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

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No definition available.

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- Definition

The amount of acquisition cost of a business combination allocated to building and improvements.

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No definition available.

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The amount of acquisition cost of a business combination allocated to land and classified as operating properties.

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No definition available.

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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.

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Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

Area of a real estate property.

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No definition available.

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The amount of acquisition cost of a business combination allocated to assets acquired.

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The amount of acquisition cost of a business combination allocated to unfavorable contracts assumed from the acquired entity.

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This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

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The amount of identifiable intangible assets recognized as of the acquisition date.

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The net amount recognized as of the acquisition date for the aggregate identifiable assets acquired in excess of or less than the aggregate liabilities assumed.

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Properties, net (Details 4) (USD $) In Thousands, unless otherwise specified	12 Months Ended					0 Months Ended
	Dec. 31, 2012	Dec. 31, 2012 Tenant relationship value	Dec. 31, 2012 In-place lease value	Dec. 31, 2012 Above-market leases	Dec. 31, 2011 Office Property Acquisition in 2011	Jul. 11, 2012 13857 McLearen Road sqft	Jul. 11, 2012 13857 McLearen Road Tenant relationship value	Jul. 11, 2012 13857 McLearen Road In-place lease value	Jul. 11, 2012 13857 McLearen Road Above-market leases	Aug. 09, 2011 310 The Bridge Street	Aug. 09, 2011 310 The Bridge Street Tenant relationship value	Aug. 09, 2011 310 The Bridge Street In-place lease value	Aug. 09, 2011 310 The Bridge Street Above-market leases	Aug. 09, 2011 310 The Bridge Street Office Property Acquisition in 2011 sqft
Acquisitions
Square footage of real estate properties (in square feet)						202,000								138,000
Acquired property, percentage leased (as a percent)						100.00%								100.00%
Land, operating properties						$ 3,507				$ 261
Building and improvements						30,177				26,577
Intangible assets on real estate acquisitions						14,993				6,575
Total assets						48,677
Below market leases						(369)
Total acquisition costs						48,308				33,413
Intangible assets on real estate acquisitions
Gross carrying amount						14,993	7,472	7,109	412	6,575	3,187	2,904	484
Weighted average amortization period of intangible assets	10 years	8 years	7 years	4 years		7 years	10 years	5 years	5 years	6 years	8 years	3 years	3 years
Costs expensed in connection with acquisition of operating properties	$ 229				$ 156