NET INCOME PER COMMON SHARE - Reconciliation between basic and diluted net income per share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2024	Jul. 31, 2023	Jul. 31, 2024	Jul. 31, 2023
NET INCOME PER COMMON SHARE
Net income attributable to G-III Apparel Group, Ltd.	$ 24,212	$ 16,438	$ 30,014	$ 19,674
Basic net income per share:
Basic common shares	44,569	45,714	45,022	45,996
Basic net income per share (in dollars per share)	$ 0.54	$ 0.36	$ 0.67	$ 0.43
Diluted net income per share:
Basic common shares	44,569	45,714	45,022	45,996
Dilutive restricted stock unit awards and stock options	914	856	1,083	996
Diluted common shares	45,483	46,570	46,105	46,992
Diluted net income per share (in dollars per share)	$ 0.53	$ 0.35	$ 0.65	$ 0.42