Investments - Scheduled maturities for fixed income securities (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Amortized cost, net
Due in one year or less	$ 2,920
Due after one year through five years	24,825
Due after five years through ten years	20,360
Due after ten years	9,689
Subtotal	57,794
ABS and MBS	1,151
Amortized cost	58,945	$ 56,293
Fair value
Due in one year or less	2,927
Due after one year through five years	24,849
Due after five years through ten years	20,451
Due after ten years	10,427
Subtotal	58,654
ABS and MBS	1,203
Total fixed income securities	$ 59,857	$ 59,044