Accrued Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2015
Payables and Accruals [Abstract]
Accrued salaries, benefits and bonus	$ 5,649	$ 6,474
Accrued professional, consulting and lobbying	2,181	3,673
Accrued warranty expense	564	780	$ 785	$ 314
Accrued income and other taxes	3,756	4,581
Other accrued liabilities	7,729	2,740
Accrued liabilities	$ 19,879	$ 18,248