INVESTMENTS HELD-TO-MATURITY (Details) - USD ($)	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Schedule of Held-to-maturity Securities [Line Items]
Amortized cost	$ 16,900,000
Fair value	16,900,000
Unrealized Gain (Loss)	0
Investments held-to-maturity	16,863,000	$ 0
Interest and investment income	$ 481,000	67,000
US Treasury Bills, Maturing April 2018 \| Commercial Paper
Schedule of Held-to-maturity Securities [Line Items]
Investments held-to-maturity		25,000,000
Commercial Paper, Maturing In 2018 \| Commercial Paper
Schedule of Held-to-maturity Securities [Line Items]
Investments held-to-maturity		14,600,000
Commercial Paper, Maturing January 2019 \| Commercial Paper
Schedule of Held-to-maturity Securities [Line Items]
Investments held-to-maturity		16,900,000
Certificates of Deposit \| Debt Securities
Schedule of Held-to-maturity Securities [Line Items]
Investments held-to-maturity		$ 100,000

Debt Securities, Held to Maturity, Amortized Cost

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Debt Securities, Held-to-maturity, Fair Value

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Amount after other than temporary impairment (OTTI) accretion, of investments in debt securities classified as held-to-maturity, expected to be converted to cash, sold or exchanged within one year or the normal operating cycle.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
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Amount after accretion (amortization) of discount (premium), and investment expense, of interest income and dividend income on nonoperating securities.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of investments, not including unrealized gains or losses on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity, held at each balance sheet date and included in earnings for the period.

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