Note 4 - Fair Values of Financial Instruments - Schedule of Financial Assets and Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Financial liabilities:
Discounts	$ 2,137
Reported Value Measurement [Member]
Financial Assets:
Cash and cash equivalents	21,891	$ 5,300
Accounts receivable	44,453	20,299
Other current assets - restricted cash	915	1,410
Financial liabilities:
Accounts payable	(15,346)	(11,742)
Debt	(19,073)	(17,450)
Senior notes, excluding discounts of $2,137	(34,500)
Other liabilities - financed insurance payable	(280)	(862)
Estimate of Fair Value Measurement [Member]
Financial Assets:
Cash and cash equivalents	21,891	5,300
Accounts receivable	44,453	20,299
Other current assets - restricted cash	915	1,410
Financial liabilities:
Accounts payable	(15,346)	(11,742)
Debt	(19,073)	(17,450)
Senior notes, excluding discounts of $2,137	(37,978)
Other liabilities - financed insurance payable	$ (280)	$ (862)