Earnings Per Share - Schedule of Basic and Diluted Per Share (Details) - CAD ($) $ in Thousands |
3 Months Ended | |
|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
|
| Schedule of Basic and Diluted Per Share [Abstract] | ||
| Net income (loss) attributable to Telesat Common Shares | $ (45,495) | $ (15,538) |
| Effect of diluted securities | ||
| Diluted net income (loss) attributable to Telesat Common Shares | $ (45,495) | $ (15,538) |