MARKETABLE SECURITIES - SCHEDULE OF CURRENT AVAILABLE-FOR-SALE MARKETABLE SECURITIES (Details) $ in Thousands	Dec. 31, 2016 USD ($) investment	Dec. 31, 2015 USD ($)
Schedule of Available-for-sale Marketable Securities
Amortized Cost	$ 89,350	$ 36,424
Gross Unrealized Gains	2	2,963
Gross Unrealized Losses	(10)	(187)
Fair Value	89,342	39,200
Aggregate fair value of available-for-sale securities with unrealized losses	$ 37,000
Number of current available-for-sale marketable debt securities in continuous unrealized loss position for greater than twelve months \| investment	0
Commercial paper
Schedule of Available-for-sale Marketable Securities
Amortized Cost	$ 49,797
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Fair Value	49,797
Treasury discount notes
Schedule of Available-for-sale Marketable Securities
Amortized Cost	34,978
Gross Unrealized Gains	0
Gross Unrealized Losses	(4)
Fair Value	34,974
Corporate debt securities
Schedule of Available-for-sale Marketable Securities
Amortized Cost	4,575	27,765
Gross Unrealized Gains	2	0
Gross Unrealized Losses	(6)	(187)
Fair Value	4,571	27,578
Equity security
Schedule of Available-for-sale Marketable Securities
Amortized Cost		8,659
Gross Unrealized Gains		2,963
Gross Unrealized Losses		0
Fair Value		$ 11,622
Total debt securities
Schedule of Available-for-sale Marketable Securities
Amortized Cost	89,350
Gross Unrealized Gains	2
Gross Unrealized Losses	(10)
Fair Value	$ 89,342

Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt securities classified as available-for-sale.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27161-111563

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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt securities classified as available-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27161-111563

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.2)
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+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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Amount of investment in debt and equity securities categorized neither as trading securities nor held-to-maturity securities and intended be sold or mature one year or operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 25
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=65884222&loc=d3e22054-111558

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