Investment in Kansas City Southern - Summarized Financial Information, Balance Sheet (Details) $ in Millions	12 Months Ended
	Dec. 31, 2022 CAD ($)	Dec. 31, 2023 CAD ($)
Assets
Current assets	$ 1,889	$ 3,002
Properties	22,385	51,744
Other non-current assets	420	582
Liabilities
Current liabilities	3,213	5,710
Other non-current liabilities	520	797
Non-controlling interest (Note 11)	$ 0	$ 919
Canada, Dollars
Liabilities
Daily exchange rate used, assets/liabilities	1.35
Kansas City Southern
Assets
Current assets	$ 1,441
Properties	12,680
Other non-current assets	340
Liabilities
Current liabilities	1,748
Long-term debt	4,232
Other non-current liabilities	1,987
Non-controlling interest (Note 11)	$ 448