v3.19.2
dividends per share (Details) - CAD ($)
$ / shares in Units, $ in Millions
3 Months Ended 6 Months Ended
Oct. 01, 2019
Aug. 01, 2019
Jun. 30, 2019
Mar. 31, 2019
Jun. 30, 2018
Mar. 31, 2018
Jun. 30, 2019
Jun. 30, 2018
Dividends per share                
Dividends per share   $ 0.5625 $ 0.5625 $ 0.5450 $ 0.5250 $ 0.5050 $ 1.1075 $ 1.0300
Dividends Declared     $ 339 $ 329 $ 315 $ 299 $ 668 $ 614
Dividend Reinvestment and Share Purchase Plan                
Dividends per share                
Maximum discount on common shares (as a percent)             5.00%  
Offering price discount on Common Shares from Treasury (as a percent) 2.00%              
Dividend reinvestment in Common Shares     $ 15   $ 14   $ 28 $ 27
Purchase plan discount     0.00%   0.00%   0.00% 0.00%