Note 6 - Employee Benefit Plans - Amounts Recognized in the Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current liabilities:
Accrued benefit liability	$ (1,315)	$ (758)
Accrued benefit liability	(4,673)	(44,144)
Accumulated other comprehensive loss	29,966	53,085
Net amount recognized	$ 23,978	$ 8,183