SIGNIFICANT ACCOUNTING POLICIES (Details 4) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Acquired Finite-Lived Intangible Assets [Line Items]
Above and below market leases Increase (decrease) rental Income	$ 448,000	$ 421,000	$ 188,000
Amortization expense for in-place lease intangibles	4,370,000	4,727,000	4,281,000
Projected amortization of in-place lease intangibles for the next five years [Abstract]
2016	3,886,000
2017	2,540,000
2018	1,513,000
2019	1,078,000
2020	724,000
Southpark Corporate Center and Springdale Business Center [Member]
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
Southpark Corporate Center and Springdale Business Center [Member] | Leases, Acquired-in-Place [Member]
Acquired operating properties [Abstract]
Intangibles acquired associated with purchase of Real Estate	3,453,000
Southpark Corporate Center and Springdale Business Center [Member] | Below market lease [Member]
Acquired operating properties [Abstract]
Intangibles acquired associated with purchase of Real Estate	$ 527,000
Ridge Creek Distribution Center III, Colorado Crossing Distribution Center and Ramona Distribution Center [Domain]
Acquired operating properties [Abstract]
Total cost of properties purchased		51,652,000
Total amount allocated to real estate properties		47,477,000
Total purchase price to land		10,822,000
Cash paid for acquired properties		48,805,000
Mortgages assumed in connection with purchase of real estate, face amount		2,617,000
Premium on mortgage loan, amount recognized at assumption of loan		230,000
Ridge Creek Distribution Center III, Colorado Crossing Distribution Center and Ramona Distribution Center [Domain] | Above Market Leases [Member]
Acquired operating properties [Abstract]
Intangibles acquired associated with purchase of Real Estate		4,000
Ridge Creek Distribution Center III, Colorado Crossing Distribution Center and Ramona Distribution Center [Domain] | Leases, Acquired-in-Place [Member]
Acquired operating properties [Abstract]
Intangibles acquired associated with purchase of Real Estate		5,074,000
Ridge Creek Distribution Center III, Colorado Crossing Distribution Center and Ramona Distribution Center [Domain] | Below market lease [Member]
Acquired operating properties [Abstract]
Intangibles acquired associated with purchase of Real Estate		$ 903,000
Northfield Distribution Center and Interchange Park II [Domain]
Acquired operating properties [Abstract]
Total cost of properties purchased			72,397,000
Total amount allocated to real estate properties			65,387,000
Total purchase price to land			13,218,000
Northfield Distribution Center and Interchange Park II [Domain] | Above Market Leases [Member]
Acquired operating properties [Abstract]
Intangibles acquired associated with purchase of Real Estate			158,000
Northfield Distribution Center and Interchange Park II [Domain] | Leases, Acquired-in-Place [Member]
Acquired operating properties [Abstract]
Intangibles acquired associated with purchase of Real Estate			8,399,000
Northfield Distribution Center and Interchange Park II [Domain] | Below market lease [Member]
Acquired operating properties [Abstract]
Intangibles acquired associated with purchase of Real Estate			$ 1,547,000