Segment Information - Revenue and Long-Lived Assets By Geography (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024		Dec. 31, 2024
Segment Reporting Information [Line Items]
Revenues		$ 467.5	$ 451.9	$ 1,318.4	$ 1,337.7
United States
Segment Reporting Information [Line Items]
Revenues	[1]	467.5	451.9	1,318.4	1,302.8
Long-Lived Assets	[2]	4,796.5		4,796.5			$ 4,820.7
Canada
Segment Reporting Information [Line Items]
Revenues		$ 0.0	$ 0.0	$ 0.0	$ 34.9	[1]

[1] Revenues classifications are based on the geography of the advertising.

[2] Reflects total assets less current assets, investments and non-current deferred tax assets.