Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Employee Stock Purchase Programs (Detail)

v3.10.0.1
Stockholders' Equity - Employee Stock Purchase Programs (Detail) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2018
Sep. 30, 2017
Sep. 30, 2018
Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock-based compensation expense $ 5,035 $ 4,313 $ 13,658 $ 12,048
National [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock-based compensation expense 929 129 1,605 312
Avenue [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock-based compensation expense 371 246 1,043 269
Checkpoint [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock-based compensation expense 1,128 910 2,336 4,271
Mustang [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock-based compensation expense 922 834 3,888 1,231
Caelum [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock-based compensation expense 152 427 92 427
Other [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock-based compensation expense 51 93 141 308
Employee Awards [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock-based compensation expense 1,012 1,104 3,075 3,528
Executive Awards [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock-based compensation expense 446 546 1,408 1,642
Non-Employee Awards [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock-based compensation expense $ 24 $ 24 $ 70 $ 60