Other Accrued Expenses and Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Accrued Liabilities And Other Liabilities Current [Abstract]
Accrued professional fees	$ 1,446	$ 1,504
Customer deposits	86	1,517
Accrued warranties	565	316
Earnout liability	375
Other accrued expenses	1,707	1,940
Total	$ 4,179	$ 5,277