The additional Preferred equity interest investment in a related party entity.

No definition available.

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Namespace Prefix:	ess_
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- Definition

Refers to income related to the restructured investment.

+ References

No definition available.

+ Details

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- Definition

This element represents a description of the nature of common ownership or management control relationships with other entities, regardless of there being transactions between the entities, when the existence of that control could result in operating results or financial position of the reporting entity significantly different from that which would have been obtained if the entities' were autonomous.

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Management And Other Fees From Affiliates

+ References

No definition available.

+ Details

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Namespace Prefix:	ess_
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Balance Type:	credit
Period Type:	duration

- Definition

Refer to Maximum Term Extended related to the restructured investment

+ References

No definition available.

+ Details

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- Definition

Number of property units acquired during the period.

+ References

No definition available.

+ Details

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- Definition

Number of units acquired.

+ References

No definition available.

+ Details

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- Definition

The Preferred equity interest investment in a related party entity.

+ References

No definition available.

+ Details

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Namespace Prefix:	ess_
Data Type:	xbrli:monetaryItemType
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- Definition

The preferred return on the investment in the related party investee.

+ References

No definition available.

+ Details

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Namespace Prefix:	ess_
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Period Type:	duration

- Definition

Maximum preferred return on preferred equity investment after first five years

+ References

No definition available.

+ Details

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Namespace Prefix:	ess_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Minimum preferred return on preferred equity investment after first five years.

+ References

No definition available.

+ Details

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Namespace Prefix:	ess_
Data Type:	num:percentItemType
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- Definition

The number of units in the community.

+ References

No definition available.

+ Details

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Namespace Prefix:	ess_
Data Type:	xbrli:integerItemType
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Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
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Period Type:	duration

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(2))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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- Definition

Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

+ 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 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

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- Definition

The amount of cash paid for brokerage fees during the current period. This element is intended to represent the brokerage fees paid by and between financial industry participants.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 25

-Subparagraph (g)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3536-108585

+ Details

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Period Type:	duration

- Definition

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

+ 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 13

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3213-108585

+ Details

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

- Definition

Amount of transactions with related party during the financial reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 850

-SubTopic 10

-Section 50

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39622-107864

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-Topic 850

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-Section 50

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 850

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

+ Details

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Balance Type:	debit
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- Details

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Related Party Transactions (Details) (USD $)	12 Months Ended			1 Months Ended		3 Months Ended
Related Party Transactions (Details) (USD $)	Dec. 31, 2014 unit	Dec. 31, 2013 unit	Dec. 31, 2012	Jul. 31, 2014 unit	Jan. 31, 2013	Sep. 30, 2012
Related Party Transaction [Line Items]
Management and other fees from affiliates	$ 16,500,000	$ 11,511,000	$ 10,865,000
Cash consideration for BRE merger	555,826,000	0	0
Short term bridge loan	8,100,000
Debt instrument, basis spread on variable rate (in hundredths)			2.50%
Number of units acquired	1,480ess_NumberOfUnitsAcquired	1,079ess_NumberOfUnitsAcquired
Cost of acquired entity	555,826,000	0	0
Executive Vice President of the Company invested	4,000,000
Limited partnership interest in partnership investments (in hundredths)	3.00%
Paragon Apartments [Member]
Related Party Transaction [Line Items]
Number of properties contributed				301
Cash consideration for BRE merger				111,000,000
Cost of acquired entity				111,000,000
Wesco III [Member]
Related Party Transaction [Line Items]
Short term bridge loan			26,000,000.0
Marcus and Millichamp Company TMMC Affiliate [Member]
Related Party Transaction [Line Items]
Preferred equity interest investment in a related party entity					8,600,000
MMI [Member]
Related Party Transaction [Line Items]
Payments for Brokerage Fees		600,000	400,000
MMC [Member]
Related Party Transaction [Line Items]
Preferred return on preferred equity investment, thereafter, maximum (in hundredths)	13.00%
Preferred return on preferred equity investment, thereafter, minimum (in hundredths)	9.00%
Maximum Term Extended (in years)	1 year
Income related to the restructured investment	400,000
Pacific Urban Residential [Member]
Related Party Transaction [Line Items]
Preferred equity interest investment in a related party entity						14,000,000
Preferred return on investment in related party investee (in hundredths)						9.50%
Maturity date						May 31, 2016
Additional preferred equity interest investment related party entity						4,000,000
Montebello [Member]
Related Party Transaction [Line Items]
Cash consideration for BRE merger						52,000,000
Number of units acquired						248
Cost of acquired entity						52,000,000
TMCC and Wesco I [Member]
Related Party Transaction [Line Items]
Cash consideration for BRE merger						38,300,000
Cost of acquired entity						$ 38,300,000
Units in the community						156