Property, Plant and Equipment Assets Amortized by Units of Production (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Assets Amortized By Units of Production [Line Items]
Unproved Oil and Gas Property, Successful Effort Method	$ 1,540,835	$ 1,463,406
Coal Properties And Surface Lands	1,358,306cnx_CoalPropertiesAndSurfaceLands	1,404,056cnx_CoalPropertiesAndSurfaceLands
Mine development	414,501cnx_MineDevelopment	354,607cnx_MineDevelopment
Property Subject to or Available for Operating Lease, Gross	263,946	393,372
Prepaid Royalties	386,245us-gaap_PrepaidRoyalties	381,348us-gaap_PrepaidRoyalties
Airshafts	468,924cnx_Airshafts	397,466cnx_Airshafts
Advances for Gas Exploration, Development and Production Amount	20,580	22,668
Property, Plant and Equipment, Gross	14,674,777us-gaap_PropertyPlantAndEquipmentGross	13,578,509us-gaap_PropertyPlantAndEquipmentGross
Assets amortized by units of production [Member]
Assets Amortized By Units of Production [Line Items]
Unproved Oil and Gas Property, Successful Effort Method	1,540,835	1,463,406
Coal Properties And Surface Lands	477,444	273,242
Mine development	11,984	238,356
Property Subject to or Available for Operating Lease, Gross	50,044	99,506
Prepaid Royalties	52,009	48,043
Airshafts	52,194	38,794
Advances for Gas Exploration, Development and Production Amount	20,580	22,668
Property, Plant and Equipment, Gross	$ 2,205,090	$ 2,184,015

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Coal Properties And Surface Lands

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Mine Development

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Discloses the period end balance sheet amount of advances for gas exploration, development and production.

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Amount of asset related to consideration paid in advance for royalties that provide economic benefits within a future period of one year or the normal operating cycle, if longer.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Amount before accumulated depreciation of physical assets used in the normal conduct of business to produce goods and services subject to or available for lease.

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Oil and Gas properties with unproved reserves under the successful effort method.

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