XML 69 R58.htm IDEA: XBRL DOCUMENT v3.19.2
STOCK BASED COMPENSATION - Additional Information (Detail) - USD ($)
$ in Millions
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]        
Intrinsic value of options exercised $ 1.5 $ 0.9 $ 1.5 $ 1.5
Stock Options        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Unrecognized compensation expenses related to stock options 15.5   $ 15.5  
Weighted average period of recognition for unrecognized compensation expenses     2 years 8 months 12 days  
Award vesting period     3 years  
Restricted Stock Units (RSUs)        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Weighted average period of recognition for unrecognized compensation expenses     3 years  
Award vesting period     3 years  
Unrecognized compensation expenses related to RSUs 26.7   $ 26.7  
Fair value of units vested (in shares) 0.9   4.8  
Performance-Based Restricted Stock Units        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Unrecognized compensation expenses related to RSUs $ 1.4   $ 1.4  
Additional shares expected to vest     243,000