Investments (Details 2) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Amortized cost
Due in one year or less	$ 1,338
Due after one year through five years	5,196
Due after five years through ten years	9,950
Due after ten years	7,473
Subtotal	23,957
ABS, RMBS and CMBS	1,865
Amortized cost	25,822	27,427
Fair value
Due in one year or less	1,359
Due after one year through five years	5,614
Due after five years through ten years	10,475
Due after ten years	8,720
Subtotal	26,168
ABS, RMBS and CMBS	1,949
Total	$ 28,117	$ 28,756