Financial Instruments

12 Months Ended

Dec. 31, 2019

Fair Value Disclosures [Abstract]

Financial Instruments

4. Financial Instruments

Financial Assets

The following tables summarize the estimated fair value of the Company’s financial assets measured on a recurring basis as of the dates indicated, which were comprised solely of available-for-sale marketable securities with remaining contractual maturities of one year or less (in thousands):

					Gross		Gross
	Valuation	Amortized			Unrealized		Unrealized		Estimated Fair
December 31, 2019	Input Level	Cost			Gains		Losses		Value
Money market funds	Level 1	$	3,495		$	—	$	—	$	3,495
U.S. Treasury securities	Level 1		1,594			1		—		1,595
Repurchase agreements	Level 2		5,000			—		—		5,000
U.S. corporate debt obligations	Level 2		5,155			—		—		5,155
U.S. commercial paper	Level 2		11,412			—		—		11,412
Total available-for-sale securities			26,656			1		—		26,657
Less amounts classified as cash equivalents			(10,293	)		—		—		(10,293	)
Amounts classified as marketable securities		$	16,363		$	1	$	—	$	16,364

					Gross		Gross
	Valuation	Amortized			Unrealized		Unrealized		Estimated Fair
December 31, 2018	Input Level	Cost			Gains		Losses		Value
Money market funds	Level 1	$	10,845		$	—	$	—	$	10,845
Total available-for-sale securities			10,845			—		—		10,845
Less amounts classified as cash equivalents			(10,845	)		—		—		(10,845	)
Amounts classified as marketable securities		$	—		$	—	$	—	$	—

There were no available-for-sale securities in an unrealized loss position as of December 31, 2019.

No significant facts or circumstances have arisen to indicate that there has been any deterioration in the creditworthiness of the issuers of these securities. There were no realized gains or losses on the available-for-sale securities in the years ended December 31, 2019 and 2018. There were no sales of available-for-sale debt securities in the years ended December 31, 2019 and 2018.