Other long-term obligations - Summary of Other Long-Term Obligations (Detail) - CAD ($) $ in Millions |
Sep. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Other Liabilities Disclosure [Abstract] | ||
| Employee retirement benefits | $ 818 | $ 811 |
| Asset retirement obligations and other environmental liabilities | 3,347 | 3,348 |
| Share-based incentive compensation liabilities | 400 | 198 |
| Operating lease liability | 169 | 149 |
| Restructuring liability | 85 | 173 |
| Other obligations | 314 | 280 |
| Total other long-term obligations | $ 5,133 | $ 4,959 |
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- Definition Asset retirement obligation and other environmental liabilities, noncurrent. No definition available.
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- Definition Aggregate carrying value as of the balance sheet date of the liabilities for stock option plans and other equity-based compensation arrangements payable after one year (or the operating cycle, if longer). Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Present value of lessee's discounted obligation for lease payments from operating lease, classified as noncurrent. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- References No definition available.
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- Definition Amount of liabilities classified as other, due after one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Obligations not otherwise itemized or categorized in the footnotes to the financial statements that are expected to be paid after one year (or the normal operating cycle, if longer), from the balance sheet date. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Amount of liability, recognized in statement of financial position, for defined benefit pension and other postretirement plans, classified as noncurrent. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Carrying amount as of the balance sheet date of known and estimated costs associated with exit from or disposal of business activities or restructurings pursuant to a duly authorized plan, which are expected to be paid after one year or beyond the next operating cycle, if longer. Costs of such activities include those for one-time termination benefits, termination of an operating lease or other contract, consolidating or closing facilities, and relocating employees, and costs associated with an ongoing benefit arrangement, but excludes costs associated with the retirement of a long-lived asset. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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