MARKETABLE SECURITIES (Tables)

12 Months Ended

Dec. 31, 2017

Marketable Securities [Abstract]

Schedule of Marketable Securities With Contractual Maturities

Marketable securities with contractual maturities of less than one year are as follows:

	December 31,
	2017									2016
	Adjusted		Gross unrealized			Gross unrealized		Market		Adjusted		Gross unrealized			Gross unrealized		Market
	cost		losses			gains		value		cost		losses			gains		value
Foreign banks and government debentures	$	22,294	$	(63	)	$	3	$	22,234	$	15,361	$	(10	)	$	51	$	15,402
Corporate debentures		20,354		(20	)		5		20,339		5,046		-			4		5,050
Total available-for-sale marketable securities	$	42,648	$	(83	)	$	8	$	42,573	$	20,407	$	(10	)	$	55	$	20,452

Marketable securities with contractual maturities from one to three years are as follows:

	December 31,
	2017									2016
	Adjusted		Gross unrealized			Gross unrealized		Market		Adjusted		Gross unrealized			Gross unrealized		Market
	cost		losses			gains		value		cost		losses			gains		value
Foreign banks and government debentures	$	14,463	$	(61	)	$	2	$	14,404	$	31,040	$	(45	)	$	76	$	31,071
Corporate debentures		9,554		(19	)		32		9,567		28,980		(26	)		65		29,019
Total available-for-sale marketable securities	$	24,017	$	(80	)	$	34	$	23,971	$	60,020	$	(71	)	$	141	$	60,090

Marketable securities with contractual maturities of more than three years are as follows:

	December 31,
	2017									2016
	Adjusted		Gross unrealized			Gross unrealized		Market		Adjusted		Gross unrealized			Gross unrealized		Market
	cost		losses			gains		value		cost		losses			gains		value
Foreign banks and government debentures	$	13,603	$	(198	)	$	-	$	13,405	$	7,738	$	(111	)	$	-	$	7,627
Corporate debentures		17,308		(257	)		-		17,051		7,281		(60	)		29		7,250
Total available-for-sale marketable securities	$	30,911	$	(455	)	$	-	$	30,456	$	15,019	$	(171	)	$	29	$	14,877

Summary of Investments With Continuous Unrealized Losses and Related Fair Values

Investments with continuous unrealized losses for less than 12 months and 12 months or greater and their related fair values as of December 31, 2017 and 2016 were as follows:

	December 31, 2017
	Investments with continuous unrealized losses for less than 12 months					Investments with continuous unrealized losses for 12 months or greater					Total investments with continuous unrealized losses
	Fair Value		Unrealized losses			Fair value		Unrealized losses			Fair value		Unrealized losses
Foreign banks and government debentures	$	40,104	$	(275	)	$	6,486	$	(48	)	$	46,590	$	(323	)
Corporate debentures		29,280		(226	)		8,173		(69	)		37,453		(295	)
Total available-for-sale marketable securities	$	69,384	$	(501	)	$	14,659	$	(117	)	$	84,043	$	(618	)

	December 31, 2016
	Investments with continuous unrealized losses for less than 12 months					Investments with continuous unrealized losses for 12 months or greater					Total investments with continuous unrealized losses
	Fair value		Unrealized losses			Fair value		Unrealized losses			Fair value		Unrealized losses
Foreign banks and government debentures	$	20,118	$	(139	)	$	2,325	$	(28	)	$	22,443	$	(167	)
Corporate debentures		13,444		(79	)		1,013		(6	)		14,457		(85	)
Total available-for-sale marketable securities	$	33,562	$	(218	)	$	3,338	$	(34	)	$	36,900	$	(252	)