Other long-term obligations - Table Narrative (Detail) - CAD ($) $ in Millions |
Jun. 30, 2025 |
Dec. 31, 2024 |
|---|---|---|
| Other Liabilities Disclosure [Abstract] | ||
| Employee retirement benefit obligations in current liabilities | $ 61 | $ 61 |
| Asset retirement obligations and other environmental liabilities in current liabilities | 291 | 291 |
| Lease liability due within one year, Operating leases | 102 | 100 |
| Undiscounted commitments | $ 48 | $ 56 |
| X | ||||||||||
- Definition Asset retirement obligation and other environmental liabilities current. No definition available.
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| X | ||||||||||
- Definition Present value of lessee's discounted obligation for lease payments from operating lease, classified as current. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- References No definition available.
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| X | ||||||||||
- Definition Amount of liability, recognized in statement of financial position, for defined benefit pension and other postretirement plans, classified as current. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Amount of unrecorded obligation to transfer funds in future for fixed or minimum amount or quantity of product and service at fixed or minimum price. Includes, but is not limited to, lease not yet commenced and take-or-pay and throughput contracts. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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