Note 8 - Lease Obligations - Lease Obligations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Amortization of right-of-use assets	$ 885	$ 1,018	$ 2,806	$ 3,023
Interest on lease liabilities	159	284	493	808
Operating lease cost	6,280	5,734	18,044	19,782
Variable lease cost	8	44	99	358
Total lease cost	7,332	7,080	21,442	23,971
Operating cash flows from finance leases	885	1,018	2,806	3,023
Operating cash flows from operating leases	4,856	5,778	14,388	20,140
Financing cash flows from finance leases	159	284	493	808
Right-of-use assets obtained in exchange for new finance lease liabilities	0	1,131	0	3,258
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 13,265	$ 122	$ 15,795	$ 2,759
Weighted-average remaining lease term—finance leases (in years) (Year)	1 year 1 month 6 days		1 year 1 month 6 days
Weighted-average remaining lease term—operating leases (in years) (Year)	4 years 8 months 12 days		4 years 8 months 12 days
Weighted-average discount rate—finance leases	4.40%		4.40%
Weighted-average discount rate—operating leases	6.30%		6.30%