Note 3 - Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2021

Notes Tables

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

	As of December 31, 2021
	Level 1		Level 2		Level 3		Total
Assets:
Money market funds	$	12,917	$	—	$	—	$	12,917
Cash in checking account		—		—		—		(45	)
Total cash and cash equivalent	$	12,917	$	—	$	—	$	12,872

	As of December 31, 2020
	Level 1		Level 2		Level 3		Total
Assets:
Money market funds	$	20,662	$	—	$	—	$	20,662
Cash in checking account		—		—		—		745
Total cash and cash equivalent	$	20,662	$	—	$	—	$	21,407