INTERIM CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - CAD ($) shares in Millions, $ in Millions	Total	Share capital	Additional paid-in capital	Accumulated other comprehensive income (loss)	Retained earnings
Beginning balance (shares) at Dec. 31, 2021	929.7
Beginning balance at Dec. 31, 2021	$ 33,829	$ 25,475	$ 66	$ (2,103)	$ 10,391
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	590				590
Other comprehensive loss (Note 6)	(270)			(270)
Dividends declared	(177)				(177)
Effect of stock-based compensation expense	7		7
Shares issued for Kansas City Southern acquisition	$ (2)
Shares issued under stock option plan (shares)	0.2
Shares issued under stock option plan	$ 8	11	(3)
Ending balance (shares) at Mar. 31, 2022	929.9
Ending balance at Mar. 31, 2022	$ 33,985	25,486	68	(2,373)	10,804
Beginning balance (shares) at Dec. 31, 2022	930.5
Beginning balance at Dec. 31, 2022	$ 38,886	25,516	78	91	13,201
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	800				800
Other comprehensive loss (Note 6)	(17)			(17)
Dividends declared	(177)				(177)
Effect of stock-based compensation expense	$ 10		10
Shares issued under stock option plan (shares)	0.4
Shares issued under stock option plan	$ 18	22	(4)
Ending balance (shares) at Mar. 31, 2023	930.9
Ending balance at Mar. 31, 2023	$ 39,520	$ 25,538	$ 84	$ 74	$ 13,824