Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2022

Accounting Policies [Abstract]

Components of Inventories

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

	December 31,
	2022		2021
Raw materials	$	341.2	$	324.2
Work in process		16.0		16.2
Finished goods		198.4		201.0
Supplies and materials		421.7		361.1
Inventories	$	977.3	$	902.5

Property, Plant and Equipment (at cost)

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

	December 31,
	2022			2021
Land and land improvements	$	192.4		$	189.8
Buildings		1,023.6			938.7
Machinery and equipment		6,709.3			6,159.1
Construction in progress		440.2			481.0
Other		146.9			102.9
Property, plant and equipment, at cost		8,512.4			7,871.5
Less accumulated depreciation		(4,612.4	)		(4,342.5	)
Property, plant and equipment, net	$	3,900.0		$	3,529.0

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 finance 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 lease or useful life, if shorter