Income Taxes - Schedule of (Benefit from) Provision for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current income tax (benefit) provision
Federal	$ (66)	$ (72)	$ (78)
State	1,525	442	494
Foreign	12	23	36
Total current income tax provision	1,471	393	452
Deferred income tax (benefit) provision:
Federal	(74,312)	5,169	25,210
State	(12,165)	3,768	(1,964)
Total deferred income tax (benefit) provision	(86,477)	8,937	23,246
Total income tax (benefit) provision	$ (85,006)	$ 9,330	$ 23,698