Represents amendment in prepayments of additional duties paid.

No definition available.

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Namespace Prefix:	giii_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Commitment And Contingencies [Line Items]

+ References

No definition available.

+ Details

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Namespace Prefix:	giii_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents Bond issue value for prepayments of additional duties as a result of reassessment.

+ References

No definition available.

+ Details

Name:	giii_ValueOfBondIssuedForPrepaymentsOfAdditionalDuties
Namespace Prefix:	giii_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount charged to advertising expense for the period, which are expenses incurred with the objective of increasing revenue for a specified brand, product or product line.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 720
-SubTopic 35
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483406/720-35-50-1

+ Details

Name:	us-gaap_AdvertisingExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of expense related to royalty payments under a contractual arrangement such as payment for mineral and drilling rights and use of technology or intellectual property.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2

+ Details

Name:	us-gaap_RoyaltyExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_LicensingAgreementsMember
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COMMITMENTS AND CONTINGENCIES - Textuals (Details) $ in Millions, $ in Millions	12 Months Ended				24 Months Ended
	Jan. 31, 2024 USD ($)	Jan. 31, 2024 CAD ($)	Jan. 31, 2023 USD ($)	Jan. 31, 2022 USD ($)	Jan. 31, 2024 USD ($)	Jan. 31, 2024 CAD ($)
Commitment And Contingencies [Line Items]
Advertising expense	$ 121.7		$ 131.6	$ 93.1
Value of bond issued for prepayments of additional duties					$ 4.8	$ 6.5
Amendment in prepayments of additional duties	6.1	$ 8.2
License Agreements
Commitment And Contingencies [Line Items]
Royalty expense	154.2		162.9	145.1
Advertising expense	$ 36.7		$ 45.2	$ 41.2