Schedule of Supplemental Information to Condensed Consolidated Statements of Cash Flows (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2025	Mar. 31, 2024
Schedule Of Cash Flow Supplemental [Line Items]
Cash paid for interest by Holdings	[1]	$ 60.9	$ 56.1
Cash paid for interest by CUSA		50.6	45.7
Cash paid for income taxes, net		3.0	2.9
Noncash investing and financing activities:
Interest expense - NCM (see Note 8)		(5.4)	(5.5)
Change in accounts payable and accrued expenses for the acquisition of theatre properties and equipment	[2]	2.0	1.4
Theatre and other assets acquired under finance leases		0.0	27.2
Dividends accrued on unvested performance and restricted stock unit awards		$ 0.2	$ 0.0

[1] Includes the cash interest paid by CUSA.

[2] Additions to theater properties and equipment included in accounts payable as of March 31, 2025 and December 31, 2024 were $8.9 and $6.9, respectively.