Note 8 - Long-term Leases - Lease Information and Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Finance (Year)	2 years 2 months 12 days	3 years 2 months 12 days
Operating (Year)	5 years 2 months 12 days	6 years 2 months 12 days
Finance	6.00%	6.00%
Operating	6.00%	6.00%
Depreciation of leased assets	$ 3,905	$ 3,906	$ 3,889
Interest of lease liabilities	807	1,064	1,306
Total finance lease costs	4,712	4,970	5,195
Operating lease costs	36,079	35,656	35,881
Variable lease costs	3,721	3,617	3,587
Short-term lease costs	1,018	1,221	1,050
Total operating lease costs	40,818	40,494	40,518
Total lease costs	$ 45,530	$ 45,464	$ 45,713