v3.26.3
Note 11 - Major Customers - Concentration Risk (Details) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Alpha Metallurgical Resources [Member]        
Net sales [1] $ 14,376 $ 13,897 $ 41,594 $ 40,257
Alpha Metallurgical Resources [Member] | Revenue Benchmark [Member] | Customer Concentration Risk [Member]        
Revenue, percent [1] 29.00% 27.00% 28.00% 26.00%
Foresight Energy Resources [Member]        
Net sales [1] $ 8,993 $ 7,400 $ 36,320 $ 33,656
Foresight Energy Resources [Member] | Revenue Benchmark [Member] | Customer Concentration Risk [Member]        
Revenue, percent [1] 18.00% 14.00% 24.00% 22.00%
Alabama Kanu Holdings [Member]        
Net sales [1] $ 6,391 $ 6,324 $ 16,977 $ 14,867
Alabama Kanu Holdings [Member] | Revenue Benchmark [Member] | Customer Concentration Risk [Member]        
Revenue, percent [1] 13.00% 12.00% 11.00% 10.00%
[1] Revenues from Alpha Metallurgical Resources, Inc., Foresight and Alabama Kanu Holdings, LLC are generated in the United States of America and are included within the Partnership's Mineral Rights segment.