Real Estate Investments - Additional Information (Detail) $ in Thousands	Dec. 31, 2015 item	Jun. 30, 2015 USD ($)	Dec. 31, 2014 item
REAL ESTATE INVESTMENTS
Total amount of project construction costs capitalized | $		$ 14,237
Bismarck, North Dakota | Multi Family Apartment Community
REAL ESTATE INVESTMENTS
Number of two-story townhomes under construction	6
Number of apartment buildings under construction	6		4
Construction in progress, number of apartment units			156