Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022
SALES AND OPERATING REVENUES:
Other revenues		$ 4,627	$ 6,363
Total sales and operating revenues		634,480	361,991
OPERATING EXPENSES:
Operating expenses		473,390	266,608
Depreciation, depletion and amortization		67,211	46,875
Asset retirement obligations accretion		1,804	1,010
Exploration costs		904	651
General and administrative		26,159	16,417
Total operating expenses		569,468	331,561
INCOME FROM OPERATIONS		65,012	30,430
Interest expense (1)	[1]	(13,711)	(11,012)
Loss on extinguishment of debt		(1,491)	0
Equity method investment (loss) income		(552)	443
INCOME BEFORE INCOME TAXES		49,258	19,861
INCOME TAX EXPENSE (BENEFIT):
Current		(164)	0
Deferred		4,629	1,756
Total income tax expense		4,465	1,756
NET INCOME		$ 44,793	$ 18,105
NET INCOME PER SHARE:
Basic (in dollars per share)		$ 1.35	$ 0.57
Diluted (in dollars per share)		$ 1.25	$ 0.55
WEIGHTED AVERAGE SHARES OUTSTANDING:
Basic (in shares)		33,133	32,043
Diluted (in shares)		36,827	33,649
(1) Interest Expense:
Interest on bank debt		$ 8,636	$ 7,563
Other interest		1,842	715
Amortization and swap related interest:
Payments on interest rate swap, net of changes in value		0	(867)
Amortization of debt issuance costs		3,233	3,601
Total amortization and swap related interest		3,233	2,734
Total interest expense	[1]	13,711	11,012
Coal Sales [Member]
SALES AND OPERATING REVENUES:
Revenues		361,926	289,376
Electric Sales [Member]
SALES AND OPERATING REVENUES:
Revenues		$ 267,927	$ 66,252

[1] Interest Expense: