XML 28 R77.htm IDEA: XBRL DOCUMENT
v2.4.0.6

Derivative Instruments - Summary of Notional for VIE Derivatives Outstanding (Detail) (USD $) In Thousands, unless otherwise specified | Sep. 30, 2012 | Dec. 31, 2011
--- | --- | ---
Schedule Of Notional For Variable Interest Entity Derivatives Outstanding [Line Items] |  |
Derivative products, Notional Amount | $ 187,121 | $ 190,653
Variable Interest Entity [Member] | Interest Rate Swaps [Member] |  |
Schedule Of Notional For Variable Interest Entity Derivatives Outstanding [Line Items] |  |
Derivative products, Notional Amount | 1,771,255 | 1,702,113
Variable Interest Entity [Member] | Interest Rate Swaps Pay Fixed Receive Variable [Member] |  |
Schedule Of Notional For Variable Interest Entity Derivatives Outstanding [Line Items] |  |
Derivative products, Notional Amount | 4,676,450 | 4,535,626
Variable Interest Entity [Member] | Currency Swaps [Member] |  |
Schedule Of Notional For Variable Interest Entity Derivatives Outstanding [Line Items] |  |
Derivative products, Notional Amount | 750,463 | 721,168
Variable Interest Entity [Member] | Credit Derivatives [Member] |  |
Schedule Of Notional For Variable Interest Entity Derivatives Outstanding [Line Items] |  |
Derivative products, Notional Amount | $ 20,747 | $ 20,934

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

X
- Definition Aggregate notional amount specified by the derivative(s). Expressed as an absolute value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 -Section 13 -Sentence Column B + Details
Name: | invest_DerivativeNotionalAmount
Namespace Prefix: | invest_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Definition Fair value of derivative liability, presented on a gross basis even when the derivative instrument is subject to master netting arrangements and qualifies for net presentation in the statement of financial position. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 205G -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 44C -Subparagraph a -Clause 1 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -Subparagraph (a),(c) -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624163-113959 + Details
Name: | us-gaap_DerivativeFairValueOfDerivativeLiability
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant