v3.3.1.900

Organization and Ownership (Tables) | 12 Months Ended
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Dec. 31, 2015
Real Estate Properties [Line Items] |
Schedule of Real Estate Properties [Table Text Block] | Our stabilized portfolio of operating properties was comprised of the following office properties at December 31, 2015:
| Number of Buildings |  | Rentable Square Feet (unaudited) |  | Number of Tenants |  | Percentage Occupied (unaudited)
Stabilized Office Properties | 101 |  |  | 13,032,406 |  |  | 517 |  |  | 94.8 | %
As of December 31, 2015, the following properties were excluded from our stabilized portfolio:
| Number of Properties/Projects |  | Estimated Rentable Square Feet (unaudited) (1)
Properties held for sale (2) | 4 |  | 465,812 |
Development projects in “lease-up" | 1 |  | 73,000 |
Development projects under construction | 5 |  | 1,910,000 |
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(1) | Estimated rentable square feet upon completion.

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- Definition Tabular disclosure of real estate properties and units in those properties that are included in the discussion of the nature of an entity's operations. + References No definition available. + Details
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