SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Narrative) (Details)	3 Months Ended
	Mar. 31, 2019 USD ($) financial_institution	Mar. 31, 2018 USD ($)	Jan. 01, 2019 USD ($)	Dec. 31, 2018 USD ($)
Concentration Risks, Types, No Concentration Percentage
Number of financial institutions where the Company holds checking deposits | financial_institution	1
Restricted Cash
Restricted cash	$ 211,000	$ 0		$ 211,000
Allowance for doubtful accounts	0			0
Income Taxes
Income tax penalties and interest accrued	0			$ 0
Income tax penalties and interest expense	0	$ 0
Recent Accounting Pronouncements
Operating lease right-of-use assets	2,928,000
Operating lease, liability	$ 3,053,000
Minimum
Property and Equipment
Useful life (in years)	3 years
Maximum
Property and Equipment
Useful life (in years)	5 years
Accounting Standards Update 2016-02
Recent Accounting Pronouncements
Operating lease right-of-use assets	$ 3,000,000
Operating lease, liability			$ 3,000,000