Reconciliation of Net Income (Loss) to Adjusted EBITDA (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2023	Mar. 31, 2022
Segment Reporting Information [Line Items]
Net income (loss)		$ (2.5)	$ (72.5)
Add (deduct):
Income tax benefit		(3.9)	(1.8)
Interest expense	[1]	36.8	38.1
Other (income) expense, net	[2]	(1.9)	3.2
Depreciation and amortization		54.9	61.7
Impairment of other assets		0.7	0.0
(Gain) loss on disposal of assets and other		0.3	(6.9)
Non-cash rent expense		(3.9)	(2.3)
Share based awards compensation expense		5.7	5.1
Adjusted EBITDA		86.2	25.2
Other Cash Distributions From Equity Investees [Member]
Add (deduct):
Cash distributions from equity investees	[3]	$ 0.0	$ 0.6

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

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

[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. operating segment.