Concentration of Credit Risk (Tables)

12 Months Ended

Dec. 31, 2020

Concentration of Credit Risk [Abstract]

Summary of Significant Customers and Percentage of Total Revenue for Specified Time Periods Derived from such Customers

The following is a list of significant customers (representing at least 10% of revenue for any period reported) and the percentage of total revenue for the specified time periods derived from such customers:



	For the year ended December 31,
Percentage of Total Revenues	2020	2019	2018

T-Mobile ⁽¹⁾	34.5%	35.1%	34.3%
AT&T Wireless	24.1%	23.8%	24.0%
Verizon Wireless	14.1%	14.0%	14.7%

(1)Prior year amounts have been adjusted to reflect the merger of T-Mobile and Sprint.

The Company’s site leasing and site development segments derive revenue from these customers. Client percentages of total revenue in each of the segments are as follows:



	For the year ended December 31,
Percentage of Domestic Site Leasing Revenue	2020	2019	2018

T-Mobile ⁽¹⁾	40.5%	40.6%	39.9%
AT&T Wireless	32.2%	32.1%	31.9%
Verizon Wireless	18.5%	18.6%	19.0%

	For the year ended December 31,
Percentage of International Site Leasing Revenue	2020	2019	2018

Oi S.A.	28.7%	31.3%	35.5%
Telefonica	18.1%	26.9%	26.7%
Claro	14.5%	11.6%	11.4%

(1)Prior year amounts have been adjusted to reflect the merger of T-Mobile and Sprint.



	For the year ended December 31,
Percentage of Site Development Revenue	2020	2019	2018

T-Mobile ⁽¹⁾	66.8%	67.5%	63.5%

(1)Prior year amounts have been adjusted to reflect the merger of T-Mobile and Sprint.