Financial Guarantee Insurance Contracts - Summary of Rollforward of RMBS Subrogation, by Estimation Approach (Detail) - Successor [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Subrogation By Estimation Approach [Roll Forward]
Discounted RMBS subrogation (gross of reinsurance), beginning balance	$ 2,829,575
Changes recognized
Discounted RMBS subrogation (gross of reinsurance), ending balance	1,855,073
Random Samples [Member]
Subrogation By Estimation Approach [Roll Forward]
Discounted RMBS subrogation (gross of reinsurance), beginning balance	2,829,575	$ 2,523,540
Changes recognized
Impact of sponsor actions	(995,000)	0
Other Changes Rmbs Subrogation	20,498	44,813
Discounted RMBS subrogation (gross of reinsurance), ending balance	$ 1,855,073	$ 2,568,353