Note 12 - Income Taxes - Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Stock-based compensation	$ 2,840	$ 2,440
Accrued expenses and other	2,538	2,423
Research credit carryforward	1,341	564
Fixed Assets	162	101
Net operating loss carryforwards	83,908	75,237
Deferred Tax Assets, Gross, Total	96,092	81,874
Valuation Allowance	(94,704)	(78,294)
Net deferred tax asset	1,388	3,580
Fixed assets and other	(1,214)	(1,176)
Purchase accounting intangibles	0	(2,116)
Net deferred tax liability	(1,214)	(3,292)
Net deferred tax asset (liability)	174	288
Start-up Costs and Other Intangibles [Member]
Capitalized costs	921	1,109
Research Tax Credit Carryforward [Member]
Capitalized costs	$ 4,382	$ 0