Income Tax Provision (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current:
Federal	$ 16,852	$ 24,509	$ 20,947
State	4,721	8,132	6,260
Foreign	271	338	480
Total current	21,844	32,979	27,687
Deferred:
Federal	(30,794)	800	(1,534)
State	(385)	516	(2,301)
Total deferred	(31,179)	1,316	(3,835)
Total income tax (benefit) expense	$ (9,335)	$ 34,295	$ 23,852