FAIR VALUE MEASUREMENTS - Fair Value of Warrant Liability Classified as Level 3 Liabilities (Details) - Level 3 - USD ($) $ in Thousands	3 Months Ended
Oct. 31, 2017	Jul. 31, 2017	Apr. 30, 2017
Fair Value of Warrant Liability Classified as Level 3 Liabilities
Beginning balance	$ 242	$ 767	$ 403
Change in fair value of warrants	(169)	(525)	364
Ending balance	$ 73	$ 242	$ 767

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

No definition available.

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- Definition

Amount of increase (decrease) of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

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- Definition

Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

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