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Properties, Net (Details 4) ft² in Thousands, $ in Thousands |  |  |  | 3 Months Ended
--- | --- | --- | --- | ---
Aug. 07, 2015 USD ($) ft² | Apr. 15, 2015 USD ($) ft² | Mar. 19, 2015 USD ($) ft² | Mar. 31, 2016 USD ($) | Mar. 31, 2015 USD ($)
2015 Acquisitions |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |
Contributed revenues |  |  |  | $ 9,200 | $ 332
Contributed net income from continuing operations |  |  |  | $ 942 | $ 170
250 W Pratt St | Baltimore, Maryland |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |
Square footage of real estate properties (in square feet) | ft² |  |  | 367 |  |
Acquired property percentage leased |  |  | 96.20% |  |
Total acquisition cost |  |  | $ 61,800 |  |
2600 Park Tower Drive | Northern Virginia |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |
Square footage of real estate properties (in square feet) | ft² |  | 237 |  |  |
Acquired property percentage leased |  | 100.00% |  |  |
Total acquisition cost |  | $ 80,500 |  |  |
100 and 30 Light Street | Baltimore, Maryland |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |
Square footage of real estate properties (in square feet) | ft² | 558 |  |  |  |
Acquired property percentage leased | 93.50% |  |  |  |
Total acquisition cost | $ 121,200 |  |  |  |
Business combination, liabilities assumed | 55,000 |  |  |  |
Fair value assumption of debt | $ 55,500 |  |  |  |

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