Note 17 - Related Party Transactions - Changes for Services (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Total Services from CONSOL Energy	$ 2,720	$ 2,741	$ 6,366	$ 6,560
Operating and Other Costs [Member]
Total Services from CONSOL Energy	856	767	1,709	1,530
Selling, General and Administrative Expenses [Member]
Total Services from CONSOL Energy	$ 1,864	$ 1,974	$ 4,657	$ 5,030