Property, Plant and Equipment

12 Months Ended

Dec. 31, 2018

Property, Plant and Equipment [Abstract]

A summary of gross property, plant and equipment at December 31 is presented in the following table:



($ in millions)	Expected useful lives (years)	2018		2017
Land		$	20.9	$	21.4
Buildings and improvements	5-50	569.1		539.2
Machinery and equipment	10-15	806.7		793.4
Molds and dies	4-7	115.8		114.5
Computer hardware and software	3-10	151.1		144.6
Construction in progress		89.1		132.7
		$	1,752.7	$	1,745.8

Depreciation expense for the years ended December 31, 2018, 2017 and 2016 was $101.7 million, $94.3 million and $88.1 million, respectively.

There were no capitalized leases included in buildings and improvements and machinery and equipment at December 31, 2018 and 2017.

We capitalize interest on borrowings during the active construction period of major capital projects. Capitalized interest is added to the cost of the underlying assets and is amortized over the useful lives of the assets. Capitalized interest for the years ended December 31, 2018, 2017 and 2016 was $0.9 million, $2.7 million and $3.6 million, respectively.

During 2018, as part of our 2018 restructuring plan, we recorded within other expense a $2.2 million non-cash asset write-down associated with the discontinued use of certain equipment. During 2016, as part of our 2016 restructuring plan, we recorded within other expense a $4.5 million non-cash asset write-down associated with the discontinued use of certain equipment.