RELATED PARTY TRANSACTIONS - Operating transactions (Details) - CAD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
|
| Ultimate parent and parent corporation | |||
| RELATED PARTY TRANSACTIONS | |||
| Revenues | $ 0.4 | $ 0.4 | $ 0.4 |
| Purchase of goods and services | 2.5 | 2.5 | 2.6 |
| Operating expenses recovered | (2.2) | (1.4) | (1.8) |
| Corporations under common control | |||
| RELATED PARTY TRANSACTIONS | |||
| Revenues | 3.6 | 3.3 | 4.1 |
| Purchase of goods and services | 126.6 | 119.3 | 147.5 |
| Operating expenses recovered | (3.6) | (2.6) | 0.2 |
| Other affiliated corporations | |||
| RELATED PARTY TRANSACTIONS | |||
| Purchase of goods and services | 51.2 | 52.2 | 30.5 |
| Acquisition of property, plant and equipment and intangible assets | $ 34.8 | $ 35.6 | $ 11.0 |