5. Leases

As the lessee, we currently lease real estate space under noncancelable operating lease agreements for our turn-key data centers at NY1, LA1, LA4, DC1, DC2, DE1, and DE2, and our corporate headquarters located in Denver, Colorado. Our leases have remaining lease terms of one year to 11 years, some of which include options to extend the leases for up to an additional 20 years. We do not include any of our renewal options in our lease terms for calculating our lease liability as the renewal options allow us to maintain operational flexibility and we are not reasonably certain we will exercise these renewal options at this time. The weighted-average remaining non-cancelable lease term for our operating leases was ten years and five years at September 30, 2018, and December 31, 2017, respectively. The weighted-average discount rate was 4.9% and 4.8% at September 30, 2018, and December 31, 2017.

During the nine months ended September 30, 2018, we extended the term of approximately 170,000 NRSF of our existing LA1 space from July 2022 to July 2029 and expanded our LA1 facility by leasing an additional 17,238 square feet, which we plan to develop into turn-key data center space. As a result of this lease modification, we remeasured the lease liability and adjusted the ROU asset by $109.6 million and $109.1 million, respectively. In addition, we assumed a $5.3 million lease liability and ROU asset associated with the acquisition of U.S. Colo in April 2018.

The components of lease expense were as follows (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2018		2017		2018		2017
Lease expense:
Operating lease expense	$	6,144	$	5,078	$	16,789	$	15,256
Variable lease expense		1,185		999		3,487		2,714
Rent expense	$	7,329	$	6,077	$	20,276	$	17,970

The future minimum lease payments to be paid under noncancelable leases in effect at September 30, 2018, are as follows (in thousands):


	Operating
Period / Year Ending December 31,	Leases
2018	$	4,221
2019		25,725
2020		26,662
2021		26,392
2022		25,995
Thereafter		153,753
Total lease payments	$	262,748
Less imputed interest		(58,324)
Total	$	204,424