Summary of Disposition and Each Property's Contribution (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Real Estate Properties [Line Items]
Net income (loss) allocable to common shares		$ (50,162)	$ (125,757)	$ (84,256)	$ (155,842)
1501 Yamato Road
Real Estate Properties [Line Items]
Sale Price				42,050
Gain (loss) on sale				906
Net income (loss) allocable to common shares		(99)		$ (259)
Office | 1501 Yamato Road
Real Estate Properties [Line Items]
Date of Sale	[1]			Jun. 15, 2018
Sale Price	[1]			$ 42,050
Gain (loss) on sale	[1]			906
Net income (loss) allocable to common shares	[1]	$ (99)		$ (259)

[1] We also recognized a loss on extinguishment of debt related to the sale of this property, resulting from a defeasance premium of $1,943.