XML 152 R135.htm IDEA: XBRL DOCUMENT v3.20.4
STOCK-BASED COMPENSATION - Restricted and Deferred Share Unit Activity (Details) - shares
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Restricted share units    
Disclosure of terms and conditions of share-based payment arrangement [line items]    
Outstanding, beginning of year (in shares) 2,472,774 2,218,925
Granted and reinvested dividends (in shares) 1,026,067 1,013,900
Exercised (in shares) (803,266) (582,314)
Forfeited (in shares) (121,681) (177,737)
Outstanding, end of year (in shares) 2,573,894 2,472,774
Deferred share units    
Disclosure of terms and conditions of share-based payment arrangement [line items]    
Outstanding, beginning of year (in shares) 1,741,884 2,004,440
Granted and reinvested dividends (in shares) 80,252 110,003
Exercised (in shares) (192,718) (348,285)
Forfeited (in shares) (9,477) (24,274)
Outstanding, end of year (in shares) 1,619,941 1,741,884