Consolidated Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Statement [Abstract]
Oil and Gas Sales Revenue	$ 1,028,117	$ 737,701	$ 658,820
Coal Products and Services Revenue	2,052,166	2,018,067	2,169,625
Other Revenue, Net	276,242	259,783	294,105
Gas Royalty Interests and Purchased Gas Sales	91,427	69,733	52,721
Freight-Outside	28,148	35,438	107,079
Other Income	207,103	111,483	113,170
Gain (Loss) on Disposition of Assets	43,601	67,480	282,006
Total Revenue and Other Income	3,726,804	3,299,685	3,677,526
Oil and Gas Property, Lease Operating Expense	118,391	96,601	90,837
Gas Gathering, Transportation, Marketing and Processing Costs	258,110	201,024	160,579
Production Tax Expense	39,418	28,676	26,145
E&P Direct Administration and Selling	55,092	49,092	47,565
E&P Depreciation, Depletion, and Amortization	314,381	231,809	205,149
Exploration and Production Costs	23,356	61,104	39,005
Production Royalty Interests and Purchased Gas Costs	77,185	57,865	41,578
Other Expenses	86,499	95,535	81,033
Results of Operations, General and Administrative Related to Oil and Gas Producing Activities	64,047	39,047	33,686
Oil and Gas Production Expense	1,036,479	860,753	725,577
Operating Expenses	1,349,832	1,345,797	1,457,913
Taxes, Miscellaneous	100,890	102,128	117,194
Direct Administration, Selling and Other Costs	44,185	49,018	54,910
Coal Depreciation, Depletion, Amortization	254,914	226,639	219,636
Freight Expense	28,148	35,438	107,079
General and Administrative Expense	45,160	40,047	42,662
Other Cost and Expense, Operating	55,321	55,802	52,900
Cost of Coal Products and Services	1,878,450	1,854,869	2,052,294
Other Nonoperating Expense	307,236	315,180	269,653
Other General and Administrative Expense	788	936	943
Depreciation, Depletion and Amortization, Nonproduction	1,896	2,674	2,330
Gains (Losses) on Extinguishment of Debt	95,267	0	0
Interest Expense	223,564	219,198	220,042
Other General Expense	628,751	537,988	492,968
Total Costs	3,543,680	3,253,610	3,270,839
Earnings Before Income Taxes	183,124	46,075	406,687
Income Taxes	14,347	(33,189)	88,728
Income (Loss) from Continuing Operations Attributable to Parent	168,777	79,264	317,959
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	(5,687)	579,792	70,114
Net Income (Loss)	163,090	659,056	388,073
Less: Net Loss (Income) Attributable to Noncontrolling Interest	0	1,386	397
Net Income Attributable to CONSOL Energy Inc Shareholders	$ 163,090	$ 660,442	$ 388,470
Earnings per share:
Income (Loss) from Continuing Operations, Per Basic Share	$ 0.73	$ 0.35	$ 1.40
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share	$ (0.02)	$ 2.54	$ 0.31
Basic	$ 0.71	$ 2.89	$ 1.71
Income (Loss) from Continuing Operations, Per Diluted Share	$ 0.73	$ 0.35	$ 1.39
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share	$ (0.03)	$ 2.52	$ 0.31
Dilutive	$ 0.70	$ 2.87	$ 1.70
Dividends Paid Per Share	$ 0.250	$ 0.375	$ 0.625