ACCOUNTS RECEIVABLE - Summary of Accounts Receivable (Details) - CAD ($) $ in Millions |
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
|---|---|---|---|
| Accounts, Notes, Loans and Financing Receivable [Line Items] | |||
| Accounts receivable, gross | $ 1,140 | $ 972 | |
| Allowance for doubtful accounts | (57) | (61) | $ (57) |
| Accounts receivable, net | 1,083 | 911 | |
| Accounts receivable - billed | |||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | |||
| Accounts receivable, gross | 467 | 433 | |
| Accounts receivable - unbilled | |||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | |||
| Accounts receivable, gross | $ 673 | $ 539 |