Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2014

The components of inventories were as follows (dollars in millions):



	December 31
	2014		2013
Raw materials	$	261.9	$	212.0
Work in process	11.3		13.9
Finished goods	216.3		210.0
Supplies and materials	175.4		158.4
Inventories	$	664.9	$	594.3

Property, Plant and Equipment (at cost)

Property, plant, and equipment consisted of the following (dollars in millions):



	December 31
	2014			2013
Land and land improvements	$	138.2		$	140.6
Buildings	659.9			628.9
Machinery and equipment	4,508.0			4,246.3
Construction in progress	154.8			168.8
Other	54.5			48.1
Property, plant, and equipment, at cost	5,515.4			5,232.7
Less accumulated depreciation	(2,657.8		)	(2,427.0		)
Property, plant, and equipment, net	$	2,857.6		$	2,805.7

Property, Plant and Equipment Estimated Useful Lives

Depreciation is computed on the straight-line basis over the estimated useful lives of the related assets. Assets under capital leases are depreciated on the straight-line method over the term of the lease or the useful life, if shorter. The following lives are used for the various categories of assets:



Buildings and land improvements	5 to 40 years
Machinery and equipment	3 to 25 years
Trucks and automobiles	3 to 10 years
Furniture and fixtures	3 to 20 years
Computers and hardware	3 to 10 years
	Period of the lease or
Leasehold improvements	useful life, if shorter