Impairment of Long-Lived Assets - Summary of Long-Lived Asset Impairment Losses (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Impaired Long-Lived Assets Held and Used [Line Items]
Total Impairment	$ 0.0	$ 2.0	$ 0.0	$ 12.1
Us Operating Segment [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Theatre properties		1.0		4.9
Theatre operating lease right-of-use assets		1.0		4.4
Investment in NCMI/NCM		0.0		0.7
Total Impairment		2.0		10.0
International Operating Segment [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Theatre properties		0.0		0.6
Theatre operating lease right-of-use assets		0.0		1.5
Total Impairment		$ 0.0		$ 2.1