Represents the number of executives.

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Represents the percentage of the maximum shares for the target number of shares awarded.

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Represents the percentage reduction in the aggregate fair value of stock option

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The period of monthly closing prices used for the estimated measure of the maximum percentage by which a share price is expected to fluctuate during a period. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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Aggregate number of common shares reserved for future issuance.

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Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Amount of noncash expense for share-based payment arrangement.

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Net number of non-option equity instruments granted to participants.

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Percentage of vesting of award under share-based payment arrangement.

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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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STOCK-BASED COMPENSATION - Additional Information (Details) $ in Thousands	3 Months Ended					9 Months Ended
	Oct. 31, 2020 USD ($) shares	Apr. 30, 2020 shares	Oct. 31, 2019 USD ($)	Apr. 30, 2019 shares	Apr. 30, 2018 shares	Oct. 31, 2020 USD ($) person shares	Oct. 31, 2019 USD ($)	Jun. 23, 2020 shares
Share-based Compensation Arrangement by Share-based Payment Award
Percentage Reduction In The Aggregate Fair Value Of Stock Option						88.50%
Percentage reduction in the aggregate fair value of stock option						88.50%
Stock compensation expense	$ 800		$ 600			$ 2,199	$ 1,512
Unrecognized compensation cost	3,800					$ 3,800
Compensation expense recognize, period						3 years
Intrinsic value of outstanding stock options	4,700					$ 4,700
Intrinsic value of exercisable stock options	$ 3,300					$ 3,300
Period used for calculations						5 years
Minimum
Share-based Compensation Arrangement by Share-based Payment Award
Period used for calculations						3 years
Maximum
Share-based Compensation Arrangement by Share-based Payment Award
Period used for calculations						5 years
2020 Plan
Share-based Compensation Arrangement by Share-based Payment Award
Number of shares of common stock reserved for issuance \| shares								500,000
Stock Options Plans
Share-based Compensation Arrangement by Share-based Payment Award
Initial vesting percentage						33.33%
Period to become exercisable						3 years
Number of shares of common stock available for award \| shares	688,999					688,999
Number of shares of common stock reserved for issuance \| shares	2,170,400					2,170,400
Intrinsic value of the stock options exercised						$ 1,200	$ 1,400
ISOs/NSOs \| 2011 Plan
Share-based Compensation Arrangement by Share-based Payment Award
Incentive stock option award maximum expiration period						10 years
Senior executives \| Performance-based restricted stock units \| 2011 Plan
Share-based Compensation Arrangement by Share-based Payment Award
Period to become exercisable						3 years
Number of executives \| person						2
Percentage of the maximum shares for the target number of shares awarded						50.00%
Senior executives \| Performance-based restricted stock units \| 2011 Plan \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award
Number of shares awarded \| shares		45,000		36,000	36,000