Property, Plant and Equipment, Net (Tables)

12 Months Ended

Dec. 31, 2020

Property, Plant and Equipment, Net [Abstract]

Property, Plant and Equipment

Property, plant and equipment, net includes the following:

	December 31
	2020		2019
Coal lands and real estate	$	50,887	$	54,647
Mineral interests	14,181		—
Plant and equipment	231,190		190,868
Property, plant and equipment, at cost	296,258		245,515
Less allowances for depreciation, depletion and amortization	123,841		107,454
	$	172,417	$	138,061