Accounts Receivable and Sales Concentrations - Summary of Activity in the Allowance for Doubtful Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Receivables [Abstract]
Balance at Beginning of Year	$ 1,221	$ 520	$ 445
Additions	142	745	208
Write- offs	(75)	(8)	(123)
Currency Impacts	(81)	(36)	(10)
Balance at End of Year	$ 1,207	$ 1,221	$ 520