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

6 Months Ended

Jun. 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 June 30, 2020 (in thousands):

	Less than 12 months
	Fair Value		Unrealized Losses
Corporate obligations	21,330		(6)
U.S. government agency securities	49,984		(3)
Total available-for sale securities in an unrealized loss position	$	71,314	$	(9)

Available-for-sale securities

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

	June 30, 2020
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Cash and cash equivalents due in 90 days or less	$	283,522	$	—	$	(1)	$	283,521
Available-for-sale securities:
Corporate obligations	56,828		162		(6)		56,984
U.S. Treasury securities	49,026		33		(3)		49,056
Certificates of deposit	245		4		—		249
Total available-for-sale securities	$	106,099	$	199	$	(9)	$	106,289
Total cash, cash equivalents and available-for-sale securities	$	389,621	$	199	$	(10)	$	389,810

	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	$	215,872	$	325	$	(28)	$	216,169
Total cash, cash equivalents and available-for-sale securities	$	453,549	$	325	$	(28)	$	453,846