Annual report pursuant to Section 13 and 15(d)

Supplementary Balance Sheet Information - Additional Information (Detail)

v3.10.0.1
Supplementary Balance Sheet Information - Additional Information (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Accounts Receivable [Abstract]      
Allowances for doubtful accounts $ 900 $ 800  
Provision for sales returns 1,458 337 $ 644
Write-downs for excess and obsolete inventory 1,100 1,900  
Disposal of internally developed software 1,185 505  
Assets Held Under Capital Lease      
Accounts Receivable [Abstract]      
Capital leased assets, Gross 400    
Sales Returns and Allowances      
Accounts Receivable [Abstract]      
Provision for sales returns $ 200 $ 200