Property, Plant, Equipment and Mine Development (Tables)

6 Months Ended

Jun. 30, 2021

Property, Plant and Equipment [Abstract]

Schedule of Property, Plant, Equipment and Mine Development

The composition of property, plant, equipment and mine development, net, as of June 30, 2021 and December 31, 2020 is set forth in the table below:

	June 30, 2021		December 31, 2020
	(Dollars in millions)
Land and coal interests	$	2,484.1	$	2,482.9
Buildings and improvements	523.3		481.0
Machinery and equipment	1,461.5		1,408.5
Less: Accumulated depreciation, depletion and amortization	(1,460.6)		(1,321.3)
Property, plant, equipment and mine development, net	$	3,008.3	$	3,051.1