Balance Sheet Information - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Allowance for doubtful accounts	$ 111		$ 111		$ 104
Recovery of amounts previously written off			176
Consigned inventory with customers	200		200		300
Allowance for inventory losses	3,800		3,800		$ 3,400
Depreciation and amortization	$ 800	$ 700	2,300	$ 2,100
Disposal of fully depreciated property and equipment			$ 900
Equipment [Member]
Property, Plant and Equipment [Line Items]
Period over which assets are depreciated			5 years
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Period over which assets are depreciated			7 years
Building [Member]
Property, Plant and Equipment [Line Items]
Period over which assets are depreciated			30 years
Minimum [Member]
Property, Plant and Equipment [Line Items]
Standard term of accounts receivable			30 days
Minimum [Member] | Computer Equipment and Software Licenses [Member]
Property, Plant and Equipment [Line Items]
Period over which assets are depreciated			3 years
Maximum [Member]
Property, Plant and Equipment [Line Items]
Standard term of accounts receivable			90 days
Useful lives of the assets			1 year
Maximum [Member] | Computer Equipment and Software Licenses [Member]
Property, Plant and Equipment [Line Items]
Period over which assets are depreciated			5 years