Marketable Securities and Equity Investments (Tables)

3 Months Ended

Mar. 31, 2019

Cash and Cash Equivalents [Abstract]

Summary of cash equivalents and marketable securities

A summary of the Company’s cash equivalents and marketable securities, which are recorded at fair value (and do not include $1.5 billion and $1.4 billion of cash as of March 31, 2019 and December 31, 2018, respectively), is shown below:

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	(in thousands)
As of March 31, 2019
Cash equivalents:
Money market funds	$	1,354,656	$	—	$	—		$	1,354,656
U.S. Treasury securities	5,996		—		—			5,996
Government-sponsored enterprise securities	11,787		—		(1		)	11,786
Corporate debt securities	4,519		—		—			4,519
Commercial paper	35,959		—		(4		)	35,955
Total cash equivalents	1,412,917		—		(5		)	1,412,912
Marketable securities:
Government-sponsored enterprise securities	15,180		2		(1		)	15,181
Corporate debt securities	231,516		88		(32		)	231,572
Commercial paper	126,515		34		(26		)	126,523
Total marketable debt securities	373,211		124		(59		)	373,276
Corporate equity securities	133,157		79,093		(1,376		)	210,874
Total marketable securities	$	506,368	$	79,217	$	(1,435	)	$	584,150
As of December 31, 2018
Cash equivalents:
Money market funds	$	1,226,603	$	—	$	—		$	1,226,603
U.S. Treasury securities	5,967		—		(1		)	5,966
Government-sponsored enterprise securities	7,124		—		(1		)	7,123
Commercial paper	58,271		—		(3		)	58,268
Total cash equivalents	1,297,965		—		(5		)	1,297,960
Marketable securities:
U.S. Treasury securities	6,026		—		—			6,026
Government-sponsored enterprise securities	10,704		—		—			10,704
Corporate debt securities	234,088		27		(450		)	233,665
Commercial paper	100,498		—		(108		)	100,390
Total marketable debt securities	351,316		27		(558		)	350,785
Corporate equity securities	133,157		40,619		(6,453		)	167,323
Total marketable securities	$	484,473	$	40,646	$	(7,011	)	$	518,108

Available-for-sale debt securities were recorded in the Company's condensed consolidated balance sheets at fair value as follows:

	As of March 31, 2019		As of December 31, 2018
	(in thousands)
Cash and cash equivalents	$	1,412,912	$	1,297,960
Marketable securities	373,276		350,785
Total	$	1,786,188	$	1,648,745

Available-for-sale debt securities by contractual maturity were as follows:

	As of March 31, 2019		As of December 31, 2018
	(in thousands)
Matures within one year	$	1,775,571	$	1,647,500
Matures after one year through five years	10,617		1,245
Total	$	1,786,188	$	1,648,745