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Properties Held for Sale and Property Dispositions (Details) $ in Millions | 1 Months Ended |
--- | --- | ---
Jan. 31, 2018 USD ($) ft² | Jun. 30, 2018 ft²
Properties Sold [Abstract] |  |
Approximate Square Feet | ft² |  | 31,150,063
600 Lexington Ave |  |
Properties Sold [Abstract] |  |
Approximate Square Feet | ft² | 303,515 |
Sales Price | $ 305.0 |
Gain on Sale (Loss) | $ 23.8 |
115-117 Stevens Avenue |  |
Properties Sold [Abstract] |  |
Approximate Square Feet | ft² | 178,000 |
Sales Price | $ 12.0 |
Gain on Sale (Loss) | $ (0.7) |
635 Madison Avenue |  |
Properties Sold [Abstract] |  |
Approximate Square Feet | ft² | 176,530 |
Sales Price | $ 153.0 |
Gain on Sale (Loss) | $ (14.1) |

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