Reconciliation of Income Tax Benefit (Provision) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Federal statutory rate	$ (8,530)	$ (1,718)	$ 3,171
State statutory, net of federal benefit	(299)	(404)	(157)
Change in federal valuation allowance	5,670	(55)	986
Permanent items	(54)	(41)	(82)
Penalties associated with SEC settlement			(1,750)
Provision to return adjustments	207	(580)	(21)
Other	456
Income tax benefit (provision)	$ (2,550)	$ (2,798)	$ 2,147