Segmented information - Narrative (Details) - CAD ($)	12 Months Ended
Sep. 30, 2024	Sep. 30, 2023
Disclosure of major customers [line items]
Revenue	$ 14,676,152,000	$ 14,296,360,000
U.S. Federal
Disclosure of major customers [line items]
Revenue	2,001,391,000	1,935,238,000
U.S. Federal \| Government
Disclosure of major customers [line items]
Revenue	$ 1,994,150,000	$ 1,923,977,000
Percentage of revenues	13.60%	13.50%

The income arising in the course of an entity's ordinary activities. Income is increases in assets, or decreases in liabilities, that result in increases in equity, other than those relating to contributions from holders of equity claims.

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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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+ Details