XML 96 R81.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Derivative Instruments - Summarize Information by Major Category of CDS Contracts (Detail) - Transactions | Jun. 30, 2018 | Dec. 31, 2017
--- | --- | ---
Successor [Member] |  |
Summary of information by major category of CDS contracts |  |
Number of CDS transactions | 2 | 2

X
- Definition Summary of information by major category of CDS contracts. + References No definition available. + Details
Name: | ambc_SummaryOfInformationByMajorCategoryOfCreditDerivativesContractsAbstract
Namespace Prefix: | ambc_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of derivative instruments of a particular group held by the entity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1B -URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5580258-113959 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5579245-113959 + Details
Name: | us-gaap_DerivativeNumberOfInstrumentsHeld
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_StatementScenarioAxis=us-gaap_SuccessorMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |