Note 5 - Accounts Receivable - Summary of Accounts Receivable (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Gross accounts receivable	$ 87,578		$ 86,625
Unearned income	(4,317)		(4,033)
Allowance for doubtful accounts	(14,100)	$ (12,742)	(11,997)	$ (18,490)
Accounts Receivable, after Allowance for Credit Loss, Total	69,161		70,595
Current trade receivables	46,754		46,918
Current unearned interest income	(2,884)		(2,678)
Long-term trade receivables	26,724		27,710
Long-term unearned interest income	$ (1,433)		$ (1,355)