XML 69 R59.htm IDEA: XBRL DOCUMENT v3.7.0.1
Equity Incentive Program - Additional Information (Details) - USD ($)
$ in Millions
1 Months Ended 3 Months Ended 6 Months Ended
Feb. 28, 2017
Jun. 30, 2017
Jun. 30, 2016
Jun. 30, 2017
Jun. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Allocated share-based compensation expense   $ 6.3 $ 5.6 $ 12.4 $ 11.0
SSARs          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Unrecognized compensation expense   0.0   0.0  
Stock Options          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Unrecognized compensation expense   11.7   $ 11.7  
Weighted average period for compensation expense to be recognized       1 year 3 months  
Restricted Stock Units (RSUs)          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Unrecognized compensation expense   30.6   $ 30.6  
Weighted average period for compensation expense to be recognized       1 year 6 months  
Performance Shares          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Unrecognized compensation expense   $ 2.4   $ 2.4  
Weighted average period for compensation expense to be recognized       2 years 7 months  
Minimum | Performance Shares          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Percentage increase of initial grant value 0.00%        
Maximum | Performance Shares          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Percentage increase of initial grant value 225.00%