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Stock Compensation Plans (Weighted Average Assumptions Used to Determine Fair Value of ESP Plan) (Details) - Employee Stock
12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Fair value of the option component of the ESP Plan      
Risk free interest rate 0.10% 1.59% 1.59%
Dividend yield 2.86% 2.71% 2.27%
Volatility factor of the expected market price of the common shares 72.00% 36.00% 36.00%
Expected life for the options (in years) 1 year 1 year 1 year