SIGNIFICANT ACCOUNTING POLICIES (Details 4)	12 Months Ended
	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($) Integer	Dec. 31, 2015 USD ($)
Acquired Finite-Lived Intangible Assets [Line Items]
Above and below market leases Increase (decrease) rental Income	$ 529,000	$ 488,000	$ 448,000
Amortization expense for in-place lease intangibles	4,535,000	$ 4,210,000	4,370,000
Projected amortization of in-place lease intangibles for the next five years [Abstract]
2018	3,576,000
2019	2,555,000
2020	1,911,000
2021	1,482,000
2022	893,000
2017 Acquisitions (Shiloh 400, Broadmoor, Hurricane Shoals 1 & 2, Southark 5-7) [Member]
Acquired operating properties [Abstract]
Total cost of properties purchased	65,243,000
Total purchase price to land	11,281,000
2017 Acquisitions (Shiloh 400, Broadmoor, Hurricane Shoals 1 & 2, Southark 5-7) [Member] | Above Market Leases [Member]
Acquired operating properties [Abstract]
Intangibles acquired associated with purchase of Real Estate	115,000
2017 Acquisitions (Shiloh 400, Broadmoor, Hurricane Shoals 1 & 2, Southark 5-7) [Member] | Leases, Acquired-in-Place [Member]
Acquired operating properties [Abstract]
Intangibles acquired associated with purchase of Real Estate	3,662,000
2017 Acquisitions (Shiloh 400, Broadmoor, Hurricane Shoals 1 & 2, Southark 5-7) [Member] | Below market lease [Member]
Acquired operating properties [Abstract]
Intangibles acquired associated with purchase of Real Estate	385,000
Flagler Center [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Number of buildings | Integer		3
2016 Acquisitions (Parc North, Flagler, Weston and Jones) [Member]
Acquired operating properties [Abstract]
Total cost of properties purchased		$ 112,158,000
Total purchase price to land		29,164,000
2016 Acquisitions (Parc North, Flagler, Weston and Jones) [Member] | Above Market Leases [Member]
Acquired operating properties [Abstract]
Intangibles acquired associated with purchase of Real Estate		393,000
2016 Acquisitions (Parc North, Flagler, Weston and Jones) [Member] | Leases, Acquired-in-Place [Member]
Acquired operating properties [Abstract]
Intangibles acquired associated with purchase of Real Estate		5,941,000
2016 Acquisitions (Parc North, Flagler, Weston and Jones) [Member] | Below market lease [Member]
Acquired operating properties [Abstract]
Intangibles acquired associated with purchase of Real Estate		894,000
2015 Acquisitions (Southpark and Springdale)
Acquired operating properties [Abstract]
Total cost of properties purchased			31,574,000
Total amount allocated to real estate properties			28,648,000
Total purchase price to land			5,494,000
2015 Acquisitions (Southpark and Springdale) | Leases, Acquired-in-Place [Member]
Acquired operating properties [Abstract]
Intangibles acquired associated with purchase of Real Estate			3,453,000
2015 Acquisitions (Southpark and Springdale) | Below market lease [Member]
Acquired operating properties [Abstract]
Intangibles acquired associated with purchase of Real Estate			$ 527,000
Real Estate Properties [Domain] | 2017 Acquisitions (Shiloh 400, Broadmoor, Hurricane Shoals 1 & 2, Southark 5-7) [Member]
Acquired operating properties [Abstract]
Total amount allocated to real estate properties	51,539,000
Real Estate Properties [Domain] | 2016 Acquisitions (Parc North, Flagler, Weston and Jones) [Member]
Acquired operating properties [Abstract]
Total amount allocated to real estate properties		22,228,000
Industrial Development [Member] | 2017 Acquisitions (Shiloh 400, Broadmoor, Hurricane Shoals 1 & 2, Southark 5-7) [Member]
Acquired operating properties [Abstract]
Total amount allocated to real estate properties	$ 10,312,000
Industrial Development [Member] | 2016 Acquisitions (Parc North, Flagler, Weston and Jones) [Member]
Acquired operating properties [Abstract]
Total amount allocated to real estate properties		$ 84,490,000