XML 40 R56.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

SIGNIFICANT ACCOUNTING POLICIES (Property, plant and equipment useful lives) (Details) | 12 Months Ended
--- | ---
Dec. 29, 2019
Buildings and improvements | Minimum |
Disclosure of detailed information about property, plant and equipment [line items] |
Useful life | 5 years
Buildings and improvements | Maximum |
Disclosure of detailed information about property, plant and equipment [line items] |
Useful life | 40 years
Manufacturing equipment | Minimum |
Disclosure of detailed information about property, plant and equipment [line items] |
Useful life | 2 years
Manufacturing equipment | Maximum |
Disclosure of detailed information about property, plant and equipment [line items] |
Useful life | 20 years
Other equipment | Minimum |
Disclosure of detailed information about property, plant and equipment [line items] |
Useful life | 3 years
Other equipment | Maximum |
Disclosure of detailed information about property, plant and equipment [line items] |
Useful life | 10 years

X
- Definition Useful Lives Or Depreciation Rates, Property, Plant And Equipment, Period + References No definition available. + Details
Name: | gil_UsefulLivesOrDepreciationRatesPropertyPlantAndEquipmentPeriod
Namespace Prefix: | gil_
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 domain members defined in one or many axes of the table. + References No definition available. + Details
Name: | ifrs-full_DisclosureOfPropertyPlantAndEquipmentLineItems
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | ifrs-full_ClassesOfPropertyPlantAndEquipmentAxis=gil_BuildingsAndLeaseholdImprovementsMember
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: |

X
- Details
Name: | ifrs-full_ClassesOfPropertyPlantAndEquipmentAxis=ifrs-full_MachineryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfPropertyPlantAndEquipmentAxis=ifrs-full_OtherPropertyPlantAndEquipmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |