Property, Plant and Equipment

12 Months Ended

Dec. 31, 2018

Property, Plant and Equipment [Abstract]

Property, plant and equipment are stated at cost, less accumulated depreciation. Interest is capitalized as a component of the cost of construction for large projects. Expenditures for betterments are capitalized whereas normal repairs and maintenance are expensed as incurred. Property, other than land, is depreciated on a straight-line basis for financial reporting purposes. When property is sold or retired, the cost of the property and the related accumulated depreciation are removed from the balance sheet, and any gain or loss on the transaction is normally included in cost of products sold.

Property, plant and equipment (and related depreciable lives) consisted of the following ($ in millions):



	December 31,
	2018		2017
Land and improvements	$	15.0	$	15.3
Buildings and improvements (20 to 40 years or remaining life of relevant lease)	142.0		145.1
Machinery and equipment (5 to 20 years)	620.9		621.9
Construction in progress	14.6		28.1
Gross property, plant and equipment	792.5		810.4
Less: Accumulated depreciation	452.2		448.5
Property, plant and equipment, net	$	340.3	$	361.9

Depreciation expense was $38.1 million, $35.7 million and $29.4 million for the years ended December 31, 2018, 2017, and 2016, respectively.