Leasehold Improvements, Equipment, Land and Construction in Progress, net

12 Months Ended

Dec. 31, 2019

Property, Plant and Equipment [Abstract]

Leasehold Improvements, Equipment, Land and Construction in Progress, net

Leasehold Improvements, Equipment and Construction in Progress, net

Leasehold improvements, equipment, and construction in progress and related accumulated depreciation and amortization is as follows:

		December 31
(millions)	Ranges of Estimated Useful Life	2019			2018
Equipment	1 - 10 Years	$	45.2		$	41.5
Software	2 - 5 Years	39.7			34.7
Vehicles	1 - 10 Years	30.0			23.6
Other	3 Years	0.6			0.6
Leasehold improvements	Shorter of lease term or economic life up to 10 years	18.8			17.7
Construction in progress		6.3			4.4
		140.6			122.5
Accumulated depreciation and amortization		(92.7		)	(82.2		)
Leasehold improvements, equipment and construction in progress, net		$	47.9		$	40.3

Asset additions are recorded at cost, which includes interest on significant projects. Depreciation is provided in amounts sufficient to relate the cost of depreciable assets to operations over their estimated useful lives or over the terms of the respective leases,

whichever is shorter, and depreciated on the straight-line basis. Plant and equipment are reviewed for impairment when conditions indicate an impairment or future impairment; the assets are either written down or the useful life is adjusted to the remaining period of estimated useful life.

The table below shows the Company's depreciation and amortization expense related to Leasehold improvements, equipment and construction in progress for the years ended December 31, 2019, 2018 and 2017, and is included in Depreciation and amortization expense within the Consolidated Statements of Income.

	Year Ended December 31,
(millions)	2019		2018		2017
Depreciation expense	$	12.8	$	9.6	$	11.3