Financial and derivative instruments - Narrative (Detail) - CAD ($) $ in Millions	Sep. 30, 2026	Dec. 31, 2025
Financial Instruments And Derivatives [Line Items]
Long-term debt, fair value	$ 3,447	$ 3,447
Master netting arrangements
Financial Instruments And Derivatives [Line Items]
Derivative collateral receivable	$ 8	$ 6

Amount of right to receive cash collateral under master netting arrangements that have not been offset against derivative liabilities.

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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+ Details