Note 2 - Summary of Significant Accounting Policies - Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Allowance for doubtful accounts	$ 111	$ 110
Provision charged to expense	0	24
(Write-offs) / Recoveries	0	(23)
Allowance for doubtful accounts	$ 111	$ 111