Discontinued Operations and Disposition of Real Estate and Real Estate Investments - Additional Information (Detail)	12 Months Ended	36 Months Ended
	Dec. 31, 2014 Property	Dec. 31, 2014 Property	Dec. 31, 2013 Property
Discontinued Operations And Disposal Groups [Abstract]
Number of properties sold	35
Number of assets held for sale			2
Number of properties included in discontinued operations		103