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, 2025	Jan. 31, 2024	Jan. 31, 2023
SIGNIFICANT ACCOUNTING POLICIES
Net income (loss) attributable to G-III Apparel Group, Ltd.	$ 193,566	$ 176,168	$ (133,061)
Basic net income (loss) per share:
Basic common shares	44,450	45,859	47,653
Basic net income (loss) per share (in dollars per share)	$ 4.35	$ 3.84	$ (2.79)
Diluted net income (loss) per share:
Basic common shares	44,450	45,859	47,653
Dilutive restricted stock unit awards and stock options	1,666	1,141
Diluted common shares	46,116	47,000	47,653
Diluted net income (loss) per share (in dollars per share)	$ 4.2	$ 3.75	$ (2.79)