Investments (Details 2) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Amortized cost
Due in one year or less	$ 3,553
Due after one year through five years	26,200
Due after five years through ten years	15,885
Due after ten years	8,382
Subtotal	54,020
ABS, RMBS and CMBS	5,652
Total amortized cost for fixed income securities	59,672	59,008
Fair value
Due in one year or less	3,593
Due after one year through five years	26,865
Due after five years through ten years	16,527
Due after ten years	9,655
Subtotal	56,640
ABS, RMBS and CMBS	5,800
Total fixed income securities	$ 62,440	$ 60,910