Capital Stock (Details) - USD ($) $ in Millions	12 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Capital Stock
Common shares as presented in the accompanying Consolidated Balance Sheets	30,645,625	30,596,940
Common shares in treasury	4,607,911	4,615,627
Board of Directors authorized an expanded stock repurchase program	$ 100.0
Stock repurchases during period, shares	0	0	0
Stock repurchase program, remaining authorized repurchase amount	$ 50.4

Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

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- Definition

Amount of stock repurchase plan authorized.

+ References

No definition available.

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- Definition

Amount remaining of a stock repurchase plan authorized.

+ References

No definition available.

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- Definition

Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

+ References

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-Publisher FASB
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-Topic 505
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- References

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- Definition

Number of common and preferred shares that were previously issued and that were repurchased by the issuing entity and held in treasury on the financial statement date. This stock has no voting rights and receives no dividends.

+ References

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-Name Accounting Standards Codification
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-SubTopic 10
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