(Guarantor Subsidiaries Income Statement) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue and Other Income:
Revenue from Contract with Customers									$ 1,472,790	$ 1,321,412	$ 1,143,514
Miscellaneous Other Income	$ 11,426	$ 10,978	$ 10,369	$ 25,887	$ 20,771	$ 19,713	$ 10,145	$ 22,650	58,660	73,279	82,120
Gain (Loss) on Sale of Assets	292	(85)	104	254	4,188	(513)	5,582	7,955	565	17,212	5,228
Total Revenue and Other Income	382,236	324,248	415,273	410,258	352,318	335,313	352,051	372,221	1,532,015	1,411,903	1,230,862
Costs and Expenses:
Operating and Other Costs	245,672	222,781	248,195	229,802	204,306	229,527	222,882	229,994	946,450	886,709	877,177
Depreciation, Depletion and Amortization	45,590	51,242	54,961	49,471	47,088	46,653	25,268	52,993	201,264	172,002	178,122
Freight Expense	5,798	2,443	17,444	17,887	21,845	21,803	17,762	12,282	43,572	73,692	46,468
Selling, General and Administrative Costs	17,631	18,526	15,705	13,484	25,008	21,180	20,338	17,079	65,346	83,605	50,027
Loss on Debt Extinguishment	773	0	1,723	1,426					3,922	0	0
Interest Expense, net	20,437	20,862	21,504	21,045	14,270	3,862	3,944	4,022	83,848	26,098	14,053
Total Costs and Expenses	335,901	315,854	359,532	333,115	312,517	323,025	290,194	316,370	1,344,402	1,242,106	1,165,847
Earnings Before Income Tax	46,335	8,394	55,741	77,143	39,801	12,288	61,857	55,851	187,613	169,797	65,015
Income Tax Expense (Benefit)	301	(690)	3,032	6,185	64,441	3,770	9,611	9,406	8,828	87,228	14,565
Net Income	46,034	9,084	52,709	70,958	(24,640)	8,518	52,246	46,445	178,785	82,569	50,450
Less: Net Income Attributable to Noncontrolling Interest	6,362	3,350	7,547	8,550	4,373	790	4,313	5,464	25,809	14,940	8,954
Net Income Attributable to CONSOL Energy Inc. Shareholders	39,672	5,734	45,162	62,408	(29,013)	7,728	47,933	40,981	152,976	67,629	41,496
Elimination
Revenue and Other Income:
Miscellaneous Other Income									(221,307)	(238,818)	(50,425)
Gain (Loss) on Sale of Assets									0	0	0
Total Revenue and Other Income									(221,307)	(238,818)	(50,425)
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	(2,468)
Interest Expense, net									(7,709)	(350,057)	0
Total Costs and Expenses									(7,709)	(352,525)	0
Earnings Before Income Tax									(213,598)	113,707	(50,425)
Income Tax Expense (Benefit)									0	0	0
Net Income									(213,598)	113,707	(50,425)
Less: Net Income Attributable to Noncontrolling Interest									25,809	14,940	8,954
Net Income Attributable to CONSOL Energy Inc. Shareholders									(239,407)	98,767	(59,379)
Parent Issuer | Reportable Legal Entities
Revenue and Other Income:
Miscellaneous Other Income									247,711	238,818	50,425
Gain (Loss) on Sale of Assets									0	0	0
Total Revenue and Other Income									247,711	238,818	50,425
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									3,922	0
Interest Expense, net									81,985	10,064	190
Total Costs and Expenses									85,907	10,064	190
Earnings Before Income Tax									161,804	228,754	50,235
Income Tax Expense (Benefit)									8,828	161,125	8,739
Net Income									152,976	67,629	41,496
Less: Net Income Attributable to Noncontrolling Interest									0	0	0
Net Income Attributable to CONSOL Energy Inc. Shareholders									152,976	67,629	41,496
Guarantor | Reportable Legal Entities
Revenue and Other Income:
Miscellaneous Other Income									27,013	67,230	78,992
Gain (Loss) on Sale of Assets									599	15,813	5,237
Total Revenue and Other Income									1,148,436	1,089,119	949,745
Costs and Expenses:
Operating and Other Costs									729,593	691,451	694,073
Depreciation, Depletion and Amortization									156,522	130,565	136,128
Freight Expense									32,679	55,269	34,865
Selling, General and Administrative Costs									51,415	67,908	40,078
Loss on Debt Extinguishment									0	0
Interest Expense, net									2,905	355,059	5,144
Total Costs and Expenses									973,114	1,300,252	910,288
Earnings Before Income Tax									175,322	(211,133)	39,457
Income Tax Expense (Benefit)									0	(73,897)	5,826
Net Income									175,322	(137,236)	33,631
Less: Net Income Attributable to Noncontrolling Interest									0	0	0
Net Income Attributable to CONSOL Energy Inc. Shareholders									175,322	(137,236)	33,631
Non-Guarantor | Reportable Legal Entities
Revenue and Other Income:
Miscellaneous Other Income									0	0	0
Gain (Loss) on Sale of Assets									0	0	0
Total Revenue and Other Income									0	0	0
Costs and Expenses:
Operating and Other Costs									2,481	272	103
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
Interest Expense, net									0	1,723	0
Total Costs and Expenses									2,481	1,995	103
Earnings Before Income Tax									(2,481)	(1,995)	(103)
Income Tax Expense (Benefit)									0	0	0
Net Income									(2,481)	(1,995)	(103)
Less: Net Income Attributable to Noncontrolling Interest									0	0	0
Net Income Attributable to CONSOL Energy Inc. Shareholders									(2,481)	(1,995)	(103)
CONSOL Coal Resources LP | Non-Guarantor | Reportable Legal Entities
Revenue and Other Income:
Miscellaneous Other Income									5,243	6,049	3,128
Gain (Loss) on Sale of Assets									(34)	1,399	(9)
Total Revenue and Other Income									357,175	322,784	281,117
Costs and Expenses:
Operating and Other Costs									214,376	194,986	183,001
Depreciation, Depletion and Amortization									44,742	41,437	41,994
Freight Expense									10,893	18,423	11,603
Selling, General and Administrative Costs									13,931	15,697	9,949
Loss on Debt Extinguishment									0	2,468
Interest Expense, net									6,667	9,309	8,719
Total Costs and Expenses									290,609	282,320	255,266
Earnings Before Income Tax									66,566	40,464	25,851
Income Tax Expense (Benefit)									0	0
Net Income									66,566	40,464	25,851
Less: Net Income Attributable to Noncontrolling Interest									0	0	0
Net Income Attributable to CONSOL Energy Inc. Shareholders									66,566	40,464	25,851
Coal Revenue
Revenue and Other Income:
Revenue from Contract with Customers	347,789	294,797	370,697	351,009	288,254	279,245	303,707	316,448	1,364,292	1,187,654	1,065,582
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									1,023,219	890,741	799,187
Coal Revenue | Non-Guarantor | Reportable Legal Entities
Revenue and Other Income:
Revenue from Contract with Customers									0	0	0
Coal Revenue | CONSOL Coal Resources LP | Non-Guarantor | Reportable Legal Entities
Revenue and Other Income:
Revenue from Contract with Customers									341,073	296,913	266,395
Terminal Revenue
Revenue and Other Income:
Revenue from Contract with Customers	16,931	16,115	16,659	15,221	17,260	15,065	14,855	12,886	64,926	60,066	31,464
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									64,926	60,066	31,464
Terminal Revenue | Non-Guarantor | Reportable Legal Entities
Revenue and Other Income:
Revenue from Contract with Customers									0	0	0
Terminal Revenue | CONSOL Coal Resources LP | 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	$ 5,798	$ 2,443	$ 17,444	$ 17,887	$ 21,845	$ 21,803	$ 17,762	$ 12,282	43,572	73,692	46,468
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									32,679	55,269	34,865
Freight Revenue | Non-Guarantor | Reportable Legal Entities
Revenue and Other Income:
Revenue from Contract with Customers									0	0	0
Freight Revenue | CONSOL Coal Resources LP | Non-Guarantor | Reportable Legal Entities
Revenue and Other Income:
Revenue from Contract with Customers									$ 10,893	$ 18,423	$ 11,603