Annual report pursuant to Section 13 and 15(d)

Revenue Recognition - Disaggregation of Revenue (Details)

v3.19.1
Revenue Recognition - Disaggregation of Revenue (Details) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Disaggregation of Revenue [Line Items]                      
Net sales $ 49,055 $ 47,923 $ 43,914 $ 40,552 $ 44,437 $ 39,018 $ 39,021 $ 38,091 $ 181,444 $ 160,567 $ 164,609
Deferred revenue balances $ 0               $ 0    
Minimum                      
Disaggregation of Revenue [Line Items]                      
Payment terms on invoiced amount                 30 days    
Maximum                      
Disaggregation of Revenue [Line Items]                      
Payment period                 3 years    
Payment terms on invoiced amount                 75 days    
Hardware, software and other products                      
Disaggregation of Revenue [Line Items]                      
Net sales                 $ 164,870 143,920 148,949
Software - security and highly interdependent with support                      
Disaggregation of Revenue [Line Items]                      
Net sales                 6,527 5,939 4,916
Maintenance, support and other services revenue                      
Disaggregation of Revenue [Line Items]                      
Net sales                 $ 10,047 $ 10,708 $ 10,744