Fair Value Of Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2019

Fair Value Of Financial Instruments [Abstract]

Fair Value Of Financial Assets Measured On A Recurring Basis

		September 30, 2019								December 31, 2018
Assets	Classification		Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
Money market funds	Cash and cash equivalents	$	5,912	$	—	$	—	$	5,912	$	50,703	$	—	$	—	$	50,703
U.S. Treasury Securities	Investments, cash and cash equivalents		—		27,919		—		27,919		—		8,480		—		8,480
Total assets measured   at fair value		$	5,912	$	27,919	$	—	$	33,831	$	50,703	$	8,480	$	—	$	59,183