Cash Equivalents, Marketable Securities and Corporate Equity Securities (Tables)

6 Months Ended

Jun. 30, 2020

Cash Equivalents, Marketable Securities and Equity Securities

Schedule of cash equivalents, marketable securities and corporate equity securities

Cash equivalents and marketable securities consisted of the following at June 30, 2020 (in thousands):

			Allowance		Gross		Gross
	Amortized		for Credit		Unrealized		Unrealized		Fair
June 30, 2020	Cost		Losses		Gains		Losses		Value
Cash equivalents and marketable securities:
Money market funds	$	485,819	$	—	$	—	$	—	$	485,819
U.S. Treasuries		26,961		—		36		—		26,997
Government agency securities		67,565		—		147		—		67,712
Corporate equity securities		3,667		—		14,525		—		18,192
Total	$	584,012	$	—	$	14,708	$	—	$	598,720

Cash equivalents, marketable securities and equity securities consisted of the following at December 31, 2019 (in thousands):
​

			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
December 31, 2019	Cost		Gains		Losses		Value
Cash equivalents and marketable securities:
Money market funds	$	230,201	$	—	$	—	$	230,201
U.S. Treasuries		71,348		20		—		71,368
Government agency securities		155,484		87		—		155,571
Equity securities included in other non-current assets:
Corporate equity securities		3,667		—		—		3,667
Total	$	460,700	$	107	$	—	$	460,807