Investments - Scheduled maturities for fixed income securities (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Amortized cost
Due in one year or less	$ 2,827
Due after one year through five years	25,060
Due after five years through ten years	17,602
Due after ten years	9,276
Subtotal	54,765
ABS, RMBS and CMBS	1,243
Amortized cost	56,008	$ 57,134
Fair value
Due in one year or less	2,849
Due after one year through five years	25,659
Due after five years through ten years	18,394
Due after ten years	10,235
Subtotal	57,137
ABS, RMBS and CMBS	1,347
Total fixed income securities	$ 58,484	$ 57,170