Note 1 - Basis of Presentation - Schedule of Basic and Dilutive Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Net Income (Loss)	$ 4,172	$ 26,404	$ (21,063)	$ 2,475	$ 30,576	$ (18,588)
Less: Net Loss Attributable to Noncontrolling Interest	0		(3,080)		0	(2,972)
Net Income (Loss) Attributable to CONSOL Energy Inc. Stockholders	$ 4,172		$ (17,983)		$ 30,576	$ (15,616)
Weighted-average shares of common stock outstanding (in shares)	34,446,605		26,031,103		34,327,282	26,009,129
Effect of dilutive shares* (in shares)	643,892		0		734,388	0
Weighted-average diluted shares of common stock outstanding (in shares)	35,090,497		26,031,103		35,061,670	26,009,129
Total Basic Earnings (Loss) per Share (in dollars per share)	$ 0.12		$ (0.69)		$ 0.89	$ (0.60)
Total Dilutive Earnings (Loss) per Share (in dollars per share)	$ 0.12		$ (0.69)		$ 0.87	$ (0.60)