Name:	ambc_DeferredCompensationArrangementwithIndividualGrantAwardValue
Namespace Prefix:	ambc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The percentage payout of the performance award grant. This is presented as a percentage of the initial target grant amount as specified in the award agreement.

No definition available.

Name:	ambc_PerformanceAwardPayout
Namespace Prefix:	ambc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Scheduled vesting period from initial grant of performance based awards.

No definition available.

Name:	ambc_PerformanceAwardScheduledVestingPeriod
Namespace Prefix:	ambc_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Number of shares initially granted to participants in accordance with deferred compensation plan.

No definition available.

Name:	ambc_ShareBasedCompensationGrant
Namespace Prefix:	ambc_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)(3)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901