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Real Estate Investments (Details Textuals 1) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2011 Property	Aug. 12, 2011	Jun. 29, 2011 sqft	Jun. 27, 2011 Three Greentree Center [Member] sqft
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net rentable square feet of properties sold			347,620	69,300
Sales price of properties sold			$ 86.7	$ 5.9
Lease percentage of sold property				13.90%
Number of properties with ownership interest	3
Gain on sale of ownership interest	$ 2.8
Remaining Ownership Interest in Real Estate Properties	11.00%
Date which note receivable obtained from third party in connection with acquisition		Aug. 02, 2011

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- Definition

Lease percentage of sold property.

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- Definition

Net Rentable Space Sold.

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- Definition

Notes Receivable Obtained From Third Party Date.

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- Definition

Realized Gains Losses on Sales of Investment Real Estate.

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- Definition

Remaining Ownership Interest in Real Estate Properties.

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- Definition

Sale Consideration Of Sold Property.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

The number of real estate properties owned as of the balance sheet date.

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