Note 18 - Related Party Transactions (Details Textual)		9 Months Ended
	Dec. 30, 2020 USD ($) shares	Sep. 30, 2021 USD ($) shares
Stock Issued During Period, Shares, Acquisitions (in shares)	7,967,690
CONSOL Coal Resources L P [Member]
Common Unit, Issued (in shares)	10,912,138
Common Stock, Fixed Exchange Ratio	0.73
Conversion of Stock, Amount Converted | $	$ 51,710
CONSOL Coal Resources L P [Member] | Affiliated Company Credit Agreement [Member] | Affiliated Entity [Member]
Common Unit, Issued (in shares)		37,322,410
Repayments of Long-term Debt, Total | $		$ 176,535