Deferred Court Costs, Net - Schedule of Deferred Court Costs (Detail) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Court costs advanced		$ 654,356	$ 636,922
Court costs recovered		(261,243)	(242,899)
Court costs reserve		(327,926)	(318,784)	$ (279,572)	$ (210,889)
Deferred court costs		$ 65,187	$ 75,239
UNITED KINGDOM
Segment Reporting Information [Line Items]
Increase (decrease) in deferred costs	$ 11,300