SHAREHOLDERS' EQUITY - Non-vested Options Outstanding and Exercisable (Details) - $ / shares			12 Months Ended
	May 23, 2019	Mar. 29, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares
Stock options granted (in shares)			3,050,000	375,000	338,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value
Stock options granted (in dollars per share)	$ 0.22	$ 0.43	$ 1.73	$ 1.90	$ 2.99
Amended and Restated Equity Incentive Plan and Non-related Plan Options
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares
Balance at the beginning of the period (in shares)			691
Stock options granted (in shares)			3,050
Stock options cancelled/forfeited (in shares)			(402)
Stock options vested (in shares)			(304)
Balance at the end of the period (in shares)			3,035	691
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value
Balance at the beginning of the period (in dollars per share)			$ 1.28
Stock options granted (in dollars per share)			0.58
Stock options cancelled/forfeited (in dollars per share)			0.74
Stock options vested (in dollars per share)			1.44
Balance at the end of the period (in dollars per share)			$ 0.64	$ 1.28