Annual report pursuant to Section 13 and 15(d)

Supplementary Balance Sheet Information - Additional Information (Detail)

v3.20.1
Supplementary Balance Sheet Information - Additional Information (Detail) - USD ($)
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Accounts Receivable [Abstract]      
Allowances for doubtful accounts $ 2,600,000 $ 900,000  
Provision for sales returns (655,000) 1,458,000 $ 337,000
Write-downs for excess and obsolete inventory 1,300,000 1,100,000  
Disposal of internally developed software   1,185,000 $ 505,000
Impairment charges on property, plant and equipment 0    
Sales Returns and Allowances      
Accounts Receivable [Abstract]      
Provision for sales returns $ 200,000 $ 200,000