Restructuring - Summary of Liabilities Recognized Related to Restructuring Plan (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Dec. 31, 2023	Dec. 31, 2021	Dec. 31, 2019
2023 Restructuring Plan [Member]
Restructuring Cost And Reserve [Line Items]
Beginning Balance	$ 14.2
Expenses	79.6
Cash payments	(24.8)
Foreign currency exchange rate changes	(0.4)
Non-cash activity	1.2
Ending Balance	69.8
Expense incurred since the start of the Restructuring Plan	92.4
Expense estimated to be recognized for the Restructuring Plan	120.0	$ 120.0
2023 Restructuring Plan [Member] | Employee Termination Benefits [Member]
Restructuring Cost And Reserve [Line Items]
Beginning Balance	9.2
Expenses	71.0
Cash payments	(23.5)
Foreign currency exchange rate changes	(0.4)
Ending Balance	56.3
Expense incurred since the start of the Restructuring Plan	80.2
Expense estimated to be recognized for the Restructuring Plan	90.0
2023 Restructuring Plan [Member] | Contract Termination [Member]
Restructuring Cost And Reserve [Line Items]
Expenses	1.8
Ending Balance	1.8
Expense incurred since the start of the Restructuring Plan	1.8
Expense estimated to be recognized for the Restructuring Plan	10.0
2023 Restructuring Plan [Member] | Other Restructuring [Member]
Restructuring Cost And Reserve [Line Items]
Beginning Balance	5.0
Expenses	6.8
Cash payments	(1.3)
Non-cash activity	1.2
Ending Balance	11.7
Expense incurred since the start of the Restructuring Plan	10.4
Expense estimated to be recognized for the Restructuring Plan	20.0
2021 Restructuring Plan [Member]
Restructuring Cost And Reserve [Line Items]
Beginning Balance	24.7
Expenses	0.9
Cash payments	(9.6)
Foreign currency exchange rate changes	(0.5)
Ending Balance	15.5
Expense incurred since the start of the Restructuring Plan	170.0
Expense estimated to be recognized for the Restructuring Plan	180.0		$ 180.0
2021 Restructuring Plan [Member] | Employee Termination Benefits [Member]
Restructuring Cost And Reserve [Line Items]
Beginning Balance	4.2
Expenses	(0.4)
Cash payments	(0.8)
Foreign currency exchange rate changes	(0.1)
Ending Balance	2.9
Expense incurred since the start of the Restructuring Plan	58.7
Expense estimated to be recognized for the Restructuring Plan	60.0
2021 Restructuring Plan [Member] | Contract Termination [Member]
Restructuring Cost And Reserve [Line Items]
Beginning Balance	17.6
Cash payments	(7.3)
Foreign currency exchange rate changes	(0.4)
Ending Balance	9.9
Expense incurred since the start of the Restructuring Plan	73.8
Expense estimated to be recognized for the Restructuring Plan	80.0
2021 Restructuring Plan [Member] | Other Restructuring [Member]
Restructuring Cost And Reserve [Line Items]
Beginning Balance	2.9
Expenses	1.3
Cash payments	(1.5)
Ending Balance	2.7
Expense incurred since the start of the Restructuring Plan	37.5
Expense estimated to be recognized for the Restructuring Plan	40.0
2019 Restructuring Plan [Member]
Restructuring Cost And Reserve [Line Items]
Beginning Balance	52.3
Expenses	17.0
Cash payments	(4.0)
Foreign currency exchange rate changes	(0.5)
Ending Balance	64.8
Expense incurred since the start of the Restructuring Plan	336.4
Expense estimated to be recognized for the Restructuring Plan	370.0			$ 370.0
2019 Restructuring Plan [Member] | Employee Termination Benefits [Member]
Restructuring Cost And Reserve [Line Items]
Beginning Balance	43.8
Expenses	14.7
Foreign currency exchange rate changes	(0.5)
Ending Balance	58.0
Expense incurred since the start of the Restructuring Plan	140.4
Expense estimated to be recognized for the Restructuring Plan	155.0
2019 Restructuring Plan [Member] | Contract Termination [Member]
Restructuring Cost And Reserve [Line Items]
Beginning Balance	5.6
Cash payments	(0.5)
Ending Balance	5.1
Expense incurred since the start of the Restructuring Plan	35.0
Expense estimated to be recognized for the Restructuring Plan	35.0
2019 Restructuring Plan [Member] | Other Restructuring [Member]
Restructuring Cost And Reserve [Line Items]
Beginning Balance	2.9
Expenses	2.3
Cash payments	(3.5)
Ending Balance	1.7
Expense incurred since the start of the Restructuring Plan	161.0
Expense estimated to be recognized for the Restructuring Plan	$ 180.0