Leases (Tables)

12 Months Ended

Dec. 31, 2018

See note 4 for further information regarding the contractual amounts (including tenant leases) owed to the Company pursuant to agreements in effect as of December 31, 2018.

Operating Leases

The following table is a summary of rental cash payments owed by the Company, as lessee, to landlords pursuant to contractual agreements in effect as of December 31, 2018. The Company is obligated under non-cancelable operating leases for land interests under 74% of its towers. The majority of these lease agreements have (1) certain termination rights that provide for cancellation after a notice period, (2) multiple renewal options at the Company's option, and (3) annual escalations. Lease agreements may also contain provisions for a contingent payment based on revenues or the gross margin derived from the communications infrastructure located on the leased land interest. Approximately 90% of our Towers site rental gross margin and more than 75% of our Towers site rental gross margin is derived from towers that reside on land that we own or control for greater than 10 and 20 years, respectively. The operating lease payments included in the table below include payments for certain renewal periods at the Company's option that are reasonably assured to be exercised and an estimate of contingent payments based on revenues and gross margins derived from existing tenant leases.



	Years Ending December 31,
	2019		2020		2021		2022		2023		Thereafter		Total
Operating leases	$	640	$	631	$	628	$	623	$	619	$	8,054	$	11,195