Business Segments (Tables)

12 Months Ended

Dec. 31, 2023

Segment Reporting [Abstract]

Schedule of Revenue by Major Customers by Reporting Segments

The following represents the revenue attributable to each of these entities as a percentage of consolidated revenue for those years:

	Percentage of Consolidated Revenue
Segment	2023		2022
Coal Mining customer	40	%	39	%
NAMining customer	22	%	17	%

Schedule of Segment Reporting Information

The following tables present revenue, operating profit, depreciation expense and capital expenditures for the years ended December 31:

	2023		2022
Revenues
Coal Mining	$	85,415	$	95,204
NAMining	90,532		85,664
Minerals Management	32,985		60,242
Unallocated Items	8,459		2,952
Eliminations	(2,597)		(2,343)
Total	$	214,794	$	241,719
Operating (loss) profit
Coal Mining	$	(71,342)	$	38,309
NAMining	3,348		2,202
Minerals Management	19,418		52,214
Unallocated Items	(21,461)		(23,233)
Eliminations	(100)		494
Total	$	(70,137)	$	69,986

Expenditures for property, plant and equipment and acquisition of mineral interests
Coal Mining	$	6,609	$	14,853
NAMining	36,073		13,203
Minerals Management	38,881		13,388
Unallocated Items	559		13,003
Total	$	82,122	$	54,447
Depreciation, depletion and amortization
Coal Mining	$	17,569	$	17,074
NAMining	8,172		6,457
Minerals Management	3,067		3,026
Unallocated Items	579		259
Total	$	29,387	$	26,816