Marketable Securities (Tables)

9 Months Ended

Sep. 30, 2019

Investments, Debt and Equity Securities [Abstract]

Schedule of Marketable Securities

The table below summarizes the marketable securities as of September 30, 2019 and December 31, 2018:

	September 30, 2019
	Amortized Cost		Unrealized Gains		Unrealized Losses			Aggregate Fair Value
	(in thousands)
Money market funds	$	8,956	$	—	$	—		$	8,956
Cash equivalents	8,956		—		—			8,956
U.S. treasury securities	74,881		41		(12		)	74,910
Corporate bonds	8,693		6		—			8,699
Short-term investments	83,574		47		(12		)	83,609
Corporate bonds	5,251		22		—			5,273
Long-term investments	5,251		22		—			5,273
Total marketable securities	$	97,781	$	69	$	(12	)	$	97,838

	December 31, 2018
	Amortized Cost		Unrealized Gains		Unrealized Losses			Aggregate Fair Value
	(in thousands)
U.S. treasury securities	$	1,000	$	—	$	—		$	1,000
Commercial paper	6,635		—		—			6,635
Money market funds	15,223		—		—			15,223
Cash equivalents	22,858		—		—			22,858
U.S. treasury securities	65,491		2		(4		)	65,489
Corporate bonds	19,708		15		(3		)	19,720
Commercial paper	11,894		—		—			11,894
Short-term investments	97,093		17		(7		)	97,103
Total marketable securities	$	119,951	$	17	$	(7	)	$	119,961