Estimated Useful Lives used to Depreciate Real Property Assets (Detail)	12 Months Ended
	Dec. 31, 2013
Land [Member]
Property, Plant and Equipment [Line Items]
Standard Depreciable Life	Not Depreciated
Buildings | Minimum
Property, Plant and Equipment [Line Items]
Standard Depreciable Life	30 years
Buildings | Maximum
Property, Plant and Equipment [Line Items]
Standard Depreciable Life	35 years
Site Improvements | Minimum
Property, Plant and Equipment [Line Items]
Standard Depreciable Life	7 years
Site Improvements | Maximum
Property, Plant and Equipment [Line Items]
Standard Depreciable Life	15 years