Property and Equipment, net

12 Months Ended

Dec. 31, 2023

Property, Plant and Equipment [Abstract]

7. Property and Equipment, net

Property and equipment, and the related accumulated depreciation and amortization as of December 31, 2023 and 2022, were as follows:


		December 31
(millions)	Estimated Useful Life	2023			2022
Equipment	1 - 10 Years	$	58.9		$	54.5
Software	3 Years		74.2			61.0
Vehicles	1 - 10 Years		40.4			39.0
Other	3 Years		1.5			1.3
	Shorter of lease term or economic life up to
Leasehold improvements	10 years		16.8			16.7
Construction in progress			9.1			6.9
Property and equipment, gross			200.9			179.4
Accumulated depreciation and amortization			(132.6	)		(119.2	)
Property and equipment, net		$	68.3		$	60.2

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

The Company's depreciation and amortization expense related to property and equipment during the years ended December 31, 2023, 2022 and 2021, which was included in Depreciation and amortization expense within the Consolidated Statements of Income, was as follows:


	Year Ended December 31,
(millions)	2023		2022		2021
Depreciation expense and amortization	$	24.1	$	19.8	$	16.4