Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net Income	$ 178,785	$ 82,569	$ 50,450
Other Comprehensive Income (Loss):
Amortization of Prior Service Credits (net of tax: $662, $1,076, $186)	(2,246)	(1,832)	(316)
Recognized Net Actuarial Loss (net of tax: $(5,590), $(9,039), $(8,524))	18,960	15,391	14,515
Settlement Loss (net of tax: $0, $(2,312), $(8,213))	0	7,841	13,983
OPEB Plan Amendments (net of tax: $0, $0, $10,420)	0	0	(28,164)
Other Comprehensive Gain (Loss) before Reclassifications (net of tax: $(14,986), $(26,360), $24,232)	49,627	73,519	(31,427)
Other Comprehensive Income (Loss)	66,341	94,919	(31,409)
Comprehensive Income	245,126	177,488	19,041
Less: Comprehensive Income Attributable to Noncontrolling Interests	25,803	14,896	9,216
Comprehensive Income Attributable to CONSOL Energy Inc. Shareholders	$ 219,323	$ 162,592	$ 9,825