MARKETABLE SECURITIES

12 Months Ended

Dec. 31, 2017

Investments, Debt and Equity Securities [Abstract]

NOTE 3:- MARKETABLE SECURITIES

Marketable securities with contractual maturities of up to one year are as follows:


	December 31,
	2017									2016
	Amortized cost		Gross unrealized gains		Gross unrealized losses			Fair value		Amortized cost		Gross unrealized gains		Gross unrealized losses			Fair value
Government and corporate debentures - fixed interest rate	$	1,026,555	$	48	$	(1,698	)	$	1,024,905	$	915,302	$	311	$	(446	)	$	915,167
Government-sponsored enterprises debentures		112,951		1		(275	)		112,677		149,972		99		(61	)		150,010
Government and corporate debentures - floating interest rate		27,681		14		(11	)		27,684		13,247		16		—			13,263

	$	1,167,187	$	63	$	(1,984	)	$	1,165,266	$	1,078,521	$	426	$	(507	)	$	1,078,440

Marketable securities with contractual maturities of over one year through five years are as follows:


	December 31,
	2017									2016
	Amortized cost		Gross unrealized gains		Gross unrealized losses			Fair value		Amortized cost		Gross unrealized gains		Gross unrealized losses			Fair value
Government and corporate debentures - fixed interest rate	$	1,985,849	$	384	$	(15,204	)	$	1,971,029	$	1,770,641	$	1,903	$	(11,024	)	$	1,761,520
Government-sponsored enterprises debentures		424,619		—		(4,687	)		419,932		520,669		282		(4,052	)		516,899
Government and corporate debentures - floating interest rate		46,247		134		(27	)		46,354		17,610		70		(2	)		17,678

	$	2,456,715	$	518	$	(19,918	)	$	2,437,315	$	2,308,920	$	2,255	$	(15,078	)	$	2,296,097

Investments with continuous unrealized losses for less than 12 months and 12 months or greater and their related fair values were as follows:


	December 31, 2017
	Less than 12 months					12 months or greater					Total
	Fair value		Unrealized losses			Fair value		Unrealized losses			Fair Value		Unrealized losses
Government and corporate debentures - fixed interest rate	$	1,647,125	$	(7,318	)	$	1,063,690	$	(9,585	)	$	2,710,815	$	(16,903	)
Government-sponsored enterprises debentures		236,403		(1,281	)		294,986		(3,681	)		531,389		(4,962	)
Government and corporate debentures - floating interest rate		27,810		(37	)		—		—			27,810		(37	)

	$	1,911,338	$	(8,636	)	$	1,358,676	$	(13,266	)	$	3,270,014	$	(21,902	)


	December 31, 2016
	Less than 12 months					12 months or greater					Total
	Fair value		Unrealized losses			Fair value		Unrealized losses			Fair Value		Unrealized losses
Government and corporate debentures - fixed interest rate	$	1,717,212	$	(11,440	)	$	40,465	$	(30	)	$	1,757,677	$	(11,470	)
Government-sponsored enterprises debentures		464,080		(4,112	)		4,999		(1	)		469,079		(4,113	)
Government and corporate debentures - floating interest rate		3,000		(2	)		—		—			3,000		(2	)

	$	2,184,292	$	(15,554	)	$	45,464	$	(31	)	$	2,229,756	$	(15,585	)

As of December 31, 2017 and 2016, interest receivable amounted to $ 19,871 and $ 17,057 respectively, and is included within other current assets in the balance sheets.