Cash, Cash Equivalents and Marketable Securities

12 Months Ended

Dec. 31, 2019

Cash and Cash Equivalents [Abstract]

Cash, Cash Equivalents and Marketable Securities

4. Cash, Cash Equivalents and Marketable Securities

A summary of cash, cash equivalents and available-for-sale marketable securities held by the Company as of December 31, 2019 and 2018 is as follows (in thousands):

	December 31, 2019
	Cost		Unrealized gains		Unrealized losses			Fair value
Cash and cash equivalents:
Cash (Level 1)	$	1,772	$	—	$	—		$	1,772
Money market funds (Level 1)		44,925		—		—			44,925
Corporate debt securities due within 3 months of date of purchase (Level 2)		—		—		—			—
Total cash and cash equivalents		46,697		—		—			46,697
Marketable securities:
Corporate debt securities due within 1 year of date of purchase (Level 2)		309,365		220		(40	)		309,545
Corporate debt securities due within 1 to 2 years of date of purchase (Level 2)		82,767		39		(3	)		82,803
Total cash, cash equivalents and marketable securities	$	438,829	$	259	$	(43	)	$	439,045

	December 31, 2018
	Cost		Unrealized gains		Unrealized losses			Fair value
Cash and cash equivalents:
Cash (Level 1)	$	2,004	$	—	$	—		$	2,004
Money market funds (Level 1)		43,401		—		—			43,401
Corporate debt securities due within 3 months of date of purchase (Level 2)		11,974		—		—			11,974
Total cash and cash equivalents		57,379		—		—			57,379
Marketable securities:
Corporate debt securities due within 1 year of date of purchase (Level 2)		426,658		14		(333	)		426,339
Total cash, cash equivalents and marketable securities	$	484,037	$	14	$	(333	)	$	483,718