CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - 6 months ended Jun. 30, 2018 - USD ($) $ in Thousands	Total	Common Stock	Capital in Excess of Par Value	Retained Earnings (Deficit)	Accumulated Other Comprehensive (Loss) Income	Common Stock in Treasury	Total CONSOL Energy Inc. Stockholders' Equity	Noncontrolling Interest
Beginning balance at Dec. 31, 2017	$ 343,641	$ 280	$ 552,793	$ (43,713)	$ (305,100)	$ 0	$ 204,260	$ 139,381
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	123,667			107,570			107,570	16,097
Actuarially Determined Long-Term Liability Adjustments (Net of $2,464 Tax)	8,179				8,178		8,178	1
Comprehensive Income	131,846			107,570	8,178		115,748	16,098
Reclassification of Stranded Tax Effect of Change in Tax Law	0			84,729	(84,729)
Separation Adjustments	(1,595)		(1,595)				(1,595)
Issuance of Common Stock	0	1	(1)
Retirement of Common Stock (91,000 shares)	(3,281)	(1)	(1,797)	(1,483)			(3,281)
Amortization of Stock-Based Compensation Awards	4,655		3,789				3,789	866
Units/Shares Withheld for Taxes	(2,871)		(1,972)				(1,972)	(899)
Distributions to Noncontrolling Interest	(11,174)							(11,174)
Ending balance at Jun. 30, 2018	$ 461,221	$ 280	$ 551,217	$ 147,103	$ (381,651)	$ 0	$ 316,949	$ 144,272