Schedule of Accrued Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Schedule of Accrued Liabilities [Line Items]
Employee compensation	$ 5,246	$ 9,560
Taxes	2,049	1,668
Royalty and license fees	1,243	1,383
Accrued purchases	521	1,191
Professional fees	827	947
Unearned revenue	1,547	960
Other accrued expenses	2,688	2,220
Total	$ 14,121	$ 17,929