Pension and Post-Employment Benefits - Unfunded Defined Benefit Pension Plan (Detail) - German Plan [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Plan net pension charge:
Service cost	$ 0.1	$ 0.1	$ 0.1
Defined Benefit Plan, Interest Cost	0.3	0.1	0.1
Amortization of actuarial net loss	(0.5)	0.5	1.0
Net periodic cost/(benefit)	$ (0.1)	$ 0.7	$ 1.2
Plan assumptions at December 31, (%):
Discount rate	3.70%	3.70%	0.90%
Inflation rate	2.25%	2.25%	2.00%
Rate of increase in compensation levels	2.75%	2.75%	2.75%