Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Capital in Excess of Par Value	Retained Earnings (Deficit)	Parent Net Investment	Accumulated Other Comprehensive (Loss) Income	Total CONSOL Energy Inc. Stockholders’ Equity	Non- Controlling Interest	Consol Coal Resources LP Units	Consol Coal Resources LP Units Capital in Excess of Par Value	Consol Coal Resources LP Units Total CONSOL Energy Inc. Stockholders’ Equity	Consol Coal Resources LP Units Non- Controlling Interest
Balance, Beginning of Period at Dec. 31, 2015	$ 1,061,839	$ 0	$ 0	$ 0	$ 1,276,482	$ (368,392)	$ 908,090	$ 153,749
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss)	50,450				41,496		41,496	8,954
Actuarially determined long term liability adjustments	(31,409)					(31,671)	(31,671)	262
Comprehensive Income (Loss)	19,041				41,496	(31,671)	9,825	9,216
Amortization of Stock-Based Compensation Awards	1,185							1,185
Distributions to Noncontrolling Interest	(21,657)							(21,657)
Net Parent Distributions	(260,284)				(260,284)		(260,284)
Balance, End of Period at Dec. 31, 2016	800,124	0	0	0	1,057,694	(400,063)	657,631	142,493
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss)	82,569			(43,713)	111,342		67,629	14,940
Actuarially determined long term liability adjustments	94,919					94,963	94,963	(44)
Comprehensive Income (Loss)	177,488			(43,713)	111,342	94,963	162,592	14,896
Amortization of Stock-Based Compensation Awards	22,085		16,212				16,212	5,873
Distributions to Noncontrolling Interest	(21,892)							(21,892)
Net Parent Distributions	(207,008)				(207,008)		(207,008)
Spin Distribution to CNX Resources	(425,000)				(425,000)		(425,000)
Separation Adjustments			537,028		(537,028)
Issuance of Common Stock		280	(280)
Units/Shares Withheld for Taxes	(2,156)		(167)				(167)	(1,989)
Balance, End of Period at Dec. 31, 2017	343,641	280	552,793	(43,713)	0	(305,100)	204,260	139,381
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss)	178,785			152,976			152,976	25,809
Actuarially determined long term liability adjustments	66,341					66,347	66,347	(6)
Comprehensive Income (Loss)	245,126			152,976	0	66,347	219,323	25,803
Amortization of Stock-Based Compensation Awards	10,235		8,392				8,392	1,843
Distributions to Noncontrolling Interest	(22,265)							(22,265)
Separation Adjustments	7,216		7,216				7,216
Issuance of Common Stock		1	(1)
Units/Shares Withheld for Taxes	(3,424)		(2,512)				(2,512)	(912)
Retirement of Outstanding Shares	(25,839)	(7)	(13,988)	(11,844)			(25,839)		$ (3,079)	$ (905)	$ (905)	$ (2,174)
Reclassification of Stranded Tax Effect of Change in Tax Law				84,729		(84,729)
Balance, End of Period at Dec. 31, 2018	$ 551,611	$ 274	$ 550,995	$ 182,148	$ 0	$ (323,482)	$ 409,935	$ 141,676