Investment in Real Estate - Fair Value Measurements on Non-Recurring Basis (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total Impairment	$ 0	$ (1,605)	$ 0	$ (1,605)
Fair Value, Measurements, Nonrecurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Sold Operating Properties		6,993		6,993
Fair Value, Measurements, Nonrecurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Sold Operating Properties		0		0
Fair Value, Measurements, Nonrecurring | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Sold Operating Properties		0		0
Fair Value, Measurements, Nonrecurring | Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Sold Operating Properties		$ 6,993		$ 6,993