XML 135 R93.htm IDEA: XBRL DOCUMENT
v3.23.3

Employee benefits - Narrative (Details) | 12 Months Ended
--- | ---
Sep. 30, 2023 CAD ($) plan | Sep. 30, 2022 CAD ($)
Disclosure of defined benefit plans [line items] |  |
Surplus in plan | $ (162,543,000) | $ (107,974,000)
Current service cost | 13,734,000 | 13,053,000
Annual contributions | 7,574,000 |
Pension cost for defined contribution plans | 282,284,000 | 241,405,000
Deferred compensation plan liabilities | 97,745,000 | 81,452,000
Deferred compensation plan assets | $ 88,076,000 | 71,863,000
U.K. |  |
Disclosure of defined benefit plans [line items] |  |
Number of defined benefit pension plans | plan | 3 |
Surplus in plan | $ 593,000 | 46,647,000
Annual contributions | 377,000 |
Other |  |
Disclosure of defined benefit plans [line items] |  |
Surplus in plan | (28,565,000) | (26,752,000)
Annual contributions | 7,197,000 |
UNITED STATES |  |
Disclosure of defined benefit plans [line items] |  |
Deferred compensation plan assets | $ 88,076,000 | 71,863,000
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 | $ 34,707,000 |
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 | $ 85,000 |
Current service cost | $ 339,000 |
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 | $ 17,819,000 |
Alecta multi-employer plan |  |
Disclosure of defined benefit plans [line items] |  |
Annual contributions | 14,867,000 |
Pension cost for defined contribution plans | $ 25,311,000 | $ 28,868,000
Proportion of total contributions to the plan | 0.57% |
Proportion of total number of active members in the plan | 0.48% |
Collective funding solvency percentage | 178.00% | 189.00%
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 | 175.00% |

X
- Definition Debt Instruments, Amount Contributed To Fair Value Of Plan Assets, Target Allocation Percentage + References No definition available. + Details
Name: | gib_DebtInstrumentsAmountContributedToFairValueOfPlanAssetsTargetAllocationPercentage
Namespace Prefix: | gib_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Deferred Compensation Plan Assets 1 + References No definition available. + Details
Name: | gib_DeferredCompensationPlanAssets1
Namespace Prefix: | gib_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Deferred Compensation Plan Liabilities + References No definition available. + Details
Name: | gib_DeferredCompensationPlanLiabilities
Namespace Prefix: | gib_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Equity Instruments, Amount Contributed To Fair Value Of Plan Assets, Target Allocation Percentage + References No definition available. + Details
Name: | gib_EquityInstrumentsAmountContributedToFairValueOfPlanAssetsTargetAllocationPercentage
Namespace Prefix: | gib_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Funding Arrangements, Collective Funding Percentage + References No definition available. + Details
Name: | gib_FundingArrangementsCollectiveFundingPercentage
Namespace Prefix: | gib_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Funding Arrangements, Collective Funding Percentage Allowed + References No definition available. + Details
Name: | gib_FundingArrangementsCollectiveFundingPercentageAllowed
Namespace Prefix: | gib_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Level Of Participation Of Entity Compared With Other Participating Entities, Proportion Of Active Members + References No definition available. + Details
Name: | gib_LevelOfParticipationOfEntityComparedWithOtherParticipatingEntitiesProportionOfActiveMembers
Namespace Prefix: | gib_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Level Of Participation Of Entity Compared With Other Participating Entities, Proportion Of Total Contributions + References No definition available. + Details
Name: | gib_LevelOfParticipationOfEntityComparedWithOtherParticipatingEntitiesProportionOfTotalContributions
Namespace Prefix: | gib_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number Of Defined Benefit Plans + References No definition available. + Details
Name: | gib_NumberOfDefinedBenefitPlans
Namespace Prefix: | gib_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition The increase (decrease) in the net defined benefit liability (asset) resulting from employee service in the current period. [Refer: Net defined benefit liability (asset)] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 19 -IssueDate 2023-01-01 -Paragraph 141 -Subparagraph a -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2023-en-r&anchor=para_141_a&doctype=Standard -URIDate 2023-03-23 + Details
Name: | ifrs-full_CurrentServiceCostNetDefinedBenefitLiabilityAsset
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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_DisclosureOfDefinedBenefitPlansLineItems
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The estimate of the expected contributions to be made to a defined benefit plan for the next annual reporting period. [Refer: Defined benefit plans [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 19 -IssueDate 2023-01-01 -Paragraph 147 -Subparagraph b -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2023-en-r&anchor=para_147_b&doctype=Standard -URIDate 2023-03-23 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 19 -IssueDate 2023-01-01 -Paragraph 148 -Subparagraph d -Clause iii -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2023-en-r&anchor=para_148_d_iii&doctype=Standard -URIDate 2023-03-23 + Details
Name: | ifrs-full_EstimateOfContributionsExpectedToBePaidToPlan
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of post-employment benefit expense relating to defined contribution plans. Defined contribution plans are post-employment benefit plans under which an entity pays fixed contributions into a separate entity (a fund) and will have no legal or constructive obligation to pay further contributions if the fund does not hold sufficient assets to pay all employee benefits relating to employee service in the current and prior periods. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 19 -IssueDate 2023-01-01 -Paragraph 53 -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2023-en-r&anchor=para_53&doctype=Standard -URIDate 2023-03-23 + Details
Name: | ifrs-full_PostemploymentBenefitExpenseDefinedContributionPlans
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The fair value of any plan assets, less the present value of the defined benefit obligation. [Refer: Plan assets [member]] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 19 -IssueDate 2023-01-01 -Paragraph 57 -Subparagraph a -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2023-en-r&anchor=para_57_a&doctype=Standard -URIDate 2023-03-23 + Details
Name: | ifrs-full_SurplusDeficitInPlan
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | ifrs-full_GeographicalAreasAxis=country_GB
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: |

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

X
- Details
Name: | ifrs-full_DefinedBenefitPlansAxis=gib_CMGUKPensionSchemeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_DefinedBenefitPlansAxis=gib_LogicaUKPensionAndLifeAssuranceSchemeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_DefinedBenefitPlansAxis=gib_LogicaDefinedBenefitPensionPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_DefinedBenefitPlansAxis=ifrs-full_MultiemployerDefinedBenefitPlansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_RangeAxis=ifrs-full_BottomOfRangeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_RangeAxis=ifrs-full_TopOfRangeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |