REAL ESTATE (Narrative) (Details) ft² in Millions	Mar. 31, 2017 ft² property
Real Estate Properties [Line Items]
Rentable square feet | ft²	11.1
Percentage of portfolio occupied	93.00%
Office Properties [Member]
Real Estate Properties [Line Items]
Number of real estate properties	28
Mixed-use Office/Retail Property [Member]
Real Estate Properties [Line Items]
Number of real estate properties	1