Stock and Other Compensation Plans - Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity (Details) - $ / shares	12 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Number of Restricted Units
Nonvested at beginning of year (in shares)	503,072	538,592	570,814
Granted (in shares)	199,985	241,472	248,710
Vested (in shares)	(242,975)	(269,347)	(274,392)
Forfeited (in shares)	(16,803)	(7,645)	(6,540)
Nonvested at end of year (in shares)	443,279	503,072	538,592
Weighted Average Grant-Date Fair Value
Nonvested at beginning of year (in dollars per share)	$ 91.66	$ 80.91	$ 69.45
Granted (in dollars per share)	102.34	98.25	85.62
Vested (in dollars per share)	85.66	76.71	64.43
Forfeited (in dollars per share)	96.87	86.37	74.87
Nonvested at end of year (in dollars per share)	$ 99.28	$ 91.66	$ 80.91

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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(3)
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- Definition

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.

+ References

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-Publisher FASB
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-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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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).

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
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-Paragraph 2
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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).

+ References

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-Publisher FASB
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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 balance sheet date.

+ References

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-Name Accounting Standards Codification
-Topic 718
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-Paragraph 2
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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.

+ References

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-Publisher FASB
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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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-Publisher FASB
-Name Accounting Standards Codification
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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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