GUARANTOR SUBSIDIARIES FINANCIAL INFORMATION - Balance Sheet (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018
Current Assets:
Cash and Cash Equivalents	$ 155,672	$ 235,677
Restricted Cash	18,696	29,258
Trade	110,454	87,589
Other Receivables	29,296	41,355
Inventories	51,191	48,646
Prepaid Expenses and Other Assets	31,044	31,430
Total Current Assets	396,353	473,955
Property, Plant and Equipment:
Property, Plant and Equipment	4,927,492	4,838,171
Less—Accumulated Depreciation, Depletion and Amortization	2,824,348	2,731,643
Total Property, Plant and Equipment—Net	2,103,144	2,106,528
Other Assets:
Deferred Income Taxes	91,837	77,545
Affiliated Credit Facility	0	0
Investment in Affiliates	0	0
Right of Use Asset - Operating Leases	82,105
Other	92,032	102,699
Total Other Assets	265,974	180,244
TOTAL ASSETS	2,765,471	2,760,727	$ 2,756,502
Current Liabilities:
Accounts Payable	130,881	130,930
Accounts Payable (Recoverable)-Related Parties	0	0
Current Portion of Long-Term Debt	37,974	134,812
Other Accrued Liabilities	239,019	226,434
Total Current Liabilities	407,874	492,176
Long-Term Debt:	713,067	734,226
Deferred Credits and Other Liabilities:
Postretirement Benefits Other Than Pensions	432,495	441,246
Pneumoconiosis Benefits	164,867	165,001
Asset Retirement Obligations	237,649	235,984
Workers’ Compensation	59,499	59,742
Salary Retirement	57,805	64,172
Operating Lease Liability	68,466
Other	13,506	16,569
Total Deferred Credits and Other Liabilities	1,034,287	982,714
Total CONSOL Energy Inc. Stockholders' Equity	468,503	409,935
Noncontrolling Interest	141,740	141,676
TOTAL LIABILITIES AND EQUITY	2,765,471	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	(137,550)	(141,129)
Investment in Affiliates	(807,972)	(605,981)
Right of Use Asset - Operating Leases	0
Other	0	0
Total Other Assets	(945,522)	(747,110)
TOTAL ASSETS	(945,522)	(747,110)
Current Liabilities:
Accounts Payable	2,398	3,822
Accounts Payable (Recoverable)-Related Parties	(380)	(125,353)
Current Portion of Long-Term Debt	0	112,013
Other Accrued Liabilities	(2,398)	(3,822)
Total Current Liabilities	(380)	(13,340)
Long-Term Debt:	(137,550)	(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	(949,332)	(734,317)
Noncontrolling Interest	141,740	141,676
TOTAL LIABILITIES AND EQUITY	(945,522)	(747,110)
CCR Non-Guarantor
Current Liabilities:
Accounts Payable (Recoverable)-Related Parties	380	3,831
Parent Issuer | Reportable Legal Entities
Current Assets:
Cash and Cash Equivalents	154,815	234,536
Restricted Cash	14,781	14,557
Trade	0	0
Other Receivables	21,026	24,352
Inventories	0	0
Prepaid Expenses and Other Assets	9,154	10,883
Total Current Assets	199,776	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	91,837	77,545
Affiliated Credit Facility	137,550	141,129
Investment in Affiliates	807,972	605,981
Right of Use Asset - Operating Leases	0
Other	35,851	40,760
Total Other Assets	1,073,210	865,415
TOTAL ASSETS	1,272,986	1,149,743
Current Liabilities:
Accounts Payable	77,955	(721)
Accounts Payable (Recoverable)-Related Parties	0	(2,291)
Current Portion of Long-Term Debt	23,185	8,157
Other Accrued Liabilities	80,455	92,534
Total Current Liabilities	181,595	97,679
Long-Term Debt:	565,083	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	57,805	64,172
Operating Lease Liability	0
Other	0	0
Total Deferred Credits and Other Liabilities	57,805	64,172
Total CONSOL Energy Inc. Stockholders' Equity	468,503	409,935
Noncontrolling Interest	0	0
TOTAL LIABILITIES AND EQUITY	1,272,986	1,149,743
Guarantor | Reportable Legal Entities
Current Assets:
Cash and Cash Equivalents	361	138
Restricted Cash	0	0
Trade	0	0
Other Receivables	7,671	15,935
Inventories	39,598	37,580
Prepaid Expenses and Other Assets	16,353	15,451
Total Current Assets	63,983	69,104
Property, Plant and Equipment:
Property, Plant and Equipment	3,961,814	3,891,873
Less—Accumulated Depreciation, Depletion and Amortization	2,275,603	2,204,896
Total Property, Plant and Equipment—Net	1,686,211	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	64,111
Other	42,650	47,031
Total Other Assets	106,761	47,031
TOTAL ASSETS	1,856,955	1,803,112
Current Liabilities:
Accounts Payable	18,259	102,995
Accounts Payable (Recoverable)-Related Parties	0	36,220
Current Portion of Long-Term Debt	11,194	11,139
Other Accrued Liabilities	122,495	105,806
Total Current Liabilities	151,948	256,160
Long-Term Debt:	144,888	151,202
Deferred Credits and Other Liabilities:
Postretirement Benefits Other Than Pensions	432,495	441,246
Pneumoconiosis Benefits	160,184	160,741
Asset Retirement Obligations	226,873	226,209
Workers’ Compensation	56,484	56,623
Salary Retirement	0	0
Operating Lease Liability	53,771
Other	12,967	16,051
Total Deferred Credits and Other Liabilities	942,774	900,870
Total CONSOL Energy Inc. Stockholders' Equity	617,345	494,880
Noncontrolling Interest	0	0
TOTAL LIABILITIES AND EQUITY	1,856,955	1,803,112
Non-Guarantor | Reportable Legal Entities
Current Assets:
Cash and Cash Equivalents	36	0
Restricted Cash	3,915	14,701
Trade	110,454	87,589
Other Receivables	0	0
Inventories	0	0
Prepaid Expenses and Other Assets	0	0
Total Current Assets	114,405	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	114,405	102,290
Current Liabilities:
Accounts Payable	7,458	0
Accounts Payable (Recoverable)-Related Parties	0	87,593
Current Portion of Long-Term Debt	0	0
Other Accrued Liabilities	350	0
Total Current Liabilities	7,808	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	106,597	14,697
Noncontrolling Interest	0	0
TOTAL LIABILITIES AND EQUITY	114,405	102,290
Non-Guarantor | CCR Non-Guarantor | Reportable Legal Entities
Current Assets:
Cash and Cash Equivalents	460	1,003
Restricted Cash	0	0
Trade	0	0
Other Receivables	599	1,068
Inventories	11,593	11,066
Prepaid Expenses and Other Assets	5,537	5,096
Total Current Assets	18,189	18,233
Property, Plant and Equipment:
Property, Plant and Equipment	965,678	946,298
Less—Accumulated Depreciation, Depletion and Amortization	548,745	526,747
Total Property, Plant and Equipment—Net	416,933	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	17,994
Other	13,531	14,908
Total Other Assets	31,525	14,908
TOTAL ASSETS	466,647	452,692
Current Liabilities:
Accounts Payable	24,811	24,834
Accounts Payable (Recoverable)-Related Parties	380	3,831
Current Portion of Long-Term Debt	3,595	3,503
Other Accrued Liabilities	38,117	31,916
Total Current Liabilities	66,903	64,084
Long-Term Debt:	140,646	146,196
Deferred Credits and Other Liabilities:
Postretirement Benefits Other Than Pensions	0	0
Pneumoconiosis Benefits	4,683	4,260
Asset Retirement Obligations	10,776	9,775
Workers’ Compensation	3,015	3,119
Salary Retirement	0	0
Operating Lease Liability	14,695
Other	539	518
Total Deferred Credits and Other Liabilities	33,708	17,672
Total CONSOL Energy Inc. Stockholders' Equity	225,390	224,740
Noncontrolling Interest	0	0
TOTAL LIABILITIES AND EQUITY	$ 466,647	$ 452,692