Note 1 - Organization and Significant Accounting Policies - Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Allowance for credit losses	$ 300	$ 327	$ 0
Allowance for credit losses	152	1,443	327
Allowance for credit losses	(164)	(1,470)	0
Allowance for credit losses	288	300	327
Deduction	$ 164	$ 1,470	$ 0