Income Taxes - Provision (Benefit) for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Federal:
Current	$ 20	$ 228	$ 175
Deferred	(893)	(19,098)	(4)
Gross Federal	(873)	(18,870)	171
State:
Current	255	650	476
Deferred	(24)	(125)	3
Gross State	231	525	479
Income tax expense (benefit)	$ (642)	$ (18,345)	$ 650