Marketable and Equity Securities (Tables)

6 Months Ended

Jun. 30, 2020

Marketable and Equity Securities

Schedule of marketable securities

			Gross		Gross
	Amortized		Unrealized		Unrealized
June 30, 2020	Cost		Gains		Losses		Fair Value
(in thousands)
Money Market Funds	$	103,231	$	—	$	—	$	103,231
Corporate Securities		266,756		786		—		267,542
Government Securities		207,010		710		(3)		207,717
	$	576,997	$	1,496	$	(3)	$	578,490
Reported as
Cash and cash equivalents							$	103,231
Marketable securities								475,259
Total investments							$	578,490
			Gross		Gross
	Amortized		Unrealized		Unrealized
December 31, 2019	Cost		Gains		Losses		Fair Value
(in thousands)
Money Market Funds	$	32,009	$	—	$	—	$	32,009
Corporate Securities		281,586		195		(30)		281,751
Government Securities		268,239		1,006		—		269,245
	$	581,834	$	1,201	$	(30)	$	583,005
Reported as
Cash and cash equivalents							$	32,009
Marketable securities								550,996
Total investments							$	583,005

Schedule of maturities of marketable securities

	Amortized		Estimated
June 30, 2020	Cost		Fair Value
(in thousands)
Mature in one year or less	$	472,639	$	474,114
Mature within two years		1,127		1,145
	$	473,766	$	475,259

Schedule of unrealized losses on available-for-sale investments

The unrealized losses on available-for-sale investments and their related fair values as of June 30, 2020 and December 31, 2019 are as follows:

	Less than 12 months				12 months or greater
			Unrealized				Unrealized
June 30, 2020	Fair value		losses		Fair value		losses
(in thousands)
Government Securities		49,973		(3)		—		—
	Less than 12 months				12 months or greater
			Unrealized				Unrealized
December 31, 2019	Fair value		losses		Fair value		losses
(in thousands)
Corporate Securities	$	46,303	$	(24)	$	13,992	$	(6)