Intangible Assets

3 Months Ended

Mar. 31, 2022

Goodwill and Intangible Assets Disclosure [Abstract]

Our identifiable intangible assets primarily consist of acquired permits and leasehold agreements, and franchise agreements, which grant us the right to operate out-of-home structures in specified locations and the right to provide advertising space on railroad and municipal transit properties. Identifiable intangible assets are amortized on a straight-line basis over their estimated useful life, which is the respective life of the agreement that in some cases includes historical experience of renewals.

Our identifiable intangible assets consist of the following:


(in millions)	Gross		Accumulated Amortization		Net
As of March 31, 2022:
Permits and leasehold agreements	$	1,311.8	$	(828.3)	$	483.5
Franchise agreements	529.3		(405.4)		123.9
Other intangible assets	4.9		(2.8)		2.1
Total intangible assets	$	1,846.0	$	(1,236.5)	$	609.5

As of December 31, 2021:
Permits and leasehold agreements	$	1,303.6	$	(816.5)	$	487.1
Franchise agreements	528.2		(402.7)		125.5
Other intangible assets	4.9		(2.6)		2.3
Total intangible assets	$	1,836.7	$	(1,221.8)	$	614.9

In the three months ended March 31, 2022, we acquired 15 displays, resulting in amortizable intangible assets for permits and leasehold agreements of $6.1 million, which are amortized using the straight-line method over their estimated useful lives, an average period of 13.4 years.

All of our intangible assets, except goodwill, are subject to amortization. Amortization expense was $14.8 million in the three months ended March 31, 2022, and $16.4 million in the three months ended March 31, 2021.