Expected Losses to be Paid - Net Expected Recoveries from Breaches of R&W Rollforward (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013	Sep. 30, 2014		Sep. 30, 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	$ 93		$ 86	$ 160		$ 294
R&W recovered during period				(284)
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	651		964	712		1,370
R&W development and accretion of discount during period	93		86	160		294
R&W recovered during period	(166)		(155)	(294)		(769)
Future net R&W benefit at the end of the period	578	[1]	895	578	[1]	895
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	509		753	569		1,082
R&W development and accretion of discount during period	35		83	84		235
R&W recovered during period	(163)		(96)	(272)		(577)
Future net R&W benefit at the end of the period	381	[1]	740	381	[1]	740
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	3		4	4		4
R&W development and accretion of discount during period	1		(1)	0		(1)
R&W recovered during period	(1)		0	(1)		0
Future net R&W benefit at the end of the period	3	[1]	3	3	[1]	3
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	263		348	274		378
R&W development and accretion of discount during period	19		37	20		24
R&W recovered during period	(79)		(16)	(91)		(33)
Future net R&W benefit at the end of the period	203	[1]	369	203	[1]	369
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	144		293	173		591
R&W development and accretion of discount during period	10		40	30		206
R&W recovered during period	(76)		(80)	(125)		(544)
Future net R&W benefit at the end of the period	78	[1]	253	78	[1]	253
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	99		108	118		109
R&W development and accretion of discount during period	5		7	34		6
R&W recovered during period	(7)		0	(55)		0
Future net R&W benefit at the end of the period	97	[1]	115	97	[1]	115
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	142		211	143		288
R&W development and accretion of discount during period	58		3	76		59
R&W recovered during period	(3)		(59)	(22)		(192)
Future net R&W benefit at the end of the period	197	[1]	155	197	[1]	155
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	93		102	98		138
R&W development and accretion of discount during period	(1)		1	(4)		(11)
R&W recovered during period	(3)		(3)	(5)		(27)
Future net R&W benefit at the end of the period	89	[1]	100	89	[1]	100
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	49		109	45		150
R&W development and accretion of discount during period	59		2	80		70
R&W recovered during period	0		(56)	(17)		(165)
Future net R&W benefit at the end of the period	$ 108	[1]	$ 55	$ 108	[1]	$ 55

[1] (1) See the section "Breaches of Representations and Warranties" below for eligible assets held in trust.