Investments (Details 2) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Amortized cost
Total fixed maturities	$ 8,633
Estimated fair value
Estimated fair value, fixed maturities	9,198	8,688
Indemnity
Amortized cost
Due in one year or less	69
Due after one year through five years	229
Due after five years through ten years	113
Due after ten years	73
Total fixed maturities	484
Estimated fair value
Due in one year or less	69
Due after one year through five years	232
Due after five years through ten years	118
Due after ten years	78
Estimated fair value, fixed maturities	497	526
Exchange
Amortized cost
Due in one year or less	377
Due after one year through five years	3,155
Due after five years through ten years	3,094
Due after ten years	1,523
Total fixed maturities	8,149
Estimated fair value
Due in one year or less	384
Due after one year through five years	3,365
Due after five years through ten years	3,303
Due after ten years	1,649
Estimated fair value, fixed maturities	$ 8,701	$ 8,162