| CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (Unaudited) (Parenthetical) - $ / shares | 3 Months Ended | |
|---|---|---|
| Dec. 31, 2017 | Dec. 31, 2016 | |
| Statement of Stockholders' Equity [Abstract] | ||
| Purchase of treasury stock (in shares) | 75,765 | 95,229 | 
| Issuance of treasury stock (in shares) | 223,971 | 205,623 | 
| Cancellations of treasury stock (in shares) | 5,214 | 0 | 
| Dividends, per share (in dollars per share) | $ 0.19 | $ 0.17 | 
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- Definition Aggregate dividends paid during the period for each share of common stock outstanding. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- References No definition available. 
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- Definition Number of treasury shares (units) reissued during the period, excluding reissuance of shares (units) held in treasury used to satisfy equity-based compensation obligations exercised by the holders of such rights. Upon reissuance of shares (units) from treasury, either the common or preferred stock (unit) reissued is outstanding. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Number of shares that have been repurchased during the period and are being held in treasury. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Number of shares of common and preferred stock retired from treasury during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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