Guarantor Subsidiaries Financial Information Guarantor Subsidiaries Comprehensive Income Statement (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 163,090us-gaap_ProfitLoss	$ 659,056us-gaap_ProfitLoss	$ 388,073us-gaap_ProfitLoss
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax, Portion Attributable to Parent	94,989	456,493	129,231
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	97,316	45,631	114,240
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred	(18,288)	(79,899)	(189,259)
Other Comprehensive Income (Loss), Net of Tax	174,017	422,225	54,212
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	337,107	1,081,281	442,285
Less: Comprehensive Loss (Income), Net of Tax, Attributable to Noncontrolling Interest	0	(1,386)	(397)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	337,107us-gaap_ComprehensiveIncomeNetOfTax	1,082,667us-gaap_ComprehensiveIncomeNetOfTax	442,682us-gaap_ComprehensiveIncomeNetOfTax
Parent Issuer
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	163,090	660,442	388,470
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax, Portion Attributable to Parent	94,989	456,493	(129,231)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	97,316	45,631	114,240
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred	(18,288)	(79,899)	(189,259)
Other Comprehensive Income (Loss), Net of Tax	174,017	422,225	54,212
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest		1,082,667	442,682
Less: Comprehensive Loss (Income), Net of Tax, Attributable to Noncontrolling Interest		0	0
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	337,107	1,082,667	442,682
Cnx Gas Guarantor [Member]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	123,273	(2,624)	24,363
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax, Portion Attributable to Parent	0	0	0
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	97,316	45,631	114,240
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred	(18,288)	(79,899)	(189,259)
Other Comprehensive Income (Loss), Net of Tax	79,028	(34,268)	(75,019)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest		(36,892)	(50,656)
Less: Comprehensive Loss (Income), Net of Tax, Attributable to Noncontrolling Interest		1,386	(397)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	202,301	(35,506)	(50,259)
Other Subsidiary Guarantors
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	328,240	455,935	547,952
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax, Portion Attributable to Parent	94,989	456,493	(129,231)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	0	0	0
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred	0	0	0
Other Comprehensive Income (Loss), Net of Tax	94,989	456,493	129,231
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest		912,428	677,183
Less: Comprehensive Loss (Income), Net of Tax, Attributable to Noncontrolling Interest		0	0
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	423,229	912,428	677,183
Non-Guarantors
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	981	585,616	80,690
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax, Portion Attributable to Parent	0	0	0
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	0	0	0
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred	0	0	0
Other Comprehensive Income (Loss), Net of Tax	0	0	0
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest		585,616	80,690
Less: Comprehensive Loss (Income), Net of Tax, Attributable to Noncontrolling Interest		0	0
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	981	585,616	80,690
Elimination
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(452,494)	(1,040,313)	(653,402)
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax, Portion Attributable to Parent	(94,989)	(456,493)	129,231
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(97,316)	(45,631)	(114,240)
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred	18,288	79,899	189,259
Other Comprehensive Income (Loss), Net of Tax	(174,017)	(422,225)	(54,212)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest		(1,462,538)	(707,614)
Less: Comprehensive Loss (Income), Net of Tax, Attributable to Noncontrolling Interest		0	0
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ (626,511)	$ (1,462,538)	$ (707,614)

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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