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Summary of Significant Accounting Policies - Deferred Leasing Intangibles Included in Total Assets (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified | Dec. 31, 2012 | Dec. 31, 2011
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Finite-Lived Intangible Assets [Line Items] |  |
Accumulated Amortization,Total Assets | $ 36,327 | $ 34,869

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- Definition Accumulated Amortization Of Intangible Lease Assets + References No definition available. + Details
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Namespace Prefix: | fr_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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- Details
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Namespace Prefix: | us-gaap_
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Balance Type: | na
Period Type: | duration