ADDITIONAL INFORMATION WITH RESPECT TO UNRESTRICTED SUBSIDIARIES - Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenue and Other Income:
Revenue from contracts with customers	$ 275,100	$ 356,982
Miscellaneous Other Income	16,170	13,292
(Loss) Gain on Sale of Assets	(14)	339
Total Revenue and Other Income	291,256	370,613
Costs and Expenses:
Operating and Other Costs	212,275	230,112
Depreciation, Depletion and Amortization	54,943	50,724
Freight Expense	3,147	6,662
Selling, General and Administrative Costs	17,670	21,923
(Gain) Loss on Debt Extinguishment	(16,833)	23,143
Interest Expense, net	15,671	18,596
Total Costs and Expenses	286,873	351,160
Earnings Before Income Tax	4,383	19,453
Income Tax Expense (Benefit)	1,908	(850)
Net Income	2,475	20,303
Less: Net Income Attributable to Noncontrolling Interest	108	5,868
Net Income Attributable to CONSOL Energy Inc. Shareholders	2,367	14,435
Company and Restricted Subsidiaries
Revenue and Other Income:
Miscellaneous Other Income	3,863	11,981
(Loss) Gain on Sale of Assets	(14)	334
Total Revenue and Other Income	214,299	284,506
Costs and Expenses:
Operating and Other Costs	163,592	177,603
Depreciation, Depletion and Amortization	43,015	39,507
Freight Expense	2,360	4,997
Selling, General and Administrative Costs	13,624	17,363
(Gain) Loss on Debt Extinguishment	(16,833)	23,143
Interest Expense, net	13,516	17,245
Total Costs and Expenses	219,274	279,858
Earnings Before Income Tax	(4,975)	4,648
Income Tax Expense (Benefit)	1,908	(850)
Net Income	(6,883)	5,498
Less: Net Income Attributable to Noncontrolling Interest	108	5,868
Net Income Attributable to CONSOL Energy Inc. Shareholders	(6,991)	(370)
Unrestricted Subsidiaries
Revenue and Other Income:
Miscellaneous Other Income	12,307	1,311
(Loss) Gain on Sale of Assets	0	5
Total Revenue and Other Income	76,957	86,107
Costs and Expenses:
Operating and Other Costs	48,683	52,509
Depreciation, Depletion and Amortization	11,928	11,217
Freight Expense	787	1,665
Selling, General and Administrative Costs	4,046	4,560
(Gain) Loss on Debt Extinguishment	0	0
Interest Expense, net	2,155	1,351
Total Costs and Expenses	67,599	71,302
Earnings Before Income Tax	9,358	14,805
Income Tax Expense (Benefit)	0	0
Net Income	9,358	14,805
Less: Net Income Attributable to Noncontrolling Interest	0	0
Net Income Attributable to CONSOL Energy Inc. Shareholders	9,358	14,805
Coal Revenue
Revenue and Other Income:
Revenue from contracts with customers	255,452	332,502
Coal Revenue | Company and Restricted Subsidiaries
Revenue and Other Income:
Revenue from contracts with customers	191,589	249,376
Coal Revenue | Unrestricted Subsidiaries
Revenue and Other Income:
Revenue from contracts with customers	63,863	83,126
Terminal Revenue
Revenue and Other Income:
Revenue from contracts with customers	16,501	17,818
Terminal Revenue | Company and Restricted Subsidiaries
Revenue and Other Income:
Revenue from contracts with customers	16,501	17,818
Terminal Revenue | Unrestricted Subsidiaries
Revenue and Other Income:
Revenue from contracts with customers	0	0
Freight Revenue
Revenue and Other Income:
Revenue from contracts with customers	3,147	6,662
Freight Revenue | Company and Restricted Subsidiaries
Revenue and Other Income:
Revenue from contracts with customers	2,360	4,997
Freight Revenue | Unrestricted Subsidiaries
Revenue and Other Income:
Revenue from contracts with customers	$ 787	$ 1,665