XML 33 R12.htm IDEA: XBRL DOCUMENT v3.24.0.1
Intangible Assets, Goodwill and Other
 12 Months Ended
Dec. 31, 2023
Goodwill and Intangible Assets Disclosure [Abstract]  
Goodwill and Intangible Assets Goodwill and Intangible Assets
Goodwill
The carrying value of goodwill was $10.1 billion for each of the years ended December 31, 2023 and 2022. For the year ended December 31, 2022, additions due to acquisitions were $7 million. There were no additions during the year ended December 31, 2023.
Intangible Assets
The following is a summary of the Company's intangible assets.

As of December 31, 2023
As of December 31, 2022
Gross Carrying ValueAccumulated AmortizationNet Book ValueGross Carrying ValueAccumulated AmortizationNet Book Value
Site rental contracts and tenant relationships
$7,880 $(4,758)$3,122 $7,850 $(4,315)$3,535 
Other intangible assets113 (56)57 143 (82)61 
Total$7,993 $(4,814)$3,179 $7,993 $(4,397)$3,596 
Amortization expense related to intangible assets is classified as "Depreciation, amortization and accretion" on the Company's consolidated statement of operations and comprehensive income (loss) and was $447 million, $446 million, and $444 million for the years ended December 31, 2023, 2022 and 2021, respectively.
The estimated annual amortization expense related to intangible assets for the years ending December 31, 2024 to 2028 is as follows:
 Years Ending December 31,
20242025202620272028
Estimated annual amortization$398 $376 $372 $288 $284