Segmented information (Schedule of Geographic Area) (Details) - CAD ($) $ in Millions	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Revenues from External Customers [Line Items]
Revenues	$ 17,304	$ 17,046	$ 16,828
Long-lived assets	49,588	48,445
Canada
Revenues from External Customers [Line Items]
Revenues	12,104	11,875	11,570
Long-lived assets	28,133	26,635
U.S.
Revenues from External Customers [Line Items]
Revenues	5,200	5,171	$ 5,258
Long-lived assets	$ 21,455	$ 21,810

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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+ Details