XML 90 R56.htm IDEA: XBRL DOCUMENT v3.20.4
Shareholders' equity - Summary of Issued Capital (Detail) - CAD ($)
$ in Millions
 9 Months Ended 12 Months Ended
Sep. 30, 2020
Sep. 30, 2019
Dec. 31, 2019
Disclosure of classes of share capital [line items]      
Balance, beginning of year $ 2,187    
Issued on exercise of equity compensation plans 2 $ 3  
Balance, end of year 2,187   $ 2,187
Common shares [member]      
Disclosure of classes of share capital [line items]      
Balance, beginning of year 2,187 $ 2,185 2,185
Issued on exercise of equity compensation plans [1] 0   2
Balance, end of year $ 2,187   $ 2,187
Balance, beginning of year 73,011,488 72,473,719 72,473,719
Issued on exercise of equity compensation plans [1] 495,255   537,769
Balance, end of year 73,506,743   73,011,488
[1] Upon vesting or exercise of equity awards, the net benefit is recorded as a reduction of other reserves and an increase to shareholders’ capital.