Marketable Securities (Tables)

6 Months Ended

Jun. 30, 2019

Investments, Debt and Equity Securities [Abstract]

Summary of marketable securities

The following is a summary of our marketable securities as of June 30, 2019 and December 31, 2018 (in thousands):

	June 30, 2019
			Gross		Gross			Estimated
	Amortized		Unrealized		Unrealized			Fair
	Cost		Gains		Losses			Value
Short-term marketable securities:*
Corporate debt securities	$	47,410	$	122	$	(52	)	$	47,480
Certificates of deposit	8,000		—		—			8,000
U.S. treasury and government agency securities	6,394		—		(11		)	6,383
Commercial paper	1,500		—		—			1,500
Total short-term marketable securities	$	63,304	$	122	$	(63	)	$	63,363
Long-term marketable securities:**
Corporate debt securities	$	46,739	$	500	$	(19	)	$	47,220
Total long-term marketable securities	46,739		500		(19		)	47,220
Total marketable securities	$	110,043	$	622	$	(82	)	$	110,583

* Represents marketable securities with a remaining maturity of less than one year.

** Represents marketable securities with a remaining maturity of one to three years classified as short-term on our condensed consolidated balance sheets.

	December 31, 2018
			Gross		Gross			Estimated
	Amortized		Unrealized		Unrealized			Fair
	Cost		Gains		Losses			Value
Short-term marketable securities:*
Corporate debt securities	$	51,184	$	—	$	(236	)	$	50,948
Certificates of deposit	7,647		—		(34		)	7,613
U.S. treasury and government agency securities	3,995		—		—			3,995
Commercial paper	12,000		—		—			12,000
Total short-term marketable securities	$	74,826	$	—	$	(270	)	$	74,556
Long-term marketable securities:**
Corporate debt securities	$	62,530	$	52	$	(433	)	$	62,149
U.S. treasury and government agency securities	2,742		—		(32		)	2,710
Certificates of deposit	1,500		—		—			1,500
Total long-term marketable securities	66,772		52		(465		)	66,359
Total marketable securities	$	141,598	$	52	$	(735	)	$	140,915

* Represents marketable securities with a remaining maturity of less than one year.

** Represents marketable securities with a remaining maturity of one to three years classified as short-term on our condensed consolidated balance sheets.