PROPERTY, PLANT AND EQUIPMENT (Tables)

6 Months Ended

Jun. 30, 2019

Property, Plant and Equipment [Abstract]

Value Of Each Of The Major Classes Of Consolidated Depreciable Assets

The following table indicates the carrying value of each of the major classes of our depreciable assets:

	(In Millions)
	June 30, 2019			December 31, 2018
Land rights and mineral rights	$	549.6		$	549.6
Office and information technology	70.6			70.0
Buildings	95.4			87.2
Mining equipment	575.8			548.5
Processing equipment	740.3			645.8
Electric power facilities	58.7			58.7
Land improvements	23.8			23.8
Asset retirement obligation	14.9			14.8
Other	27.6			25.2
Construction-in-progress	501.3			284.8
	2,658.0			2,308.4
Allowance for depreciation and depletion	(1,060.7		)	(1,022.4		)
	$	1,597.3		$	1,286.0