SIGNIFICANT ACCOUNTING POLICIES (Details 2) - USD ($)		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019
Property, Plant and Equipment [Line Items]
Right of use assets - Office Leases (operating)	[1]	$ 2,115,000	$ 0
Operating Lease, Right-of-Use Asset	[2]	11,997,000	0
Indirect leasing costs		411,000	0	$ 0
Depreciation		$ 86,590,000	$ 76,007,000	$ 69,010,000
Buildings [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)		40 years
Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)		3 years
Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)		15 years
Accounting Standards Update 2016-02 [Member]
Property, Plant and Equipment [Line Items]
Right of use assets - Office Leases (operating)					$ 2,376,000
Operating Lease, Right-of-Use Asset					$ 10,226,000
Right of use asset and lease liability for ground leases and office leases, estimated percentage of Total assets		less than 1%

[1] See Note 1(o) for information regarding the Company’s January 1, 2019, implementation of FASB ASC 842, Leases, and the Company’s right of use assets for office leases.

[2] See Ground Leases discussion below and in Note 1(o) for information regarding the Company's right of use assets for ground leases.