Note 17 - Other Employee Benefit Plans (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	6.00%
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 9,378
Defined Contribution Plan, Cost	$ 9,117	$ 8,114	$ 10,737
Minimum [Member]
Defined Contribution Plan, Employer Discretionary Contribution Percent	1.00%
Maximum [Member]
Defined Contribution Plan, Employer Discretionary Contribution Percent	6.00%
Retiree Health Benefit Act of 1992 [Member]
Multiemployer Plan, Employer Contribution, Cost, Total	$ 4,760	5,383	6,042
Multiemployer Plans, Withdrawal Obligation	46,381
Non Pension Multiemployer Plans [Member]
Letters of Credit Outstanding, Amount	16,199	17,421	$ 18,669
Long Term Disability Member [Member]
Defined Benefit Plan, Benefit Obligation, Ending Balance	$ 9,528	$ 11,374