Allowance for Doubtful Accounts Receivable and Sales Returns (Activity in Allowance for Doubtful Accounts Receivable and Sales Returns) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning Balance	$ 560
Ending Balance	597	$ 560
Allowance of doubtful AR assumed from Acquisition	81	0
Allowance for Doubtful Accounts Receivable
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning Balance	475	725
Addition (reduction) to allowance	24	(224)
Effects of foreign currency translation	(15)	(26)
Ending Balance	565	475
Allowance for Sales Returns
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning Balance	85	212
Addition (reduction) to allowance	(32)	(126)
Amounts written off	(21)	0
Effects of foreign currency translation	0	(1)
Ending Balance	$ 32	$ 85