OTHER ASSETS (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Other Assets Components [Abstract]
Leasing costs (principally commissions)	$ 92,507	$ 89,191
Accumulated amortization of leasing costs	(36,013)	(34,963)
Leasing costs (principally commissions), net of accumulated amortization	56,494	54,228
Acquired in-place lease intangibles	28,571	28,834
Accumulated amortization of acquired in-place lease intangibles	(12,552)	(11,918)
Acquired in-place lease intangibles, net of accumulated amortization	16,019	16,916
Acquired above market lease intangibles	1,723	1,721
Accumulated amortization of acquired above market lease intangibles	(1,062)	(1,007)
Acquired above market lease intangibles, net of accumulated amortization	661	714
Straight-line rents receivable	41,280	40,369
Accounts receivable	4,393	5,581
Mortgage loans receivable	1,672	1,679
Interest rate swap assets	0	3,485
Right of use assets - Office Leases (operating)	2,499	2,115
Goodwill	990	990
Prepaid expenses and other assets	17,799	18,545
Total Other Assets	$ 141,807	$ 144,622