Summary of Significant Accounting Policies - Summary of Allowance for Expected Credit Losses on Accounts Receivable (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Receivables [Abstract]
Balance, beginning of year	$ 628	$ 359	$ 155
Cumulative effect adjustment of adopting Topic 326	218
Provision for expected credit losses	721	1,246	567
Write-offs	(850)	(987)	(356)
Translation adjustments	(9)	10	(7)
Balance, end of year	$ 708	$ 628	$ 359