Share-Based Payments - Exercisable Options (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Information concerning outstanding and exercisable options
Allocated Share-based Compensation Expense	$ 44.7	$ 54.2	$ 63.8
Unrecognized compensation expense	$ 45.6	$ 50.0
Vesting period	3 years
Employee Stock Option
Information concerning outstanding and exercisable options
Weighted average grant-date fair value of stock options granted (in dollars per share)	$ 11.30
Performance Earnings Program
Information concerning outstanding and exercisable options
Weighted average grant-date fair value of stock options granted (in dollars per share)	$ 52.76	$ 42.99	$ 27.53
Vesting period	3 years
Restricted Stock Units
Information concerning outstanding and exercisable options
Weighted average grant-date fair value of stock options granted (in dollars per share)	$ 49.21	$ 41.90	$ 27.73

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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-Publisher FASB
-Name Accounting Standards Codification
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Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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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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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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