Note 23 - Segment Information - Adjusted EBITDA (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
(Loss) Earnings Before Income Tax	$ (9,242)	$ 98,097	$ 187,613
Interest Expense, net	61,186	66,464	83,848
(Gain) Loss on Debt Extinguishment	(21,352)	24,455	3,922
Interest Income	(1,230)	(2,937)	(2,146)
Depreciation, Depletion and Amortization	210,760	207,097	201,264
CCR Merger Fees	9,822	0	0
Stock/Unit-Based Compensation	11,579	12,760	10,235
Adjusted EBITDA	$ 261,523	$ 405,936	$ 484,736