Income Taxes - Changes In Unrecognized Tax Benefits (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Unrecognized tax benefits—beginning balance	$ 3.2	$ 7.9	$ 7.2
Gross increases—prior period tax positions	8.4		0.0
Gross decreases—prior period tax positions		(0.2)
Gross increases—current period tax positions	5.2	0.8	0.7
Settlements with taxing authorities	(4.4)	(5.3)	0.0
Unrecognized tax benefits—ending balance	$ 12.4	$ 3.2	$ 7.9