STOCK BASED COMPENSATION (Details Textual) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended	3 Months Ended		6 Months Ended
	Jun. 02, 2016	Aug. 31, 2013	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Aug. 31, 2018	Apr. 22, 2018	Apr. 16, 2016	Apr. 10, 2015	Sep. 19, 2014	Aug. 20, 2014	Oct. 14, 2011
STOCK BASED COMPENSATION
Stock-based compensation expense					$ 100	$ 100
Total unrecognized compensation expense			$ 43,800		$ 43,800
Unrecognized compensation cost recognition period					2 years 1 month 2 days
Vested	(137,500)
Weighted average grant date fair value, options granted					$ 7.98	$ 15.26
Compensation Arrangement by Share-based payment award, description		an amendment to increase the number of options or other awards that can be granted to any one person during a twelve (12) month period from 50,000 shares to 300,000 shares.
Unvested shares			45,828		45,828
Share-based Compensation					$ 12,272	$ 9,326
Restricted Common Stock
STOCK BASED COMPENSATION
Stock-based compensation expense			$ 100	$ 100
Restricted stock units
STOCK BASED COMPENSATION
Stock-based compensation expense					$ 300
Unrecognized compensation cost recognition period					11 months 1 day
Restricted stock units | Chief Executive Officer
STOCK BASED COMPENSATION
Granted	550,000
Granted	$ 5.87
Stock option expenses
STOCK BASED COMPENSATION
Stock-based compensation expense			$ 6,400	$ 5,200	$ 12,100	$ 9,200
First Anniversary | Restricted stock units
STOCK BASED COMPENSATION
Vested	(137,500)
Vesting period	36 months
Satisfaction Of Clinical Trial Milestones | Restricted stock units
STOCK BASED COMPENSATION
Vested	(275,000)
2011 Equity Incentive Plan
STOCK BASED COMPENSATION
Number of shares available			151,240		151,240
Common stock, capital shares reserved for future issuance		1,700,000					1,700,000					1,900,000	180,000
2011 Equity Incentive Plan | Minimum
STOCK BASED COMPENSATION
Number of shares available			180,000		180,000
Equity Incentive Plan
STOCK BASED COMPENSATION
Shares authorized										4,000,000	2,350,000
Number of shares available			36,024		36,024
Equity Incentive Plan | Maximum
STOCK BASED COMPENSATION
Shares authorized									9,000,000
Twenty Eighteen Equity Incentive Plan
STOCK BASED COMPENSATION
Shares authorized								6,000,000
Number of shares available			4,029,500		4,029,500