Note 9 - Leases - Lease Obligations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Amortization of right-of-use assets	$ 4,080	$ 5,469
Interest on lease liabilities	1,003	1,107
Operating lease cost	21,212	24,393
Variable lease cost	414	326
Total lease cost	26,709	31,295
Operating cash flows from finance leases	1,003	7,226
Operating cash flows from operating leases	24,325	24,393
Financing cash flows from finance leases	20,083	1,107
Right-of-use assets obtained in exchange for new finance lease liabilities	3,229	0
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 1,730	$ 37,080
Weighted-average remaining lease term—finance leases (Year)	1 year 9 months 18 days	2 years 10 months 24 days
Weighted-average remaining lease term—operating leases (Year)	2 years 3 months 18 days	3 years 4 months 24 days
Weighted-average discount rate—finance leases	2.30%	3.00%
Weighted-average discount rate—operating leases	5.30%	5.20%