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Stock Compensation Plans - Performance Shares (Details) - Performance Shares
12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Volatility of common stock 37.30% 19.60% 19.40%
Average correlation coefficient of peer companies 67.00% 51.00% 50.00%
Risk-free spot rate 0.20% 1.20% 2.40%
Term 3 years 3 years 3 years
Minimum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Average volatility of peer companies 27.00% 18.00% 16.00%
Maximum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Average volatility of peer companies 49.00% 31.00% 27.00%