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The percentage of acquired property that is leased at the time of acquisition, expressed as a percent.

+ Details

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- Definition

Represents costs expensed in connection with acquisitions of operating properties.

+ Details

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Namespace Prefix:	ofc
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Balance Type:	debit
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- Details

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- Definition

Represents the value of assets acquired in real estate property acquisition.

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- Definition

The aggregate amount assigned to a major class of finite-lived intangible assets acquired either individually or as part of a group of assets (in either an asset acquisition or business combination). A major class is composed of intangible assets that can be grouped together because they are similar, either by their nature or by their use in the operations of a company.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 44

-Subparagraph a(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6905858&loc=d3e16265-109275

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- Definition

The calculated weighted-average amortization period of a major class of finite-lived intangible assets acquired during the current period either individually or as part of a group of assets (in either an asset acquisition or business combination). A major class is composed of intangible assets that can be grouped together because they are similar, either by their nature or by their use in the operations of a company.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 44

-Subparagraph a(3)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (a)(3)

-URI http://asc.fasb.org/extlink&oid=6905858&loc=d3e16265-109275

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Period Type:	duration

- Definition

The amount of square footage related to a real estate property.

+ Details

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Data Type:	xbrli:decimalItemType
Balance Type:	na
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Properties, net (Details 5) (2011 Office Property Acquisition, USD $)	1 Months Ended	9 Months Ended
	Aug. 31, 2011 sqfeet	Sep. 30, 2011	Aug. 09, 2011
2011 Acquisitions
Square footage of real estate properties (in square feet)	138,000
Acquired property, percentage leased (in percent)			100.00%
Total assets			$ 33,413,000
Cost expensed in connection with acquisition of office properties		152,000
Land, operating properties
2011 Acquisitions
Total assets			251,000
Buildings and improvements
2011 Acquisitions
Total assets			26,824,000
Intangible assets on real estate acquisitions
2011 Acquisitions
Total assets			6,338,000
Intangible assets on real estate acquisitions
Weighted average amortization period of intangible assets (in years)	6
In-place lease value
Intangible assets on real estate acquisitions
Gross Carrying Amount			2,800,000
Weighted average amortization period of intangible assets (in years)	3
Tenant relationship value
Intangible assets on real estate acquisitions
Gross Carrying Amount			3,072,000
Weighted average amortization period of intangible assets (in years)	8
Above-market leases
Intangible assets on real estate acquisitions
Gross Carrying Amount			$ 466,000
Weighted average amortization period of intangible assets (in years)	3