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Deferred Costs (Details Textuals) (USD $) In Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2011 | Sep. 30, 2010 | Sep. 30, 2011 | Sep. 30, 2010
Deferred Costs (Textuals) [Abstract] |  |  |  |
Capitalized internal direct leasing costs | $ 1.7 | $ 1.4 | $ 5.4 | $ 4.7

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- Definition Deferred costs. + Details
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