Recent Accounting Pronouncements (Detail Textuals) $ in Thousands	3 Months Ended
Apr. 30, 2016 USD ($)
Accounting Changes And Error Corrections [Abstract]
Recognition of excess tax benefits on adoption of ASU 2016-09	$ 37,000

Represents effect of new accounting pronouncement or change in accounting principle effect of change on tax expenses benefit.

No definition available.

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