Note 1 - Summary of Significant Accounting Policies - Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Balance	$ 94	$ 120	$ 144
Bad debt expense	19	38	46
Write-offs	48	64	70
Balance	$ 65	$ 94	$ 120