Cash Equivalents and Short-term and Long-term Investments (Tables)

9 Months Ended

Sep. 30, 2020

Cash and Cash Equivalents [Abstract]

Available-for-Sale Securities with Unrealized Losses

The following is a summary of available-for-sale securities with unrealized losses as of September 30, 2020 (in thousands):

	Less than 12 months
	Fair Value		Unrealized Losses
Corporate obligations	18,756		(1)
U.S. government agency securities	101,674		(16)
Agency bond	4,999		(1)
Total available-for sale securities in an unrealized loss position	$	125,429	$	(18)

Available-for-Sale Securities

The following is a summary of cash, cash equivalents and available-for-sale securities as of September 30, 2020 and December 31, 2019 (in thousands):

	September 30, 2020
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Cash and cash equivalents due in 90 days or less	$	729,686	$	—	$	(1)	$	729,685
Available-for-sale securities:
Corporate obligations	39,162		57		(1)		39,218
U.S. Treasury securities	113,220		8		(16)		113,212
Certificates of deposit	245		2		—		247
Mortgage and other asset backed securities	5,000		—		(1)		4,999
Total available-for-sale securities (1)	$	157,627	$	67	$	(18)	$	157,676
Total cash, cash equivalents and available-for-sale securities	$	887,313	$	67	$	(19)	$	887,361

	December 31, 2019
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Cash and cash equivalents due in 90 days or less	$	237,677	$	—	$	—	$	237,677
Available-for-sale securities:
Corporate obligations	124,676		219		(15)		124,880
U.S. Treasury securities	78,230		98		(1)		78,327
Certificates of deposit	490		3		—		493
Mortgage and other asset backed securities	12,476		5		(12)		12,469
Total available-for-sale securities (1)	$	215,872	$	325	$	(28)	$	216,169
Total cash, cash equivalents and available-for-sale securities	$	453,549	$	325	$	(28)	$	453,846

(1)All available-for-sale securities mature within two and three years as of September 30, 2020 and December 31, 2019, respectively.