Stock-Based Compensation Plans - Summary of Fair Value Assumptions Used for Share Based Awards (Details) - Nonvested Stock Units - Performance Based - $ / shares |
12 Months Ended | ||
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Sep. 30, 2021 |
Sep. 30, 2020 |
Sep. 30, 2019 |
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| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Weighted average fair value per share (usd per share) | $ 21.81 | $ 23.21 | $ 21.22 |
| Risk-free interest rate | 0.20% | 1.60% | 2.80% |
| Expected dividend yield | 2.30% | 2.10% | 1.30% |
| Expected volatility | 42.00% | 26.00% | 26.80% |
| Expected term | 3 years | 3 years | 3 years |
| Minimum risk free interest rate | 0.13% | 1.55% | 2.66% |
| Maximum risk free interest rate | 0.23% | 1.59% | 2.82% |
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- Definition The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition The risk-free interest rate assumption that is used in valuing an option on its own shares. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition The maximum risk-free interest rate assumption that is used in valuing an option on its own shares. No definition available.
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- Definition The minimum risk-free interest rate assumption that is used in valuing an option on its own shares. No definition available.
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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- Definition Expected term of award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Weighted Average Fair Value No definition available.
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- Details
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