Note 11 - Income Taxes - Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Stock-based compensation	$ 2,440	$ 4,253
Accrued expenses and other	2,423	906
Research credit carryforward	564	0
Fixed Assets	101	385
Capitalized start-up costs and other intangibles	1,109	2,686
Net operating loss carryforwards	75,237	63,786
Deferred Tax Assets, Gross, Total	81,874	72,016
Valuation Allowance	(78,294)	(67,312)
Net deferred tax asset	3,580	4,704
Fixed assets and other	(1,176)	(1,590)
Purchase accounting intangibles	(2,116)	(2,807)
Net deferred tax liability	(3,292)	(4,397)
Net deferred tax asset (liability)	$ 288	$ 307