Financial Guarantee Insurance Contracts - Effect of Reinsurance on Premiums Written and Earned (Detail) - Successor [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct Premiums Written	$ (611)	$ 6,928	$ 3,650	$ 12,512
Assumed Reinsurance Premiums Written	0	0	0	0
Ceded Reinsurance Premiums Written	(224)	238	(1,043)	(1,577)
Premiums written, net of reinsurance	387	(6,690)	(4,693)	(14,089)
Direct Premiums Earned	27,339	47,235	59,947	99,300
Assumed Reinsurance Premiums Earned	19	20	39	41
Ceded Reinsurance Premiums Earned	1,522	4,103	3,267	8,576
Reinsurance on premiums earned, Net	$ 25,836	$ 43,152	$ 56,719	$ 90,765