Income Taxes - Components of Income Tax Provision (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current provision:
Federal	$ (1,653)	$ 4,467	$ 1,933
State	2,282	7,070	3,442
Foreign	99	88	78
Total current	728	11,625	5,453
Deferred provision:
Federal	(114,140)	(5,148)	17,765
State	1,856	(5,984)	(731)
Total deferred	(112,284)	(11,132)	17,034
Total income tax (benefit) expense	$ (111,556)	$ 493	$ 22,487