Benefit Plans - Components of Net Periodic Benefit Cost (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Retirement Benefits [Abstract]
Service cost	$ 1.7	$ 2.4	$ 2.8
Interest cost	4.1	2.5	2.0
Expected return on plan assets	(0.8)	(0.7)	(0.5)
Net actuarial loss (gain)	7.1	(16.4)	(1.5)
Net periodic benefit expense (income)	$ 12.1	$ (12.2)	$ 2.8
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Interest Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)