Derivatives and Financial Instruments - Recorded Amounts and Estimated Fair Values (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024
Derivative [Line Items]
Total debt	$ 1,398.1		$ 1,398.1		$ 1,638.7
Impairment of intangible assets	30.9	$ 0.0	30.9	$ 0.0
Recorded Amount
Derivative [Line Items]
Variable rate debt	594.5		594.5		843.8
Fixed rate debt	819.3		819.3		819.3
Total debt	1,413.8		1,413.8		1,663.1
Fair Value
Derivative [Line Items]
Variable rate debt	594.5		594.5		843.8
Fixed rate debt	834.7		834.7		814.3
Total debt	$ 1,429.2		$ 1,429.2		$ 1,658.1