STORAGE PROPERTIES - Summary (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
STORAGE FACILITIES
Storage properties	$ 4,814,261	$ 4,699,844
Less: Accumulated depreciation	(980,312)	(925,359)
Storage properties, net (including VIE assets of $86,409 and $92,612, respectively)	3,833,949	3,774,485
Land
STORAGE FACILITIES
Storage properties	908,051	858,541
Buildings and improvements
STORAGE FACILITIES
Storage properties	3,692,519	3,619,594
Equipment
STORAGE FACILITIES
Storage properties	125,204	128,111
Construction in progress
STORAGE FACILITIES
Storage properties	$ 88,487	$ 93,598

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- Definition

The cumulative amount of depreciation for real estate property held for investment purposes.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.1(3))
-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

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Amount of real estate investment property which may include the following: (1) land available-for-sale; (2) land available-for-development; (3) investments in building and building improvements; (4) tenant allowances; (5) developments in-process; (6) rental properties; and (7) other real estate investments.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.1(d))
-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

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Amount of real estate investment property, net of accumulated depreciation, which may include the following: (1) land available-for-sale; (2) land available-for-development; (3) investments in building and building improvements; (4) tenant allowances; (5) developments in-process; (6) rental properties; and (7) other real estate investments.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

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