Other (Details)	Mar. 31, 2016 shares
Additional Common Shares Authorized	13,000,000
Stock Repurchase Program, Number of Shares Authorized to be Repurchased	13,000,000
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased	12,968,760

Represents the remaining number of shares to be issued into the existing trading market at current market prices as well as through negotiated transactions under the Company's at-the-market share offering program.

No definition available.

Name:	eqr_AdditionalCommonSharesAuthorized
Namespace Prefix:	eqr_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant