CONSOLIDATED STATEMENTS OF CASH FLOWS $ in Millions, $ in Millions		12 Months Ended
		Dec. 31, 2024 CAD ($)	Dec. 31, 2023 CAD ($)		Dec. 31, 2022 CAD ($)
Operating activities
Net income (loss)		$ 3,713	$ 3,923		$ 3,517
Reconciliation of net income to cash provided by operating activities:
Depreciation and amortization (Note 10, 12, 14)		1,900	1,543		853
Deferred income tax expense (recovery) (Note 10)		28	(7,885)		136
Pension recovery and funding (Note 22)		(305)	(306)		(288)
Equity earnings of Kansas City Southern (Note 10, 11)		0	(230)		(1,074)
Remeasurement loss of Kansas City Southern (Note 10)		0	7,175		0
Dividends from Kansas City Southern (Note 11)		0			1,157
Settlement of Mexican taxes (Note 6)		(12)	(135)		0
Settlement of foreign currency forward contracts (Note 17)		(65)	0		0
Other operating activities, net		(14)	60		(67)
Change in non-cash working capital balances related to operations (Note 21)		24	(308)		(92)
Net cash provided by operating activities		5,269	4,137		4,142
Investing activities
Additions to properties		(2,825)	(2,468)		(1,557)
Additions to Meridian Speedway properties		(38)	(31)		0
Proceeds from sale of properties and other assets		64	57		58
Cash acquired on control of Kansas City Southern (Note 10)		0	298		0
Investment in government securities (Note 16)		0	(267)		0
Proceeds from settlement of government securities (Note 16)		0	274		0
Other investing activities, net		3	(25)		3
Net cash used in investing activities		(2,796)	(2,162)		(1,496)
Financing activities
Dividends paid		(709)	(707)		(707)
Issuance of Common Shares (Note 20)		69	69		32
Repayment of long-term debt, excluding commercial paper (Note 16)		(2,327)	(2,395)		(571)
Repayment of term loan (Note 16)		0	0		(636)
Net issuance (repayment) of commercial paper (Note 16)		439	1,095		(415)
Net increase in short-term borrowings (Note 16)		274	0		0
Acquisition-related financing fees (Note 10)		0	(17)		0
Other financing activities, net		2	0		0
Net cash used in financing activities		(2,252)	(1,955)		(2,297)
Effect of foreign currency fluctuations on foreign-denominated cash and cash equivalents		54	(7)		20
Cash position
Increase in cash and cash equivalents		275	13		369
Cash and cash equivalents at beginning of period(1)	[1]	464	451		82
Cash and cash equivalents at end of year		739	464	[1]	451	[1]
Supplemental disclosures of cash flow information:
Income taxes paid		958	906		408
Interest paid		$ 814	$ 825		$ 641

[1] As at January 1, 2022, cash and cash equivalents of $82 million included $13 million of restricted cash.