STOCK BASED COMPENSATION - Options that Contain Service, Performance and Market Conditions (Details) $ in Millions	9 Months Ended
Sep. 30, 2019 USD ($) shares
Stock-based compensation
Options granted (in shares)	2,657,628
Stock Options that Contain Service, Performance and Market Conditions
Stock-based compensation
Options granted (in shares)	159,501
Fair value at grant date \| $	$ 0.5
Stock Options that Contain Service, Performance and Market Conditions \| Minimum
Stock-based compensation
Derived service period	P1D
Stock Options that Contain Service, Performance and Market Conditions \| Maximum
Stock-based compensation
Derived service period	P3Y

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.

No definition available.

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- Definition

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

+ References

No definition available.

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- Definition

Description of terms of award under share-based payment arrangement.

+ 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 (a)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

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- Definition

Fair value of options vested. Excludes equity instruments other than options, for example, but not limited to, share units, stock appreciation rights, restricted stock.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

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