Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Employee Stock Purchase Programs (Details)

v3.19.2
Stockholders' Equity - Employee Stock Purchase Programs (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock-based compensation expense $ 3,373 $ 3,152 $ 6,682 $ 7,947
Avenue [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock-based compensation expense 535 322 1,286 671
Checkpoint [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock-based compensation expense 813 72 1,611 1,209
Mustang [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock-based compensation expense 622 972 1,054 2,966
Other [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock-based compensation expense 57 198 100 30
Employee Awards [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock-based compensation expense 920 1,121 1,855 2,063
Executive Awards [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock-based compensation expense 355 444 707 962
Non-Employee Awards [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock-based compensation expense $ 71 $ 23 $ 69 $ 46