REAL ESTATE INVESTMENTS AND MINIMUM FUTURE RENTALS - Real Estate Acquisitions (Details)
 12 Months Ended
Oct. 31, 2016
Mar. 31, 2015
USD ($)
Dec. 31, 2016
USD ($)
item
Dec. 31, 2015
USD ($)
Dec. 31, 2014
USD ($)
Real Estate Acquisitions          
Contract purchase price (interest in joint venture).       $ 12,686,000  
Third Party Real Estate Acquisition Costs     $ 596,000 449,000 $ 479,000
Contributions from non-controlling interests     80,000 713,000 639,000
Payment to purchase of partner's interest       6,300,000  
Allocation of purchase price for the company's real estate acquisitions          
Land     35,484,000 25,322,000  
Building     79,216,000 52,192,000  
Building Improvements     1,983,000 2,113,000  
Intangible Lease Asset     8,194,000 5,776,000  
Intangible Lease Liability     (6,288,000) (5,365,000)  
Total     118,589,000 80,038,000  
Restricted cash     $ 643,000 $ 1,074,000  
Weighted average amortization period for intangible lease assets     9 years 3 months 18 days 6 years 9 months 18 days  
Weighted average amortization period for intangible lease liabilities     13 years 6 years 4 months 24 days  
Above market lease accumulated amortization     $ 16,074,000 $ 12,392,000  
Below market lease accumulated amortization     6,386,000 5,091,000  
Net rental income due to amortization of the above/below market leases     712,000 723,000 267,000
Future amortization income of below market leases          
Deferred rental income     2,379,000 1,458,000 336,000
Minimum future contractual rents to be received          
2017     61,749,000    
2018     60,473,000    
2019     58,200,000    
2020     55,632,000    
2021     52,465,000    
Thereafter     232,241,000    
Total     520,760,000    
Unbilled Rent Receivable          
Unbilled rent receivable (including $712 related to properties held-for-sale in 2015)     $ 13,797,000 13,577,000  
Period during which amount of unbilled rent receivable is to be billed and received     25 years    
Unbilled straight-line rent receivable written off     $ 2,060,000 120,000  
Unbilled straight-line rent receivable written off related to lease termination fees       477,000  
Rental income          
Future amortization income of below market leases          
2017     1,763,000    
2018     1,798,000    
2019     1,785,000    
2020     1,633,000    
2021     1,598,000    
Thereafter     10,703,000    
Total     19,280,000    
Amortization expense          
Allocation of purchase price for the company's real estate acquisitions          
Amortization expense relating to origination costs     3,612,000 3,467,000 $ 2,430,000
Amortization of intangible lease assets          
2017     3,910,000    
2018     3,676,000    
2019     3,288,000    
2020     3,054,000    
2021     2,765,000    
Thereafter     11,265,000    
Total     27,958,000    
Intangible lease asset - above market lease | Rental income          
Amortization of intangible lease assets          
2017     765,000    
2018     688,000    
2019     586,000    
2020     560,000    
2021     554,000    
Thereafter     1,534,000    
Total     4,687,000    
Partial condemnation of land, Greenwood Village, Colorado          
Unbilled Rent Receivable          
Unbilled straight-line rent receivable written off     $ 7,000    
Pathmark supermarket in Philadelphia, Pennsylvania          
Unbilled Rent Receivable          
Unbilled straight-line rent receivable written off       89,000  
Consolidated JV | Minimum          
Real Estate Acquisitions          
Ownership interest in consolidated joint venture of the company (as a percent)     85.00%    
Multi-tenant industrial facility, Greenville, South Carolina - 1          
Real Estate Acquisitions          
Contract purchase price (real estate)     $ 8,100,000    
Third Party Real Estate Acquisition Costs     80,000    
Allocation of purchase price for the company's real estate acquisitions          
Land     693,000    
Building     6,718,000    
Building Improvements     175,000    
Intangible Lease Asset     514,000    
Total     8,100,000    
Future amortization income of below market leases          
Payments to Acquire Real Estate     8,100,000    
Multi-tenant industrial facility, Greenville, South Carolina - 2          
Real Estate Acquisitions          
Contract purchase price (real estate)     8,950,000    
Third Party Real Estate Acquisition Costs     81,000    
Allocation of purchase price for the company's real estate acquisitions          
Land     528,000    
Building     7,893,000    
Building Improvements     181,000    
Intangible Lease Asset     441,000    
Intangible Lease Liability     (93,000)    
Total     8,950,000    
Future amortization income of below market leases          
Payments to Acquire Real Estate     8,950,000    
Toro distribution facility, El Paso, Texas          
Real Estate Acquisitions          
Contract purchase price (real estate)     23,695,000    
Third Party Real Estate Acquisition Costs     72,000    
Allocation of purchase price for the company's real estate acquisitions          
Land     3,691,000    
Building     17,525,000    
Building Improvements     379,000    
Intangible Lease Asset     2,100,000    
Total     23,695,000    
Future amortization income of below market leases          
Payments to Acquire Real Estate     23,695,000    
4 Advanced Auto retail locations, Ohio          
Real Estate Acquisitions          
Contract purchase price (real estate)     6,523,000    
Mortgage incurred     4,300,000    
Third Party Real Estate Acquisition Costs     80,000    
Allocation of purchase price for the company's real estate acquisitions          
Land     653,000    
Building     5,012,000    
Building Improvements     189,000    
Intangible Lease Asset     912,000    
Intangible Lease Liability     (243,000)    
Total     6,523,000    
Future amortization income of below market leases          
Payments to Acquire Real Estate     6,523,000    
Land - The Briarbrook Village Apartments Wheaton, Illinois          
Real Estate Acquisitions          
Contract purchase price (real estate)     10,530,000    
Allocation of purchase price for the company's real estate acquisitions          
Land     10,536,000    
Total     10,536,000    
Capitalized transaction costs incurred with the asset acquisition     6,000    
Amount of mortgage to owner/operator     $ 39,411,000    
Number of apartment units in the complex purchased | item     342    
Future amortization income of below market leases          
Payments to Acquire Real Estate     $ 10,530,000    
Burlington Coat and Micro Center retail stores, St. Louis Park, Minnesota          
Real Estate Acquisitions          
Contract purchase price (real estate)     14,150,000    
Third Party Real Estate Acquisition Costs     74,000    
Allocation of purchase price for the company's real estate acquisitions          
Land     3,388,000    
Building     12,632,000    
Building Improvements     456,000    
Intangible Lease Asset     651,000    
Intangible Lease Liability     (2,977,000)    
Total     14,150,000    
Future amortization income of below market leases          
Payments to Acquire Real Estate     14,150,000    
Land - The Vue Apartments, Beachwood, Ohio          
Real Estate Acquisitions          
Contract purchase price (real estate)     13,896,000    
Allocation of purchase price for the company's real estate acquisitions          
Land     13,901,000    
Total     13,901,000    
Capitalized transaction costs incurred with the asset acquisition     5,000    
Amount of mortgage to owner/operator     $ 67,444,000    
Number of apartment units in the complex purchased | item     348    
Future amortization income of below market leases          
Payments to Acquire Real Estate     $ 13,896,000    
Famous Footwear distribution facility, Lebanon, Tennessee          
Real Estate Acquisitions          
Contract purchase price (real estate)     32,734,000    
Mortgage incurred     21,288,000    
Third Party Real Estate Acquisition Costs     195,000    
Allocation of purchase price for the company's real estate acquisitions          
Land     2,094,000    
Building     29,436,000    
Building Improvements     603,000    
Intangible Lease Asset     3,576,000    
Intangible Lease Liability     (2,975,000)    
Total     32,734,000    
Future amortization income of below market leases          
Payments to Acquire Real Estate     $ 32,734,000    
Marston Park Plaza retail stores, Littleton, Colorado          
Real Estate Acquisitions          
Contract purchase price (real estate)       17,485,000  
Mortgage incurred       11,853,000  
Third Party Real Estate Acquisition Costs       184,000  
Allocation of purchase price for the company's real estate acquisitions          
Land       6,005,000  
Building       10,109,000  
Building Improvements       700,000  
Intangible Lease Asset       1,493,000  
Intangible Lease Liability       (822,000)  
Total       17,485,000  
Future amortization income of below market leases          
Payments to Acquire Real Estate       17,485,000  
Marston Park Plaza retail stores, Littleton, Colorado | Consolidated JV          
Real Estate Acquisitions          
Ownership interest in consolidated joint venture of the company (as a percent)     90.00%    
Ownership interest in consolidated joint venture of non-controlling interest (as a percent)     10.00%    
Contributions from non-controlling interests     $ 663,000    
Interline Brands distribution facility, Louisville, Kentucky          
Real Estate Acquisitions          
Contract purchase price (real estate)       4,400,000  
Mortgage incurred       2,640,000  
Third Party Real Estate Acquisition Costs       48,000  
Allocation of purchase price for the company's real estate acquisitions          
Land       578,000  
Building       3,622,000  
Building Improvements       105,000  
Intangible Lease Asset       95,000  
Total       4,400,000  
Future amortization income of below market leases          
Payments to Acquire Real Estate       4,400,000  
Land - The Meadows Apartments, Lakemoor, Illinois          
Real Estate Acquisitions          
Contract purchase price (real estate)     9,300,000 9,300,000  
Allocation of purchase price for the company's real estate acquisitions          
Land       9,592,000  
Total       9,592,000  
Capitalized transaction costs incurred with the asset acquisition     292,000    
Amount of mortgage to owner/operator     $ 43,824,000    
Number of apartment units in the complex purchased | item     496    
Future amortization income of below market leases          
Payments to Acquire Real Estate     $ 9,300,000 9,300,000  
Represents the retail property located in Lincoln, Nebraska acquired by the entity.          
Allocation of purchase price for the company's real estate acquisitions          
Land       3,768,000  
Building       11,262,000  
Building Improvements       570,000  
Intangible Lease Asset       922,000  
Intangible Lease Liability       (3,929,000)  
Total       12,593,000  
Future amortization income of below market leases          
Contract price directly paid to the partner of unconsolidated joint venture   $ 2,636,000      
payment made to underlying mortgage of the unconsolidated joint venture   $ 3,664,000      
Represents the retail property located in Lincoln, Nebraska acquired by the entity. | Consolidated JV          
Real Estate Acquisitions          
Percentage of equity method investments control obtained   100.00%      
Future amortization income of below market leases          
Purchase price fair value adjustment   $ 960,000      
Represents the retail property located in Lincoln, Nebraska acquired by the entity. | Unconsolidated joint ventures          
Real Estate Acquisitions          
Contract purchase price (real estate)       6,300,000  
Third Party Real Estate Acquisition Costs       12,000  
Percentage of equity method investments acquired   50.00% 50.00%    
Allocation of purchase price for the company's real estate acquisitions          
Equity Method Investment Ownership Percentage Acquired   50.00% 50.00%    
Future amortization income of below market leases          
Payments to Acquire Real Estate       6,300,000  
Archway Roofing industrial facility, Louisville, Kentucky          
Real Estate Acquisitions          
Contract purchase price (real estate)       300,000  
Third Party Real Estate Acquisition Costs       15,000  
Allocation of purchase price for the company's real estate acquisitions          
Land       51,000  
Building       221,000  
Building Improvements       9,000  
Intangible Lease Asset       19,000  
Total       300,000  
Future amortization income of below market leases          
Payments to Acquire Real Estate       300,000  
JCIM - Industrial facility, McCalla, Alabama          
Real Estate Acquisitions          
Contract purchase price (real estate)       16,618,000  
Third Party Real Estate Acquisition Costs       45,000  
Allocation of purchase price for the company's real estate acquisitions          
Land       1,588,000  
Building       14,503,000  
Building Improvements       179,000  
Intangible Lease Asset       470,000  
Intangible Lease Liability       (122,000)  
Total       16,618,000  
Future amortization income of below market leases          
Payments to Acquire Real Estate       16,618,000  
FedEx And CHEP USA distribution facility, Delport Located In St Louis Missouri          
Real Estate Acquisitions          
Contract purchase price (real estate)       19,050,000  
Mortgage incurred       12,383,000  
Third Party Real Estate Acquisition Costs       81,000  
Allocation of purchase price for the company's real estate acquisitions          
Land       3,728,000  
Building       12,456,000  
Building Improvements       550,000  
Intangible Lease Asset       2,777,000  
Intangible Lease Liability       (461,000)  
Total       19,050,000  
Future amortization income of below market leases          
Payments to Acquire Real Estate       19,050,000  
Subtotals          
Real Estate Acquisitions          
Contract purchase price (real estate)     $ 118,578,000 73,453,000  
Third Party Real Estate Acquisition Costs     596,000 449,000  
Allocation of purchase price for the company's real estate acquisitions          
Land       25,310,000  
Building       52,173,000  
Building Improvements       2,113,000  
Intangible Lease Asset       5,776,000  
Intangible Lease Liability       (5,334,000)  
Total       80,038,000  
Future amortization income of below market leases          
Payments to Acquire Real Estate     118,578,000 73,453,000  
Other          
Real Estate Acquisitions          
Third Party Real Estate Acquisition Costs     $ 14,000 64,000  
Allocation of purchase price for the company's real estate acquisitions          
Land       12,000  
Building       19,000  
Intangible Lease Liability       $ (31,000)  
Deptford, New Jersey | Consolidated JV          
Real Estate Acquisitions          
Percentage of equity method investments control obtained 100.00%