Equity Method Investment, Ownership Percentage Sold

No definition available.

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- Definition

Joint Venture, Cost Of Acquired Asset, Purchase Price

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Number of acquired stores.

+ References

No definition available.

+ Details

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- Definition

Unconsolidated Joint Ventures Excess Profit Participation Percentage Forfeited

+ References

No definition available.

+ Details

Name:	exr_UnconsolidatedJointVenturesExcessProfitParticipationPercentageForfeited
Namespace Prefix:	exr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

This element represents the aggregate cost of investments accounted for under the equity method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571

+ Details

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Balance Type:	na
Period Type:	instant

- Definition

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

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of the entity's equity method investment which has been sold.

+ References

No definition available.

+ Details

Name:	us-gaap_EquityMethodInvestmentSoldCarryingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the number of stores.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfStores
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- 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://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Investing Activities
-URI http://asc.fasb.org/extlink&oid=6516133

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3179-108585

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

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.

+ References

No definition available.

+ Details

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- Details

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Investments in Unconsolidated Real Estate Ventures - Additional Information (Detail) $ in Thousands	Sep. 16, 2016 USD ($) store	Sep. 14, 2016 USD ($) store	Aug. 16, 2016 USD ($) store	Jul. 08, 2016 USD ($)	May 20, 2016 USD ($) store	Apr. 08, 2016 USD ($) store	Mar. 31, 2016 USD ($) store	Apr. 01, 2016	Mar. 31, 2015
PRISA II [Member]
Schedule of Equity Method Investments [Line Items]
Number of stores acquired \| store	23
Percent of interest sold	4.42%
Proceeds from sale of investment	$ 34,758
Carrying amount of investment sold	3,912
Gain on sale of investment	$ 30,846
Equity method ownership percentage	4.42%
Vancouver [Member]
Schedule of Equity Method Investments [Line Items]
Joint venture, cost of acquired store		$ 8,700
Number of stores \| store		1
Amount paid for interest		$ 806
Equity method ownership percentage		25.00%
Elmont [Member]
Schedule of Equity Method Investments [Line Items]
Joint venture, cost of acquired store			$ 24,700
Number of stores \| store			1
Amount paid for interest			$ 4,712
Equity method ownership percentage			50.00%
Hillsboro [Member]
Schedule of Equity Method Investments [Line Items]
Joint venture, cost of acquired store				$ 3,672
Number of stores \| store						1
Amount paid for interest				$ 376
Equity method ownership percentage				25.00%
BH [Member]
Schedule of Equity Method Investments [Line Items]
Joint venture, cost of acquired store					$ 8,000
Number of stores \| store					1
Amount paid for interest					$ 1,034
Equity method ownership percentage					20.00%
ESS PRISA LLC and ESS PRISA TWO LLC [Member]
Schedule of Equity Method Investments [Line Items]
Excess profit participation percentage forfeited in amendments								17.00%
ESS PRISA LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity method ownership percentage								4.00%	2.00%
ESS PRISA II LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity method ownership percentage								4.40%	2.00%
PREXR [Member]
Schedule of Equity Method Investments [Line Items]
Joint venture, cost of acquired store						$ 52,000
Number of stores \| store						1
Amount paid for interest						$ 12,114
Equity method ownership percentage						25.00%
Baychester [Member]
Schedule of Equity Method Investments [Line Items]
Joint venture, cost of acquired store							$ 23,000
Number of stores \| store							1
Amount paid for interest							$ 4,794
Equity method ownership percentage							44.40%