Prepaid Expenses and Other Current Assets - Components of Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid services	$ 552	$ 873
Other prepaid contracts	2,985	2,300
Restricted cash	260	375
Other	325	316
Total	$ 4,122	$ 3,864