Cash Equivalents and Investments (Tables)

3 Months Ended

Mar. 31, 2019

Cash Equivalents And Investments [Abstract]

Schedule of Fair Value of Securities, not Including Cash

The fair value of securities, not including cash at March 31, 2019 and December 31, 2018, were as follows (in thousands):

	March 31, 2019
	Amortized		Gross Unrealized					Estimated
	Cost		Gains		Losses			Fair Value
Money market funds	$	23,613	$ —		$ —			$	23,613
U.S. government securities		3,476		1	—				3,477
Corporate notes		11,284		2	—				11,286
Commercial paper		15,744	—		—				15,744
Total available-for-sale marketable debt securities	$	54,117	$	3	$	—		$	54,120
Classified as:
Cash equivalents								$	23,613
Short-term investments									30,507
Total cash equivalents and investments								$	54,120

	December 31, 2018
	Amortized		Gross Unrealized					Estimated
	Cost		Gains		Losses			Fair Value
Money market funds	$	10,606	$	—	$	—		$	10,606
U.S. government securities		9,976		—		(1	)		9,975
Corporate notes		16,514		3		(18	)		16,499
Commercial paper		36,331		—		—			36,331
Total available-for-sale marketable debt securities	$	73,427	$	3	$	(19	)	$	73,411
Classified as:
Cash equivalents								$	15,091
Short-term investments									58,320
Total cash equivalents and investments								$	73,411

Schedule of Fair Value of Short-term and Long-term Marketable Securities Classified by Maturity

The following table summarizes the fair value of the Company’s cash equivalents, short-term and long-term marketable securities classified by maturity (in thousands):

	March 31,		December 31,
	2019		2018
Due within one year	$	54,120	$	73,411
Due after one year through three years		—		—
Total available-for-sale marketable debt securities	$	54,120	$	73,411

Schedule of Available-for-Sale Securities Unrealized Loss Position

The following tables present the Company's available-for-sale securities that were in an unrealized loss position as of March 31, 2019 and December 31, 2018 (in thousands):

	As of March 31, 2019
	Less than 12 months					12 Months or Greater					Total
Assets	Fair Value		Unrealized Loss			Fair Value		Unrealized Loss			Fair Value		Unrealized Loss
Corporate notes	$	2,498	$	—		$	—	$	—		$	2,498	$	—
Total	$	2,498	$	—		$	—	$	—		$	2,498	$	—

	December 31, 2018
	Less than 12 months					12 Months or Greater					Total
Assets	Fair Value		Unrealized Loss			Fair Value		Unrealized Loss			Fair Value		Unrealized Loss
U.S. government securities	$	5,977	$	(1	)	$	—	$	—		$	5,977	$	(1	)
Corporate notes		11,521		(10	)		2,993		(8	)		14,514		(18	)
Total	$	17,498	$	(11	)	$	2,993	$	(8	)	$	20,491	$	(19	)