Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2010

Summary of Significant Accounting Policies (Tables) [Abstract]

Weighted average assumptions used to estimate the fair value for the Company's share options

	2010		2009		2008
Expected volatility (1)		32.4%		26.8%		20.3%
Expected life (2)		5 years		5 years		5 years
Expected dividend yield (3)		4.85%		4.68%		4.95%
Risk-free interest rate (4)		2.29%		1.89%		2.67%
Option valuation per share		$6.18		$3.38		$4.08

(1) Expected volatility – Estimated based on the historical volatility of EQR’s share price, on a monthly basis, for a period matching the expected life of each grant.

(2) Expected life – Approximates the actual weighted average life of all share options granted since the Company went public in 1993.

(3) Expected dividend yield – Calculated by averaging the historical annual yield on EQR shares for a period matching the expected life of each grant, with the annual yield calculated by dividing actual dividends by the average price of EQR’s shares in a given year.

(4) Risk-free interest rate – The most current U.S. Treasury rate available prior to the grant date for a period matching the expected life of each grant.

Allocation of income, franchise and excise taxes in consolidated statements of operations

	Year Ended December 31,
	2010		2009			2008
Income and other tax expense (benefit) (1)	$	292	$	2,716		$	5,235
Discontinued operations, net (2)		86		(1,073	)		(1,797	)
Provision for income, franchise and excise taxes (3)	$	378	$	1,643		$	3,438

(1) Primarily includes state and local income, excise and franchise taxes.

(2) Primarily represents federal income taxes (recovered) on the gains on sales of condominium units owned by a TRS and included in discontinued operations. Also represents state and local income, excise and franchise taxes on operating properties sold and included in discontinued operations.

(3) All provisions for income tax amounts are current and none are deferred.

Tax treatment of dividends and distributions

	Year Ended December 31,
	2010		2009		2008
Tax treatment of dividends and distributions:
Ordinary dividends	$	0.607	$	0.807	$	0.699
Long-term capital gain		0.622		0.558		0.755
Unrecaptured section 1250 gain		0.241		0.275		0.476
Dividends and distributions declared per Common Share outstanding	$	1.470	$	1.640	$	1.930