Net Rentable Space Sold.

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- Definition

Sale Consideration Of Sold Property.

+ References

No definition available.

+ Details

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- Definition

Amount of consideration received or receivable for the disposal of assets and liabilities, including discontinued operation.

+ References

No definition available.

+ Details

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- Definition

The gain (loss) resulting from the sale of a disposal group that is not a discontinued operation. It is included in income from continuing operations before income taxes in the income statement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 205

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6360339&loc=d3e1361-107760

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 45

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=8077374&loc=d3e2443-110228

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- Definition

The aggregate amount of write-downs for impairments recognized during the period for long-lived assets held for abandonment, exchange or sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 45

-Paragraph 15

-URI http://asc.fasb.org/extlink&oid=8077374&loc=d3e2611-110228

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- Definition

Net rentable area for properties owned.

+ References

No definition available.

+ Details

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- Definition

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

+ References

No definition available.

+ Details

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Real Estate Investments Acquisitions and Dispositions (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Jan. 08, 2015 property	Apr. 09, 2015 sqft	Apr. 24, 2015 sqft property
Significant Acquisitions and Disposals [Line Items]
Net gain on disposition of real estate	$ 9,019,000	$ 0
Provision for impairment on assets held for sale	1,726,000	0
1000 Atrium Way and Libertyview [Member]
Significant Acquisitions and Disposals [Line Items]
Number of Real Estate Properties			2
Sale Consideration Of Sold Property			28,300,000
Net gain on disposition of real estate	9,000,000
1000 Atrium Way [Member]
Significant Acquisitions and Disposals [Line Items]
Net Rentable Space Sold			99,668
Libertyview [Member]
Significant Acquisitions and Disposals [Line Items]
Net Rentable Space Sold			121,737
Lake Merritt Tower [Member]
Significant Acquisitions and Disposals [Line Items]
Provision for impairment on assets held for sale	1,700,000
Delaware Corporate Center I & II [Member]
Significant Acquisitions and Disposals [Line Items]
Number of Real Estate Properties	2
Net Rentable Area	200,275
Christiana Corporate Center [Member]
Significant Acquisitions and Disposals [Line Items]
Number of Real Estate Properties	3
Net Rentable Area	284,907
Subsequent Event [Member] \| Lake Merritt Tower [Member]
Significant Acquisitions and Disposals [Line Items]
Net Rentable Area				204,336
Sales of Real Estate				$ 65,000,000
Subsequent Event [Member] \| Delaware Corporate Center I & II [Member]
Significant Acquisitions and Disposals [Line Items]
Number of Real Estate Properties					2
Net Rentable Area					200,275
Subsequent Event [Member] \| Christiana Corporate Center [Member]
Significant Acquisitions and Disposals [Line Items]
Number of Real Estate Properties					3
Net Rentable Area					284,907