Accounts Receivable and Sales Concentrations - Summary of Activity in the Allowance for Doubtful Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of year	$ 1,839	$ 1,719	$ 1,069
Additions	449	754	648
Write-offs	(924)	(584)	(101)
Currency impact	12	50	(103)
Balance at end of year	$ 1,352	$ 1,839	$ 1,719