Investments in National CineMedia Inc. and Other Affiliates - Summary of Activity for Each of Company's Investments in affiliates (Detail) - Other Affiliates [Member] $ in Millions	6 Months Ended
	Jun. 30, 2025 USD ($)
Schedule Of Equity Method Investments [Line Items]
Investments, beginning balance	$ 26.2
Equity income	3.5
Cash distributions received	(6.7)
Investments, ending balance	23.0
AC JV, LLC
Schedule Of Equity Method Investments [Line Items]
Investments, beginning balance	4.1
Equity income	2.6
Cash distributions received	(2.7)
Investments, ending balance	4.0
Digital Cinema Distribution Coalition
Schedule Of Equity Method Investments [Line Items]
Investments, beginning balance	2.6
Equity income	0.3
Cash distributions received	0.0
Investments, ending balance	2.9
FE Concepts, LLC
Schedule Of Equity Method Investments [Line Items]
Investments, beginning balance	19.5
Equity income	0.6
Cash distributions received	(4.0)
Investments, ending balance	$ 16.1