Note 3 - Trade Accounts Receivable - Changes in Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Balance—beginning of year	$ 5,381	$ 4,526	$ 3,482
Provision for bad debts	2,396	917	1,044
Charge-offs	(60)	(62)	0
Recoveries	0	0	0
Balance—end of year	$ 7,717	$ 5,381	$ 4,526