Leasehold Improvements, Equipment and Construction in Progress, net

12 Months Ended

Dec. 31, 2020

Property Plant And Equipment [Abstract]

Leasehold Improvements, Equipment and Construction in Progress, net

8. Leasehold Improvements, Equipment and Construction in Progress, net

Leasehold improvements, equipment, and construction in progress and related accumulated depreciation and amortization for the years ended December 31, 2020 and 2019, were as follows:

		December 31
(millions)	Estimated Useful Life	2020			2019
Equipment	1 - 10 Years	$	50.1		$	45.2
Software	2 - 5 Years		42.3			39.7
Vehicles	1 - 10 Years		37.3			30.0
Other	3 Years		0.8			0.6
	Shorter of lease term or economic life up to
Leasehold improvements	10 years		18.0			18.8
Construction in progress			6.8			6.3
			155.3			140.6
Accumulated depreciation and amortization			(102.0	)		(92.7	)
Leasehold improvements, equipment and construction in
progress, net		$	53.3		$	47.9

Asset additions are recorded at cost, which includes interest on significant projects. Depreciation is recorded on a straight-line basis over their estimated useful lives or the terms of the respective leases, whichever is shorter. Leasehold improvements, equipment and construction in progress are reviewed for impairment when conditions indicate an impairment. If the assets are determined to be impaired, they are either written down or the useful life is adjusted to the remaining period of estimated useful life.

The Company's depreciation and amortization expense related to leasehold improvements and equipment for the years ended December 31, 2020, 2019 and 2018, which was included in Depreciation and amortization expense within the Consolidated Statements of (Loss) Income, was as follows:

	Year Ended December 31,
(millions)	2020		2019		2018
Depreciation expense and amortization	$	15.3	$	12.8	$	9.6