Note 1 - Nature of Operations, Basis of Presentation and Company Conditions (Details Textual) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2020
Retained Earnings (Accumulated Deficit), Total	$ (248,535)		$ (210,934)
Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent, Total	(36,670)	$ (16,309)
Net Cash Provided by (Used in) Operating Activities, Total	(1,565)	(13,482)
Cash and Cash Equivalents, at Carrying Value, Total	20,949	34,733	26,865	$ 3,046
Working Capital	(65,100)
Sale of Equity, Registration, Maximum Value	112,000
Revenue, Increase Amount	$ 64,700
Revenue Increase, Percent	1100.00%
Accrued Liabilities, Current, Total	$ 30,524	$ 28,300	$ 28,301