BASIS OF PRESENTATION - Schedule of Basic and Dilutive Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Numerator:
Net Income (Loss)	$ 70,958	$ 46,445
Less: Net Income Attributable to Noncontrolling Interest	8,550	5,464
Net Income Attributable to CONSOL Energy Inc. Shareholders	$ 62,408	$ 40,981
Denominator:
Weighted-average shares of common stock outstanding (in shares)	28,029,146	27,967,509
Effect of dilutive shares (in shares)	295,724	0
Weighted-average diluted shares of common stock outstanding (in shares)	28,324,870	27,967,509
Earnings per Share:
Basic (in dollars per share)	$ 2.23	$ 1.47
Dilutive (in dollars per share)	$ 2.20	$ 1.47