XML 50 R39.htm IDEA: XBRL DOCUMENT v3.10.0.1
Stock Incentive Plans - Additional Information (Details) - USD ($)
shares in Millions, $ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Jun. 30, 2018
Jun. 30, 2017
Apr. 18, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Stock-based compensation expense $ 2.3 $ 1.8 $ 4.6 $ 3.9  
Restricted Stock          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Total unrecognized compensation expenses $ 25.7   $ 25.7    
Weighted average period expected to be recognized     4 years 2 months    
2017 Stock Incentive Plan          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Shares available for grant (in shares)         3.0
Minimum | Restricted Stock          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Restricted stock granted, vesting period     1 year    
Maximum | Restricted Stock          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Restricted stock granted, vesting period     10 years