STOCKHOLDERS' EQUITY - Information Regarding All Stock Options (Details) - $ / shares	12 Months Ended
Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Shares
Stock options outstanding at beginning of year	39,311	55,311	62,666
Exercised	(21,066)	(13,200)	(15,600)
Granted	0	0	8,245
Cancelled or forfeited		(2,800)
Stock options outstanding at end of year	18,245	39,311	55,311
Exercisable	18,245	35,188	47,066
Weighted Average Exercise Price
Stock options outstanding at beginning of year	$ 18.51	$ 15.70	$ 11.50
Exercised	14.07	8.71	6.55
Granted			30.32
Cancelled or forfeited		9.20
Stock options outstanding at end of year	23.63	18.51	15.70
Exercisable	$ 23.63	$ 17.12	$ 13.14

The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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For presentations that combine terminations, the number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan or that expired.

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Weighted average price of options that were either forfeited or expired.

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

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Number of options outstanding, including both vested and non-vested options.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Number of share options (or share units) exercised during the current period.

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