Quarterly report pursuant to Section 13 or 15(d)

Revenue (Narrative) (Details)

v3.19.1
Revenue (Narrative) (Details) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Revenue from Contract with Customer [Abstract]    
Increase (decrease) in contract with customer liability $ 7,321  
Recognized deferred revenue 9,723 $ 7,516
Deferred sales incentive compensation 7,081  
Amortization expense for the deferred sales incentive compensation $ 651 $ 482