Revenue Recognition (Tables)

12 Months Ended

Dec. 31, 2023

Revenue from Contract with Customer [Abstract]

Schedule of Disaggregation of Revenue

The following table disaggregates revenue by major sources for the years ended December 31:

Major Goods/Service Lines	2023		2022
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 revenues	$	214,794	$	241,719
Timing of Revenue Recognition
Goods transferred at a point in time	$	83,273	$	92,842
Services transferred over time	131,521		148,877
Total revenues	$	214,794	$	241,719

Schedule of Contract Balances

The opening and closing balances of the Company’s current and long-term contract assets and liabilities and receivables are as follows:

	Contract balances
	Trade accounts receivable		Contract asset (current)		Contract asset (long-term)		Contract liability (current)		Contract liability (long-term)
Balance at January 1, 2023	$	37,940	$	409	$	5,985	$	833	$	1,709
Balance at December 31, 2023	37,429		—		3,712		878		1,470
Increase (decrease)	$	(511)	$	(409)	$	(2,273)	$	45	$	(239)