Financial Guarantee Insurance Contracts - Estimated Future Amortization Expense for Insurance Intangible Asset (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Amortization Of Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	$ 1,570,218		$ 1,570,218		$ 1,626,566
Accumulated amortization on insurance intangible asset	494,613		494,613		$ 414,454
2015	54,392		54,392
2016	96,632		96,632
2017	85,603		85,603
2018	77,146		77,146
2019	71,269		71,269
Thereafter	690,563		690,563
Successor [Member]
Amortization Of Intangible Assets [Line Items]
Amortization of insurance intangible assets	$ 39,013	$ 38,088	$ 89,903	$ 75,520