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           Stock Repurchase Programs (Details) (USD $) 
        In Millions, except Share data, unless otherwise specified  | 
        1 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
| 
           Jun. 30, 2013 
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           Nov. 30, 2011 
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           Jun. 30, 2013 
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           Jun. 30, 2012 
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| Stock Repurchase Programs | ||||
| Stock split | 2 | |||
| Stock Repurchase Programs | ||||
| Stock repurchase programs, authorized amount | $ 125.0 | |||
| Common shares repurchased | 828,898 | 480,400 | ||
| Common shares repurchased, cost | 27.0 | 8.9 | ||
| Amount remaining available for future stock repurchases | $ 102.2 | |||
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- Definition 
          This item represents the conversion ratio used in the calculation of a stock split. 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 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. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition 
          Equity impact of the value of stock that has been repurchased during the period and has not been retired and is not held in treasury. Some state laws may mandate 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. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition 
          The amount authorized by an entity's Board of Directors under a stock repurchase plan. No definition available. 
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- Definition 
          The remaining repurchase amount authorized by an entity's Board of Directors under a stock repurchase plan. No definition available. 
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