Derivative Instruments and Hedging Activities - Fair Value of Derivative Instruments on Gross Basis (Detail) - Designated as Hedging Instrument [Member] - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 23.8	$ 96.8
Derivative Liabilities	68.6	27.8
Foreign Exchange Forward Contracts [Member] \| Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	14.5	57.9
Foreign Exchange Forward Contracts [Member] \| Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	4.8	34.9
Foreign Exchange Forward Contracts [Member] \| Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	45.8	20.9
Foreign Exchange Forward Contracts [Member] \| Other Long-term Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	22.8	6.9
Interest Rate Swaps [Member] \| Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 4.5	$ 4.0

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.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4D
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=82924980&loc=SL51823488-111719

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4B
-Subparagraph (a),(c)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624163-113959

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=82849420&loc=SL20226000-175313

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant