Note 3 - Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2021

Notes Tables

Fair Value Measurements, Recurring and Nonrecurring [Table Text Block]

	As of September 30, 2021
	Adjusted		Unrealized		Unrealized		Market
	Cost		Gains		Losses		Value
Level 1:
Money Market Funds	$	1,535	$	-	$	-	$	1,535
U.S. Treasury securities considered cash equivalents		-		-		-		-
U.S. Treasury securities in short-term investments		29,993		11		-		30,004
Total Financial Assets	$	31,528	$	11	$	-	$	31,539

	As of December 31, 2020
	Adjusted		Unrealized		Unrealized		Market
	Cost		Gains		Losses		Value
Level 1:
Money Market Funds	$	6,035	$	-	$	-	$	6,035
U.S. Treasury securities considered cash equivalents		9,998		-		-		9,998
U.S. Treasury securities in short-term investments		24,979		15		-		24,994
Total Financial Assets	$	41,012	$	15	$	-	$	41,027