Accrued Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Payables and Accruals [Abstract]
Accrued salaries, benefits and bonus	$ 19,063		$ 8,957
Accrued professional, consulting and lobbying fees	4,894		3,870
Accrued warranty expense	898		644	$ 780	$ 314
Accrued income and other taxes	4,167		2,558
Other accrued expenses	12,070		7,473
Accrued liabilities	$ 41,092	$ 26,014	$ 23,502