Fresh Start Financial Statement Reporting - Summary of Reorganization Items in Consolidated Statements of Total Comprehensive Income (Detail) (USD $) In Thousands, unless otherwise specified	2 Months Ended	1 Months Ended	3 Months Ended	4 Months Ended	6 Months Ended
Jun. 30, 2013 Successor Ambac [Member]	Apr. 30, 2013 Predecessor Ambac [Member]	Jun. 30, 2012 Predecessor Ambac [Member]	Apr. 30, 2013 Predecessor Ambac [Member]	Jun. 30, 2012 Predecessor Ambac [Member]
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
U.S. Trustee fees		$ 13	$ 6	$ 23	$ 26
Professional fees	424	2,434	761	4,483	3,202
Gain on settlement of liabilities subject to compromise		(1,521,435)		(1,521,435)
Fresh start reporting adjustments		(1,228,251)		(1,228,251)
Costs and expenses directly related to the reorganization
Total reorganization items	$ 424	$ (2,747,239)	$ 767	$ (2,745,180)	$ 3,228

Total fresh-start fair value adjustments to assets and liabilities.

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- Definition

Amount of reorganization items related to debtor-in-possession facility financing costs.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 852

-SubTopic 10

-Section 55

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6585303&loc=d3e56145-112766

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 852

-SubTopic 10

-Section 45

-Paragraph 9

-URI http://asc.fasb.org/extlink&oid=6916575&loc=d3e55730-112764

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Statement of Position (SOP)

-Number 90-7

-Paragraph 27

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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Amount of net gain (loss) on settlement of other claims for entities in bankruptcy, reported as a reorganization item.

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Amount of other reorganization items.

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Total amount of reorganization items.

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