Note 1 - Organization and Significant Accounting Policies - Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Allowance for credit losses	$ 313	$ 288	$ 300
Additions	0	25	152
Deduction	(25)	0	(164)
Allowance for credit losses	$ 288	$ 313	$ 288