Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities:
Net income	$ 11,192	$ 82,313	$ 116,042
Adjustments to reconcile net income to net cash from operating activities:
Accretion of asset retirement obligations	1,465	1,403	1,115
Depreciation, depletion, and amortization	65,615	54,252	41,194
Amortization of debt issuance costs	934	776	491
Stock-based compensation	17,466	12,905	8,222
(Gain)/loss on disposal of equipment	(18)		756
Other income - gain on insurance recoveries		(10,192)
Other income - gain on sale of mineral rights			(2,113)
Deferred income taxes	1,675	18,714	29,229
Changes in operating assets and liabilities:
Accounts receivable	23,284	(55,692)	3,279
Prepaid expenses and other current assets	1,869	14,361	(14,378)
Inventories	(6,195)	7,810	(29,182)
Other assets and liabilities	(2,982)	(430)	1,127
Accounts payable	(4,834)	24,549	12,727
Accrued liabilities	3,194	10,267	19,361
Net cash provided by operating activities	112,665	161,036	187,870
Cash flows from investing activities:
Capital expenditures	(55,236)	(82,904)	(123,012)
Proceeds from sale of mineral rights	260		2,000
Insurance proceeds related to property, plant, and equipment		11,256
Maben preparation plant capital expenditures	(13,606)
Capitalized interest	(1,498)	(1,137)	(1,061)
Other	(755)	(608)
Net cash used for investing activities	(70,835)	(72,211)	(145,708)
Cash flows from financing activities:
Proceeds from issuance of senior note debt (net of $2,340 commissions and fees)	55,160
Proceeds from borrowings	141,500	130,000	42,000
Proceeds from stock options exercised	534		107
Payments of debt issuance costs (senior note debt)	(657)
Payment of dividends	(24,602)	(25,820)	(20,041)
Repayment of borrowings	(197,966)	(127,514)	(26,026)
Repayment of Ramaco Coal acquisition financing - related party		(40,000)	(15,000)
Repayments of insurance financing	(5,540)	(5,207)	(1,290)
Repayments of equipment finance leases	(8,636)	(6,659)	(5,062)
Shares surrendered for withholding taxes payable	(10,581)	(7,317)	(3,183)
Net cash used for financing activities	(50,788)	(82,517)	(28,495)
Net change in cash and cash equivalents and restricted cash	(8,958)	6,308	13,667
Cash and cash equivalents and restricted cash, beginning of period	42,781	36,473	22,806
Cash and cash equivalents and restricted cash, end of period	33,823	42,781	36,473
Supplemental cash flow information:
Cash paid for interest (net of amounts capitalized)	4,756	8,113	5,997
Cash paid for income taxes	1,228	771	15,500
Cash received for income tax refund		11,758
Non-cash investing and financing activities:
Leased assets obtained under new financing leases	12,000	6,144	7,888
Financed equipment purchases			6,409
Capital expenditures included in accounts payable and accrued liabilities	12,447	4,939	13,404
Financed insurance	5,811	5,803	5,587
Financed insurance (2022 adjustment recorded in 2023)		(1,136)
Accrued dividends and dividend equivalents payable	$ 7,085	7,198	5,524
Ramaco Coal Asset Acquisition
Cash flows from investing activities:
Acquisition of assets			(11,738)
Non-cash investing and financing activities:
Coal acquisition			56,551
Maben Asset Acquisition
Cash flows from investing activities:
Acquisition of Maben assets (bond recovery in 2023)		$ 1,182	(11,897)
Non-cash investing and financing activities:
Coal acquisition			$ 21,000