Schedule of Components of Lease Expense (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Finance lease cost
Amortization of right-of-use assets and interest	$ 1.1	$ 0.9	$ 0.6
Operating lease cost	17.5	15.5	16.3
Short-term lease cost	3.7	2.4	3.0
Variable lease cost	2.4	1.2	1.5
Total lease cost	$ 24.7	$ 20.0	$ 21.4