Share-Based Compensation - Schedule Of Outstanding Restricted Share Awards (Details) - $ / shares	12 Months Ended
Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Share-Based Compensation
Outstanding restricted share awards, Nonvested at October 1,	265,367	226,705	220,300
Outstanding restricted share awards, Granted, Shares	84,880	117,045	51,476
Outstanding restricted share awards, Vested, Shares	(119,811)	(75,327)	(35,753)
Outstanding restricted share awards, Cancelled, Shares	(40,711)	(3,056)	(9,318)
Outstanding restricted share awards, Nonvested at September 30,	189,725	265,367	226,705
Outstanding restricted share awards, Nonvested at October 1, Weighted Avg. Price	$ 84.29	$ 76.15	$ 66.55
Outstanding restricted share awards, Granted, Weighted Avg. Price	93.64	82.54	108.05
Outstanding restricted share awards, Vested, Weighted Avg. Price	82.28	56.87	64.40
Outstanding restricted share awards, Cancelled, Weighted Avg. Price	85.00	89.51	70.50
Outstanding restricted share awards, Nonvested at September 30, Weighted Avg. Price	$ 94.91	$ 84.29	$ 76.15

No definition available.

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- Definition

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

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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.

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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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- Definition

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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- Definition

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.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(ii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

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- Definition

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

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- Definition

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

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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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