Equity, Capital and Other Interests (Tables)

3 Months Ended

Mar. 31, 2013

Common shares and units rollforward

	2013
Common Shares
Common Shares outstanding at January 1,	325,054,654
Common Shares Issued:
Conversion of OP Units	23,964
Issuance of Common Shares	34,468,085
Exercise of share options	268,547
Employee Share Purchase Plan (ESPP)	37,704
Restricted share grants, net	210,721
Common Shares outstanding at March 31,	360,063,675
Units
Units outstanding at January 1,	13,968,758
LTIP Units, net	281,931
Conversion of OP Units to Common Shares	(23,964	)
Units outstanding at March 31,	14,226,725
Total Common Shares and Units outstanding at March 31,	374,290,400
Units Ownership Interest in Operating Partnership	3.8	%

Redeemable Noncontrolling Interest [Table Text Block]

	2013
Balance at January 1,	$	398,372
Change in market value	(50,109		)
Change in carrying value	38,494
Balance at March 31,	$	386,757

Schedule Of Preferred Stock [Table Text Block]

				Amounts in thousands
	Redemption Date (1)	Annual Dividend per Share (2)		March 31, 2013		December 31, 2012
Preferred Shares of beneficial interest, $0.01 par value;   100,000,000 shares authorized:
8.29% Series K Cumulative Redeemable Preferred; liquidation   value $50 per share; 1,000,000 shares issued and outstanding   at March 31, 2013 and December 31, 2012	12/10/26		$4.145	$	50,000	$	50,000
				$	50,000	$	50,000

(1) On or after the redemption date, redeemable preferred shares may be redeemed for cash at the option of the Company, in whole or in part, at a redemption price equal to the liquidation price per share, plus accrued and unpaid distributions, if any.

(2) Dividends on Preferred Shares are payable quarterly.

Limited Partner [Member]

Common shares and units rollforward

	2013
General and Limited Partner Units
General and Limited Partner Units outstanding at January 1,	339,023,412
Issued to General Partner:
Issuance of OP Units	34,468,085
Exercise of EQR share options	268,547
EQR’s Employee Share Purchase Plan (ESPP)	37,704
EQR's restricted share grants, net	210,721
Issued to Limited Partners:
LTIP Units, net	281,931
General and Limited Partner Units outstanding at March 31,	374,290,400
Limited Partner Units
Limited Partner Units outstanding at January 1,	13,968,758
Limited Partner LTIP Units, net	281,931
Conversion of Limited Partner OP Units to EQR Common Shares	(23,964	)
Limited Partner Units outstanding at March 31,	14,226,725
Limited Partner Units Ownership Interest in Operating Partnership	3.8	%

Redeemable Noncontrolling Interest [Table Text Block]

	2013
Balance at January 1,	$	398,372
Change in market value	(50,109		)
Change in carrying value	38,494
Balance at March 31,	$	386,757

Schedule Of Preferred Stock [Table Text Block]

				Amounts in thousands
	Redemption Date (1)	Annual Dividend per Unit (2)		March 31, 2013		December 31, 2012
Preference Units:
8.29% Series K Cumulative Redeemable Preference Units;   liquidation value $50 per unit; 1,000,000 units issued and   outstanding at March 31, 2013 and December 31, 2012	12/10/26		$4.145	$	50,000	$	50,000
				$	50,000	$	50,000

(1) On or after the redemption date, redeemable preference units may be redeemed for cash at the option of the Operating Partnership, in whole or in part, at a redemption price equal to the liquidation price per unit, plus accrued and unpaid distributions, if any, in conjunction with the concurrent redemption of the corresponding Company Preferred Shares.

(2) Dividends on Preference Units are payable quarterly.