Note 1 - Organization and Significant Accounting Policies - Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Balance at January 1	$ 835	$ 1,816
Provision charged to expense	227	(498)
Write-offs / Recoveries	(839)	(483)
Balance at December 31	$ 223	$ 835