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Share and Unit-based Plans - Directors' Phantom Stock Plan (Details)
 12 Months Ended
Dec. 31, 2021
$ / shares
shares
Dec. 31, 2020
$ / shares
shares
Dec. 31, 2019
$ / shares
shares
Phantom stock units      
Share and unit-based plans      
Number of common shares into which units can be converted (in shares) 1    
Units      
Balance at beginning of year (in shares) 4,662 7,216 0
Granted (in shares) 17,554 24,576 23,690
Vested (in shares) (22,216) (27,130) (16,474)
Forfeited (in shares) 0 0 0
Balance at end of year (in shares) 0 4,662 7,216
Weighted Average Grant Date Fair Value      
Balance at beginning of year (in dollars per share) | $ / shares $ 35.35 $ 43.29 $ 0
Granted (in dollars per share) | $ / shares 12.09 17.11 40.26
Vested (in dollars per share) | $ / shares 16.97 20.94 38.94
Forfeited (in dollars per share) | $ / shares 0 0 0
Balance at end of year (in dollars per share) | $ / shares $ 0 $ 35.35 $ 43.29
Director's Phantom Stock Plan      
Share and unit-based plans      
Deferral period for grant of units (in years) 3 years    
Number of common shares into which units can be converted (in shares) 1    
Maximum shares authorized under plan (in shares) 500,000    
Shares available for issuance under plan (in shares) 92,508