19. Operating Leases

We lease office space and equipment under non-cancelable operating leases that expire on various dates through 2022. Future minimum payments under non-cancelable operating leases with initial terms of one year or more consisted of the following at December 31, 2014:

2015	$	6,370
2016		6,091
2017		5,222
2018		1,772
2019		1,719
Beyond		1,434
Total operating lease obligations	$	22,608

Our leases include offices in Annapolis, Maryland under a lease expiring in July 2019, office space in Hanover, Maryland expiring August 2017, a facility in Seattle, Washington under a lease expiring in October 2017, and we lease a production facility in Tampa, Florida under a lease expiring in December 2022.

We also lease office space in Aliso Viejo, California under a lease expiring in December 2017, a facility near Atlanta, Georgia under a lease expiring August 2020, a facility in Richardson, Texas under a lease expiring April 2015, a facility in North Wollongong, Australia under a lease expiring April 2017 and office space in Torrance, California expiring January 2018. As a result of the 2012 acquisition of microDATA, we lease office space in Danville, Vermont expiring June 2017 and office space in Greenwood Village, Colorado expiring May 2020. Future payments on all of our leases are estimated including the minimum future rent escalations, if any, stipulated in the respective agreements.

Rent expense was $6,556, $7,634 and $7,490 for 2014, 2013, and 2012, respectively.