Derivative and Hedging Instruments - Cost of Hedging (Details) - IFRS 9 - CAD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
|
| Foreign exchange risk | ||
| Accumulated other comprehensive income (loss) [Roll Forward] | ||
| Accumulated other comprehensive income (loss), beginning of year | $ 111 | $ 0 |
| Changes in fair value | (143) | 111 |
| Amount reclassified to profit or loss | (37) | 0 |
| Accumulated other comprehensive income (loss), end of year | 5 | 111 |
| Foreign exchange and interest rate risk | ||
| Accumulated other comprehensive income (loss) [Roll Forward] | ||
| Accumulated other comprehensive income (loss), beginning of year | 8 | 18 |
| Changes in fair value | (3) | (10) |
| Amount reclassified to profit or loss | 0 | 0 |
| Accumulated other comprehensive income (loss), end of year | $ 5 | $ 8 |