Outstanding Exposure - Net Direct Economic Exposure to Selected European Countries (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	$ 2,883	[1]
Sovereign and sub-sovereign
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	1,966	[1]
Sovereign and sub-sovereign | Public Finance
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	1,397	[1]
Sovereign and sub-sovereign | Infrastructure finance
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	569	[1]
Non-sovereign
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	917	[1]
Non-sovereign | Regulated utilities
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	234	[1]
Non-sovereign | RMBS
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	683	[1]
BIG
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	1,148	[1]
Hungary
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	608	[1],[2]
Hungary | Sovereign and sub-sovereign
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	384	[1],[2]
Hungary | Sovereign and sub-sovereign | Public Finance
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	0	[1],[2]
Hungary | Sovereign and sub-sovereign | Infrastructure finance
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	384	[1],[2]
Hungary | Non-sovereign
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	224	[1],[2]
Hungary | Non-sovereign | Regulated utilities
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	0	[1],[2]
Hungary | Non-sovereign | RMBS
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	224	[1],[2]
Hungary | BIG
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	608	[1],[2]
Ireland
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	144	[1]
Ireland | Sovereign and sub-sovereign
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	0	[1]
Ireland | Sovereign and sub-sovereign | Public Finance
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	0	[1]
Ireland | Sovereign and sub-sovereign | Infrastructure finance
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	0	[1]
Ireland | Non-sovereign
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	144	[1]
Ireland | Non-sovereign | Regulated utilities
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	0	[1]
Ireland | Non-sovereign | RMBS
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	144	[1]
Ireland | BIG
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	0	[1]
Italy
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	1,591	[1]
Italy | Sovereign and sub-sovereign
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	1,042	[1]
Italy | Sovereign and sub-sovereign | Public Finance
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	1,024	[1]
Italy | Sovereign and sub-sovereign | Infrastructure finance
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	18	[1]
Italy | Non-sovereign
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	549	[1]
Italy | Non-sovereign | Regulated utilities
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	234	[1]
Italy | Non-sovereign | RMBS
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	315	[1]
Italy | BIG
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	0	[1]
Portugal
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	110	[1],[2]
Portugal | Sovereign and sub-sovereign
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	110	[1],[2]
Portugal | Sovereign and sub-sovereign | Public Finance
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	98	[1],[2]
Portugal | Sovereign and sub-sovereign | Infrastructure finance
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	12	[1],[2]
Portugal | Non-sovereign
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	0	[1],[2]
Portugal | Non-sovereign | Regulated utilities
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	0	[1],[2]
Portugal | Non-sovereign | RMBS
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	0	[1],[2]
Portugal | BIG
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	110	[1],[2]
Spain
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	430	[1],[2]
Spain | Sovereign and sub-sovereign
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	430	[1],[2]
Spain | Sovereign and sub-sovereign | Public Finance
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	275	[1],[2]
Spain | Sovereign and sub-sovereign | Infrastructure finance
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	155	[1],[2]
Spain | Non-sovereign
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	0	[1],[2]
Spain | Non-sovereign | Regulated utilities
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	0	[1],[2]
Spain | Non-sovereign | RMBS
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	0	[1],[2]
Spain | BIG
Guarantor Obligations [Line Items]
Net Par Outstanding, European Exposure	$ 430	[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 $144 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 6, Expected Loss to be Paid.