Reorganization Under Chapter 11 - Summary of Reorganization Items in Consolidated Statements of Total Comprehensive Income (Detail) (USD $) In Thousands, unless otherwise specified	2 Months Ended	3 Months Ended	6 Months Ended	1 Months Ended	4 Months Ended
	Jun. 30, 2013 Successor Ambac [Member]	Jun. 30, 2014 Successor Ambac [Member]	Jun. 30, 2014 Successor Ambac [Member]	Apr. 30, 2013 Predecessor Ambac [Member]	Apr. 30, 2013 Predecessor Ambac [Member]
Fresh-Start Adjustment [Line Items]
U.S. Trustee fees	$ 0	$ 0	$ 0	$ 13	$ 23
Professional fees	424	186	209	2,434	4,483
Debtor Reorganization Items, Gain (Loss) on Settlement of Other Claims, Net	0	0	0	(1,521,435)	(1,521,435)
Fresh Start Adjustments	0	0	0	(1,228,251)	(1,228,251)
Total reorganization items	$ 424	$ 186	$ 209	$ (2,747,239)	$ (2,745,180)