PROPERTY, PLANT & EQUIPMENT (Tables)

12 Months Ended

Dec. 31, 2015

PROPERTY, PLANT & EQUIPMENT [Abstract]

Property, Plant and Equipment

in thousands	2015	2014
Property, Plant & Equipment
Land and land improvements 1	$    2,305,801	$  2,273,874
Buildings	124,950	126,833
Machinery and equipment	4,124,808	3,952,423
Leaseholds	14,143	13,451
Deferred asset retirement costs	166,252	163,644
Construction in progress	155,333	78,617
Total, gross	$    6,891,287	$  6,608,842
Less allowances for depreciation, depletion
and amortization	3,734,997	3,537,212
Total, net	$    3,156,290	$  3,071,630

1 Includes depletable land, as follows: December 31, 2015 — $1,296,211 thousand and December 31, 2014 — $1,287,225 thousand.

Capitalized Interest Costs and Total Interest Costs Incurred

in thousands	2015	2014	2013
Capitalized interest cost	$          2,930	$        2,092	$        1,089
Total interest cost incurred before recognition
of the capitalized amount	223,518	245,459	203,677