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Properties, Net (Details 4) ft² in Thousands, $ in Millions |  | 3 Months Ended
--- | --- | ---
Feb. 15, 2017 USD ($) ft² | Mar. 31, 2017 USD ($) ft² Property
Construction and Redevelopment Activities |  |
Sale price of land | $ |  | $ 14.3
Gain on sale of land | $ |  | $ 4.2
Office properties under, or contractually committed for, construction or approved for redevelopment |  |
Construction and Redevelopment Activities |  |
Square footage of real estate properties (in square feet) | ft² |  | 1,300
Number of real estate properties | Property |  | 9
Newly redeveloped properties placed in service |  |
Construction and Redevelopment Activities |  |
Square feet of properties placed in service | ft² |  | 86
Number of real estate properties | Property |  | 3
Properties under construction or contractually committed for construction |  |
Construction and Redevelopment Activities |  |
Square footage of real estate properties (in square feet) | ft² |  | 1,300
Number of real estate properties | Property |  | 8
Properties completed Held-for-future lease | Office properties under, or contractually committed for, construction or approved for redevelopment |  |
Construction and Redevelopment Activities |  |
Number of real estate properties | Property |  | 2
Properties under or approved for redevelopment |  |
Construction and Redevelopment Activities |  |
Square footage of real estate properties (in square feet) | ft² |  | 14
Number of real estate properties | Property |  | 1
Operating Properties | Northern Virginia Defense/IT | Defense/Information Technology Locations | 3120 Fairview Park Drive |  |
Construction and Redevelopment Activities |  |
Square footage of real estate properties (in square feet) | ft² | 190 |
Transaction value | $ | $ 39.0 |

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- Definition The net gain (loss) resulting from sales and other disposals of real estate owned for investment purposes. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.14(d)) -URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882 + Details
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- Definition The cash inflow from the sale of land held for investment; excludes sales of land held as inventory or productive use. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 12 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3179-108585 + Details
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