Impairment of Long-Lived Assets - Summary of Long-Lived Asset Impairment Losses (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Impaired Long-Lived Assets Held and Used [Line Items]
Total Impairment	$ 0.0	$ 9.4	$ 0.0	$ 10.1
Us Operating Segment [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Theatre properties		3.9		3.9
Theatre operating lease right-of-use assets		3.4		3.4
Investment in NCMI/NCM		0.0		0.7
Total Impairment		7.3		8.0
International Operating Segment [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Theatre properties		0.6		0.6
Theatre operating lease right-of-use assets		1.5		1.5
Total Impairment		$ 2.1		$ 2.1