(Guarantor Subsidiaries Income Statement) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue and Other Income:
Revenue from Contract with Customers									$ 1,375,559	$ 1,472,790	$ 1,321,412
Miscellaneous Other Income	$ 16,675	$ 11,188	$ 12,194	$ 13,292	$ 11,426	$ 10,978	$ 10,369	$ 25,887	53,349	58,660	73,279
Gain on Sale of Assets	9	714	933	339	292	(85)	104	254	1,995	565	17,212
Total Revenue and Other Income	342,635	333,346	384,309	370,613	382,236	324,248	415,273	410,258	1,430,903	1,532,015	1,411,903
Costs and Expenses:
Operating and Other Costs	229,603	234,849	253,448	230,112	245,672	222,781	248,195	229,802	948,012	946,450	886,709
Depreciation, Depletion and Amortization	55,852	54,370	46,151	50,724	45,590	51,242	54,961	49,471	207,097	201,264	172,002
Freight Expense	5,552	3,599	3,854	6,662	5,798	2,443	17,444	17,887	19,667	43,572	73,692
Selling, General and Administrative Costs	14,210	14,690	16,288	21,923	17,631	18,526	15,705	13,484	67,111	65,346	83,605
Loss on Debt Extinguishment	(989)	801	1,500	23,143	773	0	1,723	1,426	24,455	3,922	0
Interest Expense, net	16,224	15,598	16,046	18,596	20,437	20,862	21,504	21,045	66,464	83,848	26,098
Total Costs and Expenses	320,452	323,907	337,287	351,160	335,901	315,854	359,532	333,115	1,332,806	1,344,402	1,242,106
Earnings Before Income Tax	22,183	9,439	47,022	19,453	46,335	8,394	55,741	77,143	98,097	187,613	169,797
Income Tax (Benefit) Expense	4,782	2,415	(1,808)	(850)	301	(690)	3,032	6,185	4,539	8,828	87,228
Net Income	17,401	7,024	48,830	20,303	46,034	9,084	52,709	70,958	93,558	178,785	82,569
Less: Net Income Attributable to Noncontrolling Interest	3,455	2,684	5,550	5,868	6,362	3,350	7,547	8,550	17,557	25,809	14,940
Net Income Attributable to CONSOL Energy Inc. Shareholders	13,946	4,340	43,280	14,435	39,672	5,734	45,162	62,408	76,001	152,976	67,629
Elimination
Revenue and Other Income:
Miscellaneous Other Income									(140,003)	(221,307)	(238,818)
Gain on Sale of Assets									0	0	0
Total Revenue and Other Income									(140,003)	(221,307)	(238,818)
Costs and Expenses:
Operating and Other Costs									0	0	0
Depreciation, Depletion and Amortization									0	0	0
Freight Expense									0	0	0
Selling, General and Administrative Costs									0	0	0
Loss on Debt Extinguishment									0	0	(2,468)
Interest Expense, net									0	(7,709)	(350,057)
Total Costs and Expenses									0	(7,709)	(352,525)
Earnings Before Income Tax									(140,003)	(213,598)	113,707
Income Tax (Benefit) Expense									0	0	0
Net Income									(140,003)	(213,598)	113,707
Less: Net Income Attributable to Noncontrolling Interest									17,557	25,809	14,940
Net Income Attributable to CONSOL Energy Inc. Shareholders									(157,560)	(239,407)	98,767
Parent Issuer | Reportable Legal Entities
Revenue and Other Income:
Miscellaneous Other Income									160,441	247,711	238,818
Gain on Sale of Assets									2,188	0	0
Total Revenue and Other Income									162,629	247,711	238,818
Costs and Expenses:
Operating and Other Costs									0	0	0
Depreciation, Depletion and Amortization									0	0	0
Freight Expense									0	0	0
Selling, General and Administrative Costs									0	0	0
Loss on Debt Extinguishment									24,455	3,922	0
Interest Expense, net									57,634	81,985	10,064
Total Costs and Expenses									82,089	85,907	10,064
Earnings Before Income Tax									80,540	161,804	228,754
Income Tax (Benefit) Expense									4,539	8,828	161,125
Net Income									76,001	152,976	67,629
Less: Net Income Attributable to Noncontrolling Interest									0	0	0
Net Income Attributable to CONSOL Energy Inc. Shareholders									76,001	152,976	67,629
Guarantor | Reportable Legal Entities
Revenue and Other Income:
Miscellaneous Other Income									(11,418)	27,013	67,230
Gain on Sale of Assets									(144)	599	15,813
Total Revenue and Other Income									1,036,948	1,148,436	1,089,119
Costs and Expenses:
Operating and Other Costs									729,232	729,593	691,451
Depreciation, Depletion and Amortization									161,290	156,522	130,565
Freight Expense									14,750	32,679	55,269
Selling, General and Administrative Costs									54,237	51,415	67,908
Loss on Debt Extinguishment									0	0	0
Interest Expense, net									2,226	2,905	355,059
Total Costs and Expenses									961,735	973,114	1,300,252
Earnings Before Income Tax									75,213	175,322	(211,133)
Income Tax (Benefit) Expense									0	0	(73,897)
Net Income									75,213	175,322	(137,236)
Less: Net Income Attributable to Noncontrolling Interest									0	0	0
Net Income Attributable to CONSOL Energy Inc. Shareholders									75,213	175,322	(137,236)
Non-Guarantor | Reportable Legal Entities
Revenue and Other Income:
Miscellaneous Other Income									38,401	0	0
Gain on Sale of Assets									0	0	0
Total Revenue and Other Income									38,401	0	0
Costs and Expenses:
Operating and Other Costs									1,605	2,481	272
Depreciation, Depletion and Amortization									0	0	0
Freight Expense									0	0	0
Selling, General and Administrative Costs									0	0	0
Loss on Debt Extinguishment									0	0	0
Interest Expense, net									0	0	1,723
Total Costs and Expenses									1,605	2,481	1,995
Earnings Before Income Tax									36,796	(2,481)	(1,995)
Income Tax (Benefit) Expense									0	0	0
Net Income									36,796	(2,481)	(1,995)
Less: Net Income Attributable to Noncontrolling Interest									0	0	0
Net Income Attributable to CONSOL Energy Inc. Shareholders									36,796	(2,481)	(1,995)
CCR | Non-Guarantor | Reportable Legal Entities
Revenue and Other Income:
Miscellaneous Other Income									5,928	5,243	6,049
Gain on Sale of Assets									(49)	(34)	1,399
Total Revenue and Other Income									332,928	357,175	322,784
Costs and Expenses:
Operating and Other Costs									217,175	214,376	194,986
Depreciation, Depletion and Amortization									45,807	44,742	41,437
Freight Expense									4,917	10,893	18,423
Selling, General and Administrative Costs									12,874	13,931	15,697
Loss on Debt Extinguishment									0	0	2,468
Interest Expense, net									6,604	6,667	9,309
Total Costs and Expenses									287,377	290,609	282,320
Earnings Before Income Tax									45,551	66,566	40,464
Income Tax (Benefit) Expense									0	0	0
Net Income									45,551	66,566	40,464
Less: Net Income Attributable to Noncontrolling Interest									0	0	0
Net Income Attributable to CONSOL Energy Inc. Shareholders									45,551	66,566	40,464
Coal Revenue
Revenue and Other Income:
Revenue from Contract with Customers	303,865	301,542	350,620	332,502	347,789	294,797	370,697	351,009	1,288,529	1,364,292	1,187,654
Coal Revenue | Elimination
Revenue and Other Income:
Revenue from Contract with Customers									0	0	0
Coal Revenue | Parent Issuer | Reportable Legal Entities
Revenue and Other Income:
Revenue from Contract with Customers									0	0	0
Coal Revenue | Guarantor | Reportable Legal Entities
Revenue and Other Income:
Revenue from Contract with Customers									966,397	1,023,219	890,741
Coal Revenue | Non-Guarantor | Reportable Legal Entities
Revenue and Other Income:
Revenue from Contract with Customers									0	0	0
Coal Revenue | CCR | Non-Guarantor | Reportable Legal Entities
Revenue and Other Income:
Revenue from Contract with Customers									322,132	341,073	296,913
Terminal Revenue
Revenue and Other Income:
Revenue from Contract with Customers	16,534	16,303	16,708	17,818	16,931	16,115	16,659	15,221	67,363	64,926	60,066
Terminal Revenue | Elimination
Revenue and Other Income:
Revenue from Contract with Customers									0	0	0
Terminal Revenue | Parent Issuer | Reportable Legal Entities
Revenue and Other Income:
Revenue from Contract with Customers									0	0	0
Terminal Revenue | Guarantor | Reportable Legal Entities
Revenue and Other Income:
Revenue from Contract with Customers									67,363	64,926	60,066
Terminal Revenue | Non-Guarantor | Reportable Legal Entities
Revenue and Other Income:
Revenue from Contract with Customers									0	0	0
Terminal Revenue | CCR | Non-Guarantor | Reportable Legal Entities
Revenue and Other Income:
Revenue from Contract with Customers									0	0	0
Freight Revenue
Revenue and Other Income:
Revenue from Contract with Customers	$ 5,552	$ 3,599	$ 3,854	$ 6,662	$ 5,798	$ 2,443	$ 17,444	$ 17,887	19,667	43,572	73,692
Freight Revenue | Elimination
Revenue and Other Income:
Revenue from Contract with Customers									0	0	0
Freight Revenue | Parent Issuer | Reportable Legal Entities
Revenue and Other Income:
Revenue from Contract with Customers									0	0	0
Freight Revenue | Guarantor | Reportable Legal Entities
Revenue and Other Income:
Revenue from Contract with Customers									14,750	32,679	55,269
Freight Revenue | Non-Guarantor | Reportable Legal Entities
Revenue and Other Income:
Revenue from Contract with Customers									0	0	0
Freight Revenue | CCR | Non-Guarantor | Reportable Legal Entities
Revenue and Other Income:
Revenue from Contract with Customers									$ 4,917	$ 10,893	$ 18,423