FINANCIAL INSTRUMENTS - Narrative (Details)	3 Months Ended	9 Months Ended
Sep. 30, 2018 USD ($)	Sep. 30, 2018 USD ($)
Fair Value Disclosures [Abstract]
Contractual maturity of current available-for-sale securities (equal to or less than one year)		1 year
Available-for-sale securities in an unrealized loss position	$ 0	$ 0
Gross realized gains	0
Gross realized losses	$ 0

Contractual Maturity of Current Available-for-Sale Securities

No definition available.

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- Definition

Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27337-111563

+ Details

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- Definition

Amount of realized gain on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27357-111563

+ Details

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- Definition

Amount of realized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

+ Details

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- References

No definition available.

+ Details

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