XML 52 R37.htm IDEA: XBRL DOCUMENT
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Organization of The Parent Company and The Operating Partnership (Textual) (Details) | Sep. 30, 2016 | Sep. 30, 2016 property | Sep. 30, 2016 ft² | Sep. 30, 2016 Real_Estate_Investment | Sep. 30, 2016 a | Sep. 30, 2016 Apartment_unit | Feb. 04, 2016 property
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Organization of The Parent Company and The Operating Partnership [Line Items] |  |  |  |  |  |  |
Number of Properties |  | 117 |  |  |  |  |
Office Properties [Member] |  |  |  |  |  |  |
Organization of The Parent Company and The Operating Partnership [Line Items] |  |  |  |  |  |  |
Number of Properties |  | 99 |  |  |  |  |
Rentable Square Feet | ft² |  |  | 5,082,963 |  |  |  |
Mixed Use Properties [Member] |  |  |  |  |  |  |
Organization of The Parent Company and The Operating Partnership [Line Items] |  |  |  |  |  |  |
Number of Properties |  | 7 |  |  |  |  |
Retail Properties [Member] |  |  |  |  |  |  |
Organization of The Parent Company and The Operating Partnership [Line Items] |  |  |  |  |  |  |
Number of Properties |  | 1 |  |  |  |  |
Core Properties [Member] |  |  |  |  |  |  |
Organization of The Parent Company and The Operating Partnership [Line Items] |  |  |  |  |  |  |
Number of Properties |  | 107 |  |  |  |  |
Development Property [Member] |  |  |  |  |  |  |
Organization of The Parent Company and The Operating Partnership [Line Items] |  |  |  |  |  |  |
Number of Properties |  | 4 |  |  |  |  |
Redevelopment Properties [Member] |  |  |  |  |  |  |
Organization of The Parent Company and The Operating Partnership [Line Items] |  |  |  |  |  |  |
Number of Properties |  | 2 |  |  |  |  |
Assets Held-for-sale [Member] |  |  |  |  |  |  |
Organization of The Parent Company and The Operating Partnership [Line Items] |  |  |  |  |  |  |
Number of Properties |  | 4 |  |  |  |  |
Assets Held-for-sale [Member] | Office Properties [Member] |  |  |  |  |  |  |
Organization of The Parent Company and The Operating Partnership [Line Items] |  |  |  |  |  |  |
Number of Properties |  | 3 |  |  |  |  |
Unconsolidated Real Estate Ventures [Member] |  |  |  |  |  |  |
Organization of The Parent Company and The Operating Partnership [Line Items] |  |  |  |  |  |  |
Number of Unconsolidated Investments in Real Estate Ventures | Real_Estate_Investment |  |  |  | 14 |  |  |
Unconsolidated Real Estate Ventures [Member] | Seven Real Estate Ventures [Member] | Office Properties [Member] |  |  |  |  |  |  |
Organization of The Parent Company and The Operating Partnership [Line Items] |  |  |  |  |  |  |
Number of Unconsolidated Investments in Real Estate Ventures | Real_Estate_Investment |  |  |  | 7 |  |  |
Rentable Square Feet | ft² |  |  | 8,000,000 |  |  |  |
Unconsolidated Real Estate Ventures [Member] | Two Real Estate Ventures [Member] | Undeveloped Land [Member] |  |  |  |  |  |  |
Organization of The Parent Company and The Operating Partnership [Line Items] |  |  |  |  |  |  |
Number of Unconsolidated Investments in Real Estate Ventures | Real_Estate_Investment |  |  |  | 2 |  |  |
Acreage of land | a |  |  |  |  | 4.3 |  |
Unconsolidated Real Estate Ventures [Member] | Two Other Real Estate Ventures [Member] | Under Active Development Land [Member] |  |  |  |  |  |  |
Organization of The Parent Company and The Operating Partnership [Line Items] |  |  |  |  |  |  |
Number of Unconsolidated Investments in Real Estate Ventures | Real_Estate_Investment |  |  |  | 2 |  |  |
Acreage of land | a |  |  |  |  | 1.4 |  |
Unconsolidated Real Estate Ventures [Member] | Two Other Real Estate Ventures [Member] | Residential Tower One [Member] |  |  |  |  |  |  |
Organization of The Parent Company and The Operating Partnership [Line Items] |  |  |  |  |  |  |
Number of Unconsolidated Investments in Real Estate Ventures | Real_Estate_Investment |  |  |  | 1 |  |  |
Number of Property units |  | 345 |  |  |  | 345 |
Unconsolidated Real Estate Ventures [Member] | Two Other Real Estate Ventures [Member] | Residential Tower Two [Member] |  |  |  |  |  |  |
Organization of The Parent Company and The Operating Partnership [Line Items] |  |  |  |  |  |  |
Number of Unconsolidated Investments in Real Estate Ventures | Real_Estate_Investment |  |  |  | 1 |  |  |
Number of Property units |  | 321 |  |  |  | 321 |
Number of Unconsolidated Investments in Real Estate Ventures |  | 1 |  |  |  |  |
Unconsolidated Real Estate Ventures [Member] | One Real Estate Venture [Member] | Apartment Complex [Member] |  |  |  |  |  |  |
Organization of The Parent Company and The Operating Partnership [Line Items] |  |  |  |  |  |  |
Number of Unconsolidated Investments in Real Estate Ventures | Real_Estate_Investment |  |  |  | 1 |  |  |
Number of Property units |  | 398 |  |  |  | 398 |
MAP Venture [Member] | Industrial Properties [Member] |  |  |  |  |  |  |
Organization of The Parent Company and The Operating Partnership [Line Items] |  |  |  |  |  |  |
Number of Properties |  | 4 |  |  |  |  | 20
Parent Company [Member] |  |  |  |  |  |  |
Organization of The Parent Company and The Operating Partnership [Line Items] |  |  |  |  |  |  |
Ownership in the Operating Partnership | 99.10% |  |  |  |  |  |
Net Rentable Square Feet | ft² |  |  | 17,800,000 |  |  |  |
Area Owned by Company of Undeveloped Parcels of Land | a |  |  |  |  | 317 |  |
Area of Additional Undeveloped Parcels of Land With Option to Purchase | a |  |  |  |  | 60 |  |
Total Potential Development Capacity | ft² |  |  | 12,300,000 |  |  |  |
Wholly-owned Management Company Subsidiaries [Member] |  |  |  |  |  |  |
Organization of The Parent Company and The Operating Partnership [Line Items] |  |  |  |  |  |  |
Net Rentable Square Feet | ft² |  |  | 28,700,000 |  |  |  |
Wholly-owned Management Company Subsidiaries [Member] | Partially Owned Properties [Member] |  |  |  |  |  |  |
Organization of The Parent Company and The Operating Partnership [Line Items] |  |  |  |  |  |  |
Net Rentable Square Feet | ft² |  |  | 10,900,000 |  |  |  |
Wholly-owned Management Company Subsidiaries [Member] | Wholly Owned Properties [Member] |  |  |  |  |  |  |
Organization of The Parent Company and The Operating Partnership [Line Items] |  |  |  |  |  |  |
Net Rentable Square Feet | ft² |  |  | 17,800,000 |  |  |  |
Wholly-owned Management Company Subsidiaries [Member] | Office and Industrial Properties [Member] | Partially Owned Properties [Member] |  |  |  |  |  |  |
Organization of The Parent Company and The Operating Partnership [Line Items] |  |  |  |  |  |  |
Net Rentable Square Feet | ft² |  |  | 10,900,000 |  |  |  |

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