Marketable Securities (Tables)

6 Months Ended

Jun. 30, 2017

Cash and Cash Equivalents [Abstract]

Summary of cash, cash equivalents and marketable securities

A summary of the Company’s cash, cash equivalents and marketable securities is shown below:

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	(in thousands)
As of June 30, 2017
Cash and cash equivalents:
Cash and money market funds	$	1,217,134	$	—	$	—		$	1,217,134
Commercial paper	5,996		—		—			5,996
Total cash and cash equivalents	$	1,223,130	$	—	$	—		$	1,223,130
Marketable securities:
Corporate equity securities	43,213		7,836		—			51,049
Commercial paper (matures within 1 year)	103,386		1		(40		)	103,347
Corporate debt securities (matures within 1 year)	218,216		4		(143		)	218,077
Corporate debt securities (matures after 1 year)	73,115		2		(70		)	73,047
Total marketable securities	$	437,930	$	7,843	$	(253	)	$	445,520
Total cash, cash equivalents and marketable securities	$	1,661,060	$	7,843	$	(253	)	$	1,668,650
As of December 31, 2016
Cash and cash equivalents:
Cash and money market funds	$	1,183,945	$	—	$	—		$	1,183,945
Total cash and cash equivalents	$	1,183,945	$	—	$	—		$	1,183,945
Marketable securities:
Government-sponsored enterprise securities (matures within 1 year)	$	15,506	$	2	$	—		$	15,508
Corporate equity securities	43,213		21,347		—			64,560
Commercial paper (matures within 1 year)	59,331		73		—			59,404
Corporate debt securities (matures within 1 year)	111,225		—		(85		)	111,140
Total marketable securities	$	229,275	$	21,422	$	(85	)	$	250,612
Total cash, cash equivalents and marketable securities	$	1,413,220	$	21,422	$	(85	)	$	1,434,557