Share-Based Compensation (Narrative) (Details)	6 Months Ended
Mar. 31, 2022 $ / shares shares
Market-Based Deferred Stock Unit
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of units/shares granted	74,364
Performance period	3 years
Weighted average grant date fair value (in dollars per unit/share) \| $ / shares	$ 427.23
Time-Based Deferred Stock Unit
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of units/shares granted	106,721
Weighted average grant date fair value (in dollars per unit/share) \| $ / shares	$ 283.34
LTIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future grant	1,300,000

Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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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).

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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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