Information Regarding Reportable Segments (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
Jan. 31, 2013
Segment Reporting Information [Line Items]
Expenses and Integration Costs	$ 4.0

Expenses and integration costs associated with acquisition.

No definition available.

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