Discontinued Operations - Income Attributable to Disposed Properties and Assets Held for Sale (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2013
Discontinued Operations And Disposal Groups [Abstract]
Rental income and recoveries	$ 9,424	$ 20,692
Rental expenses	(3,222)	(6,961)
Depreciation and amortization	(3,755)	(9,066)
Interest expense	(307)	(732)
Income attributable to disposed properties and assets held for sale	$ 2,140	$ 3,933