Stock and Other Compensation Plans (Details) - USD ($)	12 Months Ended
Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Share-based Compensation, Allocation and Classification in Financial Statements [Abstract]
Stock Based Compensation Expense	$ 23,100,000	$ 24,600,000	$ 27,500,000
Share-based Compensation, Capitalized Amount	9,000,000	9,800,000	11,500,000
Share Based Compensation, Tax Benefit	$ 4,400,000	$ 5,000,000	$ 4,700,000
Authorized Shares	11,200,000.0		8,700,000.0
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available	2,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Nonvested at beginning of year-Shares	782,431	878,104	988,637
Nonvested at beginning of year-Weighted Average	$ 57.66	$ 48.24	$ 42.22
Granted-Shares	273,497	357,323	444,543
Granted-Weighted Average	$ 74.15	$ 65.98	$ 50.50
Vested-Shares	(448,326)	(448,136)	(551,688)
Vested-Weighted Average	$ 52.23	$ 45.88	$ 39.28
Forfeited-Shares	(36,788)	(4,860)	(3,388)
Forfeited-Weighted Average	$ 63.48	$ 53.52	$ 48.55
Nonvested at end of year-Shares	570,814	782,431	878,104
Nonvested at end of year-Weighted Average	$ 69.45	$ 57.66	$ 48.24
Unrecognized Compensation Cost	$ 10,900,000
Weighted Average Recognized Period	1 year 7 months
Fair Value Restricted Stock Vested	$ 23,400,000	$ 20,600,000	$ 21,700,000
Direct Stock Purchse Plan [Abstract]
Minimum Initial Investment for Direct Stock Purchase Plan	1,250
Minimum Continuing Investment for Direct Stock Purchase Plan	25
Annual Maximum Investment for Direct Stock Purchase Plan	$ 100,000

The annual maximum dollar amount for the purchase of of shares through the Direct Stock Purchase Plan.

No definition available.

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The minimum requried dollar amount to purchase additional shares from the Direct Stock Purchase Plan after the initial investment.

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No definition available.

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The minimum initial investment required to join the Direct Stock Purchase Plan.

+ References

No definition available.

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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the beginning of the period.

+ References

No definition available.

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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the end of the period.

+ References

No definition available.

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- Definition

The weighted average fair value of nonvested awards at the beginning of the period on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

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- Definition

The weighted average fair value of nonvested awards at the end of the period on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

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- Definition

The maximum number of shares or other type of equity available for awards under the equity-based compensation plan.

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No definition available.

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Share Based Compensation, Tax Benefit due to capitalization.

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No definition available.

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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
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Represents the compensation cost capitalized during the period arising from equity-based compensation arrangements (for example, shares of stock, units, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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-Publisher FASB
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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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-Publisher FASB
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The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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-Publisher FASB
-Name Accounting Standards Codification
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-Subparagraph (c)(1)(iv)(3)
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Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

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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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The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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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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The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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