| Restricted Common Stock and Stock Appreciation Rights ("SARs") - Summary of SARs Activity (Detail) (SARs [Member]) | Sep. 30, 2013 | Sep. 30, 2012 | 
|---|---|---|
| SARs [Member] | ||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
| SARs outstanding at beginning and end of period | 28,733 | 27,983 | 
| Stock vested ending balance, Shares | 26,589 | 22,666 | 
| X | ||||||||||
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- Definition Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested No definition available. 
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| X | ||||||||||
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- Definition The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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| X | ||||||||||
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- Details 
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