- U.S. RMBS Risks with R&W Benefit (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014 risk		Dec. 31, 2013 risk
Guarantor Obligations [Line Items]
Number of Risks as of the end of the period with R&W Benefit Recorded (in policies)	45	[1]	42	[1]
Outstanding Principal and Interest on Representations and Warranties Policies	$ 4,697		$ 5,011
Prime first lien
Guarantor Obligations [Line Items]
Number of Risks as of the end of the period with R&W Benefit Recorded (in policies)	1	[1]	1	[1]
Outstanding Principal and Interest on Representations and Warranties Policies	36		38
Alt-A first lien
Guarantor Obligations [Line Items]
Number of Risks as of the end of the period with R&W Benefit Recorded (in policies)	20	[1]	19	[1]
Outstanding Principal and Interest on Representations and Warranties Policies	2,791		2,856
Option ARM
Guarantor Obligations [Line Items]
Number of Risks as of the end of the period with R&W Benefit Recorded (in policies)	10	[1]	9	[1]
Outstanding Principal and Interest on Representations and Warranties Policies	589		641
First mortgage, subprime
Guarantor Obligations [Line Items]
Number of Risks as of the end of the period with R&W Benefit Recorded (in policies)	5	[1]	5	[1]
Outstanding Principal and Interest on Representations and Warranties Policies	985		998
Closed end second lien and HELOCs
Guarantor Obligations [Line Items]
Number of Risks as of the end of the period with R&W Benefit Recorded (in policies)	4	[1]	4	[1]
Outstanding Principal and Interest on Representations and Warranties Policies	155		158
HELOCs
Guarantor Obligations [Line Items]
Number of Risks as of the end of the period with R&W Benefit Recorded (in policies)	5	[1]	4	[1]
Outstanding Principal and Interest on Representations and Warranties Policies	$ 141		$ 320

[1] A risk represents the aggregate of the financial guaranty policies that share the same revenue source for purposes of making Debt Service payments. This table shows the full future Debt Service (not just the amount of Debt Service expected to be reimbursed) for risks with projected future R&W benefit, whether pursuant to an agreement or not.