v3.26.1
SEGMENT REPORTING - Schedule of Reportable Segment Information (Details) - USD ($)
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Mar. 31, 2026
Jun. 30, 2025
Mar. 31, 2025
Jun. 30, 2026
Jun. 30, 2025
Significant segment expenses:            
Selling, general, and administrative $ (17,577,000)   $ (15,181,000)   $ (37,862,000) $ (29,783,000)
Other segment items 189,000   658,000   674,000 1,163,000
Stock-based compensation (5,912,000)   (4,751,000)   (10,820,000) (8,113,000)
Asset retirement obligations accretion (483,000)   (402,000)   (989,000) (804,000)
Depreciation, depletion, and amortization (16,811,000)   (17,038,000)   (33,424,000) (34,580,000)
Other expense (1,813,000)   (686,000)   (3,180,000) (1,144,000)
Interest expense, net (1,519,000)   (2,818,000)   (1,853,000) (5,048,000)
Income tax benefit (expense) 4,163,000   2,030,000   9,998,000 6,320,000
Net income (loss) (15,415,000) $ (18,319,000) (13,974,000) $ (9,457,000) (33,734,000) (23,431,000)
Segment capital expenditures 30,955,000   14,424,000   50,961,000 35,876,000
Other capital expenditures 49,000   4,000   49,000 4,000
Total capital expenditures (including accrued capital expenditures and capitalized interest) 31,004,000   14,428,000   51,010,000 35,880,000
Operating Segments            
SEGMENT REPORTING            
Revenue 144,799,000   152,959,000   266,412,000 287,615,000
Significant segment expenses:            
Cost of sales (exclusive of transportation costs) (105,707,000)   (111,591,000)   (194,254,000) (204,813,000)
Transportation costs (22,469,000)   (20,673,000)   (42,436,000) (39,671,000)
Selling, general, and administrative (8,969,000)   (9,307,000)   (21,798,000) (18,182,000)
Other segment items 1,445,000   1,344,000   3,297,000 (2,307,000)
Segment Adjusted EBITDA 9,099,000   12,732,000   11,221,000 (27,256,000)
Corporate Non segment            
Significant segment expenses:            
Corporate expenses (2,139,000)   (3,041,000)   (4,687,000) (7,318,000)
Metallurgical Coal            
Significant segment expenses:            
Segment capital expenditures 26,236,000   13,938,000   43,916,000 35,331,000
Metallurgical Coal | Operating Segments            
SEGMENT REPORTING            
Revenue 144,799,000   152,959,000   266,412,000 287,615,000
Significant segment expenses:            
Cost of sales (exclusive of transportation costs) (105,707,000)   (111,591,000)   (194,254,000) (204,813,000)
Transportation costs (22,469,000)   (20,673,000)   (42,436,000) (39,671,000)
Selling, general, and administrative (3,528,000)   (5,012,000)   (9,743,000) (9,704,000)
Other segment items 1,442,000   1,331,000   3,291,000 (2,294,000)
Segment Adjusted EBITDA 14,537,000   17,014,000   23,270,000 (35,721,000)
REE & Critical Minerals            
SEGMENT REPORTING            
Revenue         0  
Significant segment expenses:            
Segment capital expenditures 4,719,000   486,000   7,045,000 545,000
REE & Critical Minerals | Operating Segments            
Significant segment expenses:            
Selling, general, and administrative (5,441,000)   (4,295,000)   (12,055,000) (8,478,000)
Other segment items 3,000   13,000   6,000 13,000
Segment Adjusted EBITDA $ (5,438,000)   $ (4,282,000)   $ (12,049,000) $ (8,465,000)