(Guarantor Subsidiaries Balance Sheet) (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current Assets:
Cash and Cash Equivalents	$ 80,293	$ 235,677
Restricted Cash	0	29,258
Accounts and Notes Receivable:
Trade Receivables, net of Allowance	131,688	87,589
Other Receivables	40,984	41,355
Inventories	54,131	48,646
Prepaid Expenses and Other Assets	30,933	31,430
Total Current Assets	338,029	473,955
Property, Plant and Equipment:
Property, Plant and Equipment	5,008,180	4,838,171
Less—Accumulated Depreciation, Depletion and Amortization	2,916,015	2,731,643
Total Property, Plant and Equipment—Net	2,092,165	2,106,528
Other Assets:
Deferred Income Taxes	103,505	77,545
Right of Use Asset - Operating Leases (Note 13)	72,632
Affiliated Credit Facility	0	0
Investment in Affiliates	0	0
Other	87,471	102,699
Total Other Assets	263,608	180,244
TOTAL ASSETS	2,693,802	2,760,727	$ 2,707,099
Current Liabilities:
Accounts Payable	106,223	130,930
Accounts Payable (Recoverable)-Related Parties	0	0
Current Portion of Long-Term Debt	50,272	134,812
Other Accrued Liabilities	235,769	226,434
Total Current Liabilities	392,264	492,176
Long-Term Debt	662,838	734,226
Deferred Credits and Other Liabilities:
Postretirement Benefits Other Than Pensions	432,496	441,246
Pneumoconiosis Benefits	202,142	165,001
Asset Retirement Obligations	250,211	235,984
Workers’ Compensation	61,194	59,742
Salary Retirement	49,930	64,172
Operating Lease Liability (Note 13)	55,413
Other	14,919	16,569
Total Deferred Credits and Other Liabilities	1,066,305	982,714
Total CONSOL Energy Inc. Stockholders’ Equity	435,199	409,935
Noncontrolling Interest	137,196	141,676
TOTAL LIABILITIES AND EQUITY	2,693,802	2,760,727
Elimination
Current Assets:
Cash and Cash Equivalents	0	0
Restricted Cash		0
Accounts and Notes Receivable:
Trade Receivables, net of Allowance	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
Right of Use Asset - Operating Leases (Note 13)	0
Affiliated Credit Facility	(148,156)	(141,129)
Investment in Affiliates	(822,102)	(605,981)
Other	0	0
Total Other Assets	(970,258)	(747,110)
TOTAL ASSETS	(970,258)	(747,110)
Current Liabilities:
Accounts Payable	0	3,822
Accounts Payable (Recoverable)-Related Parties	(1,419)	(125,353)
Current Portion of Long-Term Debt	0	112,013
Other Accrued Liabilities	(2,541)	(3,822)
Total Current Liabilities	(3,960)	(13,340)
Long-Term Debt	(148,156)	(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 (Note 13)	0
Other	0	0
Total Deferred Credits and Other Liabilities	0	0
Total CONSOL Energy Inc. Stockholders’ Equity	(955,338)	(734,317)
Noncontrolling Interest	137,196	141,676
TOTAL LIABILITIES AND EQUITY	(970,258)	(747,110)
Parent Issuer | Reportable Legal Entities
Current Assets:
Cash and Cash Equivalents	79,569	234,536
Restricted Cash		14,557
Accounts and Notes Receivable:
Trade Receivables, net of Allowance	0	0
Other Receivables	28,147	24,352
Inventories	0	0
Prepaid Expenses and Other Assets	8,657	10,883
Total Current Assets	116,373	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	103,505	77,545
Right of Use Asset - Operating Leases (Note 13)	0
Affiliated Credit Facility	148,156	141,129
Investment in Affiliates	822,102	605,981
Other	30,973	40,760
Total Other Assets	1,104,736	865,415
TOTAL ASSETS	1,221,109	1,149,743
Current Liabilities:
Accounts Payable	71,153	(721)
Accounts Payable (Recoverable)-Related Parties	0	(2,291)
Current Portion of Long-Term Debt	28,225	8,157
Other Accrued Liabilities	82,452	92,534
Total Current Liabilities	181,830	97,679
Long-Term Debt	554,150	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	49,930	64,172
Operating Lease Liability (Note 13)	0
Other	0	0
Total Deferred Credits and Other Liabilities	49,930	64,172
Total CONSOL Energy Inc. Stockholders’ Equity	435,199	409,935
Noncontrolling Interest	0	0
TOTAL LIABILITIES AND EQUITY	1,221,109	1,149,743
Guarantor | Reportable Legal Entities
Current Assets:
Cash and Cash Equivalents	148	138
Restricted Cash		0
Accounts and Notes Receivable:
Trade Receivables, net of Allowance	0	0
Other Receivables	11,265	15,935
Inventories	41,478	37,580
Prepaid Expenses and Other Assets	16,524	15,451
Total Current Assets	69,415	69,104
Property, Plant and Equipment:
Property, Plant and Equipment	4,023,282	3,891,873
Less—Accumulated Depreciation, Depletion and Amortization	2,344,777	2,204,896
Total Property, Plant and Equipment—Net	1,678,505	1,686,977
Other Assets:
Deferred Income Taxes	0	0
Right of Use Asset - Operating Leases (Note 13)	56,937
Affiliated Credit Facility	0	0
Investment in Affiliates	0	0
Other	43,042	47,031
Total Other Assets	99,979	47,031
TOTAL ASSETS	1,847,899	1,803,112
Current Liabilities:
Accounts Payable	7,987	102,995
Accounts Payable (Recoverable)-Related Parties	0	36,220
Current Portion of Long-Term Debt	16,795	11,139
Other Accrued Liabilities	116,403	105,806
Total Current Liabilities	141,185	256,160
Long-Term Debt	107,043	151,202
Deferred Credits and Other Liabilities:
Postretirement Benefits Other Than Pensions	432,496	441,246
Pneumoconiosis Benefits	196,114	160,741
Asset Retirement Obligations	239,410	226,209
Workers’ Compensation	57,583	56,623
Salary Retirement	0	0
Operating Lease Liability (Note 13)	43,906
Other	14,134	16,051
Total Deferred Credits and Other Liabilities	983,643	900,870
Total CONSOL Energy Inc. Stockholders’ Equity	616,028	494,880
Noncontrolling Interest	0	0
TOTAL LIABILITIES AND EQUITY	1,847,899	1,803,112
Non-Guarantor | Reportable Legal Entities
Current Assets:
Cash and Cash Equivalents	33	0
Restricted Cash		14,701
Accounts and Notes Receivable:
Trade Receivables, net of Allowance	131,688	87,589
Other Receivables	0	0
Inventories	0	0
Prepaid Expenses and Other Assets	6	0
Total Current Assets	131,727	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
Right of Use Asset - Operating Leases (Note 13)	0
Affiliated Credit Facility	0	0
Investment in Affiliates	0	0
Other	0	0
Total Other Assets	0	0
TOTAL ASSETS	131,727	102,290
Current Liabilities:
Accounts Payable	4,278	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	4,278	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 (Note 13)	0
Other	0	0
Total Deferred Credits and Other Liabilities	0	0
Total CONSOL Energy Inc. Stockholders’ Equity	127,449	14,697
Noncontrolling Interest	0	0
TOTAL LIABILITIES AND EQUITY	131,727	102,290
CCR | Non-Guarantor | Reportable Legal Entities
Current Assets:
Cash and Cash Equivalents	543	1,003
Restricted Cash		0
Accounts and Notes Receivable:
Trade Receivables, net of Allowance	0	0
Other Receivables	1,572	1,068
Inventories	12,653	11,066
Prepaid Expenses and Other Assets	5,746	5,096
Total Current Assets	20,514	18,233
Property, Plant and Equipment:
Property, Plant and Equipment	984,898	946,298
Less—Accumulated Depreciation, Depletion and Amortization	571,238	526,747
Total Property, Plant and Equipment—Net	413,660	419,551
Other Assets:
Deferred Income Taxes	0	0
Right of Use Asset - Operating Leases (Note 13)	15,695
Affiliated Credit Facility	0	0
Investment in Affiliates	0	0
Other	13,456	14,908
Total Other Assets	29,151	14,908
TOTAL ASSETS	463,325	452,692
Current Liabilities:
Accounts Payable	22,805	24,834
Accounts Payable (Recoverable)-Related Parties	1,419	3,831
Current Portion of Long-Term Debt	5,252	3,503
Other Accrued Liabilities	39,455	31,916
Total Current Liabilities	68,931	64,084
Long-Term Debt	149,801	146,196
Deferred Credits and Other Liabilities:
Postretirement Benefits Other Than Pensions	0	0
Pneumoconiosis Benefits	6,028	4,260
Asset Retirement Obligations	10,801	9,775
Workers’ Compensation	3,611	3,119
Salary Retirement	0	0
Operating Lease Liability (Note 13)	11,507
Other	785	518
Total Deferred Credits and Other Liabilities	32,732	17,672
Total CONSOL Energy Inc. Stockholders’ Equity	211,861	224,740
Noncontrolling Interest	0	0
TOTAL LIABILITIES AND EQUITY	$ 463,325	$ 452,692