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, 2023	Jan. 31, 2022	Jan. 31, 2021
SIGNIFICANT ACCOUNTING POLICIES [Abstract]
Net income (loss) attributable to G-III Apparel Group, Ltd.	$ (133,061)	$ 200,593	$ 23,545
Basic net income (loss) per share:
Basic common shares	47,653	48,426	48,242
Basic net income (loss) per share (in dollars per share)	$ (2.79)	$ 4.14	$ 0.49
Diluted net income (loss) per share:
Basic common shares	47,653	48,426	48,242
Dilutive restricted stock unit awards and stock options		1,090	539
Diluted common shares	47,653	49,516	48,781
Diluted net income (loss) per share (in dollars per share)	$ (2.79)	$ 4.05	$ 0.48