Name:	eqr_HighestPossibleNotional
Namespace Prefix:	eqr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Lowest possible notional amount of all derivatives designated as fair value or cash flow hedging instruments. The notional amount relates to a number of currency units, shares, bushels, pounds or other units specified in a derivative instrument.

No definition available.

Name:	eqr_LowestPossibleNotional
Namespace Prefix:	eqr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 12

-Section 13

-Sentence Column B

Name:	invest_DerivativeNotionalAmount
Namespace Prefix:	invest_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

High end of the range of fixed interest rates when a range is presented for a group of interest rate derivatives.

No definition available.

Name:	us-gaap_DerivativeHigherFixedInterestRateRange
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_DerivativeLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Low end of the range of fixed interest rates when a range is presented for a group of interest rate derivatives.

No definition available.