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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Narrative) (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2018 USD ($) financial_institution	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) financial_institution	Jun. 30, 2017 USD ($)	Jan. 01, 2018 USD ($)	Dec. 31, 2017 USD ($)
Concentration Risks, Types, No Concentration Percentage [Abstract]
Number of financial institutions where the Company holds checking deposits \| financial_institution	1		1
Restricted Cash [Abstract]
Restricted cash, certificate of deposit	$ 0	$ 100,000	$ 0	$ 100,000		$ 100,000
Restricted cash, pledged mutual fund	211,000		211,000			0
Investments
Investment income		16,000		25,000
Intangible Assets, Net
Impairment of intangible assets	40,000		48,000
Revenue Recognition [Abstract]
Revenue	124,000	220,000	281,000	$ 376,000
Deferred revenue	240,000		240,000		$ 146,000	143,000
Income Taxes
Income tax penalties and interest accrued	0		0			0
Income tax penalties and interest expense	0	$ 0
Held-to-maturity Securities, Fair Value	19,500,000		19,500,000
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	0		0
Investments held-to-maturity	19,475,000		$ 19,475,000			$ 0
Minimum
Property and Equipment
Useful life (in years)			3 years
Maximum
Property and Equipment
Useful life (in years)			5 years
US Treasury Bills, Maturing April 2018
Income Taxes
Investments held-to-maturity	25,000,000		$ 25,000,000
Commercial Paper, Maturing June 2018
Income Taxes
Investments held-to-maturity	4,000,000		4,000,000
Commercial Paper, Maturing August 2018
Income Taxes
Investments held-to-maturity	2,100,000		2,100,000
Commercial Paper, Maturing September 2018
Income Taxes
Investments held-to-maturity	8,600,000		8,600,000
Commercial Paper, Maturing January 2019
Income Taxes
Investments held-to-maturity	8,800,000		8,800,000
Certificates of Deposit \| Foreign Debt Securities
Investments
Investment income	98,000		146,000
Certificates of Deposit \| Debt Securities, Maturing January 2019
Income Taxes
Investments held-to-maturity	$ 100,000		$ 100,000