Associated Estates Realty 10-Q 31 Oct 14 2014 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2014	Oct. 28, 2014
Document and Entity Information [Abstract]	'	'
Entity Registrant Name	'ASSOCIATED ESTATES REALTY CORP	'
Entity Central Index Key	'0000911635	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Document Type	'10-Q	'
Document Period End Date	30-Sep-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q3	'
Amendment Flag	'false	'
Entity Common Stock, Shares Outstanding	'	57,647,647
Entity Well-known Seasoned Issuer	'Yes	'
Entity Voluntary Filers	'No	'
Entity Current Reporting Status	'Yes	'

Consolidated_Balance_Sheets_Un

Consolidated Balance Sheets (Unaudited) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Real estate assets	'	'
Land	$248,407	$298,441
Buildings and improvements	1,333,153	1,370,560
Furniture and fixtures	39,999	39,725
Construction in progress	85,437	42,793
Gross real estate	1,706,996	1,751,519
Less: Accumulated depreciation	-396,495	-386,841
Net real estate owned	1,310,501	1,364,678
Investment in unconsolidated entities	45,921	9,321
Total net real estate	1,356,422	1,373,999
Cash and cash equivalents	5,328	4,586
Restricted cash	24,071	3,465
Accounts receivable, net	'	'
Rents	1,182	1,230
Other	2,633	1,258
Other assets, net	32,195	37,959
Total assets	1,421,831	1,422,497
LIABILITIES AND EQUITY	'	'
Mortgage notes payable	287,824	279,474
Unsecured notes	250,000	250,000
Unsecured revolving credit facility	41,500	133,500
Unsecured term loan	150,000	150,000
Total debt	729,324	812,974
Accounts payable and other liabilities	48,805	42,882
Dividends payable	12,188	12,178
Resident security deposits	3,898	4,112
Accrued interest	4,792	5,551
Total liabilities	799,007	877,697
Equity	'	'
Common shares, without par value; $.10 stated value; 91,000,000 authorized; 57,708,675 issued and 57,647,647 outstanding at September 30, 2014 and 57,595,479 issued and 57,476,192 outstanding at December 31, 2013, respectively	5,771	5,760
Paid-in capital	757,323	754,582
Accumulated distributions in excess of accumulated net income	-138,990	-213,275
Accumulated other comprehensive loss	-634	-702
Less: Treasury shares, at cost, 61,028 and 119,287 shares at September 30, 2014 and December 31, 2013, respectively	-996	-1,915
Total shareholders' equity attributable to AERC	622,474	544,450
Noncontrolling interest	350	350
Total equity	622,824	544,800
Total liabilities and equity	$1,421,831	$1,422,497

Consolidated_Balance_Sheets_Un1

Consolidated Balance Sheets (Unaudited) (Parenthetical) (Parentheticals) (USD $)	Sep. 30, 2014	Dec. 31, 2013
Stockholders' Equity:	'	'
Common stock, par value	'	'
Common stock, stated value	$0.10	$0.10
Common stock, shares authorized	91,000,000	91,000,000
Common stock, shares issued	57,708,675	57,595,479
Common stock, shares outstanding	57,647,647	57,476,192
Treasury Stock, shares	61,028	119,287

Consolidated_Statement_of_Oper

Consolidated Statement of Operations and Comprehensive Income (Unaudited) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Revenue	'	'	'	'
Property revenue	$47,444	$45,619	$143,862	$131,409
Office revenue	451	450	1,384	1,000
Property management and construction services revenue	312	0	578	0
Total revenue	48,207	46,069	145,824	132,409
Expenses	'	'	'	'
Property operating and maintenance	18,073	17,336	55,573	50,194
Depreciation and amortization	15,779	14,212	47,958	41,960
General and administrative	4,200	4,946	14,116	14,302
Development costs	162	220	690	662
Construction services	129	0	219	0
Costs associated with acquisitions	59	392	172	457
Total expenses	38,402	37,106	118,728	107,575
Operating income	9,805	8,963	27,096	24,834
Interest expense	-6,387	-7,633	-19,928	-22,449
Gain on disposition of properties	0	0	100,870	0
Income from continuing operations	3,418	1,330	108,038	2,385
Income from discontinued operations:	'	'	'	'
Operating income, net of interest expense	0	605	0	2,769
Gain on disposition of properties	0	18,072	0	26,868
Income from discontinued operations	0	18,677	0	29,637
Net income	3,418	20,007	108,038	32,022
Net income attributable to noncontrolling interests	0	-14	0	-45
Net income attributable to AERC	3,418	19,993	108,038	31,977
Allocation to participating securities	0	-85	-364	-136
Net income applicable to common shares	3,418	19,908	107,674	31,841
Earnings per common share - basic:	'	'	'	'
Income from continuing operations applicable to common shares	$0.06	$0.02	$1.87	$0.04
Income from discontinued operations	$0	$0.38	$0	$0.60
Net income applicable to common shares - basic	$0.06	$0.40	$1.87	$0.64
Earnings per common share - diluted:	'	'	'	'
Income from continuing operations applicable to common shares	$0.06	$0.02	$1.86	$0.04
Income from discontinued operations	$0	$0.38	$0	$0.59
Net income applicable to common shares - diluted	$0.06	$0.40	$1.86	$0.63
Comprehensive income:	'	'	'	'
Net income	3,418	20,007	108,038	32,022
Change in fair value and reclassification of hedge instruments	814	-622	68	1,687
Total comprehensive income	4,232	19,385	108,106	33,709
Net income attributable to noncontrolling interests	0	-14	0	-45
Total comprehensive income attributable to AERC	$4,232	$19,371	$108,106	$33,664
Dividends declared per common share	$0.20	$0.19	$0.58	$0.57
Weighted average number of common shares outstanding - basic	57,531	49,949	57,456	49,816
Weighted average number of common shares outstanding - diluted	58,033	50,267	57,928	50,376

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (Unaudited) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Cash flow from operating activities:	'	'
Net income	$108,038	$32,022
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depreciation and amortization	47,958	43,564
Gain on disposition of properties	-100,870	-26,868
Amortization of deferred financing costs and other	803	909
Share-based compensation expense	3,017	3,385
Net change in assets and liabilities:	'	'
Accounts receivable	-348	-464
Accounts payable and accrued expenses	-538	4,349
Other operating assets and liabilities	-671	452
Total adjustments	-50,649	25,327
Net cash flow provided by operating activities	57,389	57,349
Cash flow from investing activities:	'	'
Recurring fixed asset additions	-7,274	-8,310
Revenue enhancing/non-recurring fixed asset additions	-990	-1,322
Acquisition fixed asset additions	-47,584	-143,308
Development fixed asset additions	-46,224	-70,012
Net proceeds from disposition of operating properties	168,756	90,453
Contributions to joint venture	-11,841	-8,874
Deposits on potential future acquisitions	3,193	-15,721
Cash proceeds from sale of equity interest in development property	24,075	0
Escrow deposits related to property sales	52,414	0
Escrow deposit disbursements related to property acquisition	-72,292	0
Costs paid on behalf of joint venture	-6,016	0
Reimbursements of costs paid on behalf of joint venture	5,993	0
Other investing activity	-1,296	-1,667
Net cash flow provided by (used for) investing activities	60,914	-158,761
Cash flow from financing activities:	'	'
Principal amortization payments on mortgage notes payable	-1,577	-2,371
Principal repayments of mortgage notes payable	-20,038	0
Payment of debt procurement costs	-927	-2,453
Proceeds from secured construction loans	30,543	0
Proceeds from issuance of unsecured notes	0	150,000
Revolving credit facility borrowings	152,000	344,200
Revolving credit facility repayments	-244,000	-357,700
Common share dividends paid	-33,428	-28,170
Operating partnership distributions paid	0	-42
Exercise of stock options	733	1,550
Issuance of common shares	0	1,870
Purchase of treasury shares	-1,033	-704
Purchase of noncontrolling interest in partnership	0	-4,544
Other financing activities, net	166	361
Net cash flow (used for) provided by financing activities	-117,561	101,997
Increase in cash and cash equivalents	742	585
Cash and cash equivalents, beginning of period	4,586	4,740
Cash and cash equivalents, end of period	5,328	5,325
Supplemental disclosure of non-cash transactions:	'	'
Dividends declared but not paid	12,188	10,659
Net change in accounts payable related to fixed asset additions	7,651	6,770
Net change in accounts payable and security deposits related to the disposition of operating properties	-486	-690
Deconsolidation of net assets	$26,238	$0

Business

Business	9 Months Ended
	Sep. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
BUSINESS	'
	BUSINESS
	Except as the context otherwise requires, all references to "we," "our," "us," "AERC," "AEC" and the "Company" in this report collectively refer to Associated Estates Realty Corporation and its consolidated subsidiaries.
	We are a fully-integrated, self-administered and self-managed equity real estate investment trust ("REIT") specializing in multifamily ownership, operation, acquisition, development, construction, disposition and property management activities. Our primary source of income is rental revenue. Additional income is derived from property management and construction services revenue. We own a taxable REIT subsidiary that performs construction services for our own account in connection with the development of multifamily properties that we own and operate, including consolidated and unconsolidated joint ventures. As of September 30, 2014, our operating portfolio consisted of 50 apartment communities containing 13,034 units in eight states that are owned, either directly or indirectly, through subsidiaries. In conjunction with our acquisition of land for development of an apartment community, we acquired a commercial building in Los Angeles, California containing approximately 78,800 total square feet of office and commercial space. Additionally, we provide property management services for three apartment communities that we expect to acquire pursuant to existing contracts.

Significant_Accounting_Policie

Significant Accounting Policies	9 Months Ended
	Sep. 30, 2014
Accounting Policies [Abstract]	'
SIGNIFICANT ACCOUNTING POLICIES	'
	SIGNIFICANT ACCOUNTING POLICIES
	Basis of Presentation
	The accompanying unaudited consolidated financial statements have been prepared by management in accordance with accounting principles generally accepted in the United States of America ("GAAP") for interim financial information and applicable rules and regulations of the Securities and Exchange Commission. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, all adjustments consisting only of normal and recurring adjustments considered necessary for a fair statement have been included. The reported results of operations are not necessarily indicative of the results that may be expected for the full year. These financial statements should be read in conjunction with the audited financial statements and accompanying notes in our Annual Report on Form 10-K for the year ended December 31, 2013.
	Segment Reporting
	Substantially all of our properties are multifamily communities and, while the economic climate of the markets in which they are located may vary from time to time, the communities offer similar products and services and have similar economic characteristics. Management evaluates the performance of our properties and makes acquisition/disposition decisions on an individual basis. During the nine months ended September 30, 2014, substantially all of our consolidated revenue was provided by our multifamily properties. We have determined that, as of September 30, 2014, we have one reportable segment which is multifamily properties.
	Derivative Instruments and Hedging Activities
	We utilize interest rate swaps to add stability to interest expense and to manage our exposure to interest rate movements. Interest rate swaps designated as cash flow hedges involve the receipt of variable-rate amounts in exchange for fixed-rate payments over the life of the agreements without exchange of the underlying principal amount.
	We do not use derivatives for trading or speculative purposes. Further, we have a policy of only entering into contracts with major financial institutions based upon their credit ratings and other factors. When viewed in conjunction with the underlying and offsetting exposure that the derivatives are designed to hedge, we have not sustained a material loss from these hedges.
	We record all derivatives on the balance sheet at fair value. The accounting for changes in the fair value of derivatives depends on the intended use of the derivative and the resulting designation. Derivatives used to hedge the exposure to changes in the fair value of an asset, liability or firm commitment attributable to a particular risk, such as interest rate risk, are considered fair value hedges. Derivatives used to hedge the exposure to variability in expected future cash flows or other types of forecasted transactions are considered cash flow hedges.
	For derivatives designated as cash flow hedges, the effective portion of changes in the fair value of the derivative is initially reported in other comprehensive income (outside of earnings) and subsequently reclassified to earnings when the hedged transaction affects earnings, and the ineffective portion of changes in the fair value of the derivative is recognized directly in earnings. Hedge ineffectiveness is measured by comparing the changes in fair value or cash flows of the derivative hedging instrument with the changes in fair value or cash flows of the designated hedged item or transaction. For derivatives not designated as hedges, changes in fair value are recognized in earnings. See Note 11 for additional information related to our derivative and hedging activities.
	Real Estate Capitalization Policies and Depreciation
	Real estate assets are stated at cost less accumulated depreciation. Depreciation is provided on a straight-line basis over the estimated useful lives of the assets as follows:
	Buildings and improvements	5 - 30 years
	Furniture, fixtures and equipment	5 - 10 years
	We capitalize replacements and improvements, such as HVAC equipment, structural replacements, windows, appliances, flooring, carpeting and kitchen/bath replacements and renovations. Ordinary repairs and maintenance, such as unit cleaning, painting and appliance repairs, are expensed when incurred.
	We allocate the purchase price of acquired properties to net tangible and identified intangible assets and liabilities acquired based on their fair values. In making estimates of fair values for purposes of allocating the purchase price, we utilize a number of sources, including analysis provided by an advisor, independent appraisals that may be obtained in connection with the acquisition or financing of the respective property, our analysis of recently acquired and existing comparable properties in our portfolio and other market data. The intangible assets are amortized over the remaining lease terms, which is approximately 12 months. Due to the short-term nature of residential leases, we believe existing lease rates approximate market rates. Therefore, no allocation is made for above/below market leases. The intangible assets associated with one commercial lease are being amortized over the life of the lease, which is 60 months.
	For properties under development, we capitalize interest costs on funds used in construction, real estate taxes and insurance from the commencement of development activity through the time the property is substantially complete and ready for leasing. For properties under development accounted for under the equity method, we capitalize interest costs on our investment through the time the venture commences planned principal operations. We also capitalize internal costs related to our consolidated and equity method ventures, which are primarily payroll, but may also include costs such as travel, lodging and temporary construction facilities that are directly attributable to the construction of a property or asset. Certain costs associated with the lease-up of development projects, such as signs and "grand openings" are capitalized and amortized over the estimated life of average tenant relationships, which are approximately 12 months. All other internal costs associated with the lease up of development properties are expensed as incurred. Revenue from incidental operations for properties under development are recognized as reductions of capitalized project costs. Capitalized payroll costs are allocated to projects based upon time incurred by the applicable personnel. Capitalized costs related to development and construction are transferred to buildings and improvements and/or furniture and fixtures, as applicable, upon substantial completion of the project. Total capitalized interest during the three and nine months ended September 30, 2014 was $1.2 million and $3.4 million, respectively. Total capitalized interest during the three and nine months ended September 30, 2013 was $1.1 million and $2.4 million, respectively. Total capitalized payroll costs during the three and nine months ended September 30, 2014 were $860,000 and $2.5 million, respectively. Total capitalized payroll costs during the three and nine months ended September 30, 2013 were $690,000 and $2.0 million, respectively.
	We discontinue the depreciation of assets we have specifically identified as held for sale. There were no properties classified as held for sale at September 30, 2014 or December 31, 2013.
	Classification of Fixed Asset Additions
	We define recurring fixed asset additions to a property as capital expenditures made to replace worn out assets to maintain the property's value. Revenue enhancing/non-recurring fixed asset additions are defined as capital expenditures that increase the value of the property and enable us to increase rents. Acquisition/development fixed asset additions are defined as capital expenditures for the purchase or construction of new properties to be added to our portfolio, or fixed asset additions identified at the time of purchase that are not made until subsequent periods.
	Discontinued Operations
	In April 2014, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2014-08, Presentation of Financial Statements (Topic 205) and Property, Plant and Equipment (Topic 360): Reporting of Discontinued Operations and Disclosures of Components of an Entity ("ASU 2014-08"). ASU 2014-08 states that only those disposals of components of an entity that represent a strategic shift that has (or will have) a major effect on an entity's operations and financial results should be reported as discontinued operations in the financial statements. Prior accounting guidance held that a component of an entity that is a reportable segment, an operating segment, a reporting unit, a subsidiary or an asset group was eligible for discontinued operations presentation. This led to many disposals, many of which were routine in nature and did not change an entity's strategy, to be reported as discontinued operations. The amendments in ASU 2014-08 require expanded disclosure for discontinued operations, which should provide financial statement users with more information about the assets, liabilities, revenues and expenses of discontinued operations. As such, our disposition of individual properties will generally no longer meet the guidance to be classified as discontinued operations. See Note 3 for additional information related to how ASU 2014-08 affects our current reporting. This updated guidance requires prospective application for all disposals of components of an entity that occur within annual periods beginning on or after December 15, 2014 and interim periods within those years, with early adoption permitted. We adopted this guidance effective January 1, 2014.
	Revenue
	In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606) ("ASU 2014-09"). ASU 2014-09 is a comprehensive new revenue recognition model requiring a company to depict the transfer of goods or services to a customer at an amount reflecting the consideration it expects to receive in exchange for those goods or services. In adopting ASU 2014-09, companies may use either a full retrospective or a modified retrospective approach. Additionally, this guidance requires improved disclosures regarding the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers.  ASU 2014-09 is effective for the first interim period within annual reporting periods beginning after December 15, 2016, and early adoption is not permitted. The Company is currently evaluating the impact the adoption of ASU 2014-09 will have on the Company’s financial position or results of operations.
	Going Concern
	In August 2014, the FASB issued ASU 2014-15, Presentation of Financial Statements - Going Concern (Subtopic 205-40) ("ASU 2014-15").  ASU 2014-15 was issued to give clarity to stakeholders when there are conditions or events that raise substantial doubt about an entity’s ability to continue as a going concern.  The guidance calls for, in connection with the preparation of financial statements for each annual and interim reporting period, an evaluation by management over whether there are conditions or events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date that the financial statements are issued (or within one year after the date that the financial statements are available to be issued, when applicable).  ASU 2014-15 is effective for the annual reporting periods ending after December 15, 2016.  ASU 2014-15 will become effective for the Company on January 1, 2016. At this time, the adoption of ASU 2014-15 is not expected to impact the Company's consolidated financial statements.
	Reclassifications and Adjustments to Previously Issued Financial Statements
	During the three months ended June 30, 2014, certain reclassifications were made to the 2014 financial statements to conform to Accounting Standards Codification No. 360-10-45-5, Impairment and Disposal of Long-Lived Assets, and include gains recognized on the sale of long-lived assets that are not discontinued operations in income from continuing operations.
	In connection with the preparation of the financial statements as of June 30, 2014, we identified an adjustment related to the reporting of cash expenditures for development fixed asset additions and the related non-cash investing disclosure which impacted the Consolidated Statements of Cash Flows for the Year Ended December 31, 2013, by reducing cash flow from operating activities and cash used for investing activities. To correctly present cash flows expended for development fixed asset additions, the Consolidated Statements of Cash Flows for the Year Ended December 31, 2013 will include an adjustment of $8.3 million to increase net cash flow provided by operating activities, as well as a corresponding increase to net cash flow used for investing activities. We assessed the materiality of the foregoing adjustment on the prior period financial statements by examining and assessing the pertinent quantitative and qualitative criteria, and concluded that it was not material to the prior period. However, we determined it was appropriate to revise the applicable financial statements the next time such financial statements are included in a filing with the SEC. The following are selected line items from our Consolidated Statements of Cash Flows for the Year Ended December 31, 2013 illustrating the affect of the adjustment thereon:
	(in thousands)		As Reported			Adjustment			As Revised
	Cash flow from operating activities:
	Net change in assets and liabilities:
	Accounts payable and accrued expenses		$	(3,267	)	$	8,262		$	4,995
	Total adjustments		$	12,268		$	8,262		$	20,530
	Net cash flow provided by operating activities		$	73,563		$	8,262		$	81,825
	Cash flow from investing activities:
	Development fixed asset additions		$	(77,094	)	$	(8,262	)	$	(85,356	)
	Net cash flow used for investing activities		$	(211,176	)	$	(8,262	)	$	(219,438	)
	Supplemental disclosure of non-cash information:
	Net change in accounts payable related to fixed asset additions		$	14,360		$	(8,262	)	$	6,098
	There is no impact on these adjustments to the Consolidated Balance Sheets, Consolidated Statement of Shareholders’ Equity or Consolidated Statements of Operations and Comprehensive Income of the Company in any previously reported periods or any interim periods reported during the year ended December 31, 2013.

Acquisition_Development_and_Di

Acquisition, Development, and Disposition Activity	9 Months Ended
	Sep. 30, 2014
Acquisition, Development, and Disposition Activity [Abstract]	'
ACQUISITION, DEVELOPMENT, AND DISPOSITION ACTIVITY	'
	ACQUISTION, DEVELOPMENT, AND DISPOSITION ACTIVITY
	Acquisition Activity
	On September 20, 2013, we entered into an agreement to acquire a portfolio of seven properties for a total purchase price of $323.9 million, including the assumption of $28.0 million of existing mortgage financing. During the year ended December 31, 2013, we closed on three of the seven properties: The Apartments at Blakeney, St. Mary's Square and Lofts at Weston Lakeside. During the nine months ended September 30, 2014, we closed on an additional two properties: Alpha Mill Phase I and Alpha Mill Phase II, which we will operate as one property. We expect to acquire the remaining two properties based on the closing periods set forth in the following table. Each of these remaining closings is contingent upon the completed construction of the property. Our obligation to purchase these properties is subject to certain closing conditions specified in the agreement. If we choose not to purchase one or more of the properties, despite the closing conditions having been satisfied within the time period contemplated by the purchase agreement, we would forfeit the then-remaining balance of our earnest money deposits, which was, as of September 30, 2014, an aggregate of $10.0 million. This remaining balance of earnest money deposits represents our maximum exposure to loss until the closing of the remaining portfolio properties. We consider our deposits allocated to the entities developing the properties under construction to be variable interests and the development entities to be variable interest entities for which we are not the primary beneficiary as of this reporting date. Although we intend to acquire the remaining two properties, and regard our acquisition of each property as probable, there can be no assurance that we will acquire such properties.
	The table below provides details for the two remaining properties we plan to acquire:
	(Dollar amounts in thousands)
	Property		Location		Units			Estimated Closing Period	Purchase Price Allocation
	1160 Hammond		Atlanta, GA		345			Q4 2014	$	80,350
	Varela		Tampa, FL		350			Q1 2015	79,450
					695				$	159,800
	During the year ended December 31, 2012, we entered into an agreement to acquire for a purchase price of $80.2 million a 331-unit property that is being developed in Ft. Lauderdale, Florida. Our purchase obligation is conditioned upon the successful completion of the property in accordance with agreed upon plans and specifications and up to an 18-month period to allow for lease up of the property. Closing will not occur unless the conditions are satisfied, which is currently expected to occur in mid 2015. The developer may elect to terminate our agreement to purchase by agreeing to the release of our $4.0 million earnest money deposit from escrow and paying us an $8.0 million termination fee.  If we choose not to purchase the property, despite the closing conditions having been satisfied within the time period contemplated by the purchase agreement, we would forfeit our $4.0 million earnest money deposit.  This earnest money deposit represents our maximum exposure to loss until the closing of the property. We consider our deposit to be a variable interest and the development entity to be a variable interest entity for which we are not the primary beneficiary as of this reporting date.
	On June 10, 2014, we acquired Alpha Mill Phase I and Phase II, a combined 267 units, located in Charlotte, North Carolina, for a total purchase price of $45.1 million. We paid cash for this acquisition, which was funded from proceeds from the sale of Vista Germantown.
	During the nine months ended September 30, 2013, we acquired a 388-unit property located in Doral, Florida for a purchase price of $93.5 million, as well as a 152-unit property located in Dallas, Texas for a purchase price of $48.9 million.
	The following table represents the purchase price allocation for the properties acquired during the nine months ended September 30, 2014 and September 30, 2013, respectively.
			Nine Months Ended
			September 30,
			2014				2013
	(In thousands)
	Land		$	8,055			$	15,971
	Buildings and improvements		36,139				123,193
	Furniture and fixtures		463				1,154
	Existing leases (Other assets)		418				2,082
	Total		$	45,075			$	142,400
	The following table presents actual and pro forma information related to the properties acquired during the three and nine months ended September 30, 2014 and 2013, respectively. The pro forma information is presented as if the properties were acquired on January 1, 2013. We recognized acquisition costs during the nine months ended September 30, 2014 totaling $57,000, which are included in "Costs associated with acquisitions" in the Consolidated Statements of Operations and Comprehensive Income. Additionally, we recognized acquisition costs totaling $78,000 related to the current year acquisition during the last half of 2013. The pro forma presentation is presented for informational purposes only, and is not necessarily indicative of what our actual results of operations would have been had the acquisitions occurred at such time.
			Three Months Ended							Nine Months Ended
			September 30,							September 30,
	(In thousands, except per share amounts)		2014				2013			2014				2013
	Actual revenue from acquisitions		$	813			$	1,732		$	974			$	1,732
	Actual net (loss) income from acquisitions		(48		)		139			(93		)		139
	Pro forma revenue		48,207				49,022			146,885				143,393
	Pro forma net income applicable to common shares		3,673				20,929			108,238				33,931
	Pro forma earnings per common share - basic:
	Pro forma net income applicable to common shares		$	0.06			$	0.42		$	1.88			$	0.68
	Pro forma earnings per common share - diluted:
	Pro forma net income applicable to common shares		$	0.06			$	0.42		$	1.87			$	0.67
	Development Activity
	On May 28, 2013, we acquired a 3.36-acre parcel of land in the South of Market neighborhood of San Francisco, California for $46.6 million. On February 3, 2014, we entered into a 50/50 partnership with AIG Global Real Estate ("AIG") to develop and own this site known as 350 8th. The partnership is developing a 410-unit apartment community with commercial space and underground parking. See Note 6 for additional information related to this development.
	The following table identifies our consolidated development activity on which construction has commenced:
									Total
	(Dollar amounts in thousands)								Estimated									Actual		Estimated
	Under				Ownership		Total		Capital				Cost to			Total		Construction		Construction
	Construction		Location		%		Units		Cost (1)				Date			Debt		Start		Completion
	Cantabria at Turtle Creek		Dallas, TX		100.00%		249		$	56,800			$	46,436		$	25,688	Q2 2013		Q1 2015
	7001 Arlington at Bethesda		Bethesda, MD		98.10%	(2)	140		$	53,400			$	40,725		$	12,954	Q4 2012		Q2 2015
	The Desmond on Wilshire		Los Angeles, CA		100.00%		175		$	76,300			$	40,528		$	—	Q2 2013		Q4 2015
	Total						564		$	186,500			$	127,689		$	38,642
	-1	Total capital costs are calculated as if owned 100% by AEC and represent estimated costs for projects under development inclusive of all capitalized costs in accordance with GAAP. Based on current projections as of October 28, 2014.
	-2	Ownership percentage is based on current equity of the joint venture and is subject to change based on changes in total equity. Costs are shown at 100%. Joint venture partner contribution is $350.
	The following table identifies our unconsolidated development activity on which construction has commenced:
									Total
	(Dollar amounts in thousands)								Estimated				Cost			AEC					AEC				Actual	Estimated
	Under				Ownership		Total		Capital				to			Investment		Total			Share				Construction	Construction
	Construction		Location		%		Units		Cost (1)				Date			to Date		Debt			of Debt				Start	Completion
	350 8th		San Francisco, CA		50.00%		410		$	245,000			$	72,500		$	33,609	$	—		$	—	(2	)	Q2 2014	Q4 2016
	950 East Third		Los Angeles, CA		50.00%		472		$	164,000			$	35,566		$	4,547	$	—		$	—			Q3 2014	Q1 2017
	Total						882		$	409,000			$	108,066		$	38,156	$	—		$	—
	-1	Total capital costs are calculated as if owned 100% by AEC and represent estimated costs for projects under development inclusive of all capitalized costs in accordance with GAAP. Based on current projections as of October 28, 2014.
	-2	AEC has guaranteed 100% of a $143.6 million construction loan which had no outstanding balance as of September 30, 2014.
	The following table identifies our unconsolidated development activity that is in the planning phase:
	(Dollar amounts in thousands)						Estimated						AEC					AEC
					Ownership		Number		Cost to				Investment			Total		Share of
	Name		Location		%		Total Units (1)		Date				to Date			Debt		Debt
	5th and Huntington		Monrovia, CA		50.00%		154		$	15,223			$	7,765		$	—	$	—
	-1	Based on current projections as of October 28, 2014.
Disposition Activity
The results of operations and gains related to the sale of operating properties for the current period presented are reported in income from continuing operations in the accompanying Consolidated Statements of Operations and Comprehensive Income. Prior to adoption of ASU 2014-08, and in all prior periods presented, these results were reported in "Income from discontinued operations" in the accompanying Consolidated Statements of Operations and Comprehensive Income. Furthermore, the results of properties classified as held for sale are now reported in income from continuing operations. See Note 2 for additional information related to how ASU 2014-08 affects our current reporting.
During the nine months ended September 30, 2014, we completed the sale of four properties for an aggregate total sales price of $172.2 million and recognized aggregate gains of $100.9 million. Three of the properties were located in Maryland and one in Tennessee.
"Income from discontinued operations" in the accompanying Consolidated Statements of Operations and Comprehensive Income for the three and nine months ended September 30, 2013 includes the operating results for four properties sold in 2013, as well as the recognized gain related to the two properties sold during the nine months ended September 30, 2013. The following table summarizes "Income from discontinued operations":
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
(In thousands)		2013				2013
Revenue
Property revenue		$	1,904			$	8,144
Expenses
Property operating and maintenance		865				3,771
Depreciation and amortization		434				1,604
Total expenses		1,299				5,375
Operating income		605				2,769
Interest expense		—				—
Operating income, net of interest expense		605				2,769
Gain on disposition of properties		18,072				26,868
Income from discontinued operations		$	18,677			$	29,637
We have, on occasion, engaged Hancock Real Estate Strategies ("HRES"), a full service investment real estate brokerage and advisory firm, to provide certain real estate brokerage services. HRES is owned by Matthew E. Friedman, a son of our Chief Executive Officer ("CEO"). For the nine months ended September 30, 2014, in conjunction with the sale of one property in Nashville, Tennessee for $53.3 million on April 2, 2014, HRES was paid a commission totaling $244,000. For the nine months ended September 30, 2013, in conjunction with the sale of two properties and our joint venture to develop the 950 East Third land, HRES received commissions totaling $1.1 million. The aggregate value of those transactions was $122.7 million. These transactions were approved by the Company's independent directors in compliance with Company policy.

Debt

Debt	9 Months Ended
	Sep. 30, 2014
Debt Disclosure [Abstract]	'
DEBT	'
	DEBT
	The following table identifies our total debt outstanding and weighted average interest rates:
		September 30, 2014						December 31, 2013
					Weighted					Weighted
		Balance			Average Interest			Balance		Average Interest
	(Dollar amounts in thousands)	Outstanding			Rate			Outstanding		Rate
	Fixed Rate Debt:
	Secured	$	249,182		4.9	%		$	271,374	4.9	%
	Unsecured - notes	250,000			4.4	%		250,000		4.4	%
	Total Fixed Rate Debt	499,182			4.6	%		521,374		4.7	%
	Variable Rate Debt Swapped to Fixed:
	Unsecured - term loan	125,000			2.7	%		125,000		3	%
	Total Variable Rate Debt Swapped to Fixed	125,000			2.7	%		125,000		3	%
	Variable Rate Debt Unhedged:
	Secured	38,642			1.5	%		8,100		1.5	%
	Unsecured - revolver	41,500			1.5	%		133,500		1.5	%
	Unsecured - term loan	25,000			1.6	%		25,000		1.9	%
	Total Variable Rate Debt Unhedged	105,142			1.5	%		166,600		1.5	%
	Total Debt	$	729,324		3.9	%		$	812,974	3.8	%
	Unsecured Debt
	On July 25, 2014, we amended and restated our $150.0 million term loan. Among other modifications, the amendment extended the maturity date from January 3, 2018 to January 3, 2020, and reduced the interest rate spread across the pricing grid. The term loan currently bears interest at LIBOR plus a spread of 140 basis points. The interest rate spread over LIBOR is based on the Company's credit ratings and may range from 90 to 190 basis points for LIBOR-based loans. We also entered into an amendment to our unsecured revolving credit facility to implement corresponding financial covenant modifications to our unsecured revolving credit facility.
	Mortgage Notes Payable
	The following table provides information on mortgage loans repaid during the nine months ended September 30, 2014:
	(Dollar amounts in thousands)		Loans Repaid
	Property		Amount			Interest Rate
	Residence at White River		$	9,221		5.40%
	Spring Valley		10,817			5.40%
	Total/weighted average rate		$	20,038		5.40%	(1)
	-1	Represents weighted average interest rate for the loans listed.
	On April 25, 2014, the 350 8th partnership, which is accounted for under the equity method of accounting, entered into a construction loan agreement for $143.6 million with a five-year term and, based on our current credit ratings, has a per annum interest rate of LIBOR plus 160 basis points. There were no borrowings on this loan at September 30, 2014. We have guaranteed the payment of all future borrowings from this loan and the completion of construction in connection with the partnership's development. Additionally, we have drawn $25.7 million on the Cantabria at Turtle Creek construction loan and $13.0 million on the 7001 Arlington at Bethesda construction loan as of September 30, 2014. Cash paid for interest net of capitalized interest was $19.3 million and $19.8 million for the nine months ended September 30, 2014 and 2013, respectively.

Goodwill_and_Other_Intangible_

Goodwill and Other Intangible Assets	9 Months Ended
	Sep. 30, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
GOODWILL AND OTHER INTANGIBLE ASSETS	'
	GOODWILL AND OTHER INTANGIBLE ASSETS
	Goodwill
	Our goodwill was allocated to our properties on a relative fair value basis. Upon disposition of properties, the goodwill allocated is included in the calculation of the gain or loss on disposal and subsequently written off. During the nine months ended September 30, 2014, we wrote off $150,000 of our goodwill as a result of property dispositions. The carrying value of our goodwill as of September 30, 2014 and December 31, 2013 was $1.4 million and $1.5 million, respectively. Our annual review of goodwill impairment is completed during the first quarter of each year (and more frequently if events or changes in circumstances indicate the carrying value may not be recoverable). The review, completed during the three months ended March 31, 2014, determined that goodwill was not impaired, and no other events have occurred that would require goodwill to be reevaluated. In performing this analysis, we compare the net assets of each property on which goodwill has been allocated, including the amount of allocated goodwill, to its estimated fair market value. Should the estimates used to determine the fair value of the properties change, impairment may result, which could materially impact our results of operations for the period in which it is recorded.
	Intangible Assets
	We allocate a portion of the total purchase price of a property acquisition to any intangible assets identified, such as existing leases. The intangible assets are amortized over the remaining lease terms, which is approximately 12 months. Due to the short-term nature of residential leases, we believe existing lease rates approximate market rates. Therefore, no allocation is made for above/below market leases. The intangible assets associated with one commercial lease are being amortized over the life of the lease, which is 60 months. See Note 13 for additional information related to this lease.

Investment_in_Unconsolidated_E

Investment in Unconsolidated Entities Investment in Unconsolidated Entities	9 Months Ended
	Sep. 30, 2014
Investment in Unconsolidated Entities [Line Items]	'
INVESTMENT IN UNCONSOLIDATED ENTITIES	'
	INVESTMENT IN UNCONSOLIDATED ENTITIES
	350 8th
	On February 3, 2014, we entered into a partnership agreement with AIG, an unrelated third-party, for the development and operation of 350 8th, a 410-unit apartment community with commercial space and underground parking located in San Francisco, California. See Note 3 for more information related to this development. We are a 50.01% partner in this partnership. Our partner, AIG, has contributed $33.9 million to the partnership. The land upon which the partnership is developing was purchased by us for $46.6 million on May 28, 2013. As of December 31, 2013, this land was included in our consolidated financial statements. Upon the formation of our partnership with AIG, the land and improvements to date, with a carrying value of $50.3 million, were deconsolidated. Any future equity capital needs will be funded according to the partners' percentage interests in the partnership. Both partners have equal voting rights with respect to all major decisions, and all such decisions must be unanimous, including, among other things, development planning, budgeting and operational budgets. We perform construction management and property management services in accordance with the approved budgets for which we receive fees. As of September 30, 2014, we have recognized $262,500 of the construction management fee. As the partnership is not sufficiently funded to finance the activities of the entity, and not all of the capital will be funded up front, the partnership is not deemed to have sufficient equity, and has therefore been determined to be a variable interest entity. It has also been determined that we do not control the decisions that most significantly affect the economics of the entity, and that we do not hold a controlling financial interest in the entity. As such, our investment in the entity is accounted for in our consolidated financial statements using the equity method. At September 30, 2014, we have a cumulative basis difference in the partnership of $880,000 due to capitalization of interest on our investment and internal payroll and overhead costs directly related to the development of this property. This excess of our investment over our equity in the underlying net assets of the joint venture is included in "Investment in unconsolidated entities" in our Consolidated Balance Sheets, and will be amortized as a reduction to earnings on a straight-line basis over the lives of the related assets. On April 25, 2014, the partnership entered into a construction loan agreement for $143.6 million with a five-year term. There were no borrowings on this loan at September 30, 2014. We have guaranteed the payment of all future borrowings from this loan and the completion of construction in connection with the partnership's development. See Note 4 for more information related to this loan and Note 13 for more information related to the guarantees. Our maximum exposure to loss, as a result of our involvement in this entity, is the carrying value of our investment, which was $33.6 million as of September 30, 2014.
	950 East Third
	During the year ended December 31, 2013, we entered into a partnership agreement with Legendary Investors Group No. 1 LLC ("Legendary"), an unrelated third-party, for the development and operation of 950 East Third, a 472-unit apartment community located in Los Angeles, California. We are a 50.0% partner with Legendary, who contributed the land at a value of $30.0 million to the partnership. As of September 30, 2014, we have contributed $4.5 million to the partnership. We expect to fund the remaining portion of our capital contribution during the development and construction process. Both partners have equal voting rights with respect to all major decisions, and all such decisions must be unanimous, including, among other things, development planning, budgeting and operational budgets. We perform construction management and property management services in accordance with the approved budgets for which we receive fees. As of September 30, 2014, we have recognized $125,000 of the construction management fee. As the partnership is not sufficiently funded to finance the activities of the entity, and not all of the capital will be funded up front, the partnership is not deemed to have sufficient equity, and has therefore been determined to be a variable interest entity. It has also been determined that we do not control the decisions that most significantly affect the economics of the entity, and that we do not hold a controlling financial interest in the entity. As such, our investment in the entity is included in our consolidated financial statements using the equity method. At September 30, 2014, we have a cumulative basis difference in the partnership of $470,000 due to the capitalization of interest on our investment and internal payroll and overhead costs directly related to the development of this property. This excess of our investment over our equity in the underlying net assets of the partnership is included in "Investment in unconsolidated entities" in our Consolidated Balance Sheets, and will be amortized as a reduction to earnings on a straight-line basis over the lives of the related assets. Our maximum exposure to loss, as a result of our involvement in this entity, is the carrying value of our investment, which was $4.5 million as of September 30, 2014. See Note 3 for more information related to this development.
	5th and Huntington
	During the year ended December 31, 2013, we entered into a partnership agreement with LPC MM Monrovia, LLC ("Lincoln"), an unrelated third-party, for the limited purpose of acquiring a property in Monrovia, California, and to produce construction drawings for improvements to the property. The land, upon which the partnership plans to develop a 154-unit multifamily apartment community, was purchased by the partnership on August 9, 2013 for $13.1 million. We are a 50.0% partner with Lincoln, who has contributed $7.5 million to the partnership. As of September 30, 2014, we have contributed $7.8 million to the partnership. Any future equity capital needs will be funded on a 50/50 basis by the partners. Both partners have equal voting rights with respect to all major decisions, and all such decisions must be unanimous, including, among other things, development planning, budgeting and operational budgets. Lincoln will perform the day-to-day activities on behalf of the partnership. As the partnership is not sufficiently funded to finance the activities of the entity, and not all of the capital will be funded up front, the partnership is not deemed to have sufficient equity, and has therefore been determined to be a variable interest entity. It has also been determined that we do not control the decisions that most significantly affect the economics of the entity, and that we do not hold a controlling financial interest in the entity. As such, our investment in the entity is included in our consolidated financial statements using the equity method. At September 30, 2014, we have a cumulative basis difference in the partnership of $370,000 due to the capitalization of interest on our investment and internal payroll and overhead costs directly related to the development of this property. This excess of our investment over our equity in the underlying net assets of the partnership is included in "Investment in unconsolidated entities" in our Consolidated Balance Sheets, and will be amortized as a reduction to earnings on a straight-line basis over the lives of the related assets. Our maximum exposure to loss, as a result of our involvement in this entity, is the carrying value of our investment, which was $7.8 million as of September 30, 2014. See Note 3 for more information related to this development.

Noncontrolling_Interests

Noncontrolling Interests	9 Months Ended
	Sep. 30, 2014
Noncontrolling Interest [Abstract]	'
NONCONTROLLING INTERESTS	'
	NONCONTROLLING INTERESTS
	Noncontrolling Redeemable Interest
	In 1998, in conjunction with the acquisition of an operating partnership that owned two apartment communities, one of which was sold in October 2005, we issued a total of 522,032 operating partnership units ("OP units"). Holders of OP units were entitled to receive cumulative distributions per OP unit equal to the per share distributions on our common shares. When the OP units were presented for redemption, we were obligated to redeem those OP units for either common shares exchangeable on a one-for-one basis, or the cash equivalent amount, determined as the average closing price for our common shares over the 20-day period preceding the redemption, at our option. On October 23, 2013, we consummated a subsidiary merger transaction that had the effect of converting the remaining 74,083 OP units into a right to receive cash merger consideration, pursuant to which we paid $1.4 million on November 6, 2013. As of December 31, 2013, there were no remaining OP units as all remaining units had been redeemed for cash or canceled in the merger. No OP units were redeemed during the three and nine months ended September 30, 2013.
	Activity related to the noncontrolling redeemable interest is as follows:
		Three Months Ended			Nine Months Ended
		September 30,			September 30,
	(In thousands)	2013			2013
	Balance at beginning of period	$	1,734		$	1,734
	Net income attributable to noncontrolling redeemable interest	14			42
	Distribution to noncontrolling redeemable interest	(14		)	(42		)
	Balance at end of period	$	1,734		$	1,734
	Noncontrolling Interests
	On July 14, 2011, we entered into a partnership agreement with Keating Project Development, Inc., an unrelated third-party, pursuant to which we hold a 98.1% equity interest in the partnership. In March 2012, the partnership acquired a 2.5-acre parcel of land in Bethesda, Maryland for $12.2 million on which it is developing 140 apartment units and 7,000 square feet of commercial space. We have determined that this entity is not a variable interest entity and that we hold a controlling interest in the entity. As such, this entity is included in our consolidated financial statements. We have also determined that the noncontrolling interest in this entity meets the criteria to be classified as a component of permanent equity.
	On September 24, 2010, we entered into a partnership agreement with Bristol Development Group, an unrelated third-party, for the development of Vista Germantown, a 242-unit apartment community located in downtown Nashville, Tennessee. We contributed $9.4 million to the partnership and held a 90.0% equity interest in the partnership. In February 2013, we funded the redemption of the interest of the minority 10.0% partner of this partnership for $4.5 million, as a result of which we owned a 100% interest in Vista Germantown as of February 2013. On April 2, 2014, we disposed of Vista Germantown for a sales price of $53.3 million.
	The following table provides details of the activity related to the noncontrolling interests:
		Nine Months Ended
		September 30,
	(In thousands)	2014			2013
	Balance at beginning of period	$	350		$	1,344
	Net income	—			3
	Purchase of noncontrolling interest	—			(997		)
	Balance at end of period	$	350		$	350
	The following table provides details of the activity related to changes in ownership of noncontrolling interests:
		Nine Months Ended
		September 30,
		2014			2013
	Net income attributable to AERC	$	108,038		$	31,977
	Decrease in equity for purchase of noncontrolling interest	—			(3,547		)
	Change from net income attributable to AERC and net
	transfers to noncontrolling interest	$	108,038		$	28,430

Equity

Equity	9 Months Ended
	Sep. 30, 2014
Equity [Abstract]	'
EQUITY	'
	EQUITY
	The following table provides a reconciliation of significant activity in equity accounts:
		Nine Months Ended September 30, 2014
		Common				Accumulated
		Shares				Distributions			Accumulated
		(at $.10				in Excess of			Other			Treasury
		stated		Paid-In		Accumulated			Comprehensive			Shares			Noncontrolling
	(In thousands)	value)		Capital		Net Income			Loss			(at Cost)			Interest
	Balance, December 31, 2013	$	5,760	$	754,582	$	(213,275	)	$	(702	)	$	(1,915	)	$	350
	Net income attributable to AERC	—		—		108,038			—			—			—
	Other comprehensive income:
	Changes in fair value of hedge
	instruments	—		—		—			68			—			—
	Share-based compensation	—		2,016		1			—			1,952			—
	Purchase of common shares	—		—		—			—			(1,033		)	—
	Option exercises	8		725		—			—			—			—
	Issuance of common shares	3		—		—			—			—			—
	Common share dividends declared	—		—		(33,754		)	—			—			—
	Balance, September 30, 2014	$	5,771	$	757,323	$	(138,990	)	$	(634	)	$	(996	)	$	350

Earnings_Per_Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
EARNINGS PER SHARE	'
	EARNINGS PER SHARE
	The following table presents a reconciliation of basic and diluted earnings per common share:
		Three Months Ended					Nine Months Ended
		September 30,					September 30,
	(In thousands, except per share amounts)	2014		2013			2014			2013
	Numerator - basic and diluted:
	Income from continuing operations	$	3,418	$	1,330		$	108,038		$	2,385
	Net income attributable to noncontrolling interests	—		(14		)	—			(45		)
	Allocation to participating securities	—		(85		)	(364		)	(136		)
	Income from continuing operations applicable to common shares	$	3,418	$	1,231		$	107,674		$	2,204
	Income from discontinued operations applicable to common shares	$	—	$	18,677		$	—		$	29,637
	Denominator - basic:	57,531		49,949			57,456			49,816
	Effect of dilutive securities (1)	502		318			472			560
	Denominator - diluted:	58,033		50,267			57,928			50,376
	Net income applicable to common shares - basic:
	Income from continuing operations applicable to common shares	$	0.06	$	0.02		$	1.87		$	0.04
	Income from discontinued operations	—		0.38			—			0.6
	Net income attributable to common shares - basic	$	0.06	$	0.4		$	1.87		$	0.64
	Net income applicable to common shares - diluted:
	Income from continuing operations applicable to common shares	$	0.06	$	0.02		$	1.86		$	0.04
	Income from discontinued operations	—		0.38			—			0.59
	Net income attributable to common shares - diluted	$	0.06	$	0.4		$	1.86		$	0.63
	-1	The Company has excluded 93 stock options for the three and nine months ended September 30, 2013, as their inclusion would be anti-dilutive.

Equity_Based_Award_Plans

Equity Based Award Plans	9 Months Ended
	Sep. 30, 2014
Share-based Compensation [Abstract]	'
EQUITY BASED AWARD PLANS	'
	EQUITY BASED AWARD PLANS
	During the three and nine months ended September 30, 2014, we recognized share-based compensation cost of $850,000 and $3.0 million, respectively, in "General and administrative expense" in the Consolidated Statements of Operations and Comprehensive Income. During the three and nine months ended September 30, 2013, we recognized share-based compensation cost of $980,000 and $3.4 million, respectively, in "General and administrative expense" in the Consolidated Statements of Operations and Comprehensive Income. Additionally, during the three and nine months ended September 30, 2014, we capitalized $120,000 and $340,000, respectively, of share-based compensation related to time incurred on development projects. During the three and nine months ended September 30, 2013, we capitalized $90,000 and $300,000, respectively, of share-based compensation related to time incurred on development projects. See Note 2 for additional information related to capitalized payroll.
	Restricted Shares. Restricted shares generally have the same rights as our common shares, except for transfer restrictions and forfeiture provisions. We have two compensation plans under which our officers and directors may elect to defer the receipt of restricted shares. Restricted share awards deferred under these plans are reflected as deferred restricted share equivalent units ("DRSUs") in an individual bookkeeping account maintained for each participant. The vesting of DRSUs occurs on the same schedule as the restricted shares made subject to the deferral election, and the valuation and attribution of cost in our consolidated financial statements are also the same as the restricted shares subject to the deferral election. DRSUs are not included in the number of issued and outstanding common shares reflected in the "Equity" section of our Consolidated Balance Sheets. DRSUs with non-forfeitable dividend rights are included in the allocation to participating securities using the two-class method. DRSUs with forfeitable dividend rights do not qualify as participating securities, and are included in the calculation of diluted earnings per share to the extent they are not anti-dilutive for the period presented.
	The following table represents restricted share and DRSU activity for the nine months ended September 30, 2014:
				Weighted			Weighted
		Number of		Average			Average
		Restricted		Grant-Date		Number of	Grant-Date
		Shares		Fair Value		DRSUs	Fair Value
	Nonvested at beginning of period	735,184		$	10.52	34,797	$	17.15
	Granted	161,267		$	16.11	39,526	$	16.14
	Vested	171,381		$	16.36	26,603	$	17.38
	Forfeited	16,280		$	10.63	8,194	$	16.38
	Nonvested at end of period	708,790		$	10.37	39,526	$	16.14
	The weighted average grant-date fair value of restricted shares granted during the nine months ended September 30, 2013 was $10.44. The total fair value of restricted shares vested during the nine months ended September 30, 2014 and 2013 was $3.2 million and $2.7 million, respectively. The total fair value of DRSUs vested during the nine months ended September 30, 2014 and 2013 was $460,000 and $590,000, respectively, recognized as "Paid-in-capital." At September 30, 2014, there was a total of $5.5 million of unrecognized compensation cost related to non-vested restricted share awards and DRSUs that we expect to recognize over a weighted average period of 2.0 years.
	During 2014 and 2013, we issued restricted share awards in which the number of shares that will ultimately vest is subject to market conditions over a three-year period and service conditions over a four-year period. The total estimated grant-date fair value of these awards, including the awards that were deferred, were $90,000 during 2014 and $4.3 million during 2013. We used the Monte Carlo method to estimate the fair value of these awards. The Monte Carlo method, which is similar to the binomial analysis, evaluates the award for changing stock prices over the term of vesting, and uses random situations that are averaged based on past stock characteristics. There were one million simulation paths used to estimate the fair value of these awards. The expected volatility for the awards granted in 2014 and 2013 was based upon a 50/50 blend of historical and implied volatility. The historical volatility was based upon changes in the weekly closing prices of our shares over a period equal to the expected life of the restricted shares granted. The implied volatility was the trailing month average of daily implied volatilities calculated by interpolating between the volatilities implied by stock call option contracts that were closest to both the expected life and the exercise price of the restricted shares. The risk-free interest rate used was based on a yield curve derived from U.S. Treasury zero-coupon bonds on the date of grant with a maturity equal to the market condition performance periods. The expected life used was the market condition performance period.
	The following table represents the assumption ranges used in the Monte Carlo method for the multi-year restricted share awards:
		2014	2013
	Expected volatility - AERC	22.3% to 24.2%	18.1% to 22.5%
	Expected volatility - peer group	16.9% to 24.7%	14.7% to 29.5%
	Risk-free interest rate	0.02% to 0.8%	0.08% to 0.5%
	Expected life (performance period)	3 years	3 years
	Stock Options. We use the Black-Scholes option pricing model to estimate the fair value of stock options awarded. There were no options awarded, 80,930 options exercised and 5,000 options forfeited during the nine months ended September 30, 2014. There were no options awarded, 169,164 options exercised and no options forfeited during the nine months ended September 30, 2013.
	The following table represents stock option activity for the nine months ended September 30, 2014:
						Weighted-Average
		Number of		Weighted-Average		Remaining
		Stock Options		Exercise Price		Contract Life
	Outstanding at beginning of period	510,020		$	11.47
	Exercised	80,930		$	9.07
	Forfeited	5,000		$	14
	Outstanding at end of period	424,090		$	11.89	3.1
	Exercisable at end of period	382,424		$	11.52	2.6
	The aggregate intrinsic value of stock options outstanding and stock options exercisable at September 30, 2014 and 2013 was $2.3 million and $2.2 million, respectively.

Derivative_Instruments_and_Hed

Derivative Instruments and Hedging Activities	9 Months Ended
	Sep. 30, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES	'
	DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES
	We utilize interest rate swaps, from time to time, to add stability to interest risk and to manage our exposure to interest rate movements. See Note 2 for additional information related to our derivative instruments and hedging policy.
	As of September 30, 2014, the Company had the following outstanding interest rate derivatives that were designated as cash flow hedges:
	Interest Rate Derivative		Number of Instruments		Notional Amount
	Interest Rate Swaps		2		$125.0 million
	On April 2, 2013, we entered into a forward starting interest rate swap on $125.0 million of our $150.0 million unsecured term loan, fixing the rate beginning June 2, 2016 at a rate of 1.55% per annum plus the credit spread, which was 1.40% per annum as of September 30, 2014, or an all-in rate of 2.95% per annum until January 2018. The credit spread is subject to change, from time to time, from a minimum of 0.90% per annum to a maximum of 1.90% per annum over LIBOR based upon our qualified ratings as defined in the agreement. See Note 12 for additional information.
	On December 19, 2011, we entered into a forward starting interest rate swap effective June 7, 2013. This swap hedges the future cash flows of interest payments on $125.0 million of our $150.0 million unsecured term loan by fixing the rate until June 2016 at a rate of 1.26% per annum plus the credit spread, which was 1.40% per annum at September 30, 2014, or an all-in rate of 2.66% per annum. The credit spread is subject to change, from time to time, from a minimum of 0.90% per annum to a maximum of 1.90% per annum over LIBOR based upon our qualified ratings as defined in the agreement. See Note 12 for additional information.
	The following table presents the fair value of our derivative financial instruments as well as the classification on the Consolidated Balance Sheets (see Note 12 for additional information regarding the fair value of these derivative instruments):
	Fair Value of Derivative Instruments
		Asset Derivatives
		As of September 30, 2014						As of December 31, 2013
	(In thousands)	Balance Sheet Location		Fair Value				Balance Sheet Location		Fair Value
	Derivatives designated
	as hedging instruments:
	Interest rate swap	Other assets, net		$	890			Other assets, net		$	1,573
	Fair Value of Derivative Instruments
		Liability Derivatives
		As of September 30, 2014						As of December 31, 2013
	(In thousands)	Balance Sheet Location		Fair Value				Balance Sheet Location		Fair Value
	Derivatives designated
	as hedging instruments:
		Accounts payable and						Accounts payable and
	Interest rate swap	other liabilities		$	1,524			other liabilities		$	2,275
	The following table presents the effect of our derivative financial instruments on the Consolidated Statements of Operations and Comprehensive Income:
	The Effect of Derivative Instruments on the Consolidated Statements of Operations and Comprehensive Income
			Location of Gain or
	(In thousands)		(Loss) Recognized		Three Months Ended								Nine Months Ended
	Derivatives in Cash Flow Hedging		in Income		September 30,								September 30,
	Relationships (Interest Rate Swaps)		on Derivative		2014				2013				2014				2013
	Amount of gain/(loss)
	recognized in OCI on derivative				$	462			$	(964	)		$	(977	)		$	1,257
	Amount of loss reclassified from accumulated
	OCI into interest expense		Interest expense		$	(352	)		$	(342	)		$	(1,045	)		$	(430	)
	Amount of gain/(loss) recognized in
	income on derivative (ineffective portion and
	amount excluded from effectiveness testing)		Other expense		$	—			$	—			$	—			$	—
	The following table presents the effect of offsetting financial assets and liabilities on the Consolidated Balance Sheets:
	Offsetting of Derivative Assets and Liabilities
															Gross Amounts Not Offset in
															the Balance Sheets
											Net Amounts of
			Gross Amounts				Gross Amounts				Assets/Liabilities								Cash
			of Recognized				Offset in the				Presented in the				Financial				Collateral		Net
	(In thousands)		Assets/Liabilities				Balance Sheets				Balance Sheets				Instruments				Received		Amount
	30-Sep-14
	Offsetting Derivative
	Assets		$	890			$	—			$	890			$	—			$	—	$	890
	Liabilities		$	1,524			$	—			$	1,524			$	—			$	—	$	1,524
	31-Dec-13
	Offsetting Derivative
	Assets		$	1,573			$	—			$	1,573			$	—			$	—	$	1,573
	Liabilities		$	2,275			$	—			$	2,275			$	—			$	—	$	2,275
	As of September 30, 2014, the fair value of the derivative in a liability position, excluding any adjustment for nonperformance risk, was $1.6 million. As of September 30, 2014, we have not posted any collateral related to this agreement.  If we had breached any of the provisions in the agreement with our derivative counterparty at September 30, 2014, we could have been required to settle our obligations under the agreement at its termination value of $1.6 million, which includes accrued interest of $88,000. The expected amount of other comprehensive income to be reclassified as earnings within the next twelve months is $1.3 million.

Fair_Value

Fair Value	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
FAIR VALUE	'
	FAIR VALUE
	Fair value, as defined by GAAP, represents the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. The inputs used in the determination of fair value amounts and disclosures are based on the assumptions that market participants would use when pricing certain assets or liabilities. These inputs are classified in the fair value hierarchy as follows:
	Ÿ	Level 1 inputs utilize quoted prices (unadjusted) in active markets for identical assets or liabilities that we have the ability to access;
	Ÿ	Level 2 inputs may include quoted prices for similar assets and liabilities in active markets, as well as interest rates and yield curves that are observable at commonly quoted intervals; and
	Ÿ	Level 3 inputs are unobservable inputs for the asset or liability that are typically based on an entity's own assumptions as there is little, if any, related market activity.
	The inputs used in the fair value measurement should be from the highest level available. In instances where the measurement is based on inputs from different levels of the fair value hierarchy, the fair value measurement will fall within the lowest level input that is significant to the fair value measurement in its entirety.
	Cash, accounts and notes receivable, other assets, accounts payable, accrued expenses and other liabilities (except for the interest rate swap discussed below) are carried at amounts that reasonably approximate corresponding fair values because of their short term nature.
	The interest rate swap derivatives, as discussed in detail in Note 11 under "Derivative Instruments and Hedging Activities," are carried at fair value. The fair value of the derivative was determined by using a model that applies discount rates to the expected future cash flows associated with the swap. The significant inputs used in the valuation model to estimate the discount rates and expected cash flows are observable in active markets and, therefore, are Level 2 inputs.
	We estimate the fair value of our mortgage notes payable by discounting the associated cash flows using the interest rates available to us as of the dates reported for issuance of debt with similar terms, remaining maturities and loan to value ratios, which ranged from 38% to 53% at September 30, 2014. We classify the fair value of our mortgage notes payable as Level 3.
	We estimate the fair value of our unsecured debt by discounting the associated cash flows using the interest rates available to us as of the dates reported for issuance of debt with similar terms and remaining maturities. We classify the fair value of our unsecured debt as Level 2.
					Fair Value at September 30, 2014 Using
					Quoted Prices in
					Active Markets		Significant
					for Identical		Other		Significant
					Assets or		Observable		Unobservable
			Carrying		Liabilities		Inputs		Inputs
	(In thousands)		Value		(Level 1)		(Level 2)		(Level 3)
	Mortgage notes payable		$	287,824	$	—	$	—	$	298,785
	Unsecured debt		$	441,500	$	—	$	450,208	$	—
					Fair Value at December 31, 2013 Using
					Quoted Prices in
					Active Markets		Significant
					for Identical		Other		Significant
					Assets or		Observable		Unobservable
			Carrying		Liabilities		Inputs		Inputs
	(In thousands)		Value		(Level 1)		(Level 2)		(Level 3)
	Mortgage notes payable		$	279,474	$	—	$	—	$	284,886
	Unsecured debt		$	533,500	$	—	$	530,022	$	—

Contingencies

Contingencies	9 Months Ended
	Sep. 30, 2014
Commitments and Contingencies Disclosure [Abstract]	'
CONTINGENCIES	'
	CONTINGENCIES
	Legal Proceedings
	In conjunction with our May 2012 acquisition of land for development of an apartment community, we acquired a commercial building in Los Angeles, California (the "Property"), and entered into a triple net master lease (the "Lease") of the Property as landlord with Art and Architecture Books of the 21st Century as tenant ("Tenant").
	When Tenant failed to pay December 2012 rent when due under the Lease, we served Tenant with a notice to pay rent or vacate the premises pursuant to the California Code of Civil Procedure. On December 20, 2012, we filed an unlawful detainer action in the Superior Court for the State of California (the “Bankruptcy Court”). Tenant did not pay rent for January or February 2013.
	On February 19, 2013 (the scheduled trial date for our unlawful detainer suit), Tenant filed its Chapter 11 petition with the U.S. Bankruptcy Court for the Central District of California (the "California Bankruptcy Case").
	On March 29, 2013, Tenant filed a motion to assume the Lease. We opposed Tenant’s lease assumption motion. On September 12, 2013, the Bankruptcy Court granted Tenant’s motion to assume the Lease. We appealed the Bankruptcy Court’s order granting Tenant’s motion to assume the Lease to the U.S. District Court for the Central District of California (the “District Court”). On December 2, 2013, the District Court ruled in our favor and held the Bankruptcy Court had erred when it concluded the Lease had not been terminated prior to the date Tenant filed its Chapter 11 petition. Tenant appealed the District Court's decision to the U.S. Court of Appeals for the Ninth Circuit. The District Court remanded the case back to the Bankruptcy Court for further proceedings consistent with the District Court’s determination. On October 27, 2014, the Bankruptcy Court, on the matter remanded by the District Court, denied Tenant's lease assumption motion. Tenant has indicated it will appeal the Bankruptcy Court's decision, and has petitioned the Bankruptcy Court for a stay pending the outcome of Tenant's appeals.
	If we conclude, based on the outcome of this proceeding, that it is unlikely Tenant will remain at the Property, we will accelerate the amortization of the remaining intangible asset associated with the Lease at that time. The intangible asset is being amortized over the initial five-year term of the Lease, beginning May 2012, and had a balance of $980,000 at September 30, 2014. In addition, we may be required to refund to Tenant the $630,000 cure payment Tenant paid to us in connection with its assumption of the lease.
	In addition to the above, we are subject to other legal proceedings, lawsuits and other claims in the ordinary course of our business (collectively, "Litigation"). Litigation is subject to uncertainties and outcomes are difficult to predict. Many of the claims in Litigation are covered by insurance, subject to deductible amounts. With respect to current Litigation, we have determined either that a loss is not reasonably possible or that the estimated loss or range of loss, if any, will not have a material adverse impact on our financial statements. See Note 14 for additional information.
	Guarantees
	On April 25, 2014, the 350 8th partnership, in which we are a 50.01% partner and that we account for under the equity method, entered into a construction loan agreement for $143.6 million with a five-year term. We have guaranteed the payment of all future borrowings from this loan and the completion of construction in connection with the partnership's development. We have determined that the fair value of these guarantees are immaterial and thus have not recorded any liability as of September 30, 2014.

Subsequent_Events

Subsequent Events	9 Months Ended
	Sep. 30, 2014
Subsequent Events [Abstract]	'
SUBSEQUENT EVENTS	'
	SUBSEQUENT EVENTS
	Legal Proceedings. On October 10, 2014, the United States District Court for the Northern District of Ohio (the "Court") entered an order preliminarily approving a proposed settlement in the purported shareholder derivative and class action captioned Manson v. Friedman, et al. (the "Action"), currently pending in the Court. Pursuant to the proposed settlement, and in exchange for releases and a dismissal of the Action with prejudice, Mr. Jeffrey Friedman will voluntarily relinquish, and the Company will rescind, 63,714 of the 125,000 options awarded to him in 2012, and for the twelve-month period following final settlement, the Company will not award any stock options to Mr. Friedman. Also, the Company will implement additional processes relating to the future granting of equity awards and pay for plaintiffs' counsel fees and expenses approved by the Court with respect to the Action. We maintain insurance that will help defray the cost of the proposed settlement, and we do not expect the proposed settlement to have a material impact on our financial results.
	Debt. On October 1, 2014, we repaid one loan totaling $24.5 million on its scheduled maturity date. We funded this payment with borrowings on our unsecured revolving credit facility.

Significant_Accounting_Policie1

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2014
Accounting Policies [Abstract]	'
Basis of Presentation	'
	Basis of Presentation
	The accompanying unaudited consolidated financial statements have been prepared by management in accordance with accounting principles generally accepted in the United States of America ("GAAP") for interim financial information and applicable rules and regulations of the Securities and Exchange Commission. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, all adjustments consisting only of normal and recurring adjustments considered necessary for a fair statement have been included. The reported results of operations are not necessarily indicative of the results that may be expected for the full year. These financial statements should be read in conjunction with the audited financial statements and accompanying notes in our Annual Report on Form 10-K for the year ended December 31, 2013.
Segment Reporting	'
	Segment Reporting
	Substantially all of our properties are multifamily communities and, while the economic climate of the markets in which they are located may vary from time to time, the communities offer similar products and services and have similar economic characteristics. Management evaluates the performance of our properties and makes acquisition/disposition decisions on an individual basis. During the nine months ended September 30, 2014, substantially all of our consolidated revenue was provided by our multifamily properties. We have determined that, as of September 30, 2014, we have one reportable segment which is multifamily properties.
Derivative Instruments and Hedging Activities	'
	Derivative Instruments and Hedging Activities
	We utilize interest rate swaps to add stability to interest expense and to manage our exposure to interest rate movements. Interest rate swaps designated as cash flow hedges involve the receipt of variable-rate amounts in exchange for fixed-rate payments over the life of the agreements without exchange of the underlying principal amount.
	We do not use derivatives for trading or speculative purposes. Further, we have a policy of only entering into contracts with major financial institutions based upon their credit ratings and other factors. When viewed in conjunction with the underlying and offsetting exposure that the derivatives are designed to hedge, we have not sustained a material loss from these hedges.
	We record all derivatives on the balance sheet at fair value. The accounting for changes in the fair value of derivatives depends on the intended use of the derivative and the resulting designation. Derivatives used to hedge the exposure to changes in the fair value of an asset, liability or firm commitment attributable to a particular risk, such as interest rate risk, are considered fair value hedges. Derivatives used to hedge the exposure to variability in expected future cash flows or other types of forecasted transactions are considered cash flow hedges.
	For derivatives designated as cash flow hedges, the effective portion of changes in the fair value of the derivative is initially reported in other comprehensive income (outside of earnings) and subsequently reclassified to earnings when the hedged transaction affects earnings, and the ineffective portion of changes in the fair value of the derivative is recognized directly in earnings. Hedge ineffectiveness is measured by comparing the changes in fair value or cash flows of the derivative hedging instrument with the changes in fair value or cash flows of the designated hedged item or transaction. For derivatives not designated as hedges, changes in fair value are recognized in earnings. See Note 11 for additional information related to our derivative and hedging activities.
Real Estate Capitalization and Depreciation	'
	Real Estate Capitalization Policies and Depreciation
	Real estate assets are stated at cost less accumulated depreciation. Depreciation is provided on a straight-line basis over the estimated useful lives of the assets as follows:
	Buildings and improvements	5 - 30 years
	Furniture, fixtures and equipment	5 - 10 years
	We capitalize replacements and improvements, such as HVAC equipment, structural replacements, windows, appliances, flooring, carpeting and kitchen/bath replacements and renovations. Ordinary repairs and maintenance, such as unit cleaning, painting and appliance repairs, are expensed when incurred.
	We allocate the purchase price of acquired properties to net tangible and identified intangible assets and liabilities acquired based on their fair values. In making estimates of fair values for purposes of allocating the purchase price, we utilize a number of sources, including analysis provided by an advisor, independent appraisals that may be obtained in connection with the acquisition or financing of the respective property, our analysis of recently acquired and existing comparable properties in our portfolio and other market data. The intangible assets are amortized over the remaining lease terms, which is approximately 12 months. Due to the short-term nature of residential leases, we believe existing lease rates approximate market rates. Therefore, no allocation is made for above/below market leases. The intangible assets associated with one commercial lease are being amortized over the life of the lease, which is 60 months.
	For properties under development, we capitalize interest costs on funds used in construction, real estate taxes and insurance from the commencement of development activity through the time the property is substantially complete and ready for leasing. For properties under development accounted for under the equity method, we capitalize interest costs on our investment through the time the venture commences planned principal operations. We also capitalize internal costs related to our consolidated and equity method ventures, which are primarily payroll, but may also include costs such as travel, lodging and temporary construction facilities that are directly attributable to the construction of a property or asset. Certain costs associated with the lease-up of development projects, such as signs and "grand openings" are capitalized and amortized over the estimated life of average tenant relationships, which are approximately 12 months. All other internal costs associated with the lease up of development properties are expensed as incurred. Revenue from incidental operations for properties under development are recognized as reductions of capitalized project costs. Capitalized payroll costs are allocated to projects based upon time incurred by the applicable personnel. Capitalized costs related to development and construction are transferred to buildings and improvements and/or furniture and fixtures, as applicable, upon substantial completion of the project. Total capitalized interest during the three and nine months ended September 30, 2014 was $1.2 million and $3.4 million, respectively. Total capitalized interest during the three and nine months ended September 30, 2013 was $1.1 million and $2.4 million, respectively. Total capitalized payroll costs during the three and nine months ended September 30, 2014 were $860,000 and $2.5 million, respectively. Total capitalized payroll costs during the three and nine months ended September 30, 2013 were $690,000 and $2.0 million, respectively.
	We discontinue the depreciation of assets we have specifically identified as held for sale. There were no properties classified as held for sale at September 30, 2014 or December 31, 2013.
Classification of Fixed Asset Additions	'
	Classification of Fixed Asset Additions
	We define recurring fixed asset additions to a property as capital expenditures made to replace worn out assets to maintain the property's value. Revenue enhancing/non-recurring fixed asset additions are defined as capital expenditures that increase the value of the property and enable us to increase rents. Acquisition/development fixed asset additions are defined as capital expenditures for the purchase or construction of new properties to be added to our portfolio, or fixed asset additions identified at the time of purchase that are not made until subsequent periods.
New Accounting Pronouncements	'
	Discontinued Operations
	In April 2014, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2014-08, Presentation of Financial Statements (Topic 205) and Property, Plant and Equipment (Topic 360): Reporting of Discontinued Operations and Disclosures of Components of an Entity ("ASU 2014-08"). ASU 2014-08 states that only those disposals of components of an entity that represent a strategic shift that has (or will have) a major effect on an entity's operations and financial results should be reported as discontinued operations in the financial statements. Prior accounting guidance held that a component of an entity that is a reportable segment, an operating segment, a reporting unit, a subsidiary or an asset group was eligible for discontinued operations presentation. This led to many disposals, many of which were routine in nature and did not change an entity's strategy, to be reported as discontinued operations. The amendments in ASU 2014-08 require expanded disclosure for discontinued operations, which should provide financial statement users with more information about the assets, liabilities, revenues and expenses of discontinued operations. As such, our disposition of individual properties will generally no longer meet the guidance to be classified as discontinued operations. See Note 3 for additional information related to how ASU 2014-08 affects our current reporting. This updated guidance requires prospective application for all disposals of components of an entity that occur within annual periods beginning on or after December 15, 2014 and interim periods within those years, with early adoption permitted. We adopted this guidance effective January 1, 2014.
	Revenue
	In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606) ("ASU 2014-09"). ASU 2014-09 is a comprehensive new revenue recognition model requiring a company to depict the transfer of goods or services to a customer at an amount reflecting the consideration it expects to receive in exchange for those goods or services. In adopting ASU 2014-09, companies may use either a full retrospective or a modified retrospective approach. Additionally, this guidance requires improved disclosures regarding the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers.  ASU 2014-09 is effective for the first interim period within annual reporting periods beginning after December 15, 2016, and early adoption is not permitted. The Company is currently evaluating the impact the adoption of ASU 2014-09 will have on the Company’s financial position or results of operations.
	Going Concern
	In August 2014, the FASB issued ASU 2014-15, Presentation of Financial Statements - Going Concern (Subtopic 205-40) ("ASU 2014-15").  ASU 2014-15 was issued to give clarity to stakeholders when there are conditions or events that raise substantial doubt about an entity’s ability to continue as a going concern.  The guidance calls for, in connection with the preparation of financial statements for each annual and interim reporting period, an evaluation by management over whether there are conditions or events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date that the financial statements are issued (or within one year after the date that the financial statements are available to be issued, when applicable).  ASU 2014-15 is effective for the annual reporting periods ending after December 15, 2016.  ASU 2014-15 will become effective for the Company on January 1, 2016. At this time, the adoption of ASU 2014-15 is not expected to impact the Company's consolidated financial statements.
Reclassifications and Adjustments to Previously Issued Financial Statements	'
	Reclassifications and Adjustments to Previously Issued Financial Statements
	During the three months ended June 30, 2014, certain reclassifications were made to the 2014 financial statements to conform to Accounting Standards Codification No. 360-10-45-5, Impairment and Disposal of Long-Lived Assets, and include gains recognized on the sale of long-lived assets that are not discontinued operations in income from continuing operations.
	In connection with the preparation of the financial statements as of June 30, 2014, we identified an adjustment related to the reporting of cash expenditures for development fixed asset additions and the related non-cash investing disclosure which impacted the Consolidated Statements of Cash Flows for the Year Ended December 31, 2013, by reducing cash flow from operating activities and cash used for investing activities. To correctly present cash flows expended for development fixed asset additions, the Consolidated Statements of Cash Flows for the Year Ended December 31, 2013 will include an adjustment of $8.3 million to increase net cash flow provided by operating activities, as well as a corresponding increase to net cash flow used for investing activities. We assessed the materiality of the foregoing adjustment on the prior period financial statements by examining and assessing the pertinent quantitative and qualitative criteria, and concluded that it was not material to the prior period. However, we determined it was appropriate to revise the applicable financial statements the next time such financial statements are included in a filing with the SEC. The following are selected line items from our Consolidated Statements of Cash Flows for the Year Ended December 31, 2013 illustrating the affect of the adjustment thereon:
	(in thousands)		As Reported			Adjustment			As Revised
	Cash flow from operating activities:
	Net change in assets and liabilities:
	Accounts payable and accrued expenses		$	(3,267	)	$	8,262		$	4,995
	Total adjustments		$	12,268		$	8,262		$	20,530
	Net cash flow provided by operating activities		$	73,563		$	8,262		$	81,825
	Cash flow from investing activities:
	Development fixed asset additions		$	(77,094	)	$	(8,262	)	$	(85,356	)
	Net cash flow used for investing activities		$	(211,176	)	$	(8,262	)	$	(219,438	)
	Supplemental disclosure of non-cash information:
	Net change in accounts payable related to fixed asset additions		$	14,360		$	(8,262	)	$	6,098
	There is no impact on these adjustments to the Consolidated Balance Sheets, Consolidated Statement of Shareholders’ Equity or Consolidated Statements of Operations and Comprehensive Income of the Company in any previously reported periods or any interim periods reported during the year ended December 31, 2013.

Significant_Accounting_Policie2

Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2014
Property, Plant and Equipment [Line Items]	'
Estimated useful lives	'Depreciation is provided on a straight-line basis over the estimated useful lives of the assets as follows:Buildings and improvements5 - 30 yearsFurniture, fixtures and equipment5 - 10 years
Out of period adjustment	'
	The following are selected line items from our Consolidated Statements of Cash Flows for the Year Ended December 31, 2013 illustrating the affect of the adjustment thereon:
	(in thousands)	As Reported			Adjustment			As Revised
	Cash flow from operating activities:
	Net change in assets and liabilities:
	Accounts payable and accrued expenses	$	(3,267	)	$	8,262		$	4,995
	Total adjustments	$	12,268		$	8,262		$	20,530
	Net cash flow provided by operating activities	$	73,563		$	8,262		$	81,825
	Cash flow from investing activities:
	Development fixed asset additions	$	(77,094	)	$	(8,262	)	$	(85,356	)
	Net cash flow used for investing activities	$	(211,176	)	$	(8,262	)	$	(219,438	)
	Supplemental disclosure of non-cash information:
	Net change in accounts payable related to fixed asset additions	$	14,360		$	(8,262	)	$	6,098

Acquisition_Development_and_Di1

Acquisition, Development, and Disposition Activity (Tables)	9 Months Ended
	Sep. 30, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]	'
Purchase price allocation	'
	The following table represents the purchase price allocation for the properties acquired during the nine months ended September 30, 2014 and September 30, 2013, respectively.
			Nine Months Ended
			September 30,
			2014				2013
	(In thousands)
	Land		$	8,055			$	15,971
	Buildings and improvements		36,139				123,193
	Furniture and fixtures		463				1,154
	Existing leases (Other assets)		418				2,082
	Total		$	45,075			$	142,400
	The table below provides details for the two remaining properties we plan to acquire:
	(Dollar amounts in thousands)
	Property		Location		Units			Estimated Closing Period	Purchase Price Allocation
	1160 Hammond		Atlanta, GA		345			Q4 2014	$	80,350
	Varela		Tampa, FL		350			Q1 2015	79,450
					695				$	159,800
Pro forma information	'
			Three Months Ended							Nine Months Ended
			September 30,							September 30,
	(In thousands, except per share amounts)		2014				2013			2014				2013
	Actual revenue from acquisitions		$	813			$	1,732		$	974			$	1,732
	Actual net (loss) income from acquisitions		(48		)		139			(93		)		139
	Pro forma revenue		48,207				49,022			146,885				143,393
	Pro forma net income applicable to common shares		3,673				20,929			108,238				33,931
	Pro forma earnings per common share - basic:
	Pro forma net income applicable to common shares		$	0.06			$	0.42		$	1.88			$	0.68
	Pro forma earnings per common share - diluted:
	Pro forma net income applicable to common shares		$	0.06			$	0.42		$	1.87			$	0.67
Schedule of completed, current and planned development	'
	The following table identifies our consolidated development activity on which construction has commenced:
									Total
	(Dollar amounts in thousands)								Estimated									Actual		Estimated
	Under				Ownership		Total		Capital				Cost to			Total		Construction		Construction
	Construction		Location		%		Units		Cost (1)				Date			Debt		Start		Completion
	Cantabria at Turtle Creek		Dallas, TX		100.00%		249		$	56,800			$	46,436		$	25,688	Q2 2013		Q1 2015
	7001 Arlington at Bethesda		Bethesda, MD		98.10%	(2)	140		$	53,400			$	40,725		$	12,954	Q4 2012		Q2 2015
	The Desmond on Wilshire		Los Angeles, CA		100.00%		175		$	76,300			$	40,528		$	—	Q2 2013		Q4 2015
	Total						564		$	186,500			$	127,689		$	38,642
	-1	Total capital costs are calculated as if owned 100% by AEC and represent estimated costs for projects under development inclusive of all capitalized costs in accordance with GAAP. Based on current projections as of October 28, 2014.
	-2	Ownership percentage is based on current equity of the joint venture and is subject to change based on changes in total equity. Costs are shown at 100%. Joint venture partner contribution is $350.
	The following table identifies our unconsolidated development activity on which construction has commenced:
									Total
	(Dollar amounts in thousands)								Estimated				Cost			AEC					AEC				Actual	Estimated
	Under				Ownership		Total		Capital				to			Investment		Total			Share				Construction	Construction
	Construction		Location		%		Units		Cost (1)				Date			to Date		Debt			of Debt				Start	Completion
	350 8th		San Francisco, CA		50.00%		410		$	245,000			$	72,500		$	33,609	$	—		$	—	(2	)	Q2 2014	Q4 2016
	950 East Third		Los Angeles, CA		50.00%		472		$	164,000			$	35,566		$	4,547	$	—		$	—			Q3 2014	Q1 2017
	Total						882		$	409,000			$	108,066		$	38,156	$	—		$	—
	-1	Total capital costs are calculated as if owned 100% by AEC and represent estimated costs for projects under development inclusive of all capitalized costs in accordance with GAAP. Based on current projections as of October 28, 2014.
	-2	AEC has guaranteed 100% of a $143.6 million construction loan which had no outstanding balance as of September 30, 2014.
	The following table identifies our unconsolidated development activity that is in the planning phase:
	(Dollar amounts in thousands)						Estimated						AEC					AEC
					Ownership		Number		Cost to				Investment			Total		Share of
	Name		Location		%		Total Units (1)		Date				to Date			Debt		Debt
	5th and Huntington		Monrovia, CA		50.00%		154		$	15,223			$	7,765		$	—	$	—
	-1	Based on current projections as of October 28, 2014.
Summary of income from discontinued operations	'
	The following table summarizes "Income from discontinued operations":
			Three Months Ended				Nine Months Ended
			September 30,				September 30,
	(In thousands)		2013				2013
	Revenue
	Property revenue		$	1,904			$	8,144
	Expenses
	Property operating and maintenance		865				3,771
	Depreciation and amortization		434				1,604
	Total expenses		1,299				5,375
	Operating income		605				2,769
	Interest expense		—				—
	Operating income, net of interest expense		605				2,769
	Gain on disposition of properties		18,072				26,868
	Income from discontinued operations		$	18,677			$	29,637

Debt_Tables

Debt (Tables)	9 Months Ended
	Sep. 30, 2014
Debt Instrument [Line Items]	'
Outstanding debt instruments	'
	The following table identifies our total debt outstanding and weighted average interest rates:
		September 30, 2014						December 31, 2013
					Weighted					Weighted
		Balance			Average Interest			Balance		Average Interest
	(Dollar amounts in thousands)	Outstanding			Rate			Outstanding		Rate
	Fixed Rate Debt:
	Secured	$	249,182		4.9	%		$	271,374	4.9	%
	Unsecured - notes	250,000			4.4	%		250,000		4.4	%
	Total Fixed Rate Debt	499,182			4.6	%		521,374		4.7	%
	Variable Rate Debt Swapped to Fixed:
	Unsecured - term loan	125,000			2.7	%		125,000		3	%
	Total Variable Rate Debt Swapped to Fixed	125,000			2.7	%		125,000		3	%
	Variable Rate Debt Unhedged:
	Secured	38,642			1.5	%		8,100		1.5	%
	Unsecured - revolver	41,500			1.5	%		133,500		1.5	%
	Unsecured - term loan	25,000			1.6	%		25,000		1.9	%
	Total Variable Rate Debt Unhedged	105,142			1.5	%		166,600		1.5	%
	Total Debt	$	729,324		3.9	%		$	812,974	3.8	%
Mortgage notes payable	'
	The following table provides information on mortgage loans repaid during the nine months ended September 30, 2014:
	(Dollar amounts in thousands)		Loans Repaid
	Property		Amount			Interest Rate
	Residence at White River		$	9,221		5.40%
	Spring Valley		10,817			5.40%
	Total/weighted average rate		$	20,038		5.40%	(1)
	-1	Represents weighted average interest rate for the loans listed.

Noncontrolling_Interests_Table

Noncontrolling Interests (Tables)	9 Months Ended
	Sep. 30, 2014
Redeemable Noncontrolling Interest [Line Items]	'
Noncontrolling Redeemable Interest	'
	Activity related to the noncontrolling redeemable interest is as follows:
		Three Months Ended			Nine Months Ended
		September 30,			September 30,
	(In thousands)	2013			2013
	Balance at beginning of period	$	1,734		$	1,734
	Net income attributable to noncontrolling redeemable interest	14			42
	Distribution to noncontrolling redeemable interest	(14		)	(42		)
	Balance at end of period	$	1,734		$	1,734
Noncontrolling Interest	'
	The following table provides details of the activity related to the noncontrolling interests:
		Nine Months Ended
		September 30,
	(In thousands)	2014			2013
	Balance at beginning of period	$	350		$	1,344
	Net income	—			3
	Purchase of noncontrolling interest	—			(997		)
	Balance at end of period	$	350		$	350
	The following table provides details of the activity related to changes in ownership of noncontrolling interests:
		Nine Months Ended
		September 30,
		2014			2013
	Net income attributable to AERC	$	108,038		$	31,977
	Decrease in equity for purchase of noncontrolling interest	—			(3,547		)
	Change from net income attributable to AERC and net
	transfers to noncontrolling interest	$	108,038		$	28,430

Equity_Tables

Equity (Tables)	9 Months Ended
	Sep. 30, 2014
Equity [Abstract]	'
Schedule of Stockholders Equity	'
	The following table provides a reconciliation of significant activity in equity accounts:
		Nine Months Ended September 30, 2014
		Common				Accumulated
		Shares				Distributions			Accumulated
		(at $.10				in Excess of			Other			Treasury
		stated		Paid-In		Accumulated			Comprehensive			Shares			Noncontrolling
	(In thousands)	value)		Capital		Net Income			Loss			(at Cost)			Interest
	Balance, December 31, 2013	$	5,760	$	754,582	$	(213,275	)	$	(702	)	$	(1,915	)	$	350
	Net income attributable to AERC	—		—		108,038			—			—			—
	Other comprehensive income:
	Changes in fair value of hedge
	instruments	—		—		—			68			—			—
	Share-based compensation	—		2,016		1			—			1,952			—
	Purchase of common shares	—		—		—			—			(1,033		)	—
	Option exercises	8		725		—			—			—			—
	Issuance of common shares	3		—		—			—			—			—
	Common share dividends declared	—		—		(33,754		)	—			—			—
	Balance, September 30, 2014	$	5,771	$	757,323	$	(138,990	)	$	(634	)	$	(996	)	$	350

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Earnings Per Share	'
	The following table presents a reconciliation of basic and diluted earnings per common share:
		Three Months Ended					Nine Months Ended
		September 30,					September 30,
	(In thousands, except per share amounts)	2014		2013			2014			2013
	Numerator - basic and diluted:
	Income from continuing operations	$	3,418	$	1,330		$	108,038		$	2,385
	Net income attributable to noncontrolling interests	—		(14		)	—			(45		)
	Allocation to participating securities	—		(85		)	(364		)	(136		)
	Income from continuing operations applicable to common shares	$	3,418	$	1,231		$	107,674		$	2,204
	Income from discontinued operations applicable to common shares	$	—	$	18,677		$	—		$	29,637
	Denominator - basic:	57,531		49,949			57,456			49,816
	Effect of dilutive securities (1)	502		318			472			560
	Denominator - diluted:	58,033		50,267			57,928			50,376
	Net income applicable to common shares - basic:
	Income from continuing operations applicable to common shares	$	0.06	$	0.02		$	1.87		$	0.04
	Income from discontinued operations	—		0.38			—			0.6
	Net income attributable to common shares - basic	$	0.06	$	0.4		$	1.87		$	0.64
	Net income applicable to common shares - diluted:
	Income from continuing operations applicable to common shares	$	0.06	$	0.02		$	1.86		$	0.04
	Income from discontinued operations	—		0.38			—			0.59
	Net income attributable to common shares - diluted	$	0.06	$	0.4		$	1.86		$	0.63
	-1	The Company has excluded 93 stock options for the three and nine months ended September 30, 2013, as their inclusion would be anti-dilutive

Equity_Based_Award_Plans_Table

Equity Based Award Plans (Tables)	9 Months Ended
	Sep. 30, 2014
Share-based Compensation [Abstract]	'
Restricted Share Activity	'
	The following table represents restricted share and DRSU activity for the nine months ended September 30, 2014:
				Weighted			Weighted
		Number of		Average			Average
		Restricted		Grant-Date		Number of	Grant-Date
		Shares		Fair Value		DRSUs	Fair Value
	Nonvested at beginning of period	735,184		$	10.52	34,797	$	17.15
	Granted	161,267		$	16.11	39,526	$	16.14
	Vested	171,381		$	16.36	26,603	$	17.38
	Forfeited	16,280		$	10.63	8,194	$	16.38
	Nonvested at end of period	708,790		$	10.37	39,526	$	16.14
Assumptions used in Monte Carlo method	'
	The following table represents the assumption ranges used in the Monte Carlo method for the multi-year restricted share awards:
		2014	2013
	Expected volatility - AERC	22.3% to 24.2%	18.1% to 22.5%
	Expected volatility - peer group	16.9% to 24.7%	14.7% to 29.5%
	Risk-free interest rate	0.02% to 0.8%	0.08% to 0.5%
	Expected life (performance period)	3 years	3 years
Stock Option Activity	'
	The following table represents stock option activity for the nine months ended September 30, 2014:
						Weighted-Average
		Number of		Weighted-Average		Remaining
		Stock Options		Exercise Price		Contract Life
	Outstanding at beginning of period	510,020		$	11.47
	Exercised	80,930		$	9.07
	Forfeited	5,000		$	14
	Outstanding at end of period	424,090		$	11.89	3.1
	Exercisable at end of period	382,424		$	11.52	2.6

Derivative_Instruments_and_Hed1

Derivative Instruments and Hedging Activities (Tables)	9 Months Ended
	Sep. 30, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Schedule of Notional Amounts of Outstanding Derivatives	'
	As of September 30, 2014, the Company had the following outstanding interest rate derivatives that were designated as cash flow hedges:
	Interest Rate Derivative		Number of Instruments		Notional Amount
	Interest Rate Swaps		2		$125.0 million
Fair Value of Derivative Financial Instruments and their Classification on the Balance Sheet	'
	The following table presents the fair value of our derivative financial instruments as well as the classification on the Consolidated Balance Sheets (see Note 12 for additional information regarding the fair value of these derivative instruments):
	Fair Value of Derivative Instruments
		Asset Derivatives
		As of September 30, 2014						As of December 31, 2013
	(In thousands)	Balance Sheet Location		Fair Value				Balance Sheet Location		Fair Value
	Derivatives designated
	as hedging instruments:
	Interest rate swap	Other assets, net		$	890			Other assets, net		$	1,573
	Fair Value of Derivative Instruments
		Liability Derivatives
		As of September 30, 2014						As of December 31, 2013
	(In thousands)	Balance Sheet Location		Fair Value				Balance Sheet Location		Fair Value
	Derivatives designated
	as hedging instruments:
		Accounts payable and						Accounts payable and
	Interest rate swap	other liabilities		$	1,524			other liabilities		$	2,275
Effect of Derivative Financial Instruments on the Consolidated Statements of Operations and Comprehensive Income	'
	The following table presents the effect of our derivative financial instruments on the Consolidated Statements of Operations and Comprehensive Income:
	The Effect of Derivative Instruments on the Consolidated Statements of Operations and Comprehensive Income
			Location of Gain or
	(In thousands)		(Loss) Recognized		Three Months Ended								Nine Months Ended
	Derivatives in Cash Flow Hedging		in Income		September 30,								September 30,
	Relationships (Interest Rate Swaps)		on Derivative		2014				2013				2014				2013
	Amount of gain/(loss)
	recognized in OCI on derivative				$	462			$	(964	)		$	(977	)		$	1,257
	Amount of loss reclassified from accumulated
	OCI into interest expense		Interest expense		$	(352	)		$	(342	)		$	(1,045	)		$	(430	)
	Amount of gain/(loss) recognized in
	income on derivative (ineffective portion and
	amount excluded from effectiveness testing)		Other expense		$	—			$	—			$	—			$	—
Offsetting assets and liabilities	'
	Offsetting of Derivative Assets and Liabilities
															Gross Amounts Not Offset in
															the Balance Sheets
											Net Amounts of
			Gross Amounts				Gross Amounts				Assets/Liabilities								Cash
			of Recognized				Offset in the				Presented in the				Financial				Collateral		Net
	(In thousands)		Assets/Liabilities				Balance Sheets				Balance Sheets				Instruments				Received		Amount
	30-Sep-14
	Offsetting Derivative
	Assets		$	890			$	—			$	890			$	—			$	—	$	890
	Liabilities		$	1,524			$	—			$	1,524			$	—			$	—	$	1,524
	31-Dec-13
	Offsetting Derivative
	Assets		$	1,573			$	—			$	1,573			$	—			$	—	$	1,573
	Liabilities		$	2,275			$	—			$	2,275			$	—			$	—	$	2,275

Fair_Value_Tables

Fair Value (Tables)	9 Months Ended
	Sep. 30, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Schedule of Liabilities Measured at Fair Value	'
				Fair Value at September 30, 2014 Using
				Quoted Prices in
				Active Markets		Significant
				for Identical		Other		Significant
				Assets or		Observable		Unobservable
		Carrying		Liabilities		Inputs		Inputs
	(In thousands)	Value		(Level 1)		(Level 2)		(Level 3)
	Mortgage notes payable	$	287,824	$	—	$	—	$	298,785
	Unsecured debt	$	441,500	$	—	$	450,208	$	—
				Fair Value at December 31, 2013 Using
				Quoted Prices in
				Active Markets		Significant
				for Identical		Other		Significant
				Assets or		Observable		Unobservable
		Carrying		Liabilities		Inputs		Inputs
	(In thousands)	Value		(Level 1)		(Level 2)		(Level 3)
	Mortgage notes payable	$	279,474	$	—	$	—	$	284,886
	Unsecured debt	$	533,500	$	—	$	530,022	$	—

Business_Details

Business (Details)	Sep. 30, 2014
Real Estate Properties [Line Items]	'
Apartment units owned	13,034
Number of states	8
Desmond's Tower [Member]	'
Real Estate Properties [Line Items]	'
Square feet of space	78,800
Wholly Owned Properties [Member]	'
Real Estate Properties [Line Items]	'
Number of apartment communities owned	50
Unconsolidated Properties, Managed [Member]	'
Real Estate Properties [Line Items]	'
Number of apartment communities owned	3

Significant_Accounting_Policie3

Significant Accounting Policies Real Estate and Depreciation (Details)	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Property, Plant and Equipment [Line Items]	'	'
Intangible assets useful life	'12 months	'
Minimum [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Buildings and improvements	'5	'5
Furniture, fixtures and equipment	'5	'5
Maximum [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Buildings and improvements	'30	'30
Furniture, fixtures and equipment	'10	'10
Commercial Lease [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Intangible assets useful life	'60 months	'

Significant_Accounting_Policie4

Significant Accounting Policies Capitalized Costs (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]	'	'	'	'	'
Intangible assets useful life	'	'	'12 months	'	'
Interest costs capitalized	$1,200,000	$1,100,000	$3,400,000	$2,400,000	'
Payroll costs capitalized	860,000	690,000	2,500,000	2,000,000	'
Number of properties classified as held for sale	0	'	0	'	0
Amount adjusted	'	'	$8,300,000	'	'

Significant_Accounting_Policie5

Significant Accounting Policies Out of Period Adjustment (Details) (USD $)	9 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Accounts payable and accrued expenses	'	'	$4,995
Total adjustments	-50,649	25,327	20,530
Net cash flow provided by operating activities	57,389	57,349	81,825
Development fixed asset additions	'	'	-85,356
Net cash flow used for investing activities	-60,914	158,761	-219,438
Net change in accounts payable related to fixed asset additions	7,651	6,770	6,098
Adjustments for Error Corrections [Member]	'	'	'
Accounts payable and accrued expenses	'	'	8,262
Total adjustments	'	'	8,262
Net cash flow provided by operating activities	'	'	8,262
Development fixed asset additions	'	'	-8,262
Net cash flow used for investing activities	'	'	-8,262
Net change in accounts payable related to fixed asset additions	'	'	-8,262
As Reported [Member]	'	'	'
Accounts payable and accrued expenses	'	'	-3,267
Total adjustments	'	'	12,268
Net cash flow provided by operating activities	'	'	73,563
Development fixed asset additions	'	'	-77,094
Net cash flow used for investing activities	'	'	-211,176
Net change in accounts payable related to fixed asset additions	'	'	$14,360

Acquisition_Development_and_Di2

Acquisition, Development, and Disposition Activity Acquisition, Development, and Disposition Text (Details) (USD $)

3 Months Ended

9 Months Ended

12 Months Ended

9 Months Ended

9 Months Ended

9 Months Ended

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Dec. 31, 2013

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Apr. 25, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Properties

Desmond's Tower [Member]

Bristol Development Group [Member]

Current Development [Member]

Early Development [Member]

350 8th [Member]

350 8th [Member]

950 East Third [Member]

5th and Huntington [Member]

The Edge at Flagler [Member]

Alpha Mill [Member]

Alpha Mill [Member]

Doral West [Member]

Rienzi Turtle Creek [Member]

350 8th [Member]

7001 Arlington at Bethesda [Member]

Cantabria at Turtle Creek [Member]

The Desmond on Wilshire [Member]

NorthwoodRavinPortfolio [Member]

Germantown [Member]

sqft

Units

Units

Planned development [Member]

Planned development [Member]

Planned development [Member]

Planned development [Member]

Units

Units

Units

Units

Planned development [Member]

Current Development [Member]

Current Development [Member]

Current Development [Member]

Properties

Units

Units

Units

Units

Units

Units

Units

acre

Business Acquisition [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of real estate properties to acquire

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

7

'

Purchase price

'

'

$80,200,000

'

'

'

'

'

'

$46,600,000

'

'

'

'

$45,100,000

'

$93,500,000

$48,900,000

$46,600,000

'

'

'

$323,900,000

'

Mortgage loan assumed

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

28,000,000

'

Earnest money deposit

4,000,000

'

4,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

10,000,000

'

Apartment units owned

13,034

'

13,034

'

'

'

'

564

882

410

'

472

154

[1]

331

267

'

388

152

410

140

249

175

'

'

Lease up period

'

'

'18 months

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Square feet of space

'

'

'

'

'

78,800

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Termination Fee

'

'

8,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Costs associated with acquisitions

59,000

392,000

172,000

457,000

'

'

'

'

'

'

'

'

'

'

57,000

78,000

'

'

'

'

'

'

'

'

Area of land

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3.36

'

'

'

'

'

Ownership percentage

'

'

'

'

'

'

'

'

'

50.01%

'

50.00%

50.00%

'

'

'

'

'

'

'

'

'

'

'

Equity interest

100.00%

'

100.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

98.10%

[2]

100.00%

100.00%

'

'

Development costs

162,000

220,000

690,000

662,000

'

'

'

186,500,000

[3]

409,000,000

[3]

245,000,000

[3]

'

164,000,000

[3]

'

'

'

'

'

'

'

53,400,000

[3]

56,800,000

[3]

76,300,000

[3]

'

'

Costs to date

85,437,000

'

85,437,000

'

42,793,000

'

'

127,689,000

108,066,000

72,500,000

'

35,566,000

15,223,000

'

'

'

'

'

'

40,725,000

46,436,000

40,528,000

'

'

Construction loan

'

'

'

'

'

'

'

38,642,000

0

0

143,600,000

0

0

'

'

'

'

'

'

12,954,000

25,688,000

0

'

'

Long-term Construction Loan, Current, AEC Portion

'

'

'

'

'

'

'

'

0

0

[4]

'

0

0

'

'

'

'

'

'

'

'

'

'

'

Nature of Common Ownership or Management Control Relationships

'

'

'1

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Guarantee

'

'

100.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term Construction Loan

0

'

0

'

'

'

'

'

'

143,600,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Percentage of development costs to date included

'

'

100.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Noncontrolling interest cash contribution

'

'

'

'

'

'

350,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Investment in unconsolidated entities

45,921,000

'

45,921,000

'

9,321,000

'

'

'

38,156,000

33,609,000

'

4,547,000

7,765,000

'

'

'

'

'

'

'

'

'

'

'

Property dispositions

'

'

4

2

4

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total sales price

'

'

172,200,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Gain on sale of property

'

'

100,900,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Related party amount of transaction

'

'

'

122,700,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

53,300,000

Related party commissions

'

'

'

$1,100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$244,000

[1]

Based on current projections as of October 28, 2014.

[2]

Ownership percentage is based on current equity of the joint venture and is subject to change based on changes in total equity. Costs are shown at 100%. Joint venture partner contribution is $350.

[3]

Total capital costs are calculated as if owned 100% by AEC and represent estimated costs for projects under development inclusive of all capitalized costs in accordance with GAAP. Based on current projections as of October 28, 2014.

[4]

AEC has guaranteed 100% of a $143.6 million construction loan which had no outstanding balance as of September 30, 2014.

Acquisition_Development_and_Di3

Acquisition, Development, and Disposition Activity Purchase Price Allocation (Details) (USD $)	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Business Acquisition [Line Items]	'	'
Apartment units owned	13,034	'
Purchase price	$80,200,000	'
Land	8,055,000	15,971,000
Buildings and improvements	36,139,000	123,193,000
Furniture and fixtures	463,000	1,154,000
Existing leases (Other assets)	418,000	2,082,000
Total	45,075,000	142,400,000
NorthwoodRavinPortfolio [Member]	'	'
Business Acquisition [Line Items]	'	'
Apartment units owned	695	'
Purchase price	159,800	'
Perimeter Town Center [Member]	'	'
Business Acquisition [Line Items]	'	'
Apartment units owned	345	'
Purchase price	80,350	'
Varela [Member]	'	'
Business Acquisition [Line Items]	'	'
Apartment units owned	350	'
Purchase price	79,450	'
350 8th [Member] | Future Development [Member]	'	'
Business Acquisition [Line Items]	'	'
Apartment units owned	410	'
Purchase price	$46,600,000	'

Acquisition_Development_and_Di4

Acquisition, Development, and Disposition Activity Pro Forma (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]	'	'	'	'
Actual revenue from acquisitions	$813	$1,732	$974	$1,732
Actual net income from acquisitions	-48	139	-93	139
Pro forma revenue	48,207	49,022	146,885	143,393
Pro forma net income applicable to common shares	$3,673	$20,929	$108,238	$33,931
Pro forma earnings per common share - basic:	'	'	'	'
Pro forma net income applicable to common shares	$0.06	$0.42	$1.88	$0.68
Pro forma earnings per common share - diluted:	'	'	'	'
Pro forma net income applicable to common shares	$0.06	$0.42	$1.87	$0.67

Acquisition_Development_and_Di5

Acquisition, Development, and Disposition Activity Income from Discontinued Operations (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]	'	'	'	'
Property revenue	'	$1,904	'	$8,144
EXPENSES	'	'	'	'
Property operating and maintenance	'	865	'	3,771
Depreciation and amortization	'	434	'	1,604
Total expense	'	1,299	'	5,375
Operating income	'	605	'	2,769
Interest expense	'	0	'	0
Operating income, net of interest expense	0	605	0	2,769
Gain on disposition of properties	'	18,072	'	26,868
Income from discontinued operations	'	$18,677	'	$29,637

Debt_Debt_outstanding_Details

Debt Debt outstanding (Details) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014		Dec. 31, 2013
Debt Instrument [Line Items]	'		'
Secured	$287,824		$279,474
Unsecured notes	250,000		250,000
Unsecured term loan	150,000		150,000
Total debt	729,324		812,974
Weighted average interest rate	3.90%		3.80%
Loans repaid	20,038		'
Interest rate	5.40%	[1]	'
Fixed Rate Debt [Member]	'		'
Debt Instrument [Line Items]	'		'
Secured	249,182		271,374
Secured Debt Weighted Average Interest Rate	4.90%		4.90%
Unsecured notes	250,000		250,000
Total debt	499,182		521,374
Weighted average interest rate	4.60%		4.70%
Fixed Rate Debt Unsecured Notes [Member] [Domain]	'		'
Debt Instrument [Line Items]	'		'
Unsecured Debt Weighted Average Interest Rate	4.40%		4.40%
Variable Rate Debt Hedged [Member]	'		'
Debt Instrument [Line Items]	'		'
Unsecured term loan	'		125,000
Unsecured Debt Weighted Average Interest Rate	'		3.00%
Total debt	'		125,000
Weighted average interest rate	'		3.00%
Fixed Rate Debt Hedged [Member]	'		'
Debt Instrument [Line Items]	'		'
Unsecured term loan	125,000		'
Unsecured Debt Weighted Average Interest Rate	2.70%		'
Total debt	125,000		'
Weighted average interest rate	2.70%		'
Variable Rate Debt Unhedged [Member]	'		'
Debt Instrument [Line Items]	'		'
Secured	38,642		8,100
Secured Debt Weighted Average Interest Rate	1.50%		1.50%
Unsecured Debt Weighted Average Interest Rate	1.60%		'
Total debt	105,142		166,600
Weighted average interest rate	1.50%		1.50%
Variable Rate Debt Unhedged Revolver [Member]	'		'
Debt Instrument [Line Items]	'		'
Unsecured term loan	41,500		133,500
Unsecured Debt Weighted Average Interest Rate	1.50%		1.50%
Variable Rate Debt Unhedged Term Loan [Member]	'		'
Debt Instrument [Line Items]	'		'
Unsecured term loan	25,000		25,000
Unsecured Debt Weighted Average Interest Rate	'		1.90%
Residence at White River [Member]	'		'
Debt Instrument [Line Items]	'		'
Loans repaid	9,221		'
Interest rate	5.40%		'
Spring Valley [Member]	'		'
Debt Instrument [Line Items]	'		'
Loans repaid	$10,817		'
Interest rate	5.40%		'
[1]	Represents weighted average interest rate for the loans listed.

Debt_Textual_Details

Debt Textual (Details) (USD $)	0 Months Ended	9 Months Ended
	Jul. 25, 2014	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Debt Instrument [Line Items]	'	'	'	'
Debt, Amendment Date	25-Jul-14	'	'	'
Unsecured term loan	'	$150,000,000	'	$150,000,000
Investment Interest Rate Range Start	'	90.00%	'	'
Investment Interest Rate Range End	'	190.00%	'	'
Long-term Construction Loan	'	0	'	'
Debt term	'	'5 years	'	'
Debt Instrument, Description of Variable Rate Basis	'	140.00%	'	'
Cash paid for interest	'	19,300,000	19,800,000	'
Variable Rate Debt Hedged [Member]	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'
Unsecured term loan	'	'	'	125,000,000
350 8th [Member]	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'
Debt Instrument, Description of Variable Rate Basis	'	160.00%	'	'
Construction loan	'	$0	'	'

Goodwill_and_Other_Intangible_1

Goodwill and Other Intangible Assets Intangible (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2014	Sep. 30, 2014
			Residential Real Estate [Member]	Desmond's Tower [Member]
Acquired Finite-Lived Intangible Assets [Line Items]	'	'	'	'
Goodwill written-off	$150,000	'	'	'
Goodwill	$1,400,000	$1,500,000	'	'
Amortization period	'	'	'12 months	'60 months

Investment_in_Unconsolidated_E1

Investment in Unconsolidated Entities (Details) (USD $)	3 Months Ended		9 Months Ended					9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Apr. 25, 2014	Feb. 03, 2014	Sep. 30, 2014	Sep. 30, 2014
					Planned development [Member]	Planned development [Member]	Planned development [Member]	Planned development [Member]	Planned development [Member]
					350 8th [Member]	350 8th [Member]	350 8th [Member]	950 East Third [Member]	5th and Huntington [Member]
					Units			Units	Units
Investment in Unconsolidated Entities [Line Items]	'	'	'	'	'	'	'	'	'
Apartment units owned	13,034	'	13,034	'	410	'	'	472	154	[1]
Ownership percentage	'	'	'	'	50.01%	'	'	50.00%	50.00%
Partner contribution	'	'	'	'	$33,900,000	'	'	'	$7,500,000
Purchase price	'	'	80,200,000	'	46,600,000	'	'	'	'
Partnership land	'	'	'	'	'	'	'	'	13,100,000
Carrying value of partnership	'	'	'	'	'	'	50,300,000	'	'
Management fees revenue	312,000	0	578,000	0	262,500	'	'	125,000	'
Contribution of land value	'	'	'	'	'	'	'	30,000,000	'
Contribution	'	'	26,238,000	0	'	'	'	4,500,000	7,800,000
Outside basis	'	'	'	'	880,000	'	'	470,000	370,000
Maximum exposure	'	'	'	'	33,600,000	'	'	4,500,000	7,800,000
Construction loan	'	'	'	'	0	143,600,000	'	0	0
Debt term	'	'	'5 years	'	'5 years	'	'	'	'
Long-term Construction Loan	$0	'	$0	'	$143,600,000	'	'	'	'
[1]	Based on current projections as of October 28, 2014.

Noncontrolling_Interests_Nonco

Noncontrolling Interests Noncontrolling Interests Textual (Details) (USD $)	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Noncontrolling Interest [Line Items]	'	'
Opertating partnership units issued	522,032	'
OP units remaining	74,083	'
Payments for repurchase of redeemable noncontrolling interest	$1,400,000	'
OP units redeemed	0	0
Equity interest	100.00%	'
Redemption of minority interest	10.00%	'
Decrease in equity for purchase of noncontrolling interest	-4,500,000	'
Related party amount of transaction	'	122,700,000
Bethesda [Member]	'	'
Noncontrolling Interest [Line Items]	'	'
Equity interest	98.10%	'
Area of land	2.5	'
Contribution	12,200,000	'
Real estate units intended to develop	140	'
Square feet of space	7,000	'
Germantown [Member]	'	'
Noncontrolling Interest [Line Items]	'	'
Equity interest	90.00%	'
Contribution	$9,400,000	'
Real estate units intended to develop	242	'

Noncontrolling_Interests_Nonco1

Noncontrolling Interests Noncontrolling Redeemable Interest (Details) (USD $)	3 Months Ended	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Redeemable Noncontrolling Interest [Line Items]	'	'	'
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests	'	$4,500	'
Balance at beginning of period	'	'	1,734
Net income attributable to noncontrolling redeemable interest	14	'	42
Distribution to noncontrolling redeemable interest	-14	'	-42
Balance at end of period	1,734	'	1,734
Additional Paid-in Capital [Member]	'	'	'
Redeemable Noncontrolling Interest [Line Items]	'	'	'
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests	'	$0	$3,547

Noncontrolling_Interests_Nonco2

Noncontrolling Interests Noncontrolling Interest (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Noncontrolling Interest [Line Items]	'	'	'	'
Balance at beginning of period	'	'	$350	'
Balance at end of period	350	'	350	'
Net income attributable to AERC	3,418	19,993	108,038	31,977
Purchase of noncontrolling interest	'	'	-4,500	'
Change from net income attributable to AERC and net transfers from noncontrolling interest	'	'	108,038	28,430
Noncontrolling Interest [Member]	'	'	'	'
Noncontrolling Interest [Line Items]	'	'	'	'
Purchase of noncontrolling interest	'	'	0	-3,547
Bristol Development Group [Member]	'	'	'	'
Noncontrolling Interest [Line Items]	'	'	'	'
Purchase of noncontrolling interest	'	'	0	-997
Bristol Development Group [Member]	'	'	'	'
Noncontrolling Interest [Line Items]	'	'	'	'
Balance at beginning of period	'	'	350	1,344
Net income	'	'	0	3
Balance at end of period	$350	$350	$350	$350

Equity_Equity_Details

Equity Equity (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014	Dec. 31, 2013
					Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Distributions in Excess of Net Income [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]	Noncontrolling Interest [Member]	Noncontrolling Interest [Member]
Equity Note [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Balance, December 31, 2013	'	'	$544,800	'	$5,760	$754,582	($213,275)	($702)	$1,915	$350	$350
Net income attributable to AERC	3,418	19,993	108,038	31,977	'	'	108,038	'	'	'	'
Changes in fair value of hedge instruments	'	'	'	'	'	'	'	68	'	'	'
Share-based compensation	'	'	'	'	'	2,016	1	'	1,952	'	'
Purchase of common shares	'	'	'	'	'	'	'	'	-1,033	'	'
Option exercises	'	'	'	'	8	725	'	'	'	'	'
Issuance of common shares	'	'	'	'	3	'	'	'	'	'	'
Common share dividends declared	'	'	'	'	'	'	-33,754	'	'	'	'
Balance, September 30, 2014	$622,824	'	$622,824	'	$5,771	$757,323	($138,990)	($634)	$996	$350	$350

Earnings_Per_Share_Earnings_pe

Earnings Per Share Earnings per share table (Details) (USD $)	3 Months Ended				9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Numerator - basic and diluted:	'		'		'		'
Income from continuing operations	$3,418		$1,330		$108,038		$2,385
Net income attributable to noncontrolling interests	0		-14		0		-45
Allocation to participating securities	0		-85		-364		-136
Income from continuing operations applicable to common shares	3,418		1,231		107,674		2,204
Income from discontinued operations applicable to common shares	0		18,677		0		29,637
Denominator - basic:	57,531,000		49,949,000		57,456,000		49,816,000
Effect of dilutive securities	502,000	[1]	318,000	[1]	472,000	[1]	560,000	[1]
Denominator - diluted:	58,033,000		50,267,000		57,928,000		50,376,000
Earnings per common share - basic:	'		'		'		'
Income from continuing operations applicable to common shares	$0.06		$0.02		$1.87		$0.04
Income from discontinued operations	$0		$0.38		$0		$0.60
Net income applicable to common shares - basic	$0.06		$0.40		$1.87		$0.64
Earnings per common share - diluted:	'		'		'		'
Income from continuing operations applicable to common shares	$0.06		$0.02		$1.86		$0.04
Income from discontinued operations	$0		$0.38		$0		$0.59
Net income applicable to common shares - diluted	$0.06		$0.40		$1.86		$0.63
Antidilutive shares	'		93		'		93
Income from continuing operations [Member]	'		'		'		'
Numerator - basic and diluted:	'		'		'		'
Allocation to participating securities	$0		($85)		'		'
[1]	The Company has excluded 93 stock options for the three and nine months ended September 30, 2013, as their inclusion would be anti-dilutive.

Equity_Based_Award_Plans_Equit

Equity Based Award Plans Equity Based Award Plans Textual (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Total share-based compensation	$850,000	$980,000	$3,000,000	$3,400,000
Share-based compensation in capitalized payroll	120,000	90,000	340,000	300,000
Stock options awarded	'	'	0	0
Options exercised	'	'	80,930	169,164
Intrinsic value of stock options	2,300,000	2,200,000	2,300,000	2,200,000
Restricted Stock Units (RSUs) [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Weighted-Average grant date fair value	'	'	$16.14	'
Fair value of restricted shares vested	'	'	460,000	590,000
Unrecognized compensation costs	5,500,000	'	5,500,000	'
Weighted average period of unrecognized compensation cost	'	'	'2 years 0 months	'
Restricted Share and RSU's [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Weighted-Average grant date fair value	'	'	'	$10.44
Restricted Stock [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Weighted-Average grant date fair value	'	'	$16.11	'
Fair value of restricted shares vested	'	'	3,200,000	2,700,000
Restricted Stock [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Estimated grant-date fair value	'	'	$90,000	$4,300,000

Equity_Based_Award_Plans_Restr

Equity Based Award Plans Restricted Shares (Details) (USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2014
	Restricted Share and RSU's [Member]	Restricted Stock [Member]	Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Nonvested at beginning of period	'	735,184	34,797
Nonvested at beginning of period weighted average grant date fair value	'	$10.52	$17.15
Granted	'	161,267	39,526
Weighted-Average grant date fair value	$10.44	$16.11	$16.14
Vested	'	171,381	26,603
Vested weighted average grant date fair value	'	$16.36	$17.38
Forfeited	'	16,280	8,194
Forfeited weighted average grant date fair value	'	$10.63	$16.38
Nonvested at end of period	'	708,790	39,526
Nonvested at end of period weighted average grant date fair value	'	$10.37	$16.14

Equity_Based_Award_Plans_Monte

Equity Based Award Plans Monte Carlo (Details) (Restricted Stock [Member])	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Risk free rate minimum	0.02%	0.08%
Risk free rate maximum	0.80%	0.50%
Expected life of options (in years)	'3 years	'3 years
AERC [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Expected volatility minimum	22.30%	18.10%
Expected volatility maximum	24.20%	22.50%
Peer Group [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Expected volatility minimum	16.90%	14.70%
Expected volatility maximum	24.70%	29.50%

Equity_Based_Award_Plans_Stock

Equity Based Award Plans Stock Options (Details) (USD $)	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'	'	'
Outstanding at the beginning of period	510,020	'	'
Exercised	80,930	169,164	'
Forfeited	5,000	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested Options Forfeited, Number of Shares	5,000	0	'
Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price	$9.07	'	'
Outstanding at the end of the period	424,090	'	'
Forfeited	$14	'	'
Exercisable at the end of the period	382,424	'	'
Weighted average exercise price outstanding at the end of the period	$11.89	'	$11.47
Weighted-Average exercise price exercisable at the end of the period	$11.52	'	'
Weighted-Average remaining contract life outstanding at the end of the period	'3 years 1 month	'	'
Weighted-Average remaining contract life exercisable at the end of the period	'2 years 7 months	'	'

Derivative_Instruments_and_Hed2

Derivative Instruments and Hedging Activities Derivative Instruments and Hedging Activities Textual (Details) (USD $)	9 Months Ended
	Sep. 30, 2014
Derivative [Line Items]	'
Inception date	19-Dec-11
Effective date	7-Jun-13
Amount of cash flow hedge	$125,000,000
Term Loan, Amount Outstanding	150,000,000
Credit spread	1.40%
All-in rate	2.66%
Lower range of basis spread	0.90%
Higher range of basis spread	1.90%
Fair value of the derivative in a net liability position	1,600,000
Fair value of assets needed for immediate settlement	1,600,000
Derivative interest payable	88,000
Amount of other comprehensive income to be reclassified to earnings over the next twelve months	1,300,000
Fixed Rate Debt Hedged [Member]	'
Derivative [Line Items]	'
Base rate	1.26%
2013 derivative [Domain]	'
Derivative [Line Items]	'
Inception date	2-Apr-13
Effective date	2-Jun-16
Amount of cash flow hedge	$125,000,000
Base rate	1.55%
All-in rate	2.95%

Derivative_Instruments_and_Hed3

Derivative Instruments and Hedging Activities Outstanding Interest Rate Derivatives (Details) (USD $)	Sep. 30, 2014
In Millions, unless otherwise specified
Derivative [Line Items]	'
Derivative, Number of Instruments Held	2
Amount of cash flow hedge	$125

Derivative_Instruments_and_Hed4

Derivative Instruments and Hedging Activities Fair Value of Derivative Instruments and their Classification on the Balance Sheet (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Derivatives, Fair Value [Line Items]	'	'
Other assets	$890	$1,573
Other liabilities	$1,524	$2,275

Derivative_Instruments_and_Hed5

Derivative Instruments and Hedging Activities Effect of Derivative Financial Instruments on the Statements of Income and Comprehensive Income (Details) (USD $)	9 Months Ended		3 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
			Cash Flow Hedging [Member]	Cash Flow Hedging [Member]	Cash Flow Hedging [Member]	Cash Flow Hedging [Member]	Cash Flow Hedging [Member]	Cash Flow Hedging [Member]
			Interest Rate Swap [Member]	Interest Rate Swap [Member]	Interest Rate Swap [Member]	Interest Rate Swap [Member]	Interest Rate Swap [Member]	Interest Rate Swap [Member]
					Interest Expense [Member]	Interest Expense [Member]	Other Expense [Member]	Other Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'	'	'	'	'
Amount of gain/(loss) recognized in OCI on derivative	($977,000)	$1,257,000	$462,000	($964,000)	'	'	'	'
Amount of loss reclassified from accumulated OCI into interest expense	-1,045,000	-430,000	'	'	-352,000	-342,000	'	'
Amount of gain/(loss) recognized in income on derivative (ineffective portion and amount excluded from effectiveness testing)	$0	$0	'	'	'	'	$0	$0

Derivative_Instruments_and_Hed6

Derivative Instruments and Hedging Activities Offsetting financial assets and liabilities (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Offseting Liabilities [Line Items]	'	'
Derivative Asset, Fair Value, Gross Asset	$890	$1,573
Derivative Assets	890	1,573
Derivative Liability, Fair Value, Gross Liability	1,524	2,275
Derivative Liabilities	$1,524	$2,275

Fair_Value_Fair_Value_Details

Fair Value Fair Value (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
Carrying (Reported) Amount, Fair Value Disclosure [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Mortgage notes payable	$287,824,000	$279,474,000
Unsecured debt	441,500,000	533,500,000
Fair Value, Inputs, Level 1 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Mortgage notes payable	0	0
Unsecured debt	0	0
Fair Value, Inputs, Level 2 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Mortgage notes payable	0	0
Unsecured debt	450,208,000	530,022,000
Fair Value, Inputs, Level 3 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Mortgage notes payable	298,785,000	284,886,000
Unsecured debt	$0	$0
Minimum [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Loan to value ratios	38.00%	'
Maximum [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Loan to value ratios	53.00%	'

Contingencies_Details

Contingencies (Details) (USD $)	9 Months Ended
	Sep. 30, 2014
Loss Contingencies [Line Items]	'
Intangible assets	$980,000
Cure payment	630,000
Long-term Construction Loan	0
Debt term	'5 years
350 8th [Member] | Future Development [Member]	'
Loss Contingencies [Line Items]	'
Ownership percentage	50.01%
Long-term Construction Loan	$143,600,000
Debt term	'5 years

Subsequent_Events_Subsequent_E

Subsequent Events Subsequent Events (Details) (USD $)	9 Months Ended	0 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2014	Oct. 10, 2014	Oct. 02, 2014
		Subsequent Event [Member]	Subsequent Event [Member]
Subsequent Event [Line Items]	'	'	'
Legal Proceeding, date	'	10-Oct-14	'
Options forfeited per settlement	'	63,714	'
Option grants in period	'	125,000	'
Repayment of mortgage, date	'	'	1-Oct-14
Loans repaid	$20,038	'	$24,500