Prepaid Expenses and Other Current Assets - Prepaid Expenses and Other Current Assets and Other Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Prepaid Expenses	$ 1,661	$ 1,085
Deposits	61	2,099
Interest receivable on marketable securities	611	605
Employee Advance	1	1
Total prepaid expenses and other current assets	$ 2,334	$ 3,790