Earnings Per Share - Schedule of Reconciliations of the Denominators of the Basic and Diluted Per Share (Details) - shares	3 Months Ended
Mar. 31, 2026	Mar. 31, 2025
Schedule of Reconciliations of the Denominators of the Basic and Diluted Per Share [Line Items]
Basic total weighted average number of Telesat Common Shares outstanding	14,979,228	14,381,205
Effect of diluted securities
Diluted total weighted average number of Telesat Common Shares outstanding	14,979,228	14,381,205
Stock options [Member]
Effect of diluted securities
Effect of diluted securities
RSUs, DSUs and PSUs [Member]
Effect of diluted securities
Effect of diluted securities

The weighted average number of ordinary shares outstanding plus the weighted average number of ordinary shares that would be issued on the conversion of all the dilutive potential ordinary shares into ordinary shares. [Refer: Ordinary shares [member]; Weighted average [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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The potential dilutive effect on the weighted average number of ordinary shares that relate to the assumed exercise of the entity's share options.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
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Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table.

+ References

No definition available.

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The number of ordinary shares outstanding at the beginning of the period, adjusted by the number of ordinary shares bought back or issued during the period multiplied by a time-weighting factor.

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- References

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