Effect of Change within Income Statement related to the Adoption of New Compensation - Retirement Benefit Policy (Detail) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Item]
Operating expenses	$ 314.9	$ 275.3
Selling, general and administrative	271.1	220.7
Operating income	490.8	446.7
Interest expense, net	(50.7)	(47.4)
Other non-operating income (expense), net	1.0	(7.7)
Compensation-Retirement Benefits Accounting Standard [Member] \| Previous Accounting Guidance [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Item]
Operating expenses	316.3	277.4
Selling, general and administrative	272.0	221.9
Operating income	488.5	443.4
Interest expense, net	(46.0)	(42.4)
Other non-operating income (expense), net	(1.4)	(9.4)
Compensation-Retirement Benefits Accounting Standard [Member] \| Effect of Change [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Item]
Operating expenses	(1.4)	(2.1)
Selling, general and administrative	(0.9)	(1.2)
Operating income	2.3	3.3
Interest expense, net	4.7	5.0
Other non-operating income (expense), net	$ 2.4	$ (1.7)

The aggregate direct operating costs incurred during the reporting period.

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The net amount of nonoperating interest income (expense).

+ 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.

+ References

No definition available.

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The net result for the period of deducting operating expenses from operating revenues.

+ References

No definition available.

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Amount of income (expense) related to nonoperating activities, classified as other.

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- Definition

The aggregate total costs related to selling a firm's product and services, as well as all other general and administrative expenses. Direct selling expenses (for example, credit, warranty, and advertising) are expenses that can be directly linked to the sale of specific products. Indirect selling expenses are expenses that cannot be directly linked to the sale of specific products, for example telephone expenses, Internet, and postal charges. General and administrative expenses include salaries of non-sales personnel, rent, utilities, communication, etc.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.4)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 330
-SubTopic 10
-Section 30
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=68048583&loc=d3e3636-108311

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