Quarterly report pursuant to Section 13 or 15(d)

Revenue Recognition - Additional Information (Details)

v3.19.1
Revenue Recognition - Additional Information (Details) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2019
Dec. 31, 2018
Disaggregation of Revenue [Line Items]    
Deferred revenue $ 2,710 $ 2,597
Contracts for rental units $ 815  
Lease term 12 months  
Accounts receivable, net of allowances $ 3,793 $ 3,660
Minimum    
Disaggregation of Revenue [Line Items]    
Accounts receivable payment terms 30 days  
Maximum    
Disaggregation of Revenue [Line Items]    
Accounts receivable payment terms 60 days