Reportable Business Segments, Reconciliation of Segment Operating Income (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2016	Mar. 31, 2015
Reconciliation of segment operating income to consolidated income before income taxes
Segment operating income	$ 239.4	$ 260.2
Interest expense	(18.1)	(17.0)
Stock-based compensation expense	(11.6)	(10.1)
Acquisition-related expenses	(30.3)
Income before income taxes	222.3	247.3
Operating Segment
Reconciliation of segment operating income to consolidated income before income taxes
Segment operating income	292.3	281.2
Segment Reconciliation Items
Reconciliation of segment operating income to consolidated income before income taxes
Interest expense	(18.1)	(17.0)
Other income, net	1.0	4.1
Stock-based compensation expense	(11.6)	(10.1)
Acquisition-related expenses	(30.3)
Other costs	(11.0)	(10.9)
Income before income taxes	$ 222.3	$ 247.3

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-Topic 718
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-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901

Reference 3: http://www.xbrl.org/2003/role/presentationRef
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-Section 50
-Paragraph 2
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Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
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Sum of operating profit and nonoperating income or expense before Income or Loss from equity method investments, income taxes, extraordinary items, and noncontrolling interest.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Amount of the cost of borrowed funds accounted for as interest expense.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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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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