COMMITMENTS AND CONTINGENCIES

Contractual Obligations

We had no significant commitments and contractual obligations as of December 31, 2017.

Other Commitments

We have various LOCs outstanding with multiple state agencies which are considered to be immaterial to the consolidated financial statements. The LOCs typically have one to three-year contract requirements and contain automatic renewal terms.

Legal Contingencies

We are involved, from time to time, in lawsuits arising in the normal course of business. We believe these pending lawsuits will not have a material adverse impact on our financial position or statement of operations.

On February 1, 2018, we learned of a complaint filed naming us and our subsidiary, Spok, Inc., as defendants in GroupChatter, LLC v. Spok Holdings, Inc., et. al., Civ. A. No. 6:18-cv-00048, U.S. District Court for the Eastern District of Texas, alleging infringement of U.S. Patent Nos. 7,969,959; 9,699,637; 9,615,239; and 9,294,888. We are evaluating the allegations asserted in this complaint and intend to defend against the claims vigorously. At this time we are unable to predict the outcome of this litigation, though we do not believe it will have a material adverse effect on our financial condition.

Operating Leases

We have operating leases for office and transmitter locations. Substantially all of these leases have lease terms ranging from one month to five years. We continue to review our office and transmitter locations, and intend to replace, reduce or consolidate leases, where possible.

Future minimum lease payments under non-cancelable operating leases at December 31, 2017 were as follows:



For the Year Ended December 31,	(Dollars in thousands)
2018	$	6,126
2019	3,873
2020	2,924
2021	2,538
2022	1,065
Thereafter	885
Total	$	17,411

These leases typically include renewal options and escalation clauses. Where material, we recognize rent expense on a straight-line basis over the lease period. The difference between rent paid and rent expense is recorded as accrued other and other long-term liabilities on the consolidated balance sheets.

Total rent expense under operating leases for the years ended December 31, 2017, 2016 and 2015, was approximately $17.7 million, $17.9 million and $18.5 million, respectively.