FINANCIAL INSTRUMENTS - Earnings Impact of (Gain) Loss from Risk Management Positions (Detail) - CAD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2026 |
Sep. 30, 2025 |
Sep. 30, 2026 |
Sep. 30, 2025 |
|
| Disclosure of detailed information about financial instruments [line items] | ||||
| (Gain) Loss on Risk Management | $ 7 | $ (2) | $ 80 | $ (79) |
| Realized (Gain) Loss | ||||
| Disclosure of detailed information about financial instruments [line items] | ||||
| (Gain) Loss on Risk Management | 5 | 17 | 98 | (14) |
| Unrealized (Gain) Loss | ||||
| Disclosure of detailed information about financial instruments [line items] | ||||
| (Gain) Loss on Risk Management | $ 2 | $ (19) | $ (18) | $ (65) |