WARRANTS (Narrative) (Details) $ / shares in Units, $ in Thousands				1 Months Ended		2 Months Ended	9 Months Ended
	Dec. 19, 2017 USD ($) $ / shares shares	Dec. 18, 2017 USD ($) $ / shares	Sep. 28, 2017 USD ($) $ / shares shares	Sep. 30, 2017 USD ($) $ / shares	Feb. 28, 2017 USD ($) $ / shares shares	Oct. 31, 2017 $ / shares shares	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($) $ / shares	Dec. 31, 2017 USD ($)	Oct. 02, 2017 shares	Jun. 17, 2013 $ / shares shares	Jan. 31, 2013 $ / shares
Warrant liabilities
Fair value of common stock issued							$ 27		$ 20
Proceeds from exercise of warrants							260	$ 0
Placement Agent
Warrant liabilities
Warrant fair value			$ 174
Warrant share price (in dollars per share) | $ / shares			$ 4.85
Bridge Warrants | Founders
Warrant liabilities
Warrants to purchase shares of common stock (in unit/shares) | shares											249,999
Exercise price (in dollars per unit/share) | $ / shares											$ 0.20
Fair value of the warrants							1,600
Fair value of common stock issued							1,600
Private Placement Warrants, February 2017, After Modifications
Warrant liabilities
Warrant fair value	$ 6,700
Underwriting Warrant
Warrant liabilities
New shares issued (in shares) | shares			1,976,919
Underwriting Warrant | Placement Agent
Warrant liabilities
New shares issued (in shares) | shares			98,846
Private Placement Warrants, February 2017
Warrant liabilities
Warrant fair value	$ 13,400	$ 4,100
Warrant share price (in dollars per share) | $ / shares	$ 8.18	$ 8.18
Fair value adjustment expense	$ 4,100
Class of warrant or right, inducement expense	6,700
Induced conversion of convertible debt expense	2,600
Proceeds from exercise of warrants	$ 6,700
Private Placement Warrants, February 2017 | Investors, Executives and Board Members
Warrant liabilities
Exercise price (in dollars per unit/share) | $ / shares	$ 8.25
Private Placement Warrants, September 2017
Warrant liabilities
Warrant fair value				$ 3,600
Capital Units | Private Placement Warrants - 2016 | Investors, Executives and Board Members
Warrant liabilities
Exercise price (in dollars per unit/share) | $ / shares					$ 8.25
Capital Units | Private Placement Warrants, September 2017 | Investors, Executives and Board Members
Warrant liabilities
Exercise price (in dollars per unit/share) | $ / shares						$ 4.85
Common stock warrants | Investor
Warrant liabilities
Warrant term, period end after closing					30 months
Common stock warrants | Placement Agent
Warrant liabilities
Warrant term, period start after closing					6 months
Private Placement Warrants - 2016 | Private Placement Warrants - 2016
Warrant liabilities
Warrants to purchase shares of common stock (in unit/shares) | shares					1,626,898
Private Placement Warrants - 2016 | Private Placement Warrants, February 2017
Warrant liabilities
Warrants to purchase shares of common stock (in unit/shares) | shares	1,626,898
Private Placement Warrants - 2016 | Private Placement Warrants, February 2017 | Investor
Warrant liabilities
New shares issued (in shares) | shares	1,626,898
Private Placement Warrants - 2016 | Private Placement Warrants, September 2017
Warrant liabilities
Warrants to purchase shares of common stock (in unit/shares) | shares			1,745,581			1,976,919				231,338
Warrant term, period start after closing					6 months
Warrant term, period end after closing					36 months
Private Placement Warrants - 2016 | Capital Units | Private Placement Warrants - 2016 | Investor
Warrant liabilities
New shares issued (in shares) | shares					1,626,898
Private Placement Warrants - 2016 | Capital Units | Private Placement Warrants, September 2017 | Investors, Executives and Board Members
Warrant liabilities
New shares issued (in shares) | shares						1,976,919
Private Placement, Offering One | Placement Agent
Warrant liabilities
Partners' capital account, units, sold in private placement (in warrants) | shares			87,279
Private Placement, Offering Two | Placement Agent
Warrant liabilities
Partners' capital account, units, sold in private placement (in warrants) | shares			11,567
Investor Relations | Consulting Warrant Issued In August2014
Warrant liabilities
Exercise price (in dollars per unit/share) | $ / shares												$ 0.40
Investor Relations | Private Placement Warrants - 2016
Warrant liabilities
Warrant fair value					$ 2,084
Warrant share price (in dollars per share) | $ / shares					$ 4.91
Minimum | Underwriting Warrant
Warrant liabilities
Warrant share price (in dollars per share) | $ / shares			$ 4.49
Minimum | Private Placement Warrants, September 2017
Warrant liabilities
Warrant share price (in dollars per share) | $ / shares				$ 4.49				$ 4.49
Maximum | Underwriting Warrant
Warrant liabilities
Warrant share price (in dollars per share) | $ / shares			$ 4.69
Maximum | Private Placement Warrants, September 2017
Warrant liabilities
Warrant share price (in dollars per share) | $ / shares				$ 4.69				$ 4.69
Common Units Class B | Founders
Warrant liabilities
Warrants to purchase shares of common stock (in unit/shares) | shares											124,998
General and administrative expenses | Bridge Warrants | Founders
Warrant liabilities
Fair value adjustment expense							$ 2
Measurement Input, Expected Term | Private Placement Warrants, February 2017
Warrant liabilities
Warrants and Rights Outstanding, Term		1 year 8 months 1 day
Measurement Input, Expected Term | Common Stock | Private Placement Warrants - 2016
Warrant liabilities
Warrants and Rights Outstanding, Term	1 day
Measurement Input, Expected Term | Common Stock | Underwriting Warrant
Warrant liabilities
Warrants and Rights Outstanding, Term			3 years
Measurement Input, Expected Term | Investor Relations | Private Placement Warrants - 2016
Warrant liabilities
Warrants and Rights Outstanding, Term					3 years
Measurement Input, Price Volatility | Underwriting Warrant
Warrant liabilities
Warrants and Rights Outstanding, Measurement Input		0.60
Measurement Input, Price Volatility | Private Placement Warrants, February 2017
Warrant liabilities
Warrants and Rights Outstanding, Measurement Input	0.10
Measurement Input, Price Volatility | Investor Relations | Private Placement Warrants - 2016
Warrant liabilities
Warrants and Rights Outstanding, Measurement Input					0.60
Measurement Input, Expected Dividend Rate | Private Placement Warrants, February 2017
Warrant liabilities
Warrants and Rights Outstanding, Measurement Input	0.0125
Measurement Input, Expected Dividend Rate | Common Stock | Private Placement Warrants - 2016
Warrant liabilities
Warrants and Rights Outstanding, Measurement Input	0	0.0178
Measurement Input, Expected Dividend Rate | Investor Relations | Private Placement Warrants - 2016
Warrant liabilities
Warrants and Rights Outstanding, Measurement Input					0.00
Measurement Input, Expected Dividend Rate | Minimum | Underwriting Warrant
Warrant liabilities
Warrants and Rights Outstanding, Measurement Input			0.0159
Measurement Input, Expected Dividend Rate | Minimum | Private Placement Warrants, September 2017
Warrant liabilities
Warrants and Rights Outstanding, Measurement Input				0.0159				0.0159
Measurement Input, Expected Dividend Rate | Maximum | Underwriting Warrant
Warrant liabilities
Warrants and Rights Outstanding, Measurement Input			0.0163
Measurement Input, Expected Dividend Rate | Maximum | Private Placement Warrants, September 2017
Warrant liabilities
Warrants and Rights Outstanding, Measurement Input				0.0163				0.0163
Measurement Input, Risk Free Interest Rate [Member] | Investor Relations | Private Placement Warrants - 2016
Warrant liabilities
Warrants and Rights Outstanding, Measurement Input					0.0150