Other Current Liabilities - Other Current Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Other Liabilities Current [Abstract]
Accrued vendor payable	$ 1,800	$ 1,900
Accrued legal payable	1,400	100
Customer rebates and credits	1,100	300
Sales tax liability	500	100
Deferred rent liability	400	500
Warrant liability	400	400
Other	100	100
Other current liabilities, Total	$ 5,732	$ 3,399