Financial Guarantee Insurance Contracts - Effect of Reinsurance on Premiums Written and Earned (Detail) - Successor [Member] - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct Premiums Written									$ 53,837	$ 37,572	$ 288,310
Assumed Reinsurance Premiums Written									0	0	0
Ceded Reinsurance Premiums Written									8,772	3,001	6,842
Premiums written, net of reinsurance									45,065	34,571	281,468
Direct Premiums Earned									215,564	336,025	261,634
Assumed Reinsurance Premiums Earned									85	87	137
Ceded Reinsurance Premiums Earned									18,362	23,517	15,411
Reinsurance on premiums earned, Net	$ 49,867	$ 53,218	$ 41,402	$ 52,800	$ 114,463	$ 71,535	$ 60,879	$ 65,718	$ 197,287	$ 312,595	$ 246,360