XML 22 R77.htm IDEA: XBRL DOCUMENT
v2.4.0.6

Income Taxes (Details) | 6 Months Ended
--- | ---
Jun. 30, 2012
Internal Revenue Service (IRS) [Member] |
Tax Years Subject To Examination By Major Jurisdictions |
Tax Year | 2005
New York State [Member] |
Tax Years Subject To Examination By Major Jurisdictions |
Tax Year | 2008
New York City [Member] |
Tax Years Subject To Examination By Major Jurisdictions |
Tax Year | 2011
United Kingdom [Member] |
Tax Years Subject To Examination By Major Jurisdictions |
Tax Year | 2006
Italy [Member] |
Tax Years Subject To Examination By Major Jurisdictions |
Tax Year | 2007

X
- Details
Name: | abk_TaxYearsSubjectToExaminationByMajorJurisdictionsAbstract
Namespace Prefix: | abk_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tax year being audited in the income tax examination, in CCYY format. + References No definition available. + Details
Name: | us-gaap_IncomeTaxExaminationYearUnderExamination
Namespace Prefix: | us-gaap_
Data Type: | xbrli:gYearItemType
Balance Type: | na
Period Type: | duration