FINANCIAL INSTRUMENTS

9 Months Ended

Sep. 30, 2019

Investments, Debt and Equity Securities [Abstract]

All marketable securities were classified as available-for-sale at September 30, 2019 and December 31, 2018.

The following tables show the Company’s cash, cash equivalents and available-for-sale securities by significant investment category as of September 30, 2019 and December 31, 2018, respectively:



As of September 30, 2019	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Aggregate Fair Value		Cash and Cash Equivalents		Short-term Marketable Securities ⁽¹⁾		Long-term Marketable Securities ⁽²⁾
Level 1:
Cash	$	294,543	$	—	$	—		$	294,543	$	294,543	$	—	$	—

Level 2:
Money market instruments	128,678		—		—			128,678		128,678		—		—
Corporate debt securities	519,693		3,713		(67		)	523,339		—		206,782		316,557
U.S. government agency securities	204,371		1,073		(97		)	205,347		—		90,790		114,557
Foreign and other	549		142		(1		)	690		—		—		690
Subtotal	853,291		4,928		(165		)	858,054		128,678		297,572		431,804
Total	$	1,147,834	$	4,928	$	(165	)	$	1,152,596	$	423,220	$	297,572	$	431,804



As of December 31, 2018	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Aggregate Fair Value		Cash and Cash Equivalents		Short-term Marketable Securities ⁽¹⁾		Long-term Marketable Securities⁽²⁾
Level 1:
Cash	$	228,809	$	—	$	—		$	228,809	$	228,809	$	—	$	—

Level 2:
Money market instruments	205,736		—		—			205,736		205,736		—		—
Corporate debt securities	564,852		214		(2,288		)	562,778		2,000		376,545		184,233
Commercial paper	77,702		—		—			77,702		21,964		55,738		—
U.S. government agency securities	240,436		144		(697		)	239,883		31,474		156,967		51,442
Foreign and other	5,126		139		(1		)	5,264		3,999		1,076		189
Subtotal	1,093,852		497		(2,986		)	1,091,363		265,173		590,326		235,864
Total	$	1,322,661	$	497	$	(2,986	)	$	1,320,172	$	493,982	$	590,326	$	235,864

(1) The Company’s short-term marketable securities mature in one year or less.

(2) The Company’s long-term marketable securities mature between one and five years.

As of September 30, 2019, the Company’s investments in an unrealized loss position were not significant, and since the Company has the ability and intent to hold all investments that have been in a continuous loss position until maturity or recovery, no other-than-temporary impairment was deemed to have occurred.