STOCK-BASED COMPENSATION - Stock Options - Activity (Details) $ / shares in Units, $ in Millions	12 Months Ended
May 31, 2020 USD ($) $ / shares shares
STOCK-BASED COMPENSATION
Options outstanding (in shares)	453,050
Weighted average exercise price \| $ / shares	$ 27.79
Weighted-Average Remaining Contractual Term - Outstanding (in years)	5 years 1 month 6 days
Aggregate Intrinsic Value - Outstanding \| $	$ 14.6
Shares - Exercisable at end of year (in shares)	434,218

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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.

+ 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 (c)(1)(iii)
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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

+ References

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

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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