PROPERTY, PLANT & EQUIPMENT (Tables)

12 Months Ended

Dec. 31, 2017

PROPERTY, PLANT & EQUIPMENT [Abstract]

Property, Plant and Equipment

in thousands	2017	2016
Property, Plant & Equipment
Land and land improvements 1	$    2,742,285	$  2,374,051
Buildings	135,655	127,369
Machinery and equipment	4,740,212	4,316,243
Leaseholds	17,354	17,595
Deferred asset retirement costs	172,631	168,258
Construction in progress	161,175	182,302
Total, gross	$    7,969,312	$  7,185,818
Less allowances for depreciation, depletion
and amortization	4,050,381	3,924,380
Total, net	$    3,918,931	$  3,261,438

1 Includes depletable land, as follows: December 31, 2017 — $1,606,303 thousand and December 31, 2016 — $1,327,402 thousand.

Capitalized Interest Costs and Total Interest Costs Incurred

in thousands	2017	2016	2015
Capitalized interest cost	$          5,177	$        7,468	$        2,930
Total interest cost incurred before recognition
of the capitalized amount	300,699	141,544	223,518