Benefit Plans - Amounts Recorded in Consolidated Balance Sheets (Detail) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Non-current liabilities	$ (70.8)	$ (93.2)
Accumulated benefit obligation	88.7	112.7
Pension plans
Defined Benefit Plan Disclosure [Line Items]
Current liabilities	(5.9)	(5.7)
Non-current liabilities	(56.2)	(76.0)
Benefit obligations in excess of the fair value of plan assets	(62.1)	(81.7)
Other post-retirement plans
Defined Benefit Plan Disclosure [Line Items]
Current liabilities	(1.3)	(1.3)
Non-current liabilities	(7.7)	(10.0)
Benefit obligations in excess of the fair value of plan assets	$ (9.0)	$ (11.3)