XML 148 R109.htm IDEA: XBRL DOCUMENT
v3.25.3

Share-based payments - Stock options (Details) - $ / shares | 12 Months Ended
--- | ---
Sep. 30, 2025 | Sep. 30, 2024
Disclosure of classes of share capital [line items] |  |
Weighted average share price for share options at date of exercise (in CAD per share) | $ 155.80 | $ 145.60
Stock options |  |
Disclosure of classes of share capital [line items] |  |
Vesting period for stock options | 4 years |
Expiration period for stock options | 10 years |
Stock options | Class A subordinate voting shares |  |
Disclosure of classes of share capital [line items] |  |
Number of shares reserved for issuance under the stock option plan (in shares) | 15,371,067 |

X
- Definition Share-Based Compensation Arrangement By Share-Based Payment Award, Award Vesting Period 2 + References No definition available. + Details
Name: | gib_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod2
Namespace Prefix: | gib_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Share-Based Compensation Arrangement By Share-Based Payment Award, Expiration Period 1 + References No definition available. + Details
Name: | gib_ShareBasedCompensationArrangementByShareBasedPaymentAwardExpirationPeriod1
Namespace Prefix: | gib_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition 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. + Details
Name: | ifrs-full_DisclosureOfClassesOfShareCapitalLineItems
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of shares reserved for issue under options and contracts for the sale of shares. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Note Effective 2027-01-01 -Name IFRS -Number 19 -IssueDate 2025-01-01 -Paragraph B10 -Subparagraph a -Clause vii -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_B10_a_vii&doctype=Appendix&subtype=B -URIDate 2025-03-27 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Note Effective 2027-01-01 -Name IFRS -Number 19 -IssueDate 2025-01-01 -Paragraph 160 -Subparagraph a -Clause vii -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_160_a_vii&doctype=Standard -URIDate 2025-03-27 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Note Expiry date 2027-01-01 -Name IAS -Number 1 -IssueDate 2025-01-01 -Paragraph 79 -Subparagraph a -Clause vii -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_79_a_vii&doctype=Standard -URIDate 2025-03-27 + Details
Name: | ifrs-full_SharesReservedForIssueUnderOptionsAndContractsForSaleOfShares
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The weighted average share price at the date of exercise for share options that are exercised in a share-based payment arrangement. [Refer: Types of share-based payment arrangements [domain]; Weighted average [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 2 -IssueDate 2025-01-01 -Paragraph 45 -Subparagraph c -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2025-en-r&anchor=para_45_c&doctype=Standard -URIDate 2025-03-27 + Details
Name: | ifrs-full_WeightedAverageExercisePriceOfShareOptionsInSharebasedPaymentArrangementExercisedDuringPeriodAtDateOfExercise2019
Namespace Prefix: | ifrs-full_
Data Type: | dtr-2022:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | ifrs-full_TypesOfSharebasedPaymentArrangementsAxis=gib_EmployeeStockOptionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfShareCapitalAxis=gib_ClassASubordinateVotingSharesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |