CASH, CASH EQUIVALENTS AND SHORT-TERM INVESTMENTS (Details) - Held-to-maturity Securities - USD ($) $ in Millions	12 Months Ended
Jan. 31, 2021	Jan. 31, 2020
Cash and Cash Equivalents
Maturity period	292 days	165 days
Accrued interest on held-to-maturity securities	$ 0.1	$ 0.5
Weighted average annual interest rates of CDs (as a percent)	0.20%	1.80%

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