Segments - Holdings - Reconciliation of Net Income (Loss) to Adjusted EBITDA (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2025	Mar. 31, 2024
Add (deduct):
Interest expense	[1]	$ 38.5	$ 37.7
Other income, net	[2]	(4.4)	(17.7)
Depreciation and amortization		49.5	49.4
(Gain) loss on disposal of assets and other		(4.1)	0.4
Non-cash rent expense		(2.8)	(4.4)
Share-based awards compensation expense		8.2	6.4
Adjusted EBITDA		36.4	70.7
CNK
Segment Reporting Information [Line Items]
Net (loss) income		(38.6)	25.3
Add (deduct):
Income tax (benefit) expense		(14.7)	(27.7)
Interest expense		38.5	37.7
Cash distributions from equity investees		4.8	1.3
Depreciation and amortization		49.5	49.4
Non-cash rent expense		(2.8)	(4.4)
Share-based awards compensation expense		(8.2)	(6.4)
Other Cash Distributions From Equity Investees [Member]
Add (deduct):
Cash distributions from equity investees	[3]	$ 4.8	$ 1.3

[1] Includes amortization of debt issuance costs, amortization of original issue discount, and amortization of accumulated (losses) gains for amended swap agreements.

[2] Includes interest income, foreign currency exchange gain, interest expense - NCM, equity in income of affiliates and net (loss) gain on investment in NCMI.

[3] Reflects cash distributions received from equity investees that were recorded as a reduction of the respective investment balances. These distributions are reported entirely within the U.S. reportable segment. Holdings Capital Expenditures by Reportable Segment The following table is a breakdown of capital expenditures by reportable segment for Holdings:     Three Months Ended       March 31,       2025     2024   Capital expenditures             U.S.   $ 16.9     $ 18.1   International     5.2       5.4   Total capital expenditures   $ 22.1     $ 23.5