PROPERTY, PLANT AND EQUIPMENT (Tables)

12 Months Ended

Dec. 31, 2017

PROPERTY, PLANT AND EQUIPMENT

Schedule of property, plant and equipment

	2017		2016
	(in thousands)
Mining equipment and processing facilities	$	1,847,037	$	1,854,001
Land and mineral rights		449,152		439,236
Buildings, office equipment and improvements		310,167		304,696
Construction and mine development in progress		47,223		26,025
Mine development costs		280,609		297,030
Property, plant and equipment, at cost		2,934,188		2,920,988
Less accumulated depreciation, depletion and amortization		(1,457,532)		(1,335,145)
Total property, plant and equipment, net	$	1,476,656	$	1,585,843