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Fair value of deferred stock units paid

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Period from grant date during which share-based compensation awards may be exercised.

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Aggregate cash paid by the entity during the period to settle equity instruments granted under equity-based payment arrangements.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Aggregate proceeds received by the entity during the annual period from exercises of stock or unit options and conversion of similar instruments granted under equity-based payment arrangements.

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Unrecognized cost of unvested share-based compensation awards.

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Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Disclosure of the aggregate tax benefit realized from the exercise of stock options and the conversion of similar instruments during the annual period.

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The aggregate cash inflow comprised of the amount received from (a) employees to acquire the entity's shares under incentive awards, including stock option exercises and restricted stock arrangements, and (b) the excess tax benefit arising from such transactions.

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No definition available.

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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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

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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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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- Definition

Price of a single share of a number of saleable stocks of a company.

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No definition available.

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Share-Based Compensation (Narratives) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future grant	4,840,837
Deferred Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of units/shares granted	284,000
Weighted-average grant date fair value of units/shares	$ 136.37
Cash payments made for deferred stock units	$ 2.9	$ 9.6	$ 2.1
Unrecognized compensation costs	$ 41.4
Unrecognized compensation costs, period for recognition, years	2 years 2 months
Fair value of deferred stock units paid	$ 41.6	$ 35.5	$ 31.8
Deferred Stock Units [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting or deferral Period	2 years
Deferred Stock Units [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting or deferral Period	5 years
Director Deferred Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period after service in which to elect payment	10 years
Market-Based Deferred Stock Unit [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of units/shares granted	130,167	119,272
Vesting or deferral Period	3 years
Weighted-average grant date fair value of units/shares	$ 135.49	$ 194.51
Time-Based Deferred Stock Unit [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of units/shares granted	153,792
Weighted-average grant date fair value of units/shares	$ 137.12
Employee Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercisable period from grant date	10 years
Vesting or deferral Period	3 years
Weighted-average grant date fair value of stock option		$ 37.19	$ 29.10
Closing stock price	$ 150.34
Intrinsic value of stock options exercised	$ 115.3	$ 115.5	$ 125.3
Unrecognized compensation costs	$ 1.1
Unrecognized compensation costs, period for recognition, years	11 months
Cash received from option exercises	$ 141.3
Tax benefit realized from stock option exericses	39.8
Excess tax benefit	$ 25.0
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of units/shares granted	33,000
Weighted-average grant date fair value of units/shares	$ 138.00
Unrecognized compensation costs	$ 5.1
Unrecognized compensation costs, period for recognition, years	2 years 7 months
Fair value of vested restricted stock	$ 4.3	$ 1.4	$ 12.1
Restricted Stock [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting or deferral Period	1 year
Restricted Stock [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting or deferral Period	4 years
Materials Technologies [Member] \| Deferred Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs	$ 7.0