Financial Guarantee Insurance Contracts - Effect of Reinsurance on Premiums Written and Earned (Detail) (USD $) In Thousands, unless otherwise specified	2 Months Ended	3 Months Ended						8 Months Ended	12 Months Ended	1 Months Ended	3 Months Ended	4 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Dec. 31, 2013	Dec. 31, 2014	Apr. 30, 2013	Mar. 31, 2013	Apr. 30, 2013	Dec. 31, 2012
Successor [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct Premiums Written								$ (80,309)	$ (288,310)
Assumed Reinsurance Premiums Written								0	0
Ceded Reinsurance Premiums Written								(7,810)	(6,842)
Premiums written, net of reinsurance								72,499	281,468
Direct Premiums Earned								226,326	261,634
Assumed Reinsurance Premiums Earned								65	137
Ceded Reinsurance Premiums Earned								12,873	15,411
Reinsurance on premiums earned, Net	58,039	33,969	64,831	65,013	82,547	84,530	70,949	213,518	246,360
Predecessor [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct Premiums Written												(14,125)	(277,508)
Assumed Reinsurance Premiums Written												0	0
Ceded Reinsurance Premiums Written												(1,098)	(23,371)
Premiums written, net of reinsurance												13,027	254,137
Direct Premiums Earned												138,468	434,488
Assumed Reinsurance Premiums Earned												32	155
Ceded Reinsurance Premiums Earned												8,500	20,039
Reinsurance on premiums earned, Net										$ 29,744	$ 100,256	$ 130,000	$ 414,604