Restructuring - Summary of Liabilities Recognized Related to Restructuring Plan (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2025	Sep. 30, 2025	Feb. 28, 2025	Dec. 31, 2023	Dec. 31, 2019
2025 Restructuring Plan [Member]
Restructuring Cost And Reserve [Line Items]
Expenses	$ 13.5	$ 43.3
Cash payments		(26.5)
Foreign currency exchange rate changes		0.1
Ending Balance	16.9	16.9
Expense incurred since the start of the Restructuring Plan	43.3	43.3
Expense estimated to be recognized for the Restructuring Plan	85.0	85.0	$ 85.0
2025 Restructuring Plan [Member] | Employee Termination Benefits [Member]
Restructuring Cost And Reserve [Line Items]
Expenses	6.3	33.2
Cash payments		(24.4)
Foreign currency exchange rate changes		0.1
Ending Balance	8.9	8.9
Expense incurred since the start of the Restructuring Plan	33.2	33.2
Expense estimated to be recognized for the Restructuring Plan	67.0	67.0
2025 Restructuring Plan [Member] | Contract Termination [Member]
Restructuring Cost And Reserve [Line Items]
Expenses	7.6	7.6
Cash payments		(0.8)
Ending Balance	6.8	6.8
Expense incurred since the start of the Restructuring Plan	7.6	7.6
Expense estimated to be recognized for the Restructuring Plan	10.0	10.0
2025 Restructuring Plan [Member] | Other Restructuring [Member]
Restructuring Cost And Reserve [Line Items]
Expenses	(0.4)	2.5
Cash payments		(1.3)
Ending Balance	1.2	1.2
Expense incurred since the start of the Restructuring Plan	2.5	2.5
Expense estimated to be recognized for the Restructuring Plan	8.0	8.0
2023 Restructuring Plan [Member]
Restructuring Cost And Reserve [Line Items]
Beginning Balance		27.1
Expenses	(0.6)	3.0
Cash payments		(22.2)
Foreign currency exchange rate changes		1.7
Ending Balance	9.6	9.6
Expense incurred since the start of the Restructuring Plan	116.5	116.5
Expense estimated to be recognized for the Restructuring Plan				$ 117.0
2023 Restructuring Plan [Member] | Employee Termination Benefits [Member]
Restructuring Cost And Reserve [Line Items]
Beginning Balance		18.8
Expenses	(0.7)	(1.4)
Cash payments		(12.8)
Foreign currency exchange rate changes		1.3
Ending Balance	5.9	5.9
Expense incurred since the start of the Restructuring Plan	92.4	92.4
2023 Restructuring Plan [Member] | Contract Termination [Member]
Restructuring Cost And Reserve [Line Items]
Beginning Balance		1.4
Expenses	0.1	2.9
Cash payments		(3.2)
Ending Balance	1.1	1.1
Expense incurred since the start of the Restructuring Plan	6.0	6.0
2023 Restructuring Plan [Member] | Other Restructuring [Member]
Restructuring Cost And Reserve [Line Items]
Beginning Balance		6.9
Expenses		1.5
Cash payments		(6.2)
Foreign currency exchange rate changes		0.4
Ending Balance	2.6	2.6
Expense incurred since the start of the Restructuring Plan	18.1	18.1
2019 Restructuring Plan [Member]
Restructuring Cost And Reserve [Line Items]
Beginning Balance		43.1
Expenses	2.9	20.0
Cash payments		(57.4)
Foreign currency exchange rate changes		3.3
Ending Balance	9.0	9.0
Expense incurred since the start of the Restructuring Plan	387.5	387.5
Expense estimated to be recognized for the Restructuring Plan	400.0	400.0			$ 400.0
2019 Restructuring Plan [Member] | Employee Termination Benefits [Member]
Restructuring Cost And Reserve [Line Items]
Beginning Balance		38.0
Expenses	0.3	7.4
Cash payments		(43.0)
Foreign currency exchange rate changes		3.3
Ending Balance	5.7	5.7
Expense incurred since the start of the Restructuring Plan	159.5	159.5
Expense estimated to be recognized for the Restructuring Plan	160.0	160.0
2019 Restructuring Plan [Member] | Contract Termination [Member]
Restructuring Cost And Reserve [Line Items]
Beginning Balance		3.8
Cash payments		(1.6)
Ending Balance	2.2	2.2
Expense incurred since the start of the Restructuring Plan	35.0	35.0
Expense estimated to be recognized for the Restructuring Plan	35.0	35.0
2019 Restructuring Plan [Member] | Other Restructuring [Member]
Restructuring Cost And Reserve [Line Items]
Beginning Balance		1.3
Expenses	2.6	12.6
Cash payments		(12.8)
Ending Balance	1.1	1.1
Expense incurred since the start of the Restructuring Plan	193.0	193.0
Expense estimated to be recognized for the Restructuring Plan	$ 205.0	$ 205.0