Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2019

Fair Value of Company's Financial Assets Measured on Recurring Basis

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 are comprised solely of available-for-sale securities classified as cash equivalents (in thousands):

March 31, 2019	Input Level	Amortized Cost			Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Money market funds	Level 1	$	19,735		$	—	$	—	$	19,735
Total available-for-sale securities classified as cash equivalents			19,735			-		-		19,735
Less amounts classified as cash equivalents			(19,735	)		—		—		(19,735	)
Amounts classified as marketable securities		$	—		$	—	$	—	$	—

December 31, 2018	Input Level	Amortized Cost			Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair 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		$	—		$	—	$	—	$	—