Dispositions - Additional Information (Details)	Jan. 12, 2017 USD ($) ft²	Dec. 31, 2016 ft²
Long Lived Assets Held For Sale [Line Items]
Area of office properties		10,800,000
Subsequent Event [Member] | Waterview [Member]
Long Lived Assets Held For Sale [Line Items]
Area of office properties	636,768
Sale agreement amount | $	$ 460,000,000