS and MBS	1,104
Total	$ 39,989	$ 42,565