INTANGIBLE LEASE ASSETS AND LIABILITIES (Components) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Intangible lease assets:
Intangible leased assets	$ 169,138	$ 182,147
Intangible lease liabilities:
Below market leases net of amortization	17,257	20,523
Below market lease, accumulated amortization	$ 31,445	$ 25,800
Below market lease, weighted average useful life	6 years 7 months 6 days	7 years 3 months 18 days
In-place leases and other intangibles
Intangible lease assets:
Intangible leased assets	$ 152,991	$ 164,724
Accumulated amortization	$ 131,018	$ 111,670
Useful life	9 years 9 months 18 days	10 years 4 months 24 days
Acquired above-market leases
Intangible lease assets:
Intangible leased assets	$ 16,147	$ 17,423
Accumulated amortization	$ 22,065	$ 19,310
Useful life	7 years 6 months	7 years 10 months 24 days