Real Estate Investments - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Real Estate Properties [Line Items]
Land	$ 37,812	$ 24,511
Main Street Land
Real Estate Properties [Line Items]
Land	2,300	1,800
Bermuda Crossroads
Real Estate Properties [Line Items]
Land	5,500
Whetstone Apartments
Real Estate Properties [Line Items]
Land	2,600
Sandbridge Commons
Real Estate Properties [Line Items]
Land	$ 5,200