Note 8 - Equity Investment (Details Textual) - Sisecam Wyoming [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Equity Method Investment, Ownership Percentage	49.00%
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	$ (6,800)	$ 0	$ 1,700
Equity Method Investment, Difference Between Carrying Amount and Underlying Equity	$ 121,300	$ 126,300
Weighted Average Useful Life of Equity Method Investment Difference Between Carrying Amount And Underlying Equity (Year)	27 years