Cash, Cash Equivalents and Short-Term Investments (Tables)

6 Months Ended

Jun. 30, 2019

Cash And Cash Equivalents [Abstract]

Schedule of Cash and Cash Equivalents and Short-Term Investments by Significant Investment Category

The following tables show the Company’s cash and cash equivalents and short-term investments by significant investment category as of June 30, 2019 and December 31, 2018 (in thousands):

	June 30, 2019
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value		Cash and Cash Equivalents		Short-Term Investments
Cash	$	2,564	$	—	$	—	$	2,564	$	2,564	$	—
Level 1 (1):
Money market funds		6,528		—		—		6,528		6,528		—
U.S. treasury securities		4,990		6		—		4,996		—		4,996
Subtotal		11,518		6		—		11,524		6,528		4,996
Level 2 (2):
Commercial paper		9,678		—		—		9,678		1,548		8,130
Corporate debt obligations		3,038		4		—		3,042		—		3,042
Repurchase agreements		3,001		—		—		3,001		3,001		—
Asset-backed securities		4,401		3		—		4,404		—		4,404
Subtotal		20,118		7		—		20,125		4,549		15,576
Total	$	34,200	$	13		—	$	34,213	$	13,641	$	20,572

	December 31, 2018
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value		Cash and Cash Equivalents		Short-Term Investments
Cash	$	3,044	$	—	$	—		$	3,044	$	3,044	$	—
Level 1 (1):
Money market funds		5,482		—		—			5,482		5,482		—
U.S. treasury securities		1,988		—		—			1,988		—		1,988
Subtotal		7,470		—		—			7,470		5,482		1,988
Level 2 (2):
Commercial paper		10,639		—		—			10,639		2,095		8,544
Corporate debt obligations		5,964		—		(7	)		5,957		—		5,957
Repurchase agreements		3,000		—		—			3,000		3,000		—
Asset-backed securities		3,682		—		(2	)		3,680		—		3,680
Subtotal		23,285		—		(9	)		23,276		5,095		18,181
Total	$	33,799		—	$	(9	)	$	33,790	$	13,621	$	20,169

⁽¹⁾ Level 1 fair value estimates are based on quoted prices in active markets for identical assets or liabilities.

⁽²⁾ Level 2 fair value estimates are based on observable inputs other than quoted prices in active markets for identical assets and liabilities, quoted prices for identical or similar assets or liabilities in inactive markets, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.  

Schedule of Contractual Maturities of Short-term Investments

Contractual maturities of short-term investments as of June 30, 2019 are as follows (in thousands):