Real Estate Investments - Additional Information (Details) - Omaha, Nebraska - Multifamily $ in Thousands	Mar. 31, 2018 USD ($) item
REAL ESTATE INVESTMENTS
Number of apartment buildings under construction | item	1
Number of apartment units under construciton | item	18
Construction contract amount	$ 2,031
Construction contract, amount completed to date	749
Construction contract, retainage amount included in payables	$ 71