Schedule of Components of Lease Expense (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Finance lease cost
Amortization of right-of-use assets	$ 0.9	$ 0.6	$ 0.9
Interest on lease liabilities	0.0	0.0	0.1
Operating lease cost	15.5	16.3	16.6
Short-term lease cost	2.4	3.0	0.8
Variable lease cost	1.2	1.5	1.7
Total lease cost	$ 20.0	$ 21.4	$ 20.1