Guarantor Subsidiaries Balance Sheet (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Jan. 02, 2013	Dec. 31, 2012	Jan. 02, 2012	Dec. 31, 2011	Jan. 02, 2011
Current Assets:
Cash and Cash Equivalents	$ 327,420	$ 21,862	$ 21,862	$ 375,736	$ 375,736	$ 32,794
Accounts and Notes Receivable:
Trade	332,574		428,328
Notes, Loans and Financing Receivable, Net, Current	25,861		318,387
Other Receivables	243,973		131,131
Securitized			37,846
Inventories	157,914		170,808
Income Taxes Receivable, Current	10,705		0
Deferred Income Taxes	211,303		84,777
Restricted Cash and Cash Equivalents, Current	0		48,294
Prepaid Expenses	135,842		148,431
Assets of Disposal Group, Including Discontinued Operation, Current	0		149,230
Total Current Assets	1,445,592		1,539,094
Property, Plant and Equipment:
Property, Plant and Equipment, Gross	13,578,509		12,121,557
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	4,136,247		3,613,499
Disposal Group, Including Discontinued Operation, Property, Plant, and Equipment, Net	0		1,682,909
Total Property, Plant and Equipment-Net	9,442,262		10,190,967
Other Assets:
Restricted Cash	0		20,379
Investments in Unconsolidated Equity Affiliates	291,675		222,830
Notes, Loans and Financing Receivable, Net, Noncurrent	125		25,977
Other	214,013		216,235
Disposal Group, Including Discontinued Operation, Other Assets	0		782,112
Total Other Assets	505,813		1,267,533
Total Assets	11,393,667		12,997,594
Current Liabilities:
Accounts Payable	514,580		498,515
Accounts Payable (Recoverable)- Related Parties	0		0
Current Portion Long-Term Debt	11,455		12,484
Short-term Non-bank Loans and Notes Payable	0		25,073
Accrued Income Taxes			34,219
Borrowings under Securitization Facility	0		37,846
Other Accrued Liabilities	565,697		545,748
Other Accrued Liabilities, Current	122,902		144,352
Liabilities of Disposal Group, Including Discontinued Operation, Current	28,239		233,214
Total Current Liabilities	1,119,971		1,387,099
Long-Term Debt	3,115,963		3,123,600
Capital Lease Obligations	47,596		49,413
Liabilities of Disposal Group, Including Discontinued Operation	0		1,573
Long-Term Debt:	3,163,559		3,174,586
Deferred Tax Liabilities, Net, Noncurrent	242,643		326,685
Deferred Credits and Other Liabilities
Postretirement Benefits Other Than Pensions	961,127		882,600
Pneumoconiosis	111,971		114,136
Mine Closing	320,723		289,818
Gas Well Closing	175,603		146,002
Workers' Compensation	71,468		60,396
Salary Retirement	48,252		218,004
Reclamation	40,706		47,965
Other	131,355		118,307
Liabilities of Disposal Group, Including Discontinued Operation, Noncurrent	0		2,278,251
Total Deferred Credits and Other Liabilities	2,103,848		4,482,164
Total CONSOL Energy Inc. Stockholders' Equity	5,006,289		3,953,792
Noncontrolling Interest	0		(47)
TOTAL LIABILITIES AND EQUITY	11,393,667		12,997,594
Parent Issuer
Current Assets:
Cash and Cash Equivalents	320,473		17,491
Accounts and Notes Receivable:
Trade	0		0
Notes, Loans and Financing Receivable, Net, Current	1,238		154
Other Receivables	17,657		6,335
Securitized			0
Inventories	0		0
Income Taxes Receivable, Current	(16,262)
Deferred Income Taxes	219,566		174,176
Restricted Cash and Cash Equivalents, Current			0
Prepaid Expenses	43,698		29,589
Assets of Disposal Group, Including Discontinued Operation, Current			0
Total Current Assets	586,370		227,745
Property, Plant and Equipment:
Property, Plant and Equipment, Gross	220,355		216,448
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	145,754		126,048
Disposal Group, Including Discontinued Operation, Property, Plant, and Equipment, Net			0
Total Property, Plant and Equipment-Net	74,601		90,400
Other Assets:
Restricted Cash			0
Investments in Unconsolidated Equity Affiliates	11,965,054		9,917,050
Notes, Loans and Financing Receivable, Net, Noncurrent	125		239
Other	145,401		118,938
Disposal Group, Including Discontinued Operation, Other Assets			0
Total Other Assets	12,110,580		10,036,227
Total Assets	12,771,551		10,354,372
Current Liabilities:
Accounts Payable	180,261		177,734
Accounts Payable (Recoverable)- Related Parties	4,563,327		3,599,216
Current Portion Long-Term Debt	1,029		1,554
Short-term Non-bank Loans and Notes Payable	0		25,073
Accrued Income Taxes			20,488
Borrowings under Securitization Facility			0
Other Accrued Liabilities	144,612		135,407
Liabilities of Disposal Group, Including Discontinued Operation, Current	0		0
Total Current Liabilities	4,889,229		3,959,472
Long-Term Debt	3,004,213		3,004,798
Capital Lease Obligations	1,245		717
Liabilities of Disposal Group, Including Discontinued Operation			0
Long-Term Debt:	3,005,458		3,005,515
Deferred Tax Liabilities, Net, Noncurrent	(232,904)		(884,310)
Deferred Credits and Other Liabilities
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	48,252		218,004
Reclamation	0		0
Other	55,227		101,899
Liabilities of Disposal Group, Including Discontinued Operation, Noncurrent			0
Total Deferred Credits and Other Liabilities	(129,425)		(564,407)
Total CONSOL Energy Inc. Stockholders' Equity	5,006,289		3,953,792
Noncontrolling Interest			0
TOTAL LIABILITIES AND EQUITY	12,771,551		10,354,372
Cnx Gas Guarantor [Member]
Current Assets:
Cash and Cash Equivalents	6,238		3,352
Accounts and Notes Receivable:
Trade	71,911		58,126
Notes, Loans and Financing Receivable, Net, Current	0		315,730
Other Receivables	207,128		214,748
Securitized			0
Inventories	15,185		14,133
Income Taxes Receivable, Current	26,967
Deferred Income Taxes	(8,263)		(26,072)
Restricted Cash and Cash Equivalents, Current			0
Prepaid Expenses	65,701		86,186
Assets of Disposal Group, Including Discontinued Operation, Current			0
Total Current Assets	384,867		666,203
Property, Plant and Equipment:
Property, Plant and Equipment, Gross	6,919,972		5,956,207
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	1,188,464		960,613
Disposal Group, Including Discontinued Operation, Property, Plant, and Equipment, Net			0
Total Property, Plant and Equipment-Net	5,731,508		4,995,594
Other Assets:
Restricted Cash			0
Investments in Unconsolidated Equity Affiliates	206,060		143,876
Notes, Loans and Financing Receivable, Net, Noncurrent	0		0
Other	30,728		65,935
Disposal Group, Including Discontinued Operation, Other Assets			0
Total Other Assets	236,788		209,811
Total Assets	6,353,163		5,871,608
Current Liabilities:
Accounts Payable	324,226		166,182
Accounts Payable (Recoverable)- Related Parties	23,287		23,981
Current Portion Long-Term Debt	6,258		5,953
Short-term Non-bank Loans and Notes Payable	332,487		0
Accrued Income Taxes			13,731
Borrowings under Securitization Facility			0
Other Accrued Liabilities	89,080		57,074
Liabilities of Disposal Group, Including Discontinued Operation, Current	0		0
Total Current Liabilities	775,338		266,921
Long-Term Debt	0		0
Capital Lease Obligations	42,852		46,081
Liabilities of Disposal Group, Including Discontinued Operation			0
Long-Term Debt:	42,852		46,081
Deferred Tax Liabilities, Net, Noncurrent	475,547		439,725
Deferred Credits and Other Liabilities
Postretirement Benefits Other Than Pensions	0		0
Pneumoconiosis	0		0
Mine Closing	0		0
Gas Well Closing	119,429		80,097
Workers' Compensation	0		0
Salary Retirement	0		0
Reclamation	0		0
Other	61,190		24,518
Liabilities of Disposal Group, Including Discontinued Operation, Noncurrent			0
Total Deferred Credits and Other Liabilities	656,166		544,340
Total CONSOL Energy Inc. Stockholders' Equity	4,878,807		5,014,313
Noncontrolling Interest			(47)
TOTAL LIABILITIES AND EQUITY	6,353,163		5,871,608
Other Subsidiary Guarantors
Current Assets:
Cash and Cash Equivalents	0		159
Accounts and Notes Receivable:
Trade	0		0
Notes, Loans and Financing Receivable, Net, Current	24,623		2,503
Other Receivables	14,969		33,289
Securitized			0
Inventories	99,320		121,311
Income Taxes Receivable, Current	0
Deferred Income Taxes	0		(63,327)
Restricted Cash and Cash Equivalents, Current			48,294
Prepaid Expenses	24,915		31,286
Assets of Disposal Group, Including Discontinued Operation, Current			0
Total Current Assets	163,827		173,515
Property, Plant and Equipment:
Property, Plant and Equipment, Gross	6,412,378		5,923,723
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	2,783,043		2,508,769
Disposal Group, Including Discontinued Operation, Property, Plant, and Equipment, Net			0
Total Property, Plant and Equipment-Net	3,629,335		3,414,954
Other Assets:
Restricted Cash			20,379
Investments in Unconsolidated Equity Affiliates	70,222		769,058
Notes, Loans and Financing Receivable, Net, Noncurrent	0		25,738
Other	28,831		21,174
Disposal Group, Including Discontinued Operation, Other Assets			0
Total Other Assets	99,053		836,349
Total Assets	3,892,215		4,424,818
Current Liabilities:
Accounts Payable	493		145,469
Accounts Payable (Recoverable)- Related Parties	(5,055,923)		(3,749,584)
Current Portion Long-Term Debt	3,372		4,221
Short-term Non-bank Loans and Notes Payable	0		0
Accrued Income Taxes			0
Borrowings under Securitization Facility			0
Other Accrued Liabilities	322,606		343,739
Liabilities of Disposal Group, Including Discontinued Operation, Current	0		0
Total Current Liabilities	(4,729,452)		(3,256,155)
Long-Term Debt	111,750		118,802
Capital Lease Obligations	1,724		1,148
Liabilities of Disposal Group, Including Discontinued Operation			0
Long-Term Debt:	113,474		119,950
Deferred Tax Liabilities, Net, Noncurrent	0		771,270
Deferred Credits and Other Liabilities
Postretirement Benefits Other Than Pensions	961,127		882,600
Pneumoconiosis	111,971		114,136
Mine Closing	320,723		289,818
Gas Well Closing	56,174		65,905
Workers' Compensation	71,136		60,090
Salary Retirement	0		0
Reclamation	40,706		47,965
Other	14,938		(8,110)
Liabilities of Disposal Group, Including Discontinued Operation, Noncurrent			0
Total Deferred Credits and Other Liabilities	1,576,775		2,223,674
Total CONSOL Energy Inc. Stockholders' Equity	6,931,418		5,337,349
Noncontrolling Interest			0
TOTAL LIABILITIES AND EQUITY	3,892,215		4,424,818
Non-Guarantors
Current Assets:
Cash and Cash Equivalents	709		860
Accounts and Notes Receivable:
Trade	260,663		370,202
Notes, Loans and Financing Receivable, Net, Current	0		0
Other Receivables	4,219		5,159
Securitized			37,846
Inventories	43,409		35,364
Income Taxes Receivable, Current	0
Deferred Income Taxes	0		0
Restricted Cash and Cash Equivalents, Current			0
Prepaid Expenses	1,528		1,370
Assets of Disposal Group, Including Discontinued Operation, Current			149,230
Total Current Assets	310,528		600,031
Property, Plant and Equipment:
Property, Plant and Equipment, Gross	25,804		25,179
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	18,986		18,069
Disposal Group, Including Discontinued Operation, Property, Plant, and Equipment, Net			1,682,909
Total Property, Plant and Equipment-Net	6,818		1,690,019
Other Assets:
Restricted Cash			0
Investments in Unconsolidated Equity Affiliates	0		0
Notes, Loans and Financing Receivable, Net, Noncurrent	0		0
Other	9,053		10,188
Disposal Group, Including Discontinued Operation, Other Assets			782,112
Total Other Assets	9,053		792,300
Total Assets	326,399		3,082,350
Current Liabilities:
Accounts Payable	9,600		9,130
Accounts Payable (Recoverable)- Related Parties	136,822		254,787
Current Portion Long-Term Debt	796		756
Short-term Non-bank Loans and Notes Payable	0		0
Accrued Income Taxes			0
Borrowings under Securitization Facility			37,846
Other Accrued Liabilities	9,399		9,528
Liabilities of Disposal Group, Including Discontinued Operation, Current	28,239		233,214
Total Current Liabilities	184,856		545,261
Long-Term Debt	0		0
Capital Lease Obligations	1,775		1,467
Liabilities of Disposal Group, Including Discontinued Operation			1,573
Long-Term Debt:	1,775		3,040
Deferred Tax Liabilities, Net, Noncurrent	0		0
Deferred Credits and Other Liabilities
Postretirement Benefits Other Than Pensions	0		0
Pneumoconiosis	0		0
Mine Closing	0		0
Gas Well Closing	0		0
Workers' Compensation	332		306
Salary Retirement	0		0
Reclamation	0		0
Other	0		0
Liabilities of Disposal Group, Including Discontinued Operation, Noncurrent			2,278,251
Total Deferred Credits and Other Liabilities	332		2,278,557
Total CONSOL Energy Inc. Stockholders' Equity	139,436		255,492
Noncontrolling Interest			0
TOTAL LIABILITIES AND EQUITY	326,399		3,082,350
Elimination
Current Assets:
Cash and Cash Equivalents	0		0
Accounts and Notes Receivable:
Trade	0		0
Notes, Loans and Financing Receivable, Net, Current	0		0
Other Receivables	0		(128,400)
Securitized			0
Inventories	0		0
Income Taxes Receivable, Current	0
Deferred Income Taxes	0		0
Restricted Cash and Cash Equivalents, Current			0
Prepaid Expenses	0		0
Assets of Disposal Group, Including Discontinued Operation, Current			0
Total Current Assets	0		(128,400)
Property, Plant and Equipment:
Property, Plant and Equipment, Gross	0		0
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	0		0
Disposal Group, Including Discontinued Operation, Property, Plant, and Equipment, Net			0
Total Property, Plant and Equipment-Net	0		0
Other Assets:
Restricted Cash			0
Investments in Unconsolidated Equity Affiliates	(11,949,661)		(10,607,154)
Notes, Loans and Financing Receivable, Net, Noncurrent	0		0
Other	0		0
Disposal Group, Including Discontinued Operation, Other Assets			0
Total Other Assets	(11,949,661)		(10,607,154)
Total Assets	(11,949,661)		(10,735,554)
Current Liabilities:
Accounts Payable	0		0
Accounts Payable (Recoverable)- Related Parties	332,487		(128,400)
Current Portion Long-Term Debt	0		0
Short-term Non-bank Loans and Notes Payable	(332,487)		0
Accrued Income Taxes			0
Borrowings under Securitization Facility			0
Other Accrued Liabilities	0		0
Liabilities of Disposal Group, Including Discontinued Operation, Current	0		0
Total Current Liabilities	0		(128,400)
Long-Term Debt			0
Capital Lease Obligations	0		0
Liabilities of Disposal Group, Including Discontinued Operation			0
Long-Term Debt:	0		0
Deferred Tax Liabilities, Net, Noncurrent	0		0
Deferred Credits and Other Liabilities
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
Liabilities of Disposal Group, Including Discontinued Operation, Noncurrent			0
Total Deferred Credits and Other Liabilities	0		0
Total CONSOL Energy Inc. Stockholders' Equity	(11,949,661)		(10,607,154)
Noncontrolling Interest			0
TOTAL LIABILITIES AND EQUITY	$ (11,949,661)		$ (10,735,554)