Supplemental Quarterly Info (Unaudited) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Dec. 31, 2012	Jun. 30, 2012	Mar. 31, 2012	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Sales	$ 772,258	$ 753,080	$ 808,238	$ 759,948	$ 799,997	$ 681,717	$ 807,198	$ 878,118
Freight-Outside	3,946	11,563	13,426	10,125	14,061	27,430	49,472	49,293	35,438	107,079	175,633
Cost of Goods Sold and Other Operating Charges (exclusive of depreciation, depletion and amortization shown below)	562,386	560,247	557,094	552,126	612,000	543,158	565,601	601,723	2,228,952	2,221,859	2,266,560
Freight Expense	3,946	11,563	13,426	10,125	14,061	27,430	49,472	49,293	35,438	107,079	175,444
Net Income (Loss)									659,056	388,073	632,497
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, Net of Tax	591,144	8,120	42,060	(21,375)	1,904	14,814	(3,050)	16,290	579,792	70,114	(49,178)
Income (Loss) from Continuing Operations Attributable to Parent	146,595	(72,169)	107,580	8,562	(3,725)	(26,316)	155,789	80,906	79,264	317,959	681,675
Net Income Attributable to CONSOL Energy Inc Shareholders	$ 738,183	$ (63,651)	$ 149,903	$ (12,526)	$ (1,564)	$ (11,368)	$ 152,739	$ 97,196	$ 660,442	$ 388,470	$ 632,497
Basic	$ 3.22	$ (0.28)	$ 0.66	$ (0.05)	$ (0.01)	$ (0.05)	$ 0.67	$ 0.43	$ 2.89	$ 1.71	$ 2.79
Income (Loss) from Continuing Operations, Per Diluted Share	$ 0.64	$ (0.31)	$ 0.47	$ 0.04	$ (0.02)	$ (0.12)	$ 0.68	$ 0.35	$ 0.35	$ 1.39	$ 2.98
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share	$ 2.56	$ 0.03	$ 0.18	$ (0.09)	$ 0.01	$ 0.07	$ (0.01)	$ 0.07	$ 2.52	$ 0.31	$ (0.22)
Income (Loss) from Continuing Operations, Per Basic Share	$ 0.64	$ (0.31)	$ 0.47	$ 0.04	$ (0.02)	$ (0.12)	$ 0.68	$ 0.36	$ 0.35	$ 1.40	$ 3.01
Diluted	$ 3.20	$ (0.28)	$ 0.65	$ (0.05)	$ (0.01)	$ (0.05)	$ 0.67	$ 0.42	$ 2.87	$ 1.70	$ 2.76
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share	$ 2.58	$ 0.03	$ 0.19	$ (0.09)	$ 0.01	$ 0.07	$ (0.01)	$ 0.07	$ 2.54	$ 0.31	$ (0.22)
Weighted Average Number of Shares Outstanding, Basic									228,728,628	227,593,524	226,680,369
Diluted									230,077,942	229,141,767	229,003,599