STOCK-BASED COMPENSATION - Summary of Change in Number of Non-Vested Options to Purchase Shares of Common Stock (Details) - $ / shares shares in Thousands	6 Months Ended
	Jul. 31, 2020	Jul. 31, 2019
STOCK-BASED COMPENSATION
Shares, Non-vested, Beginning balance	448	375
Shares, Granted	172	92
Shares, Vested	(62)	(33)
Shares, Forfeitures	(9)	(28)
Shares, Non-vested, Ending balance	549	406
Weighted Average Fair Value, Non-vested, Beginning balance	$ 9.74	$ 10.05
Weighted Average Fair Value, Granted	5.68	11.68
Weighted Average Fair Value, Vested	10.21	8.74
Weighted Average Fair Value, Forfeitures	8.08	11.27
Weighted Average Fair Value, Non-vested, Ending balance	$ 8.44	$ 10.50