Commitment and Contingencies - Narrative (Details)			3 Months Ended		7 Months Ended	9 Months Ended		60 Months Ended	80 Months Ended
	Jul. 29, 2021 Displays	Jul. 28, 2021	Sep. 30, 2025 USD ($) Displays	Sep. 30, 2024 USD ($)	Dec. 31, 2020 USD ($)	Sep. 30, 2025 USD ($) Displays	Sep. 30, 2024 USD ($)	Dec. 31, 2026	Apr. 01, 2028 USD ($)	Dec. 31, 2024 USD ($)
Other Commitments [Line Items]
Equipment Deployment Costs Percentage					30.00%
Recoupment						$ 0
Intangible assets related to franchise agreements balance			$ 2,459,000,000			2,459,000,000				$ 2,444,200,000
Impairment charges			0	$ 0		0	$ 17,900,000
Franchise agreements
Other Commitments [Line Items]
Intangible assets related to franchise agreements balance			904,200,000			904,200,000				$ 888,800,000
Standalone letters of credit and sublimit to revolving credit facility
Other Commitments [Line Items]
Letters of credit outstanding, amount			72,300,000			72,300,000
Surety Bond
Other Commitments [Line Items]
Surety bonds outstanding			109,600,000			109,600,000
MTA Agreement
Other Commitments [Line Items]
Contract term	13 years	10 years
Contract term extension option	5 years
MTA Agreement | Subsequent event
Other Commitments [Line Items]
Revenue share percentage								65.00%
Additional equipment deployment cost percentage									2.50%
Metropolitan Transportation Authority ("MTA")
Other Commitments [Line Items]
Impairment charges							$ 17,900,000
MTA equipment deployment costs
Other Commitments [Line Items]
Recoupment						0
MTA equipment deployment costs | Franchise agreements
Other Commitments [Line Items]
Intangible asset related to franchise agreements additions						15,300,000
Intangible assets related to franchise agreements balance			$ 23,500,000			$ 23,500,000
Metropolitan Transportation Authority ("MTA")
Other Commitments [Line Items]
Equipment Deployment Costs Percentage					70.00%
Maximum | MTA Agreement | Subsequent event
Other Commitments [Line Items]
Decrease in revenue percentage									5.00%
Maximum | Metropolitan Transportation Authority ("MTA")
Other Commitments [Line Items]
MTA equipment deployment costs					$ 50,700,000
Minimum | Subsequent event
Other Commitments [Line Items]
Recoupment									$ 0
MTA digital advertising screens on subway and train platforms
Other Commitments [Line Items]
Number of displays | Displays	5,433		5,016			5,016
MTA smaller-format digital advertising screens rolling stock
Other Commitments [Line Items]
Number of displays | Displays	15,896		15,904			15,904
MTA communication displays
Other Commitments [Line Items]
Number of displays | Displays	9,283		6,421			6,421
MTA displays installed
Other Commitments [Line Items]
Number of displays | Displays			27,341			27,341
Number of display additions | Displays			90			1,096