Business Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014
Sales and operating results of reportable segments
Sales	$ 1,550.8us-gaap_SalesRevenueNet	$ 1,600.5us-gaap_SalesRevenueNet	$ 3,125.2us-gaap_SalesRevenueNet	$ 3,192.2us-gaap_SalesRevenueNet
Income before income taxes	276.5	248.4	564.0	521.2
Interest expense	(15.7)us-gaap_InterestExpense	(15.0)us-gaap_InterestExpense	(30.6)us-gaap_InterestExpense	(29.9)us-gaap_InterestExpense
Operating Segments [Member]
Sales and operating results of reportable segments
Income before income taxes	334.2	302.1	681.0	630.1
Architecture & Software [Member]
Sales and operating results of reportable segments
Sales	674.3	686.8	1,382.1	1,382.7
Income before income taxes	200.8	190.2	422.2	402.1
Control Products & Solutions [Member]
Sales and operating results of reportable segments
Sales	876.5	913.7	1,743.1	1,809.5
Income before income taxes	133.4	111.9	258.8	228.0
Segment Reconciling Items [Member]
Sales and operating results of reportable segments
Purchase accounting depreciation and amortization	(5.2)	(5.8)	(10.6)	(10.4)
Non-operating pension costs	(15.4)	(14.0)	(31.6)	(28.0)
Corporate, Non-Segment [Member]
Sales and operating results of reportable segments
General corporate - net	(21.4)	(18.9)	(44.2)	(40.6)
Interest expense	$ (15.7)	$ (15.0)	$ (30.6)	$ (29.9)

General Corporate - Net

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- Definition

Non-operating pension costs consist of defined benefit plan interest cost, expected return on plan assets, amortization of actuarial gains and losses and the impacts of any plan curtailments or settlements. These costs are excluded from segment operating earnings.

+ References

No definition available.

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- Definition

Purchase accounting depreciation and amortization that is not allocated to the segments for the purposes of determining segment operating earnings.

+ References

No definition available.

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- Definition

This element represents the income or loss from continuing operations attributable to the economic entity which may also be defined as revenue less expenses from ongoing operations, after income or loss from equity method investments, but before income taxes, extraordinary items, and noncontrolling interest.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 940

-SubTopic 20

-Section 25

-Paragraph 1

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 10

-Article 5

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- Definition

Amount of the cost of borrowed funds accounted for as interest expense.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391

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-Name Accounting Standards Codification

-Topic 942

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-04.9)

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- Definition

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

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