XML 139 R118.htm IDEA: XBRL DOCUMENT v3.10.0.1
Share-based Compensation - Performance Units Narratives (Details) - USD ($)
$ / shares in Units, $ in Millions
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award      
Recognition period for unrecognized share based compensation 2 years 146 days    
Share based compensation not yet recognized $ 7.9    
Performance units      
Share-based Compensation Arrangement by Share-based Payment Award      
Award vesting period 3 years    
Percentage of earn-out granted 100.00%    
Recognition period for unrecognized share based compensation 1 year 256 days    
Share based compensation not yet recognized $ 0.3    
Granted (usd per share) $ 49.38 $ 37.34 $ 19.69
Fair value of shares vested $ 0.1 $ 0.8 $ 1.8
Performance units | Minimum      
Share-based Compensation Arrangement by Share-based Payment Award      
Percentage of earn-out granted 0.00%    
Performance units | Maximum      
Share-based Compensation Arrangement by Share-based Payment Award      
Percentage of earn-out granted 200.00%