Annual report pursuant to Section 13 and 15(d)

Stock Plans and Management Compensation (Details 3)

v3.22.4
Stock Plans and Management Compensation (Details 3) - USD ($)
$ / shares in Units, $ in Millions
12 Months Ended
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2020
Share-Based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]      
Percentage of Premium Paid Out in Deferred Company Common Stock 20.00%    
Performance Shares [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Share-Based Compensation Expense $ 3.6 $ 13.5 $ 13.8
Share-Based Compensation Expense, Tax Benefit 0.9 3.3 3.4
Fair Value of Shares Vested During the Period $ 14.6 $ 18.6 $ 3.4
Share-Based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]      
Outstanding at January 1 192,000    
Awarded Grants in Period 207,000    
Forfeited (5,000)    
Vested (203,000)    
Outstanding at December 31 191,000 192,000  
Weighted Average Grant Date Fair Value $ 90.97 $ 76.15  
Awarded - Weighted Average Grant Date Fair Value 70.32    
Forfeited - Weighted Average Grant Date Fair Value 81.31    
Vested - Weighted Average Grant Date Fair Value $ 56.11    
Unrecognized Compensation Cost $ 3.3    
Unrecognized Compensation Cost, Period for Recognition 1 year 6 months    
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term 2 years 10 months 24 days 2 years 10 months 24 days 2 years 10 months 24 days
Non-Vested Stock Awards [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Share-Based Compensation Expense $ 18.2 $ 16.3 $ 13.3
Share-Based Compensation Expense, Tax Benefit 4.5 4.0 3.3
Fair Value of Shares Vested During the Period $ 16.7 $ 11.3 $ 6.6
Share-Based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]      
Outstanding at January 1 635,000    
Awarded Grants in Period 226,000    
Forfeited (28,000)    
Vested (232,000)    
Outstanding at December 31 601,000 635,000  
Weighted Average Grant Date Fair Value $ 82.14 $ 66.81  
Awarded - Weighted Average Grant Date Fair Value 93.62 $ 91.14 $ 64.13
Forfeited - Weighted Average Grant Date Fair Value 83.15    
Vested - Weighted Average Grant Date Fair Value $ 51.32    
Unrecognized Compensation Cost $ 12.5    
Age of Grantee   62 years  
Unrecognized Compensation Cost, Period for Recognition 1 year 2 months 12 days    
Awards Vesting Period (in years) 3 years    
Stock Options and SAR's [Member]      
Share-Based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]      
Period for Stock Options and SARs to be Exercisable (in years) 10 years    
Awards Vesting Period (in years) 4 years    
Outstanding on December 31 1 month 6 days    
Exercisable and Vested on December 31 1 month 6 days    
Vested and Expected to Vest on December 31 1 month 6 days    
Stock Options and SAR's [Member] | $23.79 [Member]      
Share-Based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]      
Outstanding Options, Weighted Average Remaining Years of Contractual Life (in years) 1 year 1 month 6 days    
Stock Options and SAR's [Member] | Greater Than $14.68 [Member]      
Share-Based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]      
Outstanding Options, Weighted Average Remaining Years of Contractual Life (in years) 1 month 6 days    
Stock Options and SAR's [Member] | $5.87 to $14.68 [Member]      
Share-Based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]      
Outstanding Options, Weighted Average Remaining Years of Contractual Life (in years) 8 months 12 days    
Stock Options and SAR's [Member] | $5.86 [Member]      
Share-Based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]      
Outstanding Options, Weighted Average Remaining Years of Contractual Life (in years) 0 years    
Share-based Payment Arrangement, Tranche Two [Member] | Performance Shares [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Weighted Average Price at Grant Date (in dollars per share) $ 91.62 $ 87.48 $ 61.91
Share-Based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]      
Awarded Grants in Period 24,320 24,560 26,750
Share-based Payment Arrangement, Tranche One [Member] | Performance Shares [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Weighted Average Price at Grant Date (in dollars per share) $ 94.59 $ 91.44 $ 64.72
Risk-Free Interest Rate 1.70% 0.20% 1.40%
Dividend Yield 1.50% 1.20% 1.50%
Volatility Factor 54.80% 65.60% 46.60%