GUARANTOR SUBSIDIARIES FINANCIAL INFORMATION - Balance Sheet (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Current Assets:
Cash and Cash Equivalents	$ 133,331	$ 235,677
Restricted Cash	1,518	29,258
Trade	109,793	87,589
Other Receivables	29,204	41,355
Inventories	48,839	48,646
Prepaid Expenses and Other Assets	34,439	31,430
Total Current Assets	357,124	473,955
Property, Plant and Equipment:
Property, Plant and Equipment	4,973,400	4,838,171
Less—Accumulated Depreciation, Depletion and Amortization	2,866,649	2,731,643
Total Property, Plant and Equipment—Net	2,106,751	2,106,528
Other Assets:
Deferred Income Taxes	91,772	77,545
Affiliated Credit Facility	0	0
Investment in Affiliates	0	0
Right of Use Asset - Operating Leases	77,411
Other	90,177	102,699
Total Other Assets	259,360	180,244
TOTAL ASSETS	2,723,235	2,760,727	$ 2,745,928
Current Liabilities:
Accounts Payable	125,320	130,930
Accounts Payable (Recoverable)-Related Parties	0	0
Current Portion of Long-Term Debt	45,215	134,812
Other Accrued Liabilities	240,617	226,434
Total Current Liabilities	411,152	492,176
Long-Term Debt:	689,563	734,226
Deferred Credits and Other Liabilities:
Postretirement Benefits Other Than Pensions	427,442	441,246
Pneumoconiosis Benefits	164,972	165,001
Asset Retirement Obligations	242,816	235,984
Workers’ Compensation	59,092	59,742
Salary Retirement	54,622	64,172
Operating Lease Liability	66,432
Other	13,697	16,569
Total Deferred Credits and Other Liabilities	1,029,073	982,714
Total CONSOL Energy Inc. Stockholders' Equity	454,486	409,935
Noncontrolling Interest	138,961	141,676
TOTAL LIABILITIES AND EQUITY	2,723,235	2,760,727
Elimination
Current Assets:
Cash and Cash Equivalents	0	0
Restricted Cash	0	0
Trade	0	0
Other Receivables	0	0
Inventories	0	0
Prepaid Expenses and Other Assets	0	0
Total Current Assets	0	0
Property, Plant and Equipment:
Property, Plant and Equipment	0	0
Less—Accumulated Depreciation, Depletion and Amortization	0	0
Total Property, Plant and Equipment—Net	0	0
Other Assets:
Deferred Income Taxes	0	0
Affiliated Credit Facility	(154,155)	(141,129)
Investment in Affiliates	(882,762)	(605,981)
Right of Use Asset - Operating Leases	0
Other	0	0
Total Other Assets	(1,036,917)	(747,110)
TOTAL ASSETS	(1,036,917)	(747,110)
Current Liabilities:
Accounts Payable	0	3,822
Accounts Payable (Recoverable)-Related Parties	(2,882)	(125,353)
Current Portion of Long-Term Debt	0	112,013
Other Accrued Liabilities	0	(3,822)
Total Current Liabilities	(2,882)	(13,340)
Long-Term Debt:	(154,155)	(141,129)
Deferred Credits and Other Liabilities:
Postretirement Benefits Other Than Pensions	0	0
Pneumoconiosis Benefits	0	0
Asset Retirement Obligations	0	0
Workers’ Compensation	0	0
Salary Retirement	0	0
Operating Lease Liability	0
Other	0	0
Total Deferred Credits and Other Liabilities	0	0
Total CONSOL Energy Inc. Stockholders' Equity	(1,018,841)	(734,317)
Noncontrolling Interest	138,961	141,676
TOTAL LIABILITIES AND EQUITY	(1,036,917)	(747,110)
CCR Non-Guarantor
Current Liabilities:
Accounts Payable (Recoverable)-Related Parties	2,882	3,831
Parent Issuer | Reportable Legal Entities
Current Assets:
Cash and Cash Equivalents	92,472	234,536
Restricted Cash	0	14,557
Trade	0	0
Other Receivables	22,772	24,352
Inventories	0	0
Prepaid Expenses and Other Assets	7,125	10,883
Total Current Assets	122,369	284,328
Property, Plant and Equipment:
Property, Plant and Equipment	0	0
Less—Accumulated Depreciation, Depletion and Amortization	0	0
Total Property, Plant and Equipment—Net	0	0
Other Assets:
Deferred Income Taxes	91,772	77,545
Affiliated Credit Facility	154,155	141,129
Investment in Affiliates	882,762	605,981
Right of Use Asset - Operating Leases	0
Other	34,187	40,760
Total Other Assets	1,162,876	865,415
TOTAL ASSETS	1,285,245	1,149,743
Current Liabilities:
Accounts Payable	88,838	(721)
Accounts Payable (Recoverable)-Related Parties	0	(2,291)
Current Portion of Long-Term Debt	25,710	8,157
Other Accrued Liabilities	82,441	92,534
Total Current Liabilities	196,989	97,679
Long-Term Debt:	579,148	577,957
Deferred Credits and Other Liabilities:
Postretirement Benefits Other Than Pensions	0	0
Pneumoconiosis Benefits	0	0
Asset Retirement Obligations	0	0
Workers’ Compensation	0	0
Salary Retirement	54,622	64,172
Operating Lease Liability	0
Other	0	0
Total Deferred Credits and Other Liabilities	54,622	64,172
Total CONSOL Energy Inc. Stockholders' Equity	454,486	409,935
Noncontrolling Interest	0	0
TOTAL LIABILITIES AND EQUITY	1,285,245	1,149,743
Guarantor | Reportable Legal Entities
Current Assets:
Cash and Cash Equivalents	30,191	138
Restricted Cash	0	0
Trade	0	0
Other Receivables	6,376	15,935
Inventories	37,500	37,580
Prepaid Expenses and Other Assets	20,220	15,451
Total Current Assets	94,287	69,104
Property, Plant and Equipment:
Property, Plant and Equipment	3,995,982	3,891,873
Less—Accumulated Depreciation, Depletion and Amortization	2,307,111	2,204,896
Total Property, Plant and Equipment—Net	1,688,871	1,686,977
Other Assets:
Deferred Income Taxes	0	0
Affiliated Credit Facility	0	0
Investment in Affiliates	0	0
Right of Use Asset - Operating Leases	60,556
Other	42,692	47,031
Total Other Assets	103,248	47,031
TOTAL ASSETS	1,886,406	1,803,112
Current Liabilities:
Accounts Payable	7,671	102,995
Accounts Payable (Recoverable)-Related Parties	0	36,220
Current Portion of Long-Term Debt	14,906	11,139
Other Accrued Liabilities	119,984	105,806
Total Current Liabilities	142,561	256,160
Long-Term Debt:	108,330	151,202
Deferred Credits and Other Liabilities:
Postretirement Benefits Other Than Pensions	427,442	441,246
Pneumoconiosis Benefits	160,075	160,741
Asset Retirement Obligations	231,877	226,209
Workers’ Compensation	56,178	56,623
Salary Retirement	0	0
Operating Lease Liability	52,208
Other	13,150	16,051
Total Deferred Credits and Other Liabilities	940,930	900,870
Total CONSOL Energy Inc. Stockholders' Equity	694,585	494,880
Noncontrolling Interest	0	0
TOTAL LIABILITIES AND EQUITY	1,886,406	1,803,112
Non-Guarantor | Reportable Legal Entities
Current Assets:
Cash and Cash Equivalents	57	0
Restricted Cash	1,518	14,701
Trade	109,793	87,589
Other Receivables	0	0
Inventories	0	0
Prepaid Expenses and Other Assets	0	0
Total Current Assets	111,368	102,290
Property, Plant and Equipment:
Property, Plant and Equipment	0	0
Less—Accumulated Depreciation, Depletion and Amortization	0	0
Total Property, Plant and Equipment—Net	0	0
Other Assets:
Deferred Income Taxes	0	0
Affiliated Credit Facility	0	0
Investment in Affiliates	0	0
Right of Use Asset - Operating Leases	0
Other	0	0
Total Other Assets	0	0
TOTAL ASSETS	111,368	102,290
Current Liabilities:
Accounts Payable	5,406	0
Accounts Payable (Recoverable)-Related Parties	0	87,593
Current Portion of Long-Term Debt	0	0
Other Accrued Liabilities	0	0
Total Current Liabilities	5,406	87,593
Long-Term Debt:	0	0
Deferred Credits and Other Liabilities:
Postretirement Benefits Other Than Pensions	0	0
Pneumoconiosis Benefits	0	0
Asset Retirement Obligations	0	0
Workers’ Compensation	0	0
Salary Retirement	0	0
Operating Lease Liability	0
Other	0	0
Total Deferred Credits and Other Liabilities	0	0
Total CONSOL Energy Inc. Stockholders' Equity	105,962	14,697
Noncontrolling Interest	0	0
TOTAL LIABILITIES AND EQUITY	111,368	102,290
Non-Guarantor | CCR Non-Guarantor | Reportable Legal Entities
Current Assets:
Cash and Cash Equivalents	10,611	1,003
Restricted Cash	0	0
Trade	0	0
Other Receivables	56	1,068
Inventories	11,339	11,066
Prepaid Expenses and Other Assets	7,094	5,096
Total Current Assets	29,100	18,233
Property, Plant and Equipment:
Property, Plant and Equipment	977,418	946,298
Less—Accumulated Depreciation, Depletion and Amortization	559,538	526,747
Total Property, Plant and Equipment—Net	417,880	419,551
Other Assets:
Deferred Income Taxes	0	0
Affiliated Credit Facility	0	0
Investment in Affiliates	0	0
Right of Use Asset - Operating Leases	16,855
Other	13,298	14,908
Total Other Assets	30,153	14,908
TOTAL ASSETS	477,133	452,692
Current Liabilities:
Accounts Payable	23,405	24,834
Accounts Payable (Recoverable)-Related Parties	2,882	3,831
Current Portion of Long-Term Debt	4,599	3,503
Other Accrued Liabilities	38,192	31,916
Total Current Liabilities	69,078	64,084
Long-Term Debt:	156,240	146,196
Deferred Credits and Other Liabilities:
Postretirement Benefits Other Than Pensions	0	0
Pneumoconiosis Benefits	4,897	4,260
Asset Retirement Obligations	10,939	9,775
Workers’ Compensation	2,914	3,119
Salary Retirement	0	0
Operating Lease Liability	14,224
Other	547	518
Total Deferred Credits and Other Liabilities	33,521	17,672
Total CONSOL Energy Inc. Stockholders' Equity	218,294	224,740
Noncontrolling Interest	0	0
TOTAL LIABILITIES AND EQUITY	$ 477,133	$ 452,692