Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2018

Accounting Policies [Abstract]

Components of Inventories

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

	December 31,
	2018		2017
Raw materials	$	307.8	$	279.8
Work in process		13.9		12.6
Finished goods		199.0		217.0
Supplies and materials		274.9		253.1
Inventories	$	795.6	$	762.5

Property, Plant and Equipment (at cost)

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

	December 31,
	2018			2017
Land and land improvements	$	161.9		$	156.0
Buildings		795.5			729.8
Machinery and equipment		5,481.6			5,162.5
Construction in progress		176.7			194.5
Other		75.4			68.4
Property, plant and equipment, at cost		6,691.1			6,311.2
Less accumulated depreciation		(3,582.5	)		(3,386.3	)
Property, plant and equipment, net	$	3,108.6		$	2,924.9

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
Leasehold improvements	Period of the leaseor useful life, if shorter