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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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STOCKHOLDERS' EQUITY - Stock grant agreements with non employees, Stock options (Details)	1 Months Ended	3 Months Ended	9 Months Ended
	Apr. 30, 2018 individual shares	Sep. 30, 2019 shares	Sep. 30, 2019 shares
Share-Based Compensation Awards
Granted (in shares)		0	356,000
Stock options \| Nonemployees
Share-Based Compensation Awards
Number of individuals \| individual	1
2015 Plan \| Nonemployees
Share-Based Compensation Awards
Granted (in shares)	72,373
Vesting period	4 years
Term of award	10 years
2015 Plan \| Nonemployees \| Tranche one
Share-Based Compensation Awards
Vesting period	12 months
Vesting (as a percent)	25.00%
2015 Plan \| Nonemployees \| Tranche two
Share-Based Compensation Awards
Vesting period	3 years