SIGNIFICANT ACCOUNTING POLICIES - Reconciliation between Basic and Diluted Net Income (loss) per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Jan. 31, 2024	Jan. 31, 2023	Jan. 31, 2022
SIGNIFICANT ACCOUNTING POLICIES [Abstract]
Net income (loss) attributable to G-III Apparel Group, Ltd.	$ 176,168	$ (133,061)	$ 200,593
Basic net income (loss) per share:
Basic common shares	45,859	47,653	48,426
Basic net income (loss) per share (in dollars per share)	$ 3.84	$ (2.79)	$ 4.14
Diluted net income (loss) per share:
Basic common shares	45,859	47,653	48,426
Dilutive restricted stock unit awards and stock options	1,141		1,090
Diluted common shares	47,000	47,653	49,516
Diluted net income (loss) per share (in dollars per share)	$ 3.75	$ (2.79)	$ 4.05