Property and Equipment

12 Months Ended

Dec. 31, 2017

Property, Plant and Equipment [Abstract]

Property and equipment and related accumulated depreciation are as follows (in millions):



	December 31,
	2017		2016
Land	$	52.9	$	34.2
Buildings	198.0		160.3
Technology equipment	248.4		213.0
Software	591.4		508.2
Furniture, fixtures and other equipment	151.6		122.1
Leasehold improvements	91.6		76.4
Construction-in-progress	12.1		18.3
	1,346.0		1,132.5
Less accumulated depreciation and amortization	996.2		896.8
Properties, net	$	349.8	$	235.7

At December 31, 2016, there was approximately $2.5 million of assets under capital lease, net of accumulated depreciation of $2.2 million, included in the above table. We had minimal assets under capital lease as of December 31, 2017.

Software assets are comprised of the following (in millions):



	December 31, 2017				December 31, 2016
	Carrying Amount		Accumulated Amortization		Carrying Amount		Accumulated Amortization
Internally developed software	$	324.0	$	287.9	$	296.4	$	266.0
Purchased software	183.8		159.5		155.3		143.0
Software from business acquisitions	83.6		52.8		56.5		44.5
Total	$	591.4	$	500.2	$	508.2	$	453.5

During the years ended December 31, 2017, 2016 and 2015, we capitalized software costs of $24.1 million, $21.5 million and $23.3 million, respectively. Construction-in-progress as of December 31, 2017 and 2016 includes internally developed software costs of $11.5 million and $14.9 million, respectively, which have not yet been put into service.

Depreciation expense for the years ended December 31, 2017, 2016 and 2015, was $99.8 million, $78.2 million and $77.6 million, respectively.

In December 2014, we entered into a transaction under which Industrial Revenue Bonds (“IRBs”) were issued by a municipality to finance the purchase and/or construction of certain real and personal property. Pursuant to the terms of the IRBs, we transferred title of certain fixed assets to the municipality. Tax benefits associated with the IRBs include a provision for a 10-year property tax abatement and sales tax exemption on the property financed with the proceeds of the IRBs. The municipality holds legal title to the bond financed assets and leases them to us subject to an option to purchase for nominal consideration, which we may exercise at any time. We are the bondholder as well as the lessee of the property purchased with the IRBs proceeds. We record the property on our Consolidated Balance Sheet as all risks and benefits remain with us, along with a capital lease obligation to repay the proceeds of the IRBs. Moreover, as holder of the bonds, we have the right to offset the amounts due under the leases with the amounts due to us from the bonds. Accordingly, no net debt associated with the IRBs is reflected in our Consolidated Balance Sheet. Upon maturity or redemption of the bonds, which is within our sole control, title to the leased property reverts back to us. At December 31, 2017 and 2016, we held IRBs with an aggregate principal amount of $103.9 million and $87.6 million, respectively.