Summary Financial Information for National CineMedia (Detail) - USD ($) $ in Millions		3 Months Ended		12 Months Ended
		Mar. 31, 2023	Mar. 31, 2022	Dec. 29, 2022
Schedule Of Equity Method Investments [Line Items]
Net loss		$ 3.1	$ 74.0
N C M I [Member]
Schedule Of Equity Method Investments [Line Items]
Gross revenue			35.9	$ 249.2	[1]
Operating income (loss)			(22.5)	6.9	[1]
Net loss			(46.0)	(66.2)	[1]
Net loss attributable to NCMI			$ (25.2)	(28.7)	[1]
Current assets	[2]			164.4
Noncurrent assets	[2]			628.0
Current liabilities	[2]			1,203.1
Noncurrent liabilities	[2]			53.3
Noncontrolling interests	[2]			51.3
Members deficit	[2]			$ (464.0)

[1] Financial information for NCMI for the quarter ended ended March 31, 2023 was not available at time of this filing.

[2] Financial information for NCMI as of March 31, 2023 was not available at time of this filing.