Financial and derivative instruments - Summary of realized and unrealized gain or (loss) on derivative instruments (Detail) - CAD ($) $ in Millions |
3 Months Ended | |
|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
|
| Derivative Instruments and Hedging Activities Disclosure [Abstract] | ||
| Revenues | $ 65 | $ 15 |