Segments - Holdings - Selected Financial Information by Geographic Area (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 921.8	$ 874.8	$ 2,235.2	$ 2,427.8
Reportable Geographical Components
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	921.8	874.8	2,235.2	2,427.8
Theatre properties and equipment, net	1,121.2		1,121.2		$ 1,161.7
Reportable Geographical Components | U.S.
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	744.8	686.2	1,779.0	1,907.2
Theatre properties and equipment, net	973.3		973.3		1,002.1
Reportable Geographical Components | Brazil
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	70.9	70.3	183.8	183.5
Theatre properties and equipment, net	47.6		47.6		54.7
Reportable Geographical Components | Other international countries
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	109.5	122.0	281.0	347.8
Theatre properties and equipment, net	100.3		100.3		$ 104.9
Reportable Geographical Components | Eliminations
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ (3.4)	$ (3.7)	$ (8.6)	$ (10.7)