FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS - Current Available-for-Sale Marketable Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Schedule of Available-for-sale Marketable Securities
Amortized Cost	$ 49,924	$ 19,993
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(12)	0
Fair Value	49,912	19,993
Treasury discount notes
Schedule of Available-for-sale Marketable Securities
Amortized Cost	49,924
Gross Unrealized Gains	0
Gross Unrealized Losses	(12)
Fair Value	$ 49,912
Commercial paper
Schedule of Available-for-sale Marketable Securities
Amortized Cost		19,993
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Fair Value		$ 19,993

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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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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