Pension and Post-Employment Benefits - Reconciliation of Fair Value of Plan Assets Measured Using Significant Unobservable Inputs (Detail) - United Kingdom Plan [Member] - Significant Unobservable Inputs (Level 3) [Member] - Other Assets [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 431.8	$ 162.2
Realized/unrealized gains/(losses):
Relating to assets still held at the reporting date	16.9	(206.6)
Purchases, issuances and settlements	(33.7)	502.8
Exchange effect	23.7	(26.6)
Ending balance	$ 438.7	$ 431.8