PROPERTY, PLANT & EQUIPMENT

12 Months Ended

Dec. 31, 2017

PROPERTY, PLANT & EQUIPMENT [Abstract]

PROPERTY, PLANT & EQUIPMENT

NOTE 4: PROPERTY, PLANT & EQUIPMENT

Balances of major classes of assets and allowances for depreciation, depletion and amortization at December 31 are as follows:

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 with respect to qualifying construction projects and total interest costs incurred before recognition of the capitalized amount for the years ended December 31 are as follows:

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