Restructuring - Summary of Restructuring Activities (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restructuring Reserve [Roll Forward]
Accrual as of beginning of period	$ 108.7	$ 98.0	$ 74.0
Charges	194.2	88.0	70.9
Utilization, Cash	(135.7)	(72.6)	(45.6)
Utilization, Non-cash	(9.5)	(4.7)	(1.3)
Accrual as of end of period	157.7	108.7	98.0
Employee termination benefits
Restructuring Reserve [Roll Forward]
Accrual as of beginning of period	103.3	93.0	69.4
Charges	167.8	74.5	62.9
Utilization, Cash	(118.3)	(64.2)	(39.3)
Utilization, Non-cash	0.0	0.0	0.0
Accrual as of end of period	152.8	103.3	93.0
Asset impairments
Restructuring Reserve [Roll Forward]
Accrual as of beginning of period	0.0	0.0	0.0
Charges	9.5	4.7	1.3
Utilization, Cash	0.0	0.0	0.0
Utilization, Non-cash	(9.5)	(4.7)	(1.3)
Accrual as of end of period	0.0	0.0	0.0
Contract termination costs
Restructuring Reserve [Roll Forward]
Accrual as of beginning of period	5.4	5.0	4.6
Charges	3.0	1.5	1.7
Utilization, Cash	(3.5)	(1.1)	(1.3)
Utilization, Non-cash	0.0	0.0	0.0
Accrual as of end of period	4.9	5.4	5.0
Other related costs
Restructuring Reserve [Roll Forward]
Accrual as of beginning of period	0.0	0.0	0.0
Charges	13.9	7.3	5.0
Utilization, Cash	(13.9)	(7.3)	(5.0)
Utilization, Non-cash	0.0	0.0	0.0
Accrual as of end of period	$ 0.0	$ 0.0	$ 0.0

Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation.

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Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

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Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of decrease in the reserve for full or partial settlement through consideration other than cash.

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