advance billings and customer deposits - Reconciliation of contract liabilities (Details) - CAD ($) $ in Millions |
Jun. 30, 2026 |
Dec. 31, 2025 |
Jun. 30, 2025 |
|---|---|---|---|
| advance billings and customer deposits | |||
| Gross contract liabilities | $ 965 | $ 1,026 | |
| Reclassification to contract assets of contracts with contract liabilities less than contract assets | (108) | (119) | |
| Reclassification from contract assets of contracts with contract assets less than contract liabilities | (13) | (17) | |
| Contract liabilities | $ 844 | $ 893 | $ 890 |