XML 58 R48.htm IDEA: XBRL DOCUMENT v3.8.0.1
Stock-based Compensation - Narrative (Details) - USD ($)
3 Months Ended
Feb. 17, 2016
Mar. 31, 2018
Mar. 31, 2017
Stock-based Compensation arrangements      
Stock based compensation expense   $ 5,400,000 $ 8,300,000
Restricted Stock Units      
Stock-based Compensation arrangements      
Granted (in shares)   71,400  
Granted (in dollars per share)   $ 23.42  
Performance Share Awards | Minimum      
Stock-based Compensation arrangements      
Annual forfeiture rate assumption (as a percent)   0.00%  
Performance Share Awards | Maximum      
Stock-based Compensation arrangements      
Annual forfeiture rate assumption (as a percent)   5.00%  
Performance Share Awards Based on Internal Performance Metrics      
Stock-based Compensation arrangements      
Right to receive additional shares, maximum (as a percent)   100.00%  
Employee Performance Share Awards      
Stock-based Compensation arrangements      
Granted (in shares)   531,670  
Granted (in dollars per share)   $ 23.25  
Number of years over which performance criteria is to be met   3 years  
Hybrid Performance Share Awards      
Stock-based Compensation arrangements      
Granted (in shares)   321,720  
Granted (in dollars per share)   $ 23.25  
Minimum operating cash flow for the year preceding the performance period   $ 100,000,000  
Hybrid Performance Share Awards | Hybrid performance share awards, percentage vesting on the first anniversary      
Stock-based Compensation arrangements      
Award vesting rights (as a percent)   25.00%  
Hybrid Performance Share Awards | Hybrid performance share awards, percentage vesting on the second anniversary      
Stock-based Compensation arrangements      
Award vesting rights (as a percent)   25.00%  
Hybrid Performance Share Awards | Hybrid performance share awards, percentage vesting on the third anniversary      
Stock-based Compensation arrangements      
Award vesting rights (as a percent)   50.00%  
Performance Shares Based on Market Conditions      
Stock-based Compensation arrangements      
Right to receive shares (as a percent)   100.00%  
Right to receive an additional award in cash (as a percent)   100.00%  
TSR Performance Share Awards      
Stock-based Compensation arrangements      
Granted (in shares)   482,581  
Granted (in dollars per share) $ 19.92    
Performance period   3 years  
TSR Performance Share Awards | Minimum      
Stock-based Compensation arrangements      
Granted (in dollars per share)   $ 8.44  
TSR Performance Share Awards | Maximum      
Stock-based Compensation arrangements      
Granted (in dollars per share)   $ 17.09