Intangible Assets

12 Months Ended

Dec. 31, 2023

INTANGIBLE ASSETS

The following table sets forth the gross amount and related accumulated amortization of the Company’s intangible assets at December 31:


	2023						2022
In millions	Gross carrying amount		Accumulated amortization		Net carrying amount		Gross carrying amount		Accumulated amortization		Net carrying amount
Customer relationships	$	2,384.4	$	(1,731.4)	$	653.0	$	2,183.7	$	(1,592.1)	$	591.6
Other	419.6		(243.1)		176.5		261.7		(213.4)		48.3
Total finite-lived intangible assets	$	2,804.0	$	(1,974.5)	$	829.5	$	2,445.4	$	(1,805.5)	$	639.9
Trademarks (indefinite-lived)	2,610.3		—		2,610.3		2,624.1		—		2,624.1
Total	$	5,414.3	$	(1,974.5)	$	3,439.8	$	5,069.5	$	(1,805.5)	$	3,264.0

Intangible asset amortization expense for 2023, 2022 and 2021 was $165.2 million, $142.7 million and $123.6 million, respectively.

Future estimated amortization expense on existing intangible assets in the next five years as of December 31, 2023 amounts to approximately: