Note 6 - Contract Assets and Liabilities (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Contract With Customer Liability, Revenue Recognized Including Opening Balance		$ 176,200	$ 110,900	$ 116,100
Contract with Customer, Liability, Cumulative Catch-up Adjustment to Revenue, Change in Estimate of Transaction Price	$ 13,975	(3,856)	$ 152,100
Aggregate Affirmative Claim Recovery Estimate Included in Contract Asset and Liability	39,000	37,700
Performance Obligations [Member]
Contract with Customer, Liability, Cumulative Catch-up Adjustment to Revenue, Change in Estimate of Transaction Price	$ 153,900	$ 176,100