Note 6 - Accounts Receivable - Summary of Accounts Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Gross accounts receivable	$ 70,925	$ 86,625
Unearned income	(3,354)	(4,033)
Allowance for doubtful accounts	(13,619)	(11,997)	$ (18,490)
Accounts Receivable, after Allowance for Credit Loss, Total	53,952	70,595
Current trade receivables	37,262	46,918
Current unearned interest income	(2,397)	(2,678)
Long-term trade receivables	20,044	27,710
Long-term unearned interest income	$ (957)	$ (1,355)