Equity, Capital and other Interests (Tables)

9 Months Ended

Sep. 30, 2011

Class of Stock [Line Items]

Common shares and units rollforward

	2011
Common Shares
Common Shares outstanding at January 1,		290,197,242
Common Shares Issued:
Conversion of OP Units		324,649
Issuance of Common Shares		3,038,980
Exercise of share options		2,914,476
Employee Share Purchase Plan (ESPP)		98,766
Restricted share grants, net		148,708
Common Shares Other:
Conversion of restricted shares to LTIP Units		(101,988	)
Common Shares outstanding at September 30,		296,620,833
Units
Units outstanding at January 1,		13,612,037
LTIP Units, net		120,112
Conversion of restricted shares to LTIP Units		101,988
Conversion of OP Units to Common Shares		(324,649	)
Units outstanding at September 30,		13,509,488
Total Common Shares and Units outstanding at September 30,		310,130,321
Units Ownership Interest in Operating Partnership		4.4	%

Preferred shares schedule

			Annual		Amounts in thousands
	Redemption Date (1)		Dividend per Share (2)		September 30, 2011		December 31, 2010
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 September 30, 2011 and December 31, 2010		12/10/26	$	4.145	$	50,000	$	50,000
6.48% Series N Cumulative Redeemable Preferred; liquidation value $250 per share; 600,000 shares issued and outstanding at September 30, 2011 and December 31, 2010 (3)		6/19/08	$	16.20		150,000		150,000
					$	200,000	$	200,000

(1) On or after the redemption date, redeemable preferred shares (Series K and N) 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 all series of Preferred Shares are payable quarterly at various pay dates. The dividend listed for Series N is a Preferred Share rate and the equivalent Depositary Share annual dividend is $1.62 per share.

(3) The Series N Preferred Shares have a corresponding depositary share that consists of ten times the number of shares and one-tenth the liquidation value and dividend per share.

OPERATING PARTNERSHIP

Class of Stock [Line Items]

Redeemable noncontrolling interests rollforward

	2011
Balance at January 1,	$	383,540
Change in market value		(16,023	)
Change in carrying value		11,281
Balance at September 30,	$	378,798

Preferred shares schedule

	Redemption Date (1)		Annual Dividend per Unit (2)		Amounts in thousands
					September 30, 2011		December 31, 2010
Preference Units:
8.29% Series K Cumulative Redeemable Preference Units; liquidation value $50 per unit; 1,000,000 units issued and outstanding at September 30, 2011 and December 31, 2010		12/10/26	$	4.145	$	50,000	$	50,000
6.48% Series N Cumulative Redeemable Preference Units; liquidation value $250 per unit; 600,000 units issued and outstanding at September 30, 2011 and December 31, 2010 (3)		6/19/08	$	16.20		150,000		150,000
					$	200,000	$	200,000

(1) On or after the redemption date, redeemable preference units (Series K and N) 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 all series of Preference Units are payable quarterly at various pay dates. The dividend listed for Series N is a Preference Unit rate and the equivalent depositary unit annual dividend is $1.62 per unit.

(3) The Series N Preference Units have a corresponding depositary unit that consists of ten times the number of units and one-tenth the liquidation value and dividend per unit.

General And Limited Partner [Member]

Class of Stock [Line Items]

Common shares and units rollforward

	2011
General and Limited Partner Units
General and Limited Partner Units outstanding at January 1,		303,809,279
Issued to General Partner:
Issuance of OP Units		3,038,980
Exercise of EQR share options		2,914,476
EQR’s Employee Share Purchase Plan (ESPP)		98,766
EQR restricted share grants, net		148,708
Issued to Limited Partners:
LTIP Units, net		120,112
General and Limited Partner Units outstanding at September 30,		310,130,321
Limited Partner Units
Limited Partner Units outstanding at January 1,		13,612,037
Limited Partner LTIP Units, net		120,112
Conversion of EQR restricted shares to LTIP Units		101,988
Conversion of Limited Partner OP Units to EQR Common Shares		(324,649	)
Limited Partner Units outstanding at September 30,		13,509,488
Limited Partner Units Ownership Interest in Operating Partnership		4.4	%

LIMITED PARTNERS

Class of Stock [Line Items]

Redeemable noncontrolling interests rollforward

	2011
Balance at January 1,	$	383,540
Change in market value		(16,023	)
Change in carrying value		11,281
Balance at September 30,	$	378,798