Quarterly report pursuant to Section 13 or 15(d)

Share-Based Compensation (Narrative) (Details)

v3.20.1
Share-Based Compensation (Narrative) (Details) - USD ($)
$ in Millions
3 Months Ended 12 Months Ended
Mar. 31, 2020
Mar. 31, 2019
Dec. 31, 2019
RSUs      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
TSR, maximum percent of performance period 5.00%    
Grant date fair value $ 0.7 $ 2.6  
Unrecognized compensation costs $ 19.0    
Period for recognition 1 year 6 months    
RSUs | Vesting Percentage, Minimum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Award vesting rights 0.00% 0.00%  
RSUs | Vesting Percentage, Maximum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Award vesting rights 300.00% 200.00%  
Performance-based Equity Awards      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Grant date fair value $ 2.9 $ 4.3  
Performance-based Equity Awards | Vesting Percentage, Minimum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Award vesting rights 0.00%   0.00%
Performance-based Equity Awards | Vesting Percentage, Maximum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Award vesting rights 30000.00%   200.00%
Cash-Settled RSUs      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Unrecognized compensation costs $ 0.6    
Period for recognition 1 year 9 months    
Award vesting period 3 years