Land, Buildings, Equipment and Software, Net

Land, buildings and equipment, net were as follows:



	Estimated Useful Lives	December 31,
(in millions except as noted)	(Years)	2018			2017
Land		$	2		$	3
Building and building equipment	25 to 50	7			17
Leasehold improvements	Varies	246			247
Office furniture and equipment	3 to 15	901			784
Other	4 to 20	2			1
Construction in progress		64			24
Subtotal		1,222			1,076
Accumulated depreciation		(894		)	(819		)
Land, Buildings and Equipment, Net		$	328		$	257

Depreciation expense and operating lease rent expense were as follows:



	Year Ended December 31,
(in millions)	2018		2017		2016
Depreciation expense	$	121	$	125	$	130
Operating lease rent expense	$	208	$	267	$	299

We lease buildings and equipment, substantially all of which are accounted for as operating leases. Certain leases were accounted for as capital leases and the remaining net book value of those assets, included in Land, Buildings and Equipment, net were approximately $24 million and $32 million at December 31, 2018 and 2017, respectively.

Future minimum operating lease commitments that have initial or remaining non-cancelable lease terms in excess of one year at December 31, 2018 were as follows (in millions):



2019		2020		2021		2022		2023		Thereafter
$	153	$	113	$	78	$	53	$	33	$	76

Internal Use and Product Software

Internal use and product software are included in Other long-term assets on the Company's Consolidated Balance Sheets. Additions to Internal Use and Product Software as well as year-end balances for these assets were as follows:



(in millions)	Year Ended December 31,
Additions to:	2018		2017		2016
Internal use software	$	47	$	36	$	39
Product software	8		10		10



(in millions)	December 31,
Capitalized Costs, Net	2018		2017
Internal use software⁽¹⁾	$	123	$	106
Product software⁽¹⁾	18		22

__________


(1)	See Note 8 – Supplementary Financial Information for additional information.

Useful lives of our internal use and product software generally vary from one to seven years.

During 2016 we determined that it was probable that we would not fully complete our NY MMIS project in its current form. As a result of this decision an impairment charge of approximately $28 million was recorded in Cost of services. We also recorded an additional impairment charge in 2016 related to the 2015 HE charge of approximately $9 million in Restructuring and asset impairment.