Note 11 - Income Taxes (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Unrecognized Tax Benefits	$ 10,170	$ 8,925	$ 5,140
Unrecognized Tax Benefits that Would Impact Effective Tax Rate		0
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	8,100	$ 10,800
Domestic Tax Authority [Member]
Operating Loss Carryforwards	222,000
Operating Loss Carryforwards, Not Subject to Expiration	196,400
Tax Credit Carryforward, Amount	8,600
State and Local Jurisdiction [Member]
Operating Loss Carryforwards	204,400
Tax Credit Carryforward, Amount	$ 8,100