Note 17 - Additional Information With Respect to Unrestricted Subsidiaries - Income Statement (Details) - USD ($) $ in Thousands		3 Months Ended						9 Months Ended
		Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenue		$ 214,292			$ 321,444			$ 610,688	$ 1,049,609
Miscellaneous Other Income		21,001			11,188			71,107	36,674
Gain (Loss) on Sale of Assets		7,926			714			15,241	1,986
Total Revenue and Other Income		243,219			333,346			697,036	1,088,269
Operating and Other Costs		153,031			234,849			481,712	718,410
Depreciation, Depletion and Amortization		54,959			54,370			156,057	151,245
Freight Expense		12,909			3,599			19,141	14,115
Selling, General and Administrative Costs		11,117			14,690			39,726	52,901
(Gain) Loss on Debt Extinguishment		(1,078)			801			(17,911)	25,444
Interest Expense, net		15,723			15,598			46,116	50,240
Total Costs and Expenses		246,661			323,907			724,841	1,012,355
(Loss) Earnings Before Income Tax		(3,442)			9,439			(27,805)	75,914
Income Tax Expense (Benefit)		5,918			2,415			143	(243)
Net Income (loss)		(9,360)	$ (21,063)	$ 2,475	7,024	$ 48,830	$ 20,303	(27,948)	76,157
Less: Net (Loss) Income Attributable to Noncontrolling Interest		(2,136)			2,684			(5,108)	14,102
Net (Loss) Income Attributable to CONSOL Energy Inc. Shareholders		(7,224)			4,340			(22,840)	62,055
Coal Revenue [Member]
Revenue	[1]	184,375			301,542			542,140	984,665
Terminal Revenue [Member]
Revenue		17,008			16,303			49,407	50,829
Freight Revenue [Member]
Revenue		12,909			3,599			19,141	14,115
Parent Company and Restricted Subsidiaries [Member]
Miscellaneous Other Income		11,454			391			32,119	4,528
Gain (Loss) on Sale of Assets		7,867			714			15,182	1,991
Total Revenue and Other Income		184,370			246,264			517,818	806,433
Operating and Other Costs		118,857			180,487			373,774	552,671
Depreciation, Depletion and Amortization		33,070			43,284			110,720	117,606
Freight Expense		9,682			2,699			14,356	10,586
Selling, General and Administrative Costs		8,238			11,850			30,441	42,548
(Gain) Loss on Debt Extinguishment		(1,078)			801			(17,911)	25,444
Interest Expense, net		13,203			14,011			39,187	45,745
Total Costs and Expenses		181,972			253,132			550,567	794,600
(Loss) Earnings Before Income Tax		2,398			(6,868)			(32,749)	11,833
Income Tax Expense (Benefit)		5,918			2,415			143	(243)
Net Income (loss)		(3,520)			(9,283)			(32,892)	12,076
Less: Net (Loss) Income Attributable to Noncontrolling Interest		(2,136)			2,684			(5,108)	14,102
Net (Loss) Income Attributable to CONSOL Energy Inc. Shareholders		(1,384)			(11,967)			(27,784)	(2,026)
Parent Company and Restricted Subsidiaries [Member] | Coal Revenue [Member]
Revenue		138,359			226,157			406,754	738,499
Parent Company and Restricted Subsidiaries [Member] | Terminal Revenue [Member]
Revenue		17,008			16,303			49,407	50,829
Parent Company and Restricted Subsidiaries [Member] | Freight Revenue [Member]
Revenue		9,682			2,699			14,356	10,586
Subsidiaries [Member]
Miscellaneous Other Income		9,547			10,797			38,988	32,146
Gain (Loss) on Sale of Assets		59			0			59	(5)
Total Revenue and Other Income		58,849			87,082			179,218	281,836
Operating and Other Costs		34,174			54,362			107,938	165,739
Depreciation, Depletion and Amortization		21,889			11,086			45,337	33,639
Freight Expense		3,227			900			4,785	3,529
Selling, General and Administrative Costs		2,879			2,840			9,285	10,353
(Gain) Loss on Debt Extinguishment		0			0			0	0
Interest Expense, net		2,520			1,587			6,929	4,495
Total Costs and Expenses		64,689			70,775			174,274	217,755
(Loss) Earnings Before Income Tax		(5,840)			16,307			4,944	64,081
Income Tax Expense (Benefit)		0			0			0	0
Net Income (loss)		(5,840)			16,307			4,944	64,081
Less: Net (Loss) Income Attributable to Noncontrolling Interest		0			0			0	0
Net (Loss) Income Attributable to CONSOL Energy Inc. Shareholders		(5,840)			16,307			4,944	64,081
Subsidiaries [Member] | Coal Revenue [Member]
Revenue		46,016			75,385			135,386	246,166
Subsidiaries [Member] | Terminal Revenue [Member]
Revenue		0			0			0	0
Subsidiaries [Member] | Freight Revenue [Member]
Revenue		$ 3,227			$ 900			$ 4,785	$ 3,529

[1] For the three and nine months ended September 30, 2020 and 2019, the PAMC segment had revenues from the following customers, each comprising over 10% of the Company's total sales: