Guarantor Subsidiaries Balance Sheet (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Dec. 31, 2012
Schedule of Condensed Consolidating Balance Sheets [Line Items]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	$ 185,509	$ 291,675
Current Assets:
Cash and Cash Equivalents	225,563	327,420	21,064	21,862
Accounts and Notes Receivable:
Trade	299,939	332,574
Notes Receivable, Related Parties, Current		25,861
Other Receivables	382,652	243,973
Inventories	145,372	157,914
Recoverable Income Taxes	41,971	10,705
Deferred Income Taxes	127,731	211,303
Prepaid Expenses	101,867	135,842
Total Current Assets	1,325,095	1,445,592
Property, Plant and Equipment:
Property, Plant and Equipment	14,463,328	13,578,509
Less-Accumulated Depreciation, Depletion and Amortization	4,499,344	4,136,247
Total Property, Plant and Equipment-Net	9,963,984	9,442,262
Other Assets:
Notes, Loans and Financing Receivable, Net		125
Other	244,347	214,013
Total Other Assets	429,856	505,813
Total Assets	11,718,935	11,393,667	12,737,072
Current Liabilities:
Accounts Payable	610,725	514,580
Accounts Payable (Recoverable)- Related Parties	0	0
Short-Term Notes Payable		0
Current Portion Long-Term Debt	12,225	11,455
Short-Term Notes Payable	0
Other Accrued Liabilities	610,704	565,697
Liabilities of Disposal Group, Including Discontinued Operation, Current	12,992	28,239
Total Current Liabilities	1,246,646	1,119,971
Long-Term Debt:	3,279,322	3,163,559
Deferred Credits and Other Liabilities
Deferred Tax Liabilities, Net		242,643
Deferred Tax Liabilities, Net, Noncurrent	395,025	242,643
Postretirement Benefits Other Than Pensions	652,050	961,127
Pneumoconiosis	111,514	111,971
Mine Closing	321,776	320,723
Gas Well Closing	180,520	175,603
Workers' Compensation	73,398	71,468
Salary Retirement	48,231	48,252
Reclamation	34,499	40,706
Other	121,355	131,355
Total Deferred Credits and Other Liabilities	1,938,368	2,103,848
Total CONSOL Energy Inc. Stockholders' Equity	5,254,599	5,006,289
TOTAL LIABILITIES AND EQUITY	11,718,935	11,393,667
Parent Issuer [Member]
Schedule of Condensed Consolidating Balance Sheets [Line Items]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	12,481,970	11,965,054
Current Assets:
Cash and Cash Equivalents	191,555	320,473
Accounts and Notes Receivable:
Trade	0	0
Notes Receivable, Related Parties, Current		1,238
Other Receivables	49,930	17,657
Inventories	0	0
Recoverable Income Taxes	57,067	(16,262)
Deferred Income Taxes	127,366	219,566
Prepaid Expenses	39,202	43,698
Total Current Assets	465,120	586,370
Property, Plant and Equipment:
Property, Plant and Equipment	165,885	173,719
Less-Accumulated Depreciation, Depletion and Amortization	118,444	122,022
Total Property, Plant and Equipment-Net	47,441	51,697
Other Assets:
Notes, Loans and Financing Receivable, Net		125
Other	172,625	145,401
Total Other Assets	12,654,595	12,110,580
Total Assets	13,167,156	12,748,647
Current Liabilities:
Accounts Payable	102,157	91,553
Accounts Payable (Recoverable)- Related Parties	4,502,239	4,629,131
Short-Term Notes Payable		0
Current Portion Long-Term Debt	1,571	1,029
Short-Term Notes Payable	0
Other Accrued Liabilities	163,415	144,612
Liabilities of Disposal Group, Including Discontinued Operation, Current	0	0
Total Current Liabilities	4,769,382	4,866,325
Long-Term Debt:	3,125,439	3,005,458
Deferred Credits and Other Liabilities
Deferred Tax Liabilities, Net		(232,904)
Deferred Tax Liabilities, Net, Noncurrent	(89,966)
Postretirement Benefits Other Than Pensions	0	0
Pneumoconiosis	0	0
Mine Closing	0	0
Gas Well Closing	0	0
Workers' Compensation	0	0
Salary Retirement	48,231	48,252
Reclamation	0	0
Other	59,471	55,227
Total Deferred Credits and Other Liabilities	17,736	(129,425)
Total CONSOL Energy Inc. Stockholders' Equity	5,254,599	5,006,289
TOTAL LIABILITIES AND EQUITY	13,167,156	12,748,647
CNX Gas Guarantor [Member]
Schedule of Condensed Consolidating Balance Sheets [Line Items]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	92,188	206,060
Current Assets:
Cash and Cash Equivalents	33,121	6,238
Accounts and Notes Receivable:
Trade	95,746	71,911
Notes Receivable, Related Parties, Current		0
Other Receivables	323,154	207,128
Inventories	14,086	15,185
Recoverable Income Taxes	(15,096)	26,967
Deferred Income Taxes	365	(8,263)
Prepaid Expenses	36,182	65,701
Total Current Assets	487,558	384,867
Property, Plant and Equipment:
Property, Plant and Equipment	7,694,180	6,919,972
Less-Accumulated Depreciation, Depletion and Amortization	1,410,235	1,188,464
Total Property, Plant and Equipment-Net	6,283,945	5,731,508
Other Assets:
Notes, Loans and Financing Receivable, Net		0
Other	23,264	30,728
Total Other Assets	115,452	236,788
Total Assets	6,886,955	6,353,163
Current Liabilities:
Accounts Payable	400,751	324,226
Accounts Payable (Recoverable)- Related Parties	152,871	23,287
Short-Term Notes Payable		332,487
Current Portion Long-Term Debt	6,590	6,258
Short-Term Notes Payable	566,150
Other Accrued Liabilities	109,704	89,080
Liabilities of Disposal Group, Including Discontinued Operation, Current	0	0
Total Current Liabilities	1,236,066	775,338
Long-Term Debt:	38,907	42,852
Deferred Credits and Other Liabilities
Deferred Tax Liabilities, Net		475,547
Deferred Tax Liabilities, Net, Noncurrent	484,991
Postretirement Benefits Other Than Pensions	0	0
Pneumoconiosis	0	0
Mine Closing	0	0
Gas Well Closing	120,899	119,429
Workers' Compensation	0	0
Salary Retirement	0	0
Reclamation	0	0
Other	56,788	61,190
Total Deferred Credits and Other Liabilities	662,678	656,166
Total CONSOL Energy Inc. Stockholders' Equity	4,949,304	4,878,807
TOTAL LIABILITIES AND EQUITY	6,886,955	6,353,163
Other Guarantors Subsidiaries [Member]
Schedule of Condensed Consolidating Balance Sheets [Line Items]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	78,231	70,222
Current Assets:
Cash and Cash Equivalents	0	0
Accounts and Notes Receivable:
Trade	0	0
Notes Receivable, Related Parties, Current		24,623
Other Receivables	5,673	14,969
Inventories	95,450	99,320
Recoverable Income Taxes	0	0
Deferred Income Taxes	0	0
Prepaid Expenses	24,655	24,915
Total Current Assets	125,778	163,827
Property, Plant and Equipment:
Property, Plant and Equipment	6,577,039	6,459,014
Less-Accumulated Depreciation, Depletion and Amortization	2,950,922	2,806,775
Total Property, Plant and Equipment-Net	3,626,117	3,652,239
Other Assets:
Notes, Loans and Financing Receivable, Net		0
Other	39,822	28,831
Total Other Assets	118,053	99,053
Total Assets	3,869,948	3,915,119
Current Liabilities:
Accounts Payable	93,156	89,201
Accounts Payable (Recoverable)- Related Parties	(5,286,273)	(5,121,727)
Short-Term Notes Payable		0
Current Portion Long-Term Debt	3,393	3,372
Short-Term Notes Payable
Other Accrued Liabilities	329,341	322,606
Liabilities of Disposal Group, Including Discontinued Operation, Current	0	0
Total Current Liabilities	(4,860,383)	(4,706,548)
Long-Term Debt:	113,100	113,474
Deferred Credits and Other Liabilities
Deferred Tax Liabilities, Net		0
Deferred Tax Liabilities, Net, Noncurrent	0
Postretirement Benefits Other Than Pensions	652,050	961,127
Pneumoconiosis	111,514	111,971
Mine Closing	321,776	320,723
Gas Well Closing	59,621	56,174
Workers' Compensation	73,053	71,136
Salary Retirement	0	0
Reclamation	34,499	40,706
Other	5,096	14,938
Total Deferred Credits and Other Liabilities	1,257,609	1,576,775
Total CONSOL Energy Inc. Stockholders' Equity	7,359,622	6,931,418
TOTAL LIABILITIES AND EQUITY	3,869,948	3,915,119
Non-Guarantors [Member]
Schedule of Condensed Consolidating Balance Sheets [Line Items]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	0	0
Current Assets:
Cash and Cash Equivalents	887	709
Accounts and Notes Receivable:
Trade	204,193	260,663
Notes Receivable, Related Parties, Current		0
Other Receivables	3,895	4,219
Inventories	35,836	43,409
Recoverable Income Taxes	0	0
Deferred Income Taxes	0	0
Prepaid Expenses	1,828	1,528
Total Current Assets	246,639	310,528
Property, Plant and Equipment:
Property, Plant and Equipment	26,224	25,804
Less-Accumulated Depreciation, Depletion and Amortization	19,743	18,986
Total Property, Plant and Equipment-Net	6,481	6,818
Other Assets:
Notes, Loans and Financing Receivable, Net		0
Other	8,636	9,053
Total Other Assets	8,636	9,053
Total Assets	261,756	326,399
Current Liabilities:
Accounts Payable	14,661	9,600
Accounts Payable (Recoverable)- Related Parties	65,013	136,822
Short-Term Notes Payable		0
Current Portion Long-Term Debt	671	796
Short-Term Notes Payable	0
Other Accrued Liabilities	8,244	9,399
Liabilities of Disposal Group, Including Discontinued Operation, Current	12,992	28,239
Total Current Liabilities	101,581	184,856
Long-Term Debt:	1,876	1,775
Deferred Credits and Other Liabilities
Deferred Tax Liabilities, Net		0
Deferred Tax Liabilities, Net, Noncurrent	0
Postretirement Benefits Other Than Pensions	0	0
Pneumoconiosis	0	0
Mine Closing	0	0
Gas Well Closing	0	0
Workers' Compensation	345	332
Salary Retirement	0	0
Reclamation	0	0
Other	0	0
Total Deferred Credits and Other Liabilities	345	332
Total CONSOL Energy Inc. Stockholders' Equity	157,954	139,436
TOTAL LIABILITIES AND EQUITY	261,756	326,399
Consolidation, Eliminations [Member]
Schedule of Condensed Consolidating Balance Sheets [Line Items]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	(12,466,880)	(11,949,661)
Current Assets:
Cash and Cash Equivalents	0	0
Accounts and Notes Receivable:
Trade	0	0
Notes Receivable, Related Parties, Current		0
Other Receivables	0	0
Inventories	0	0
Recoverable Income Taxes	0	0
Deferred Income Taxes	0	0
Prepaid Expenses	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:
Notes, Loans and Financing Receivable, Net		0
Other	0	0
Total Other Assets	(12,466,880)	(11,949,661)
Total Assets	(12,466,880)	(11,949,661)
Current Liabilities:
Accounts Payable	0	0
Accounts Payable (Recoverable)- Related Parties	566,150	332,487
Short-Term Notes Payable		(332,487)
Current Portion Long-Term Debt	0	0
Short-Term Notes Payable	(566,150)
Other Accrued Liabilities	0	0
Liabilities of Disposal Group, Including Discontinued Operation, Current	0	0
Total Current Liabilities	0	0
Long-Term Debt:	0	0
Deferred Credits and Other Liabilities
Deferred Tax Liabilities, Net		0
Deferred Tax Liabilities, Net, Noncurrent	0
Postretirement Benefits Other Than Pensions	0	0
Pneumoconiosis	0	0
Mine Closing	0	0
Gas Well Closing	0	0
Workers' Compensation	0	0
Salary Retirement	0	0
Reclamation	0	0
Other	0	0
Total Deferred Credits and Other Liabilities	0	0
Total CONSOL Energy Inc. Stockholders' Equity	(12,466,880)	(11,949,661)
TOTAL LIABILITIES AND EQUITY	$ (12,466,880)	$ (11,949,661)