OTHER INTANGIBLE ASSETS AND LIABILITIES - Amortization of Acquired Leases (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Finite-Lived Intangible Assets [Line Items]
Acquired below-market lease amortization	$ 79	$ 150	$ 278	$ 552
Acquired above-market leases
Finite-Lived Intangible Assets [Line Items]
Acquired leases amortization	3	1	9	8
Acquired In-Place Leases
Finite-Lived Intangible Assets [Line Items]
Acquired leases amortization	$ 253	$ 303	$ 806	$ 1,047

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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