Marketable Securities (Tables)

9 Months Ended

Sep. 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 September 30, 2017
Cash and cash equivalents:
Cash and money market funds	$	1,350,891	$	—	$	—		$	1,350,891
Government-sponsored enterprise securities	14,979		—		—			14,979
Commercial paper	14,610		—		(2		)	14,608
Corporate debt securities	4,488		—		—			4,488
Total cash and cash equivalents	$	1,384,968	$	—	$	(2	)	$	1,384,966
Marketable securities:
Corporate equity securities	43,213		13,731		—			56,944
Commercial paper (matures within 1 year)	75,186		1		(20		)	75,167
Corporate debt securities (matures within 1 year)	235,679		8		(106		)	235,581
Corporate debt securities (matures after 1 year)	59,651		—		(61		)	59,590
Total marketable securities	$	413,729	$	13,740	$	(187	)	$	427,282
Total cash, cash equivalents and marketable securities	$	1,798,697	$	13,740	$	(189	)	$	1,812,248
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