Property, Plant & Equipment (Tables)

12 Months Ended

Dec. 31, 2011

Property, Plant & Equipment [Abstract]

Property Plant & Equipment

		00,000,000		00,000,000	00,000,000
in thousands	2011		2010
Property, Plant & Equipment
Land and land improvements		$2,122,350		$2,096,046
Buildings		163,178		159,458
Machinery and equipment		4,206,870		4,222,242
Leaseholds		9,238		7,458
Deferred asset retirement costs		136,289		142,441
Construction in progress		67,621		65,169
Total, gross		$6,705,546		$6,692,814
Less allowances for depreciation, depletion   and amortization		3,287,367		3,059,900
Total, net		$3,418,179		$3,632,914

Capitalized interest costs and total interest costs incurred

		00,000,000		00,000,000		00,000,000
in thousands	2011		2010		2009
Capitalized interest cost		$2,675		$3,637		$10,721
Total interest cost incurred before recognition   of the capitalized amount		223,303		185,240		185,983