Derivative Instruments and Hedging Activities Carrying Values of Derivative Instruments (Detail) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Foreign currency contracts \| Fair value, measurements, recurring
Derivative [Line Items]
Derivative liabilities	$ (0.8)	$ (2.3)
Foreign currency contracts \| Level 2 \| Fair value, measurements, recurring
Derivative [Line Items]
Derivative liabilities	(0.8)	(2.3)
Interest rate contracts \| Fair value, measurements, recurring
Derivative [Line Items]
Derivative liabilities	(12.2)	(18.1)
Interest rate contracts \| Level 2 \| Fair value, measurements, recurring
Derivative [Line Items]
Derivative liabilities	(12.2)	(18.1)
Designated as Hedging Instrument
Derivative [Line Items]
Derivative Net Carrying Value	(13.0)	(20.4)
Designated as Hedging Instrument \| Foreign currency contracts
Derivative [Line Items]
Derivative Net Carrying Value	(0.8)	(2.3)
Designated as Hedging Instrument \| Interest rate contracts
Derivative [Line Items]
Derivative Net Carrying Value	(12.2)	(18.1)
Prepaid Expenses and Other Current Assets \| Designated as Hedging Instrument
Derivative [Line Items]
Fair Value— Assets	1.2	1.0
Prepaid Expenses and Other Current Assets \| Designated as Hedging Instrument \| Foreign currency contracts
Derivative [Line Items]
Fair Value— Assets	1.2	1.0
Prepaid Expenses and Other Current Assets \| Designated as Hedging Instrument \| Interest rate contracts
Derivative [Line Items]
Fair Value— Assets	0.0	(18.1)
Other Current Liabilities \| Designated as Hedging Instrument
Derivative [Line Items]
Fair Value— (Liabilities)	(14.2)	(21.4)
Other Current Liabilities \| Designated as Hedging Instrument \| Foreign currency contracts
Derivative [Line Items]
Fair Value— (Liabilities)	$ (2.0)	$ (3.3)

Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

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Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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- Definition

Fair value of the assets less the liabilities of a derivative or group of derivatives.

+ References

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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

+ References

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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