Investments (Details 2) - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Amortized cost
Due in one year or less	$ 4,226
Due after one year through five years	28,770
Due after five years through ten years	16,870
Due after ten years	5,086
Subtotal	54,952
ABS, RMBS and CMBS	1,949
Amortized cost	56,901	$ 56,576
Fair value
Due in one year or less	4,247
Due after one year through five years	29,347
Due after five years through ten years	17,293
Due after ten years	5,715
Subtotal	56,602
ABS, RMBS and CMBS	2,054
Total fixed income securities	$ 58,656	$ 57,839