MARKETABLE SECURITIES (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 59,115	$ 93,301
Unrealized Gains	447	36
Unrealized Losses	(13)	(336)
Fair Value	$ 59,549	93,001
Maturities of marketable securities	1 year 6 months
Municipal bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 29,495	44,802
Unrealized Gains	156	13
Unrealized Losses	(5)	(110)
Fair Value	29,646	44,705
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	29,620	48,499
Unrealized Gains	291	23
Unrealized Losses	(8)	(226)
Fair Value	$ 29,903	$ 48,296

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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

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-Publisher FASB
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Period between issuance and maturity of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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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.

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