Investments (Details 2) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Amortized cost
Due in one year or less	$ 3,062
Due after one year through five years	25,246
Due after five years through ten years	16,198
Due after ten years	8,541
Subtotal	53,047
ABS, RMBS and CMBS	5,540
Total amortized cost for fixed income securities	58,587
Fair value
Due in one year or less	3,105
Due after one year through five years	26,005
Due after five years through ten years	16,955
Due after ten years	9,378
Subtotal	55,443
ABS, RMBS and CMBS	5,718
Total fixed income securities	$ 61,161	$ 60,910