Note 14 - Leases - Components of Expense and Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Fixed operating lease expense	$ 17,695	$ 24,359
Variable operating lease expense	6,884	3,835
Total operating lease expense	24,579	28,194
Cash paid for operating leases	25,330	24,293
ROU assets obtained in exchange for operating lease obligations	0	0
Amortization of right of use assets	27,846	24,066	$ 15,691
Interest expense	3,501	2,375
Total finance lease expense	$ 31,347	$ 26,441
Weighted average remaining lease term (in years) (Year)	2 years 10 days	2 years 8 months 4 days
Weighted average discount rate	6.21%	5.79%
Longwall Shields [Member]
Cash paid for operating leases	$ 18,380	$ 0