Income Taxes - Components of Company's Income Tax Provision (Benefit) (Detail) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current tax expense:
Federal			$ 0	$ 0	$ 0
State			185	161	377
Foreign			(9)	264	68
Total			176	425	445
Deferred tax expense (benefit):
Federal			801	(544)	2,092
State			344	476	709
Foreign			9	205	301
Change in valuation allowance	$ (3,700)	$ (3,600)	3,700	3,000
Total			4,854	3,137	3,102
Unrecognized tax benefit				(33)	(370)
Income tax provision			$ 5,030	$ 3,529	$ 3,177