XML 80 R65.htm IDEA: XBRL DOCUMENT v3.10.0.1
Stock-Based Compensation - Performance Share Awards (Details) - USD ($)
$ / shares in Units, $ in Millions
12 Months Ended 24 Months Ended 48 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2021
Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]          
Allocated share-based compensation expense $ 11.0 $ 8.5 $ 7.1    
Performance Shares Awards          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Award requisite service period 3 years        
Period for share issuance after vesting 60 days        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]          
Total compensation cost not yet recognized $ 3.4 $ 3.7      
Total compensation cost not yet recognized, period for recognition 1 year 9 months 18 days 1 year 6 months 7 days      
Performance Shares Awards | Minimum          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Potential vesting percentage 0.00%        
Performance Shares Awards | Maximum          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Potential vesting percentage 200.00%        
Market Condition Performance Share Awards          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Expected dividend yield (percent) 0.00% 0.00%      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]          
Outstanding (in shares) 120,359       120,359
Granted (in shares) 52,074        
Vested (in shares) (83,977)        
Forfeited (in shares) (5,549)        
Outstanding (in shares) 82,907 120,359      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]          
Outstanding, weighted-average grant date fair value (in dollars per share) $ 52.84       $ 52.84
Granted, weighted-average grant date fair value (in dollars per share) 52.07        
Vested, weighted-average grant date fair value (in dollars per share) 50.88        
Forfeited, weighted-average grant date fair value (in dollars per share) 59.01        
Outstanding, weighted-average grant date fair value (in dollars per share) $ 53.92 $ 52.84      
Performance Condition Performance Share Awards          
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]          
Outstanding (in shares) 35,507       35,507
Granted (in shares) 26,037        
Vested (in shares) (18,717)        
Forfeited (in shares) (1,373)        
Outstanding (in shares) 41,454 35,507      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]          
Outstanding, weighted-average grant date fair value (in dollars per share) $ 45.72       $ 45.72
Granted, weighted-average grant date fair value (in dollars per share) 46.21        
Vested, weighted-average grant date fair value (in dollars per share) 39.18        
Forfeited, weighted-average grant date fair value (in dollars per share) 51.04        
Outstanding, weighted-average grant date fair value (in dollars per share) $ 49.81 $ 45.72      
Stock Appreciation Rights (SARs) [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Period for share issuance after vesting 60 days        
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]          
Award performance period 2 years        
Allocated share-based compensation expense $ 1.2        
Stock Appreciation Rights (SARs) [Member] | Minimum          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Potential vesting percentage 0.00%        
Stock Appreciation Rights (SARs) [Member] | Maximum          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Potential vesting percentage 370.00%        
Scenario, Forecast | Stock Appreciation Rights (SARs) [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Award requisite service period       2 years 4 years