SUBSEQUENT EVENTS (Details) $ / shares in Units, $ in Thousands					12 Months Ended
	Feb. 14, 2020 USD ($) shares	Feb. 11, 2020 shares	Jan. 21, 2020 shares	Apr. 16, 2018	Dec. 31, 2019 $ / shares shares	Jan. 31, 2020 shares	Jan. 20, 2020 shares	Dec. 31, 2018 $ / shares shares	May 31, 2018 shares	Apr. 30, 2018 shares
Subsequent events
Common stock, authorized					16,666,667			16,666,667	25,000,000	4,000,000
Common stock, par value (in dollars per share) | $ / shares					$ 0.00001			$ 0.00001
Stockholders' Equity, Reverse Stock Split					On February 11, 2020, the Company effected a reverse stock split of its common stock, par value $0.00001 per share, at a ratio of 1-for-30 (the "2020 Reverse Stock Split"). As a result of the 2020 Reverse Stock Split, (i) every 30 shares of the issued and outstanding common stock were automatically converted into one newly issued and outstanding share of common stock, without any change in the par value per share; (ii) the number of shares of common stock into which each outstanding warrant or option to purchase common stock is exercisable was proportionally decreased, and (iii) the number of authorized shares of common stock outstanding was proportionally decreased. Shares of common stock underlying outstanding stock options and other equity instruments convertible into common stock were proportionately reduced and the respective exercise prices, if applicable, were proportionately increased in accordance with the terms of the agreements governing such securities. On April 16, 2018, the Company effected a reverse stock split of its common stock, par value $0.00001 per share, at a ratio of 1-for-25 (the "2018 Reverse Stock Split"). As a result of the 2018 Reverse Stock Split, (i) every 25 shares of the issued and outstanding Common Stock were automatically converted into 1 newly issued and outstanding share of Common Stock, without any change in the par value per share; (ii) shares of Common Stock underlying outstanding stock options and other equity instruments convertible into Common Stock were proportionately reduced and the respective exercise prices, if applicable, were proportionately increased in accordance with the terms of the agreements governing such securities, and (iii) the number of authorized shares of Common Stock outstanding was proportionally decreased.
Stockholders' Equity Note, Stock Split, Conversion Ratio				0.04
Subsequent event
Subsequent events
Stock Issued During Period, Shares, New Issues	40,975
Proceeds from Issuance of Common Stock | $	$ 286
Common stock, authorized		16,666,667	500,000,000			500,000,000	25,000,000
Increased share reserve		26,667	800,000
Shares authorized for issuance		32,000	960,000
Stockholders' Equity Note, Stock Split, Conversion Ratio		0.0333