COMMITMENTS AND CONTINGENCIES - Textuals (Details) $ in Millions, $ in Millions			1 Months Ended	12 Months Ended
	Mar. 14, 2018 CAD ($)	Mar. 14, 2018 USD ($)	Oct. 27, 2017	Jan. 31, 2020 CAD ($)	Jan. 31, 2020 USD ($)	Jan. 31, 2019 USD ($)	Jan. 31, 2018 USD ($)
Commitment And Contingencies [Line Items]
Advertising expense					$ 94.7	$ 87.8	$ 105.6
CBSA
Commitment And Contingencies [Line Items]
Reassessment period to additional duties			90 days
Licenses
Commitment And Contingencies [Line Items]
Royalty expense					178.8	165.7	154.3
Advertising expense					48.3	$ 46.2	$ 43.4
G-III Apparel Canada ULC
Commitment And Contingencies [Line Items]
Value of bond issued for prepayments of additional duties	$ 26.9	$ 20.9
Deferred expenses				$ 12.8	$ 9.7