Segment Information - Schedule of Gross Premiums Written, Net Premiums Earned and Net Change in Fair Value of Credit Derivatives (Detail) - Successor [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting Information [Line Items]
Gross Premiums Written	$ (4,041)	$ (11,192)	$ (28,821)	$ (10,130)
Net premiums earned	41,402	60,879	94,202	126,597
Net Change In Fair Value Of Credit Derivatives	3,955	10,293	16,821	7,794
Reportable Geographical Components [Member] | United States [Member]
Segment Reporting Information [Line Items]
Gross Premiums Written	(4,675)	(547)	(18,432)	(2,913)
Net premiums earned	34,632	49,710	80,746	102,448
Net Change In Fair Value Of Credit Derivatives	238	4,724	1,094	8,681
Reportable Geographical Components [Member] | United Kingdom [Member]
Segment Reporting Information [Line Items]
Gross Premiums Written	5,404	(2,139)	14,755	7,035
Net premiums earned	6,704	7,997	13,092	15,579
Net Change In Fair Value Of Credit Derivatives	0	0	0	0
Reportable Geographical Components [Member] | Other International [Member]
Segment Reporting Information [Line Items]
Gross Premiums Written	(4,770)	(8,506)	(25,144)	(14,252)
Net premiums earned	66	3,172	364	8,570
Net Change In Fair Value Of Credit Derivatives	$ 3,717	$ 5,569	$ 15,727	$ (887)