Income Tax - Segregation of Income Tax Provision Based on Location of Operations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current
Federal	$ 0	$ 0	$ 0
State	6	315	132
Total current	6	315	132
Deferred
Federal		(72,413)	71,838
State	540	(348)	(171)
Total deferred	540	(72,761)	71,667
Total income tax expense (benefit)	$ 546	$ (72,446)	$ 71,799