Debt - Component of Debt (Detail) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Unamortized original issue discount and debt issuance costs	$ (30.9)	$ (35.1)
Debt	6,644.3	6,720.0
Less: current portion of long-term debt	50.8	51.5
Long-term debt	6,593.5	6,668.5
Secured Debt | Senior Secured Credit Facilities
Debt Instrument [Line Items]
Debt Instrument Carrying Amount	4,675.2	4,755.1
Senior Notes
Debt Instrument [Line Items]
Debt Instrument Carrying Amount	2,000.0
Senior Notes | 5.5% Senior Notes due 2027
Debt Instrument [Line Items]
Debt Instrument Carrying Amount	$ 2,000.0	$ 2,000.0