Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2016

Summary of Significant Accounting Policies [Abstract]

Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions And Methodology [Table Text Block]

The fair value for the Company's share options was estimated at the time the share options were granted using the Black-Scholes option pricing model with the primary grant in each year having the following weighted average assumptions:

	2016	2015	2014
Expected volatility (1)	26.3%	26.6%	27.0%
Expected life (2)	5 years	5 years	5 years
Expected dividend yield (3)	3.04%	3.13%	3.78%
Risk-free interest rate (4)	1.27%	1.29%	1.50%
Option valuation per share	$13.02	$13.68	$9.12

(1) Expected volatility – Estimated based on the historical ten-year volatility of EQR’s share price measured on a monthly basis.

(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 regular dividends (excluding any special 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 [Table Text Block]

The Company provided for income, franchise and excise taxes allocated as follows in the consolidated statements of operations and comprehensive income for the years ended December 31, 2016, 2015 and 2014 (amounts in thousands):

	Year Ended December 31,
	2016		2015		2014
Income and other tax expense (benefit) (1)	$	1,613	$	917	$	1,394
Discontinued operations, net (2)	12		15		8
Provision for income, franchise and excise taxes (3)	$	1,625	$	932	$	1,402

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

(2) Primarily represents state and local income, excise and franchise taxes on operating properties sold prior to January 1, 2014 and included in discontinued operations. The amounts included in discontinued operations for the years ending December 31, 2016, 2015 and 2014 represent trailing activity for properties sold in 2013 and prior years. None of the properties sold during the years ended December 31, 2016, 2015 and 2014 met the new criteria for reporting discontinued operations.

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

Tax Treatment Of Dividends And Distributions [Table Text Block]

During the years ended December 31, 2016, 2015 and 2014, the Company’s tax treatment of dividends and distributions were as follows (unaudited):

	Year Ended December 31,
	2016		2015		2014
Tax treatment of dividends and distributions:
Ordinary dividends	$	0.722	$	1.591	$	1.475
Qualified dividends	—		0.037		0.088
Long-term capital gain	9.176		0.443		0.280
Unrecaptured section 1250 gain	3.117		0.139		0.157
Dividends and distributions declared per
Common Share/Unit outstanding	$	13.015	$	2.210	$	2.000

Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block]

As of December 31, 2015, the following amounts of deferred financing costs were reclassified (amounts in thousands):

	As Originally Presented		Reclassification Adjustments			As Presented Herein
Deferred financing costs, net	$	54,004	$	(54,004	)	$	—
Other assets	$	422,027	$	6,872		$	428,899
Mortgage notes payable, net	$	4,704,870	$	(19,736	)	$	4,685,134
Notes, net	$	5,876,352	$	(27,396	)	$	5,848,956