STOCK-BASED COMPENSATION - Summary of Activity under Company's Stock Option Plans (Details) - $ / shares shares in Thousands	6 Months Ended		12 Months Ended
	Jul. 31, 2020	Jul. 31, 2019	Jan. 31, 2020	Jan. 31, 2019
STOCK-BASED COMPENSATION
Shares, Outstanding, Beginning balance	1,271	1,140	1,140
Shares, Granted	172	92
Shares, Exercised	(35)	(59)
Shares, Forfeited	(16)	(38)
Shares, Outstanding, Ending balance	1,392	1,135	1,271	1,140
Shares, Exercisable	843	729
Weighted Average Exercise Price, Outstanding, Beginning balance	$ 44.83	$ 44.01	$ 44.01
Weighted Average Exercise Price, Granted	33.81	50.30
Weighted Average Exercise Price, Exercised	20.82	26.36
Weighted Average Exercise Price, Forfeited	47.62	46.34
Weighted Average Exercise Price, Outstanding, Ending balance	44.04	45.37	$ 44.83	$ 44.01
Weighted Average Exercise Price, Exercisable	$ 46.38	$ 45.90
Weighted Average Remaining Term (Years), Outstanding	7 years 1 month 24 days	7 years 4 months 9 days	7 years 2 months 4 days	7 years 6 months 14 days
Weighted Average Remaining Term (Years), Exercisable	6 years	6 years 4 months 28 days
Weighted Average Fair Value, Outstanding	$ 10.51	$ 11.45	$ 11.06	$ 11.22
Weighted Average Fair Value, Exercisable	$ 11.87	$ 11.97