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Stock-Based Compensation (Details) - USD ($)
$ / shares in Units, $ in Millions
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]      
Outstanding at beginning of period (in shares) 969,928 873,849 1,040,569
Granted (in shares) 302,596 304,795 243,940
Converted (in shares) (291,064) (205,616) (320,810)
Expired (in shares) (7,900) (500) (82,050)
Forfeited (in shares) (9,728) (2,600) (7,800)
Outstanding at end of period (in shares) 963,832 969,928 873,849
Vested (in shares) 476,389 463,422 441,424
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]      
Outstanding at beginning of period, Weighted average grant-date fair value (in dollars per share) $ 15.89 $ 12.30 $ 9.97
Granted, Weighted average grant-date fair value (in dollars per share) 23.22 24.18 17.52
Converted, Weighted average grant-date fair value (in dollars per share) 17.14 12.74 9.47
Expired, Weighted average grant-date fair value (in dollars per share) 23.78 28.38 9.22
Forfeited, Weighted average grant-date fair value (in dollars per share) 23.37 26.76 13.55
Outstanding at end of period, Weighted average grant-date fair value (in dollars per share) 17.67 15.89 12.30
Vested (in dollars per share) $ 11.11 $ 10.25 $ 7.61
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]      
Share-based compensation expense $ 7.0 $ 5.0 $ 3.6
Unrecognized share-based compensation expense $ 6.7    
Unrecognized share-based compensation, weighted average recognition period 1 year 6 months    
Restricted Stock [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Requisite service period   3 years  
Stock Units [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Requisite service period   3 years  
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]      
Historical volatility period 3 years 3 years  
Risk-free interest rate 2.50% 2.40% 1.70%
Expected volatility rate 35.60% 33.80% 34.70%
Market Condition Award [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]      
Granted, Weighted average grant-date fair value (in dollars per share) $ 24.75 $ 31.60 $ 20.18
Performance Condition Award [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]      
Granted, Weighted average grant-date fair value (in dollars per share) $ 22.80 $ 25.15 $ 16.72
Time-Based Awards [Member] | Maximum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]      
Number of additional outstanding shares issued (in shares) 1,198,507    
Director [Member] | Time-Based Awards [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]      
Vested (in shares) 337,060    
Director [Member] | Time-Based Awards [Member] | Minimum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Requisite service period   6 months  
Director [Member] | Time-Based Awards [Member] | Maximum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Requisite service period   12 months