Expected Losses to be Paid - Net Expected Recoveries from Breaches of R&W Rollforward (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Estimated Benefit From Recoveries From Breaches of R and W Net of Reinsurance [Roll Forward]
R&W development and accretion of discount during period	$ 48		$ 157
R&W recovered during period	(384)
Gross R&W amounts recovered	41		92
U.S. RMBS
Estimated Benefit From Recoveries From Breaches of R and W Net of Reinsurance [Roll Forward]
Future net R&W benefit at the beginning of the period	712		1,370
R&W development and accretion of discount during period	48		157
R&W recovered during period	(39)	[1]	(89)	[1]
Future net R&W benefit at the end of the period	721		1,438
Total first lien
Estimated Benefit From Recoveries From Breaches of R and W Net of Reinsurance [Roll Forward]
Future net R&W benefit at the beginning of the period	569		1,082
R&W development and accretion of discount during period	39		149
R&W recovered during period	(38)	[1]	(62)	[1]
Future net R&W benefit at the end of the period	570		1,169
Prime first lien
Estimated Benefit From Recoveries From Breaches of R and W Net of Reinsurance [Roll Forward]
Future net R&W benefit at the beginning of the period	4		4
R&W development and accretion of discount during period	(1)		0
R&W recovered during period	0	[1]	0	[1]
Future net R&W benefit at the end of the period	3		4
Alt-A first lien
Estimated Benefit From Recoveries From Breaches of R and W Net of Reinsurance [Roll Forward]
Future net R&W benefit at the beginning of the period	274		378
R&W development and accretion of discount during period	3		(8)
R&W recovered during period	(8)	[1]	(8)	[1]
Future net R&W benefit at the end of the period	269		362
Option ARM
Estimated Benefit From Recoveries From Breaches of R and W Net of Reinsurance [Roll Forward]
Future net R&W benefit at the beginning of the period	173		591
R&W development and accretion of discount during period	9		153
R&W recovered during period	(30)	[1]	(54)	[1]
Future net R&W benefit at the end of the period	152		690
First mortgage, subprime
Estimated Benefit From Recoveries From Breaches of R and W Net of Reinsurance [Roll Forward]
Future net R&W benefit at the beginning of the period	118		109
R&W development and accretion of discount during period	28		4
R&W recovered during period	0	[1]	0	[1]
Future net R&W benefit at the end of the period	146		113
Second lien
Estimated Benefit From Recoveries From Breaches of R and W Net of Reinsurance [Roll Forward]
Future net R&W benefit at the beginning of the period	143		288
R&W development and accretion of discount during period	9		8
R&W recovered during period	(1)	[1]	(27)	[1]
Future net R&W benefit at the end of the period	151		269
Closed end second lien and HELOCs
Estimated Benefit From Recoveries From Breaches of R and W Net of Reinsurance [Roll Forward]
Future net R&W benefit at the beginning of the period	98		138
R&W development and accretion of discount during period	(3)		(9)
R&W recovered during period	0	[1]	(21)	[1]
Future net R&W benefit at the end of the period	95		108
HELOCs
Estimated Benefit From Recoveries From Breaches of R and W Net of Reinsurance [Roll Forward]
Future net R&W benefit at the beginning of the period	45		150
R&W development and accretion of discount during period	12		17
R&W recovered during period	(1)	[1]	(6)	[1]
Future net R&W benefit at the end of the period	$ 56		$ 161

[1] Gross amounts recovered were $41 million and $92 million for First Quarter 2014 and 2013, respectively.