SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) - Share based compensation assumptions	12 Months Ended
May 31, 2018	May 31, 2017
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) - Share based compensation assumptions [Line Items]
Dividend yield	0.00%	0.00%
Minimum [Member]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) - Share based compensation assumptions [Line Items]
Expected volatility	59.80%	53.64%
Risk free interest rate	1.61%	1.08%
Expected life	3 years 9 months	3 years 9 months
Maximum [Member]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) - Share based compensation assumptions [Line Items]
Expected volatility	61.28%	54.73%
Risk free interest rate	2.53%	1.23%
Expected life	6 years	6 years 3 months

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- Definition

The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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- Definition

The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. 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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- Definition

The risk-free interest rate assumption that is used in valuing an option on its own shares.

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- Definition

Expected term of share-based compensation awards, 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
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(i)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.D.2)
-URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809

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