Note 11 - Financial Instruments (Details Textual) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss, Current	$ 0	$ 46,000
Debt Instrument, Fair Value Disclosure, Total	29,500,000	28,100,000
Fair Value of Total Debt Less of Carrying Value	4,300,000	5,200,000
Fair Value, Inputs, Level 2 [Member] | Bank Time Deposits and Government Agency Securities [Member]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss, Current	$ 0	$ 46,000