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- Definition

Equity Method Investments, Number Of Investments Purchased

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Equity Method Investments, Number Of Investments Sold

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Equity Method Investments, Number Of Stores Acquired

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Equity Method Investments, Number Of Stores Sold

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Exchange Of Real Estate For Interest In Joint Venture

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- Definition

Investment In Unconsolidated Real Estate Entities, Net Of Distributions

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- Definition

Number Of Stores Sold

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- Definition

Preferred Stock Investment, Dividend Rate

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Preferred Stock Investment, Period After Which Dividend Rate Is Subject To Increase

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- Definition

Preferred Stock Investment, Redemption Restriction Period

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- Definition

The percentage of excess profit participation in unconsolidated joint ventures.

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- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
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- Definition

Amount of gain (loss) on sale or disposal of an equity method investment.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(b)(7)(c))
-URI http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
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-Section S99
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-Subparagraph (SX 210.5-03(b)(9)(a))
-URI http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227

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- Definition

The cash outflow associated with the purchase of or advances to an equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
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- Definition

The cash inflow associated with the sale of equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
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-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3179-108585

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- Definition

Cash received for the sale of real estate that is not part of an investing activity during the current period.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 45
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Investments in Unconsolidated Real Estate Entities (Details) $ in Thousands		1 Months Ended	9 Months Ended
	Mar. 01, 2021 USD ($) store	Jun. 30, 2021 USD ($) store joint_venture	Sep. 30, 2021 USD ($) store	Sep. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)
Schedule of Equity Method Investments [Line Items]
Number of Stores \| store			257
Equity Ownership %	55.00%
Investment balance			$ 310,569		$ 350,318
Gain on sale of joint ventures		$ 525
Number of stores sold \| store	16
Proceeds from sale of real estate assets and investments in real estate ventures	$ 132,759
Real estate exchanged for interest in joint venture	$ 33,878
Amount invested			$ 20,834	$ 13,937
Number of joint venture stores purchased \| store			15
Number of joint ventures sold \| joint_venture		2
Proceeds from sale of joint ventures		$ 1,888
Number of joint ventures purchased \| joint_venture		2
Minimum
Schedule of Equity Method Investments [Line Items]
Equity Ownership %			10.00%
Excess Profit %			19.00%
Maximum
Schedule of Equity Method Investments [Line Items]
Equity Ownership %			50.00%
Excess Profit %			50.00%
PR EXR Self Storage, LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores \| store			5
Equity Ownership %			25.00%
Excess Profit %			40.00%
Investment balance			$ 59,633		60,092
WICNN JV LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores \| store			0
Equity Ownership %			10.00%
Excess Profit %			35.00%
Investment balance			$ 0		36,032
ESS-CA TIVS JV LP
Schedule of Equity Method Investments [Line Items]
Number of Stores \| store			16
Equity Ownership %			55.00%
Excess Profit %			60.00%
Investment balance			$ 33,543		0
GFN JV, LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores \| store			0
Equity Ownership %			10.00%
Excess Profit %			30.00%
Investment balance			$ 0		18,397
ESS-NYFL JV LP
Schedule of Equity Method Investments [Line Items]
Number of Stores \| store			11
Equity Ownership %			16.00%
Excess Profit %			24.00%
Investment balance			$ 11,959		12,211
PRISA Self Storage LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores \| store			85
Equity Ownership %			4.00%
Excess Profit %			4.00%
Investment balance			$ 8,694		8,815
Alan Jathoo JV LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores \| store			9
Equity Ownership %			10.00%
Excess Profit %			10.00%
Investment balance			$ 7,651		7,780
Storage Portfolio IV JV LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores \| store			15
Equity Ownership %			10.00%
Excess Profit %			30.00%
Investment balance			$ 20,528		0
Storage Portfolio III JV LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores \| store			5
Equity Ownership %			10.00%
Excess Profit %			30.00%
Investment balance			$ 5,613		5,726
ESS Bristol Investments LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores \| store			8
Equity Ownership %			10.00%
Excess Profit %			30.00%
Investment balance			$ 2,715		2,810
Extra Space Northern Properties Six LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores \| store			10
Equity Ownership %			10.00%
Excess Profit %			35.00%
Investment balance			$ (2,855)		(2,541)
Storage Portfolio II JV LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores \| store			36
Equity Ownership %			10.00%
Excess Profit %			30.00%
Investment balance			$ (5,954)		(5,441)
VRS Self Storage, LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores \| store			16
Equity Ownership %			45.00%
Excess Profit %			54.00%
Investment balance			$ (14,570)		17,186
Storage Portfolio I LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores \| store			24
Equity Ownership %			34.00%
Excess Profit %			49.00%
Investment balance			$ (39,817)		(39,144)
Other minority owned stores
Schedule of Equity Method Investments [Line Items]
Number of Stores \| store			17
Investment balance			$ 23,429		28,395
SmartStop Self Storage REIT, Inc. Preferred Stock
Schedule of Equity Method Investments [Line Items]
Investment balance			$ 200,000		$ 200,000
Investment, preferred dividend rate			6.25%
Period after which preferred stock dividend is subject to increase			5 years
Investment redemption restriction period			5 years
WICNN JV LLC and GFN JV, LLC
Schedule of Equity Method Investments [Line Items]
Number of joint venture stores sold \| store		17
Gain on sale of joint ventures		$ 5,739