Other Long-Term Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Other Liabilities Disclosure [Abstract]
Deferred rent	$ 1,613	$ 1,850
Uncertain tax positions, interest and penalties not recognized	1,602	1,582
Accrued general and administrative expenses	3	4
Total other long-term liabilities	$ 3,218	$ 3,436