STOCK-BASED COMPENSATION - Summary of Change in Number of Non-Vested Options to Purchase Shares of Common Stock (Details) - $ / shares shares in Thousands	3 Months Ended
Apr. 30, 2020	Apr. 30, 2019
STOCK-BASED COMPENSATION
Shares, Non-vested, Beginning balance	448	375
Shares, Granted	172	92
Shares, Vested	(61)	(33)
Shares, Forfeitures	(2)	(4)
Shares, Non-vested, Ending balance	557	430
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	11.68	11.68
Weighted Average Fair Value, Non-vested, Ending balance	$ 8.42	$ 10.48

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- Definition

Gross number of share options (or share units) granted during the period.

+ References

No definition available.

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- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)(1)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

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- Definition

Number of non-vested options outstanding.

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No definition available.

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- Definition

Number of non-vested options forfeited.

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- Definition

Weighted average grant-date fair value of non-vested options forfeited.

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- Definition

Weighted average grant-date fair value of non-vested options outstanding.

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- Definition

Number of options vested.

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- Definition

Weighted average grant-date fair value of options vested.

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