XML 139 R101.htm IDEA: XBRL DOCUMENT
v3.24.4

Employee benefits - Weighted average duration of benefit obligations (Details) | 12 Months Ended
--- | ---
Sep. 30, 2024 | Sep. 30, 2023
U.K. |  |
Disclosure of defined benefit plans [line items] |  |
Weighted average duration of defined benefit obligation | 13 years | 13 years
France |  |
Disclosure of defined benefit plans [line items] |  |
Weighted average duration of defined benefit obligation | 17 years | 17 years
Germany |  |
Disclosure of defined benefit plans [line items] |  |
Weighted average duration of defined benefit obligation | 10 years | 10 years
Other |  |
Disclosure of defined benefit plans [line items] |  |
Weighted average duration of defined benefit obligation | 9 years | 9 years

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_DisclosureOfDefinedBenefitPlansLineItems
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The weighted average duration of a defined benefit obligation. [Refer: Weighted average [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 19 -IssueDate 2024-01-01 -Paragraph 147 -Subparagraph c -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2024-en-r&anchor=para_147_c&doctype=Standard -URIDate 2024-03-27 + Details
Name: | ifrs-full_WeightedAverageDurationOfDefinedBenefitObligation2019
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | ifrs-full_GeographicalAreasAxis=country_GB
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_GeographicalAreasAxis=country_FR
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_GeographicalAreasAxis=country_DE
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_GeographicalAreasAxis=gib_OtherCountriesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |