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v3.25.3

Employee benefits - Narrative (Details) | 12 Months Ended
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Sep. 30, 2025 CAD ($) plan | Sep. 30, 2024 CAD ($)
Disclosure of defined benefit plans [line items] |  |
Surplus in plan | $ (143,559,000) | $ (167,920,000)
Current service cost | 16,290,000 | 14,165,000
Annual contributions | 9,525,000 |
Pension cost for defined contribution plans | 324,486,000 | 296,470,000
Deferred compensation plan liabilities | 139,317,000 | 124,447,000
Deferred compensation plan assets | $ 125,388,000 | 112,270,000
U.K. |  |
Disclosure of defined benefit plans [line items] |  |
Number of defined benefit pension plans | plan | 3 |
Surplus in plan | $ 55,084,000 | 22,230,000
Annual contributions | 433,000 |
Other |  |
Disclosure of defined benefit plans [line items] |  |
Surplus in plan | (35,596,000) | (32,668,000)
Annual contributions | 9,092,000 |
UNITED STATES |  |
Disclosure of defined benefit plans [line items] |  |
Deferred compensation plan assets | $ 125,388,000 | 112,270,000
CMG U.K. Pension Scheme | U.K. |  |
Disclosure of defined benefit plans [line items] |  |
Equity investments, target allocation percentage of plan assets | 65.00% |
Surplus in plan | $ 38,071,000 |
Logica U.K. Pension & Life Assurance Scheme | U.K. |  |
Disclosure of defined benefit plans [line items] |  |
Equity investments, target allocation percentage of plan assets | 15.00% |
Bond investments, target allocation percentage of plan assets | 85.00% |
Surplus in plan | $ 94,000 |
Current service cost | $ 367,000 |
Logica Defined Benefit Pension Plan | U.K. |  |
Disclosure of defined benefit plans [line items] |  |
Equity investments, target allocation percentage of plan assets | 10.00% |
Bond investments, target allocation percentage of plan assets | 90.00% |
Surplus in plan | $ 19,547,000 |
Alecta multi-employer plan |  |
Disclosure of defined benefit plans [line items] |  |
Pension cost for defined contribution plans | $ 26,589,000 | $ 23,422,000
Proportion of total contributions to the plan | 0.63% |
Proportion of total number of active members in the plan | 0.46% |
Collective funding solvency percentage | 167.00% | 163.00%
Alecta multi-employer plan | Minimum |  |
Disclosure of defined benefit plans [line items] |  |
Collective funding solvency allowed | 125.00% |
Alecta multi-employer plan | Maximum |  |
Disclosure of defined benefit plans [line items] |  |
Collective funding solvency allowed | 170.00% |

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