Investment in Real Estate - Fair Value Measurements on Non-Recurring Basis (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013
Fair Value Assets Measured On Nonrecurring Basis [Line Items]
Long-lived Assets Sold Impairment	$ (1,047)	[1]
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Assets Measured On Nonrecurring Basis [Line Items]
Long-lived Asssets Held for Sale	0
Significant Other Observable Inputs (Level 2)
Fair Value Assets Measured On Nonrecurring Basis [Line Items]
Long-lived Asssets Held for Sale	0
Unobservable Inputs (Level 3)
Fair Value Assets Measured On Nonrecurring Basis [Line Items]
Long-lived Asssets Held for Sale	6,875	[1]
Fair Value, Measurements, Nonrecurring [Member]
Fair Value Assets Measured On Nonrecurring Basis [Line Items]
Long-lived Asssets Held for Sale	$ 6,875	[1]

[1] Excludes industrial properties for which impairment of $1,605 was recorded during the nine months ended September 30, 2013 since the related assets are sold or recorded at carrying value, which is lower than estimated fair value at September 30, 2013.