GUARANTOR SUBSIDIARIES FINANCIAL INFORMATION - Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenue and Other Income:
Revenue from contracts with customers	$ 371,182		$ 404,800		$ 728,165	$ 788,917
Miscellaneous Other Income	12,194		10,369		25,486	36,256
Gain (Loss) on Sale of Assets	933		104		1,272	358
Total Revenue and Other Income	384,309		415,273		754,923	825,531
Costs and Expenses:
Operating and Other Costs	253,448		248,195		483,561	477,997
Depreciation, Depletion and Amortization	46,151		54,961		96,875	104,432
Freight Expense	3,854		17,444		10,516	35,331
Selling, General and Administrative Costs	16,288		15,705		38,211	29,189
Loss on Debt Extinguishment	1,500		1,723		24,643	3,149
Interest Expense, net	16,046		21,504		34,642	42,549
Total Costs and Expenses	337,287		359,532		688,448	692,647
Earnings Before Income Tax	47,022		55,741		66,475	132,884
Income Tax (Benefit) Expense	(1,808)		3,032		(2,658)	9,217
Net Income	48,830	$ 20,303	52,709	$ 70,958	69,133	123,667
Less: Net Income Attributable to Noncontrolling Interest	5,550		7,547		11,418	16,097
Net Income Attributable to CONSOL Energy Inc. Shareholders	43,280		45,162		57,715	107,570
Elimination
Revenue and Other Income:
Miscellaneous Other Income	(54,883)		(66,928)		(99,226)	(144,572)
Gain (Loss) on Sale of Assets	0		0		0	0
Total Revenue and Other Income	(54,883)		(66,928)		(99,226)	(144,572)
Costs and Expenses:
Operating and Other Costs	0		0		0	0
Depreciation, Depletion and Amortization	0		0		0	0
Freight Expense	0		0		0	0
Selling, General and Administrative Costs	0		0		0	0
Loss on Debt Extinguishment	0		0		0	0
Interest Expense, net	0		(1,784)		0	(3,735)
Total Costs and Expenses	0		(1,784)		0	(3,735)
Earnings Before Income Tax	(54,883)		(65,144)		(99,226)	(140,837)
Income Tax (Benefit) Expense	0		0		0	0
Net Income	(54,883)		(65,144)		(99,226)	(140,837)
Less: Net Income Attributable to Noncontrolling Interest	5,550		7,547		11,418	16,097
Net Income Attributable to CONSOL Energy Inc. Shareholders	(60,433)		(72,691)		(110,644)	(156,934)
Parent Issuer | Reportable Legal Entities
Revenue and Other Income:
Miscellaneous Other Income	55,908		70,678		109,700	160,990
Gain (Loss) on Sale of Assets	1,291		8		1,291	0
Total Revenue and Other Income	57,199		70,686		110,991	160,990
Costs and Expenses:
Operating and Other Costs	0		0		0	0
Depreciation, Depletion and Amortization	0		0		0	0
Freight Expense	0		0		0	0
Selling, General and Administrative Costs	0		0		0	0
Loss on Debt Extinguishment	1,500		1,723		24,643	3,149
Interest Expense, net	14,227		20,769		31,291	41,054
Total Costs and Expenses	15,727		22,492		55,934	44,203
Earnings Before Income Tax	41,472		48,194		55,057	116,787
Income Tax (Benefit) Expense	(1,808)		3,032		(2,658)	9,217
Net Income	43,280		45,162		57,715	107,570
Less: Net Income Attributable to Noncontrolling Interest	0		0		0	0
Net Income Attributable to CONSOL Energy Inc. Shareholders	43,280		45,162		57,715	107,570
Guarantor | Reportable Legal Entities
Revenue and Other Income:
Miscellaneous Other Income	(8,869)		5,583		(6,337)	16,601
Gain (Loss) on Sale of Assets	(348)		110		(14)	296
Total Revenue and Other Income	273,346		313,458		548,404	616,555
Costs and Expenses:
Operating and Other Costs	194,580		190,023		372,184	366,843
Depreciation, Depletion and Amortization	34,815		43,065		74,322	81,722
Freight Expense	2,890		13,083		7,887	26,498
Selling, General and Administrative Costs	13,335		12,364		30,698	22,828
Loss on Debt Extinguishment	0		0		0	0
Interest Expense, net	262		735		443	1,495
Total Costs and Expenses	245,882		259,270		485,534	499,386
Earnings Before Income Tax	27,464		54,188		62,870	117,169
Income Tax (Benefit) Expense	0		0		0	0
Net Income	27,464		54,188		62,870	117,169
Less: Net Income Attributable to Noncontrolling Interest	0		0		0	0
Net Income Attributable to CONSOL Energy Inc. Shareholders	27,464		54,188		62,870	117,169
Non-Guarantor | Reportable Legal Entities
Revenue and Other Income:
Miscellaneous Other Income	19,000		0		19,000	0
Gain (Loss) on Sale of Assets	0		0		0	0
Total Revenue and Other Income	19,000		0		19,000	0
Costs and Expenses:
Operating and Other Costs	418		873		833	1,568
Depreciation, Depletion and Amortization	0		0		0	0
Freight Expense	0		0		0	0
Selling, General and Administrative Costs	0		0		0	0
Loss on Debt Extinguishment	0		0		0	0
Interest Expense, net	0		0		0	0
Total Costs and Expenses	418		873		833	1,568
Earnings Before Income Tax	18,582		(873)		18,167	(1,568)
Income Tax (Benefit) Expense	0		0		0	0
Net Income	18,582		(873)		18,167	(1,568)
Less: Net Income Attributable to Noncontrolling Interest	0		0		0	0
Net Income Attributable to CONSOL Energy Inc. Shareholders	18,582		(873)		18,167	(1,568)
Non-Guarantor | CCR Non-Guarantor | Reportable Legal Entities
Revenue and Other Income:
Miscellaneous Other Income	1,038		1,036		2,349	3,237
Gain (Loss) on Sale of Assets	(10)		(14)		(5)	62
Total Revenue and Other Income	89,647		98,057		175,754	192,558
Costs and Expenses:
Operating and Other Costs	58,450		57,299		110,544	109,586
Depreciation, Depletion and Amortization	11,336		11,896		22,553	22,710
Freight Expense	964		4,361		2,629	8,833
Selling, General and Administrative Costs	2,953		3,341		7,513	6,361
Loss on Debt Extinguishment	0		0		0	0
Interest Expense, net	1,557		1,784		2,908	3,735
Total Costs and Expenses	75,260		78,681		146,147	151,225
Earnings Before Income Tax	14,387		19,376		29,607	41,333
Income Tax (Benefit) Expense	0		0		0	0
Net Income	14,387		19,376		29,607	41,333
Less: Net Income Attributable to Noncontrolling Interest	0		0		0	0
Net Income Attributable to CONSOL Energy Inc. Shareholders	14,387		19,376		29,607	41,333
Coal Revenue
Revenue and Other Income:
Revenue from contracts with customers	350,620		370,697		683,123	721,706
Coal Revenue | Elimination
Revenue and Other Income:
Revenue from contracts with customers	0		0		0	0
Coal Revenue | Parent Issuer | Reportable Legal Entities
Revenue and Other Income:
Revenue from contracts with customers	0		0		0	0
Coal Revenue | Guarantor | Reportable Legal Entities
Revenue and Other Income:
Revenue from contracts with customers	262,965		278,023		512,342	541,280
Coal Revenue | Non-Guarantor | Reportable Legal Entities
Revenue and Other Income:
Revenue from contracts with customers	0		0		0	0
Coal Revenue | Non-Guarantor | CCR Non-Guarantor | Reportable Legal Entities
Revenue and Other Income:
Revenue from contracts with customers	87,655		92,674		170,781	180,426
Terminal Revenue
Revenue and Other Income:
Revenue from contracts with customers	16,708		16,659		34,526	31,880
Terminal Revenue | Elimination
Revenue and Other Income:
Revenue from contracts with customers	0		0		0	0
Terminal Revenue | Parent Issuer | Reportable Legal Entities
Revenue and Other Income:
Revenue from contracts with customers	0		0		0	0
Terminal Revenue | Guarantor | Reportable Legal Entities
Revenue and Other Income:
Revenue from contracts with customers	16,708		16,659		34,526	31,880
Terminal Revenue | Non-Guarantor | Reportable Legal Entities
Revenue and Other Income:
Revenue from contracts with customers	0		0		0	0
Terminal Revenue | Non-Guarantor | CCR Non-Guarantor | Reportable Legal Entities
Revenue and Other Income:
Revenue from contracts with customers	0		0		0	0
Freight Revenue
Revenue and Other Income:
Revenue from contracts with customers	3,854		17,444		10,516	35,331
Freight Revenue | Elimination
Revenue and Other Income:
Revenue from contracts with customers	0		0		0	0
Freight Revenue | Parent Issuer | Reportable Legal Entities
Revenue and Other Income:
Revenue from contracts with customers	0		0		0	0
Freight Revenue | Guarantor | Reportable Legal Entities
Revenue and Other Income:
Revenue from contracts with customers	2,890		13,083		7,887	26,498
Freight Revenue | Non-Guarantor | Reportable Legal Entities
Revenue and Other Income:
Revenue from contracts with customers	0		0		0	0
Freight Revenue | Non-Guarantor | CCR Non-Guarantor | Reportable Legal Entities
Revenue and Other Income:
Revenue from contracts with customers	$ 964		$ 4,361		$ 2,629	$ 8,833