Quarterly report pursuant to Section 13 or 15(d)

Revenue Recognition - Additional Information (Details)

v3.10.0.1
Revenue Recognition - Additional Information (Details) - USD ($)
$ in Thousands
Sep. 30, 2018
Dec. 31, 2017
Revenue from Contract with Customer [Abstract]    
Deferred revenue $ 2,480 $ 1,919
Accounts receivable, net of allowances 2,988 $ 2,760
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-10-01    
Revenue from Contract with Customer [Abstract]    
Remaining performance obligation, amount $ 311  
Disaggregation of Revenue [Line Items]    
Remaining performance obligation, period 3 months  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01    
Revenue from Contract with Customer [Abstract]    
Remaining performance obligation, amount $ 744  
Disaggregation of Revenue [Line Items]    
Remaining performance obligation, period 1 year  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01    
Revenue from Contract with Customer [Abstract]    
Remaining performance obligation, amount $ 1,369  
Disaggregation of Revenue [Line Items]    
Remaining performance obligation, period