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Earnings Per Share (EPS) - Additional Information (Detail) | Sep. 30, 2012 | Sep. 30, 2011
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Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |  |
Unvested Restricted Stock Awards Outstanding | 745,712 | 688,708

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- Definition Number of unvested restricted stock awards outstanding included in participating securities. + References No definition available. + Details
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Namespace Prefix: | fr_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

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- Details
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Period Type: | duration