Investments - Scheduled maturities for fixed income securities (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Amortized cost
Due in one year or less	$ 3,026
Due after one year through five years	25,251
Due after five years through ten years	17,315
Due after ten years	9,495
Subtotal	55,087
ABS, RMBS and CMBS	1,176
Amortized cost	56,263	$ 57,134
Fair value
Due in one year or less	3,050
Due after one year through five years	25,913
Due after five years through ten years	18,290
Due after ten years	10,728
Subtotal	57,981
ABS, RMBS and CMBS	1,278
Total fixed income securities	$ 59,259	$ 57,170