Outstanding Exposure (Details 4) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	$ 3,982	[1]
Greece
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	17	[1]
Hungary
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	637	[1],[2]
Ireland
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	278	[1]
Italy
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	1,878	[1]
Portugal
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	226	[1]
Spain
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	946	[1],[2]
Sovereign and sub-sovereign exposure
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	2,185	[1]
Sovereign and sub-sovereign exposure | Public finance
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	1,392	[1]
Sovereign and sub-sovereign exposure | Infrastructure finance
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	793	[1]
Sovereign and sub-sovereign exposure | Greece
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	0	[1]
Sovereign and sub-sovereign exposure | Greece | Public finance
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	0	[1]
Sovereign and sub-sovereign exposure | Greece | Infrastructure finance
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	0	[1]
Sovereign and sub-sovereign exposure | Hungary
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	417	[1],[2]
Sovereign and sub-sovereign exposure | Hungary | Public finance
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	0	[1],[2]
Sovereign and sub-sovereign exposure | Hungary | Infrastructure finance
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	417	[1],[2]
Sovereign and sub-sovereign exposure | Ireland
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	24	[1]
Sovereign and sub-sovereign exposure | Ireland | Public finance
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	0	[1]
Sovereign and sub-sovereign exposure | Ireland | Infrastructure finance
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	24	[1]
Sovereign and sub-sovereign exposure | Italy
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	1,105	[1]
Sovereign and sub-sovereign exposure | Italy | Public finance
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	1,020	[1]
Sovereign and sub-sovereign exposure | Italy | Infrastructure finance
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	85	[1]
Sovereign and sub-sovereign exposure | Portugal
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	197	[1]
Sovereign and sub-sovereign exposure | Portugal | Public finance
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	101	[1]
Sovereign and sub-sovereign exposure | Portugal | Infrastructure finance
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	96	[1]
Sovereign and sub-sovereign exposure | Spain
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	442	[1],[2]
Sovereign and sub-sovereign exposure | Spain | Public finance
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	271	[1],[2]
Sovereign and sub-sovereign exposure | Spain | Infrastructure finance
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	171	[1],[2]
Non Sovereign Debt
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	1,797	[1]
Non Sovereign Debt | Regulated utilities
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	229	[1]
Non Sovereign Debt | RMBS
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	676	[1]
Non Sovereign Debt | Commercial receivable
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	87	[1]
Non Sovereign Debt | Pooled corporate
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	805	[1]
Non Sovereign Debt | Greece
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	17	[1]
Non Sovereign Debt | Greece | Regulated utilities
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	0	[1]
Non Sovereign Debt | Greece | RMBS
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	0	[1]
Non Sovereign Debt | Greece | Commercial receivable
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	0	[1]
Non Sovereign Debt | Greece | Pooled corporate
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	17	[1]
Non Sovereign Debt | Hungary
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	220	[1],[2]
Non Sovereign Debt | Hungary | Regulated utilities
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	0	[1],[2]
Non Sovereign Debt | Hungary | RMBS
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	220	[1],[2]
Non Sovereign Debt | Hungary | Commercial receivable
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	0	[1],[2]
Non Sovereign Debt | Hungary | Pooled corporate
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	0	[1],[2]
Non Sovereign Debt | Ireland
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	254	[1]
Non Sovereign Debt | Ireland | Regulated utilities
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	0	[1]
Non Sovereign Debt | Ireland | RMBS
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	142	[1]
Non Sovereign Debt | Ireland | Commercial receivable
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	9	[1]
Non Sovereign Debt | Ireland | Pooled corporate
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	103	[1]
Non Sovereign Debt | Italy
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	773	[1]
Non Sovereign Debt | Italy | Regulated utilities
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	229	[1]
Non Sovereign Debt | Italy | RMBS
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	314	[1]
Non Sovereign Debt | Italy | Commercial receivable
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	62	[1]
Non Sovereign Debt | Italy | Pooled corporate
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	168	[1]
Non Sovereign Debt | Portugal
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	29	[1]
Non Sovereign Debt | Portugal | Regulated utilities
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	0	[1]
Non Sovereign Debt | Portugal | RMBS
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	0	[1]
Non Sovereign Debt | Portugal | Commercial receivable
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	14	[1]
Non Sovereign Debt | Portugal | Pooled corporate
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	15	[1]
Non Sovereign Debt | Spain
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	504	[1],[2]
Non Sovereign Debt | Spain | Regulated utilities
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	0	[1],[2]
Non Sovereign Debt | Spain | RMBS
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	0	[1],[2]
Non Sovereign Debt | Spain | Commercial receivable
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	2	[1],[2]
Non Sovereign Debt | Spain | Pooled corporate
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	502	[1],[2]
Below investment grade (BIG)
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	1,145	[1]
Below investment grade (BIG) | Greece
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	0	[1]
Below investment grade (BIG) | Hungary
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	599	[1],[2]
Below investment grade (BIG) | Ireland
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	7	[1]
Below investment grade (BIG) | Italy
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	1	[1]
Below investment grade (BIG) | Portugal
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	113	[1]
Below investment grade (BIG) | Spain
Financial Guaranty Portfolio
Net Economic Exposure to Selected European Countries	$ 425	[1],[2]

[1] While the Company’s exposures are shown in U.S. dollars, the obligations the Company insures are in various currencies, including U.S. dollars, Euros and British pounds sterling. Included in the table above is $142 million of reinsurance assumed on a 2004 - 2006 pool of Irish residential mortgages that is part of the Company’s remaining legacy mortgage reinsurance business. One of the residential mortgage-backed securities included in the table above includes residential mortgages in both Italy and Germany, and only the portion of the transaction equal to the portion of the original mortgage pool in Italian mortgages is shown in the table.

[2] See Note 5, Expected Loss to be Paid.