Investments (Details 2) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Amortized cost
Due in one year or less	$ 1,304
Due after one year through five years	5,025
Due after five years through ten years	11,086
Due after ten years	7,640
Subtotal	25,055
ABS, RMBS and CMBS	2,144
Total	27,199
Fair value
Due in one year or less	1,333
Due after one year through five years	5,438
Due after five years through ten years	11,634
Due after ten years	8,448
Subtotal	26,853
ABS, RMBS and CMBS	2,239
Total	$ 29,092	$ 28,756