Note 11 - Accounts Receivable Securitization (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Payments of Financing Costs, Total	$ 2,368	$ 9,002	$ 12,492
Line of Credit [Member] | Accounts Receivable Securitization Facility [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 100,000
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage	0.60%
Accounts Receivable Eligible for Securitization	$ 21,649	31,868
Line of Credit Facility, Fair Value of Amount Outstanding	0	0
Letters of Credit Outstanding, Amount	21,806	31,218
Line of Credit Facility, Remaining Borrowing Capacity	0	650
Debt Instrument, Collateral Amount	157
Payments of Financing Costs, Total	1,048	$ 1,156	$ 1,441
Line of Credit [Member] | Accounts Receivable Securitization Facility [Member] | Restricted Cash, Current [Member]
Debt Instrument, Collateral Amount	$ 157
Line of Credit [Member] | Accounts Receivable Securitization Facility [Member] | Minimum [Member]
Line of Credit Facility, Commitment Fee Percentage	2.00%
Line of Credit [Member] | Accounts Receivable Securitization Facility [Member] | Maximum [Member]
Line of Credit Facility, Commitment Fee Percentage	2.50%