Note 16 - Segment Information - Adjusted EBITDA (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2022	Mar. 31, 2021
Net (Loss) Income		$ (4,450)	$ 26,404
Less: Income Tax Benefit		(3,522)	5,185
Add: Interest Expense, net		14,352	15,261
Less: Interest Income		1,329	858
Earnings (Loss) Before Interest & Taxes (EBIT)		5,051	45,992
Depreciation, Depletion and Amortization		55,954	59,897
Earnings (Loss) Before Interest, Taxes and DD&A (EBITDA)		61,005	105,889
Stock-Based Compensation		4,201	1,509
Loss on Debt Extinguishment		(2,122)	683
Unrealized Mark-to-Market Loss on Commodity Derivative Instruments		(101,902)	(0)
Total Pre-tax Adjustments		108,225	826
Adjusted EBITDA	[1]	169,230	106,715
Pennsylvania Mining Complex [Member]
Net (Loss) Income		2,097	42,450
Less: Income Tax Benefit		0	0
Add: Interest Expense, net		189	642
Less: Interest Income		415	(0)
Earnings (Loss) Before Interest & Taxes (EBIT)		1,871	43,092
Depreciation, Depletion and Amortization		50,956	54,781
Earnings (Loss) Before Interest, Taxes and DD&A (EBITDA)		52,827	97,873
Stock-Based Compensation		3,529	1,312
Loss on Debt Extinguishment		(0)	(0)
Unrealized Mark-to-Market Loss on Commodity Derivative Instruments		(101,902)
Total Pre-tax Adjustments		105,431	1,312
Adjusted EBITDA		158,258	99,185
CONSOL Marine Terminal [Member]
Net (Loss) Income		11,613	9,149
Less: Income Tax Benefit		0	0
Add: Interest Expense, net		1,531	1,537
Less: Interest Income		(0)	(0)
Earnings (Loss) Before Interest & Taxes (EBIT)		13,144	10,686
Depreciation, Depletion and Amortization		1,165	1,214
Earnings (Loss) Before Interest, Taxes and DD&A (EBITDA)		14,309	11,900
Stock-Based Compensation		168	61
Loss on Debt Extinguishment		(0)	(0)
Unrealized Mark-to-Market Loss on Commodity Derivative Instruments		(0)
Total Pre-tax Adjustments		168	61
Adjusted EBITDA		14,477	11,961
Other Segments [Member]
Net (Loss) Income		(18,160)	(25,195)
Less: Income Tax Benefit		(3,522)	5,185
Add: Interest Expense, net		12,632	13,082
Less: Interest Income		914	858
Earnings (Loss) Before Interest & Taxes (EBIT)		(9,964)	(7,786)
Depreciation, Depletion and Amortization		3,833	3,902
Earnings (Loss) Before Interest, Taxes and DD&A (EBITDA)		(6,131)	(3,884)
Stock-Based Compensation		504	136
Loss on Debt Extinguishment		(2,122)	683
Unrealized Mark-to-Market Loss on Commodity Derivative Instruments		(0)
Total Pre-tax Adjustments		2,626	(547)
Adjusted EBITDA		$ (3,505)	$ (4,431)

[1] Refer to “Reconciliation of Segment Information to Consolidated Amounts” for the reconciliation of Adjusted EBITDA, a non-GAAP measure, to its most directly comparable GAAP measure.