Retirement Plans - Components of Estimated Net Periodic Benefit (Income)/Cost (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 6.2	$ 8.8	$ 10.9
Expected return on assets	14.2	(13.9)	(14.8)
Amortization, net	(3.8)	3.1	1.8
Settlements	0.0	0.0	3.9
Net pension (income) expense	$ (4.2)	$ (2.0)	$ 1.8
Weighted-average assumption used to calculate net pension (income) cost:
Discount rate	2.60%	3.20%	3.30%
Expected return on plan assets	6.00%	6.00%	6.30%
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 6.2	$ 8.7