MARKETABLE SECURITIES (Schedule of Fair Value, Cost and Gross Unrealized Holding Gains of Securities Owned) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Fair value	$ 14,512	$ 47,220
Cost or amortized cost	13,501	46,269
Gross unrealized holding losses	2	42
Gross unrealized holding gains	2	2
Certificates of deposit [Member]
Debt Securities, Available-for-sale [Line Items]
Fair value	1,589	2,773
Cost or amortized cost	1,591	2,790
Gross unrealized holding losses	2	17
Gross unrealized holding gains
U.S. Goverment and agency bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Fair value	11,413	25,215
Cost or amortized cost	11,411	25,236
Gross unrealized holding losses		22
Gross unrealized holding gains	2	1
U.S Treasury bills [Member]
Debt Securities, Available-for-sale [Line Items]
Fair value	499	18,241
Cost or amortized cost	499	18,243
Gross unrealized holding losses		3
Gross unrealized holding gains		$ 1

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

No definition available.

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- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563

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- Definition

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

+ References

No definition available.

+ Details

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- Definition

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References

No definition available.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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