Financial Guarantee Insurance Contracts - Effect of Reinsurance on Premiums Written and Earned (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014 Successor Ambac [Member]	Mar. 31, 2013 Predecessor Ambac [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct Premiums Written	$ (5,766)	$ (3,530)
Assumed Reinsurance Premiums Written	0	0
Ceded Reinsurance Premiums Written	456	(1,014)
Premiums written, net of reinsurance	(6,222)	(2,516)
Direct Premiums Earned	86,183	107,079
Assumed Reinsurance Premiums Earned	68	24
Ceded Reinsurance Premiums Earned	3,704	6,847
Reinsurance on premiums earned, Net	$ 82,547	$ 100,256