Background and Business Description Background and Business Description - Additional Information (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
December 2014 Payment of Deferred Amounts	$ 1,138,500
December 2014 Redemption of Surplus Notes	$ 413,587

Estimated payment of Surplus Notes (including accrued interest) that will be paid by the Segregated Account and Ambac Assurance in December 2014. Such amounts are due once the Rehabilitator of the Segregated Account pays 26.67% of Deferred Amounts in December 2014 (as required under both the amended Rehabilitation Plan and other agreements that Ambac Assurance was a party to).

No definition available.

Name:	ambc_December2014PaymentofSurplusNotes
Namespace Prefix:	ambc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant