AvalonBay Communities (AVB) 10-K 23 Feb 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Jan. 31, 2018	Jun. 30, 2017
Document and Entity Information
Entity Registrant Name	AVALONBAY COMMUNITIES INC
Entity Central Index Key	915,912
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		138,095,504
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 26,425,741,640

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Real estate:
Land and improvements	$ 4,237,318	$ 3,941,250
Buildings and improvements	15,708,666	14,314,981
Furniture, fixtures and equipment	615,288	532,994
Total Capitalized Cost	20,561,272	18,789,225
Less accumulated depreciation	(4,218,379)	(3,743,632)
Net operating real estate	16,342,893	15,045,593
Construction in progress, including land	1,306,300	1,882,262
Land held for development	68,364	84,293
Real estate assets held for sale, net	0	20,846
Total real estate, net	17,717,557	17,032,994
Cash and cash equivalents	67,088	214,994
Cash in escrow	134,818	114,983
Resident security deposits	32,686	32,071
Investments in unconsolidated real estate entities	163,475	175,116
Deferred development costs	45,819	40,179
Prepaid expenses and other assets	253,378	256,934
Total assets	18,414,821	17,867,271
LIABILITIES AND EQUITY
Unsecured notes, net	5,852,764	4,463,302
Variable rate unsecured credit facility	0	0
Mortgage notes payable, net	1,476,706	2,567,578
Dividends payable	196,094	185,397
Payables for construction	85,377	100,998
Accrued expenses and other liabilities	308,189	274,676
Accrued interest payable	43,116	38,307
Resident security deposits	58,473	57,023
Liabilities related to real estate assets held for sale	0	808
Total liabilities	8,020,719	7,688,089
Commitments and contingencies
Redeemable noncontrolling interests	6,056	7,766
Equity:
Preferred stock, $0.01 par value; $25 liquidation preference; 50,000,000 shares authorized at December 31, 2017 and 2016; zero shares issued and outstanding at December 31, 2017 and 2016	0	0
Common stock, $0.01 par value; 280,000,000 shares authorized at December 31, 2017 and 2016; 138,094,154 and 137,330,904 shares issued and outstanding at December 31, 2017 and 2016, respectively	1,381	1,373
Additional paid-in capital	10,235,475	10,105,654
Accumulated earnings less dividends	188,609	94,899
Accumulated other comprehensive loss	(37,419)	(30,510)
Total equity	10,388,046	10,171,416
Total liabilities and equity	$ 18,414,821	$ 17,867,271

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, liquidation preference (in dollars per share)	$ 25	$ 25
Preferred stock, shares authorized	50,000,000	50,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	280,000,000	280,000,000
Common stock, shares issued	138,094,154	137,330,904
Common stock, shares outstanding	138,094,154	137,330,904

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue:
Rental and other income	$ 2,154,481	$ 2,039,656	$ 1,846,081
Management, development and other fees	4,147	5,599	9,947
Total revenue	2,158,628	2,045,255	1,856,028
Expenses:
Operating expenses, excluding property taxes	503,946	478,437	448,747
Property taxes	221,375	204,837	193,499
Interest expense, net	199,661	187,510	175,615
Loss (gain) on extinguishment of debt, net	25,472	7,075	(26,736)
Depreciation expense	584,150	531,434	477,923
General and administrative expense	50,673	45,771	42,774
Expensed acquisition, development and other pursuit costs, net of recoveries	2,736	9,922	6,822
Casualty and impairment loss (gain), net	6,250	(3,935)	(10,542)
Total expenses	1,594,263	1,461,051	1,308,102
Income before equity in income of unconsolidated real estate entities, gain on sale of communities, (loss) gain on other real estate transactions, and income taxes	564,365	584,204	547,926
Equity in income of unconsolidated real estate entities	70,744	64,962	70,018
Gain on sale of communities	252,599	374,623	115,625
(Loss) gain on other real estate transactions	(10,907)	10,224	9,647
Income before income taxes	876,801	1,034,013	743,216
Income tax expense	141	305	1,483
Net income	876,660	1,033,708	741,733
Net loss attributable to noncontrolling interests	261	294	305
Net income attributable to common stockholders	876,921	1,034,002	742,038
Other comprehensive income (loss):
(Loss) income on cash flow hedges	(13,979)	(5,556)	5,354
Cash flow hedge losses reclassified to earnings	7,070	6,433	5,774
Comprehensive income	$ 870,012	$ 1,034,879	$ 753,166
Earnings per common share—basic:
Net income per common share - basic (in dollars per share)	$ 6.36	$ 7.53	$ 5.54
Earnings per common share—diluted:
Net income per common share - diluted (in dollars per share)	$ 6.35	$ 7.52	$ 5.51

CONSOLIDATED STATEMENTS OF EQUI

CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Total	Total AvalonBay stockholders' equity	Common stock	Additional paid-in capital	Accumulated earnings less dividends	Accumulated other comprehensive loss	Noncontrolling interests
Beginning Balance (in shares) at Dec. 31, 2014			132,050,382
Beginning Balance at Dec. 31, 2014	$ 9,046,405	$ 9,046,405	$ 1,320	$ 9,354,685	$ (267,085)	$ (42,515)	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to common stockholders	742,038	742,038			742,038
Income (loss) on cash flow hedges	5,354	5,354				5,354
Cash flow hedge losses reclassified to earnings	5,774	5,774				5,774
Change in redemption value of redeemable noncontrolling interest	965	965		(1,088)	2,053
Dividends declared to common stockholders	(673,670)	(673,670)			(673,670)
Issuance of common stock, net of withholdings	687,402	687,402	$ 50	688,677	(1,325)
Issuance of common stock, net of withholdings (in shares)			4,951,649
Amortization of deferred compensation	26,258	26,258		26,258
Ending Balance (in shares) at Dec. 31, 2015			137,002,031
Ending Balance at Dec. 31, 2015	9,840,526	9,840,526	$ 1,370	10,068,532	(197,989)	(31,387)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to common stockholders	1,034,002	1,034,002			1,034,002
Income (loss) on cash flow hedges	(5,556)	(5,556)				(5,556)
Cash flow hedge losses reclassified to earnings	6,433	6,433				6,433
Change in redemption value of redeemable noncontrolling interest	1,489	1,489			1,489
Dividends declared to common stockholders	(741,313)	(741,313)			(741,313)
Issuance of common stock, net of withholdings	10,695	10,695	$ 3	11,982	(1,290)
Issuance of common stock, net of withholdings (in shares)			328,873
Amortization of deferred compensation	25,140	25,140		25,140
Ending Balance (in shares) at Dec. 31, 2016			137,330,904
Ending Balance at Dec. 31, 2016	10,171,416	10,171,416	$ 1,373	10,105,654	94,899	(30,510)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to common stockholders	876,921	876,921			876,921
Income (loss) on cash flow hedges	(13,979)	(13,979)				(13,979)
Cash flow hedge losses reclassified to earnings	7,070	7,070				7,070
Change in redemption value of redeemable noncontrolling interest	2,026	2,026			2,026
Dividends declared to common stockholders	(783,912)	(783,912)			(783,912)
Issuance of common stock, net of withholdings	100,304	100,304	$ 8	101,621	(1,325)
Issuance of common stock, net of withholdings (in shares)			763,250
Amortization of deferred compensation	28,200	28,200		28,200
Ending Balance (in shares) at Dec. 31, 2017			138,094,154
Ending Balance at Dec. 31, 2017	$ 10,388,046	$ 10,388,046	$ 1,381	$ 10,235,475	$ 188,609	$ (37,419)	$ 0

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income	$ 876,660	$ 1,033,708	$ 741,733
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation expense	584,150	531,434	477,923
Amortization of deferred financing costs	7,657	7,661	6,871
Amortization of debt premium	(5,915)	(18,866)	(24,261)
Loss (gain) on extinguishment of debt, net	25,472	7,075	(26,736)
Amortization of stock-based compensation	17,920	15,082	15,321
Equity in (income) loss of, and return on, unconsolidated real estate entities and noncontrolling interests, net of eliminations	(19,798)	8,870	12,225
Casualty and impairment loss (gain), net	8,568	(3,935)	(17,303)
Abandonment of development pursuits	388	1,743	0
Cash flow hedge losses reclassified to earnings	7,070	6,433	5,774
Gain on sale of real estate assets	(281,745)	(442,916)	(158,852)
Decrease (increase) in resident security deposits, prepaid expenses and other assets	3,076	(5,403)	12,783
Increase in accrued expenses, other liabilities and accrued interest payable	32,754	19,386	29,189
Net cash provided by operating activities	1,256,257	1,160,272	1,074,667
Cash flows from investing activities:
Development/redevelopment of real estate assets including land acquisitions and deferred development costs	(979,947)	(1,201,026)	(1,569,326)
Acquisition of real estate assets, including partnership interest	(462,317)	(393,316)	0
Capital expenditures - existing real estate assets	(65,181)	(66,971)	(48,170)
Capital expenditures - non-real estate assets	(8,809)	(5,881)	(7,695)
Proceeds from sale of real estate, net of selling costs	503,039	532,717	282,163
Insurance proceeds for property damage claims	16,233	17,196	44,142
Mortgage note receivable lending	(17,590)	(19,115)	0
(Decrease) increase in payables for construction	(15,621)	2,196	(3,230)
Distributions from unconsolidated real estate entities	89,305	111,598	109,181
Investments in unconsolidated real estate entities	(24,493)	(9,750)	(6,582)
Net cash used in investing activities	(965,381)	(1,032,352)	(1,199,517)
Cash flows from financing activities:
Issuance of common stock, net	111,093	15,526	690,184
Dividends paid	(772,657)	(726,749)	(655,248)
Issuance of mortgage notes payable	206,800	0	0
Repayments of mortgage notes payable, including prepayment penalties	(1,313,025)	(168,076)	(853,604)
Issuance of unsecured notes	1,696,826	1,122,488	873,088
Repayment of unsecured notes, including prepayment penalties	(300,000)	(504,403)	0
Payment of deferred financing costs	(17,552)	(16,240)	(7,343)
Redemption of noncontrolling interest and units for cash by minority partners	0	0	(1,088)
Payment of capital lease obligation	(18,951)	0	0
Receipts (payments) for termination of forward interest rate swaps	391	(14,847)	0
Payments related to tax withholding for share-based compensation	(10,450)	(8,562)	(6,076)
Distributions to DownREIT partnership unitholders	(42)	(41)	(38)
Contributions from joint venture and profit-sharing partners	1,038	0	0
Distributions to joint venture and profit-sharing partners	(418)	(407)	(372)
Preferred interest obligation redemption and dividends	(2,000)	(1,960)	(14,410)
Net cash (used in) provided by financing activities	(418,947)	(303,271)	25,093
Net decrease in cash and cash equivalents	(128,071)	(175,351)	(99,757)
Cash and cash equivalents and restricted cash, beginning of year	329,977	505,328	605,085
Cash and cash equivalents and restricted cash, end of year	201,906	329,977	505,328
Cash paid during the year for interest, net of amount capitalized	207,842	194,059	188,782
Supplemental Cash Flow Information [Abstract]
Cash and cash equivalents and restricted cash, end of year	$ 329,977	$ 505,328	$ 605,085

CONSOLIDATED STATEMENTS OF CAS7

CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical)	12 Months Ended
	Dec. 31, 2017USD ($)shares	Dec. 31, 2016USD ($)homeshares	Dec. 31, 2015USD ($)shares
Supplemental disclosures of non-cash investing and financing activities
Common stock issued through the dividend reinvestment plan (in shares) | shares	3,058	2,396	2,142
Common stock issued through the dividend reinvestment plan	$ 558,000	$ 424,000	$ 372,000
Number of shares withheld to satisfy employees' tax withholding and other liabilities | shares	60,319	53,453	45,090
Shares withheld to satisfy employees' tax withholding and other liabilities, value	$ 10,542,000	$ 8,356,000	$ 5,979,000
Number of shares forfeited | shares	3,388
Shares cancelled upon forfeiture	$ 588,000	694,000	726,000
Common stock dividends declared but not paid	196,094,000	185,397,000	171,257,000
Change in redemption value of redeemable noncontrolling interest	(2,026,000)	(1,489,000)	(965,000)
Increase (decrease) in derivative assets	(12,114,000)	12,085,000
Increase (decrease) in derivative liabilities	1,171,000
Cash flow hedge losses reclassified to earnings	7,070,000	6,433,000	5,774,000
Net operating real estate	16,342,893,000	15,045,593,000
Income (loss) on cash flow hedges	(13,979,000)	(5,556,000)	5,354,000
Casualty and impairment loss (gain), net	$ 6,250,000	$ (3,935,000)	$ (10,542,000)
Restricted Stock and Restricted Stock Converted From Performance Shares [Member]
Supplemental disclosures of non-cash investing and financing activities
Granted (in shares) | shares	201,824	197,018	157,779
Restricted Stock Converted From Performance Shares [Member]
Supplemental disclosures of non-cash investing and financing activities
Granted (in shares) | shares	128,482	115,618	95,826
Restricted stock
Supplemental disclosures of non-cash investing and financing activities
Granted (in shares) | shares	73,342	81,400	61,953
Fair value of shares issued	$ 13,171,000	$ 13,217,000	$ 10,720,000
Number of shares forfeited | shares	3,388	4,262	1,529
Accumulated earnings less dividends
Supplemental disclosures of non-cash investing and financing activities
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests	$ 65,000
Change in redemption value of redeemable noncontrolling interest	(2,026,000)	$ (1,489,000)	$ (2,053,000)
Deferred Compensation, Share-based Payments [Member] | Non Employee Director [Member]
Supplemental disclosures of non-cash investing and financing activities
Fair value of shares issued		3,894,000	3,552,000
Avalon Maplewood [Member]
Supplemental disclosures of non-cash investing and financing activities
Net operating real estate	16,361,000
Casualty and impairment loss (gain), net	$ 2,338,000
Avalon at Edgewater [Member]
Supplemental disclosures of non-cash investing and financing activities
Net operating real estate			21,844,000
Casualty and impairment loss (gain), net		$ (8,702,000)	(15,538,000)
New England [Member]
Supplemental disclosures of non-cash investing and financing activities
Casualty and impairment loss (gain), net			4,195,000
New England [Member] | Avalon at Edgewater [Member]
Supplemental disclosures of non-cash investing and financing activities
Casualty and impairment loss (gain), net			$ 26,039,000
Non Employee Director [Member] | Deferred Compensation, Share-based Payments [Member]
Supplemental disclosures of non-cash investing and financing activities
Granted (in shares) | shares		44,327	46,589
Secured notes | Notes Payable Maturities 2020 [Member] | Avalon Hoboken [Member]
Supplemental disclosures of non-cash investing and financing activities
Assumed principal amount of indebtedness		$ 67,904,000
Secured notes | Notes Payable Maturities 2020 [Member] | Avalon Columbia Pike [Member]
Supplemental disclosures of non-cash investing and financing activities
Assumed principal amount of indebtedness		$ 70,507,000
West Hollywood Affordable [Member]
Supplemental disclosures of non-cash investing and financing activities
Apartment homes | home		77
Accounts receivable, net		$ 18,643,000

Organization, Basis of Presenta

Organization, Basis of Presentation, and Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Organization, Basis of Presentation, and Significant Accounting Policies	Organization, Basis of Presentation and Significant Accounting Policies Organization and Basis of Presentation AvalonBay Communities, Inc. (the “Company,” which term, unless the context otherwise requires, refers to AvalonBay Communities, Inc. together with its subsidiaries), is a Maryland corporation that has elected to be treated as a real estate investment trust (“REIT”) for federal income tax purposes under the Internal Revenue Code of 1986 (the “Code”). The Company focuses on the development, redevelopment, acquisition, ownership and operation of multifamily communities primarily in New England, the New York/New Jersey metro area, the Mid-Atlantic, the Pacific Northwest, and Northern and Southern California. At December 31, 2017 , the Company owned or held a direct or indirect ownership interest in 267 operating apartment communities containing 77,614 apartment homes in 12 states and the District of Columbia, of which nine communities containing 3,752 apartment homes were under redevelopment. In addition, the Company owned or held a direct or indirect ownership interest in 21 communities under development that are expected to contain an aggregate of 6,544 apartment homes (unaudited) when completed. The Company also owned or held a direct or indirect ownership interest in land or rights to land in which the Company expects to develop an additional 29 communities that, if developed as expected, will contain an estimated 9,496 apartment homes (unaudited). Capitalized terms used without definition have meanings provided elsewhere in this Form 10-K. Principles of Consolidation The accompanying Consolidated Financial Statements include the accounts of the Company and its wholly-owned subsidiaries, certain joint venture partnerships, subsidiary partnerships structured as DownREITs and any variable interest entities that qualify for consolidation. All significant intercompany balances and transactions have been eliminated in consolidation. The Company accounts for joint venture entities and subsidiary partnerships in accordance with the consolidation guidance. The Company evaluates the partnership of each joint venture entity and determines first whether to follow the variable interest entity (“VIE”) or the voting interest entity (“VOE”) model. Once the appropriate consolidation model is identified, the Company then evaluates whether it should consolidate the venture. Under the VIE model, the Company consolidates an investment when it has control to direct the activities of the venture and the obligation to absorb losses or the right to receive benefits that could potentially be significant to the VIE. Under the VOE model, the Company consolidates an investment when 1) it controls the investment through ownership of a majority voting interest if the investment is not a limited partnership or 2) it controls the investment through its ability to remove the other partners in the investment, at its discretion, when the investment is a limited partnership. The Company generally uses the equity method of accounting for its investment in joint ventures, under all other potential scenarios, including where the Company holds a noncontrolling limited partner interest in a joint venture. Any investment in excess of the Company's cost basis at acquisition or formation of an equity method venture, will be recorded as a component of the Company's investment in the joint venture and recognized over the life of the underlying fixed assets of the venture as a reduction to its equity in income from the venture. Investments in which the Company has little or no influence are accounted for using the cost method. Revenue and Gain Recognition Rental income related to the Company’s residential and retail leases is recognized on an accrual basis when due from residents and/or retail tenants, as required by the accounting guidance applicable to leases, which provides guidance on classification and recognition. In accordance with the Company's standard residential lease terms, rental payments are generally due on a monthly basis. Any cash concessions given at the inception of the lease are amortized over the approximate life of the lease, which is generally one year. The Company records a charge to income for outstanding receivables greater than 90 days past due as a component of operating expenses, excluding property taxes on the accompanying Consolidated Statements of Comprehensive Income. The Company will adopt ASU 2014-09, Revenue from Contracts with Customers and ASU 2017-05, Other Income-Gains and Losses from the Derecognition of Nonfinancial Assets, as of January 1, 2018 using the modified retrospective approach, applying the provisions of the new standards to contracts that are not completed as of the date of adoption. Under the new standards, revenue is recognized when persuasive evidence of an arrangement exists, delivery has occurred, the fee is fixed or determinable, and collectability is probable. The majority of the Company’s revenue is derived from residential and retail rental income and other lease income, which are scoped out from this standard and included in the current lease accounting framework, and will be accounted for under ASU 2016-02, Leases, discussed under Recently Issued and Adopted Accounting Standards below. Revenue streams that are in the scope of the new standards include: • Management fees - The Company has investment interests in real estate joint ventures, some of which the Company manages (i) the venture, (ii) the associated operating communities owned by those ventures and/or (iii) the development or redevelopment of those operating communities. For these activities, the Company receives asset management, property management, development and/or redevelopment fee revenue. The performance obligation is the management of the venture, community or other defined task such as the development or redevelopment of the community. While the individual activities that comprise the performance obligation of the management fees can vary day to day, the nature of the overall performance obligation to provide management service is the same and considered by the Company to be a series of services that have the same pattern of transfer to the customer and the same method to measure progress toward satisfaction of the performance obligation. The Company recognizes revenue for management fees as earned on a monthly basis and has concluded this is appropriate under the new standard. • Non-recurring rental and non-rental related income - The Company recognizes revenue for rental related income not included as a components of a lease, such as reservation and application fees, as well as for non-rental related income, as earned, and has concluded this is appropriate under the new standard. • Gains or losses on sales of real estate - The Company accounts for the sale of real estate assets and any related gain recognition in accordance with the accounting guidance applicable to sales of real estate, which establishes standards for recognition of profit on all real estate sales transactions, other than retail land sales. The Company recognizes the sale, and associated gain or loss from the disposition, provided that the earnings process is complete and the Company does not have significant continuing involvement. Subsequent to the adoption of the new standard, a gain or loss is recognized when the criteria for an asset to be derecognized are met, which include when (i) a contract exists and (ii) the buyer obtained control of the nonfinancial asset that was sold. As a result, the Company may recognize a gain on a real estate disposition transaction that previously did not qualify as a sale or for full profit recognition due to the timing of the transfer of control or certain forms of continuing involvement. In addition, subsequent to the adoption of the new standard, a gain or loss recognized on the sale of a nonfinancial asset to an unconsolidated entity will be recognized at 100%, and not the Company’s proportionate ownership percentage. Due to the nature and timing of the Company’s identified revenue streams and existing open contracts as of December 31, 2017, the Company does not anticipate the adoption of the new standards will have a material impact on its financial position or results of operations. Real Estate Operating real estate assets are stated at cost and consist of land and improvements, buildings and improvements, furniture, fixtures and equipment, and other costs incurred during their development, redevelopment and acquisition. Significant expenditures which improve or extend the life of an existing asset and that will benefit the Company for periods greater than a year, are capitalized. Expenditures for maintenance and repairs are charged to expense as incurred. The Company generally expenses purchases of personal property made for replacement purposes. Project costs related to the development, construction and redevelopment of real estate projects (including interest and related loan fees, property taxes and other direct costs) are capitalized as a cost of the project. Indirect project costs that relate to several projects are capitalized and allocated to the projects to which they relate. Indirect costs not clearly related to development, construction and redevelopment activity are expensed as incurred. For development, capitalization (i) begins when the Company has determined that development of the future asset is probable, (ii) can be suspended if there is no current development activity underway, but future development is still probable and (iii) ends when the asset, or a portion of an asset, is delivered and is ready for its intended use, or the Company's intended use changes such that capitalization is no longer appropriate. For land parcels improved with operating real estate, for which the Company intends to pursue development, the Company generally manages the current improvements until such time as all tenant obligations have been satisfied or eliminated through negotiation, and construction of new apartment communities is ready to begin. Revenue from incidental operations received from the current improvements on land parcels in excess of any incremental costs are recorded as a reduction of total capitalized costs of the respective Development Right and not as part of net income. Incidental operating costs in excess of incidental operating income are expensed in the period incurred. For redevelopment efforts, the Company capitalizes costs either (i) in advance of taking homes out of service when significant renovation of the common area has begun until the redevelopment is completed, or (ii) when an apartment home is taken out of service for redevelopment until the redevelopment is completed and the apartment home is available for a new resident. Rental income and operating costs incurred during the initial lease-up or post-redevelopment lease-up period are recognized in earnings as incurred. The Company defers external costs associated with originating new leases, recognizing the impact of these costs in earnings over the term of the lease. The adoption of ASU 2017-01 on October 1, 2016, impacted the Company's accounting framework for the acquisition of operating communities. Prior to adoption, the acquisition of an operating community was viewed as an acquisition of a business, and the Company identified and recorded each asset acquired and liability assumed in such transaction at its estimated fair value at the date of acquisition, and expensed all costs incurred related to acquisitions of operating communities. Subsequent to adoption of ASU 2017-01 on October 1, 2016, the Company assesses each acquisition of an operating community to determine if it meets the definition of a business or if it qualifies as an asset acquisition. The Company generally views acquisitions of individual operating communities as asset acquisitions, and results in the capitalization of acquisition costs, and the allocation of purchase price to the assets acquired and liabilities assumed, based on the relative fair value of the respective assets and liabilities. The purchase price allocation to tangible assets, such as land and improvements, buildings and improvements, and furniture, fixtures and equipment, and the in-place lease intangible assets, is as reflected in real estate assets and depreciated over their estimated useful lives. Any purchase price allocation to intangible assets, other than in-place lease intangibles, is included in prepaid expenses and other assets on the accompanying Consolidated Balance Sheets and amortized over the term of the acquired intangible asset. The Company values land based on a market approach, looking to recent sales of similar properties, adjusting for differences due to location, the state of entitlement as well as the shape and size of the parcel. Improvements to land are valued using a replacement cost approach and consider the structures and amenities included for the communities. The approach applied industry standard replacement costs adjusted for geographic specific considerations and reduced by estimated depreciation. The value for furniture, fixtures and equipment is also determined based on a replacement cost approach, considering costs for both items in the apartment homes as well as common areas and was adjusted for estimated depreciation. The fair value of buildings acquired is estimated using the replacement cost approach, assuming the buildings were vacant at acquisition. The replacement cost approach considers the composition of structures acquired, adjusted for an estimate of depreciation. The estimate of depreciation is made considering industry standard information, depreciation curves for the identified asset classes and estimated useful life of the acquired property. The value of the acquired lease-related intangibles considered the estimated cost of leasing the apartment homes as if the acquired building(s) were vacant, as well as the value of the current leases relative to market-rate leases. The in-place lease value is determined using an average total lease-up time, the number of apartment homes and net revenues generated during the lease-up time. The lease-up period for an apartment community is assumed to be 12 months to achieve stabilized occupancy. Net revenues use market rent considering actual leasing and industry rental rate data. The value of current leases relative to a market-rate lease is based on market rents obtained for market comparables, and considered a market derived discount rate. Given the heterogeneous nature of multifamily real estate, the fair values for the land, debt, real estate assets and in-place leases incorporated significant unobservable inputs and therefore are considered to be Level 3 prices within the fair value hierarchy. Consideration for acquisitions is typically in the form of cash unless otherwise disclosed. Depreciation is calculated on buildings and improvements using the straight-line method over their estimated useful lives, which range from seven to 30 years. Furniture, fixtures and equipment are generally depreciated using the straight-line method over their estimated useful lives, which range from three years (primarily computer-related equipment) to seven years. Income Taxes The Company elected to be treated as a REIT for U.S. federal income tax purposes for its tax year ended December 31, 1994 and has not revoked such election. A REIT is a corporate entity which holds real estate interests and can deduct from its federally taxable income qualifying dividends it pays if it meets a number of organizational and operational requirements, including a requirement that it currently distribute at least 90% of its adjusted taxable income to stockholders. Therefore, as a REIT, the Company generally will not be subject to corporate level federal income tax on its taxable income if it annually distributes 100% of its taxable income to its stockholders. The states in which the Company operates have similar tax provisions which recognize the Company as a REIT for state income tax purposes. Management believes that all such conditions for the exemption from income taxes on ordinary income have been or will be met for the periods presented. Accordingly, no provision for federal and state income taxes has been made. If the Company fails to qualify as a REIT in any taxable year, it will be subject to federal corporate income taxes at regular corporate rates and may not be able to qualify as a corporate REIT for four subsequent taxable years. Even if the Company qualifies for taxation as a REIT, the Company may be subject to certain state and local taxes on its income and property, and to federal income and excise taxes on its undistributed taxable income and in certain other instances. The Company did not incur any charges or receive refunds of excise taxes related to the years ended December 31, 2017 , 2016 and 2015 . In addition, taxable income from non-REIT activities performed through taxable REIT subsidiaries (“TRS”) is subject to federal, state and local income taxes. The Company incurred income tax expense of $141,000 , $305,000 and $1,483,000 in 2017 , 2016 and 2015 , respectively, associated primarily with activities transacted through a TRS. As of December 31, 2017 and 2016 , the Company did not have any unrecognized tax benefits. The Company does not believe that there will be any material changes in its unrecognized tax positions over the next 12 months. The Company is subject to examination by the respective taxing authorities for the tax years 2014 through 2016 . On December 22, 2017, H.R. 1, the Tax Cuts and Jobs Act (the “TCJA”), was enacted. The TCJA makes major changes to the Code, including lowering the statutory U.S. federal income tax rate from 35% to 21% effective January 1, 2018. The Company has completed its assessment of the Act and does not believe it will have a material impact on its financial position or results of operations. The following reconciles net income attributable to common stockholders to taxable net income for the years ended December 31, 2017 , 2016 and 2015 (unaudited, dollars in thousands): 2017 Estimate 2016 Actual 2015 Actual Net income attributable to common stockholders $ 876,921 $ 1,034,002 $ 742,038 GAAP gain on sale of communities (in excess of) less than tax gain (85,873 ) (195,029 ) (20,900 ) Depreciation/amortization timing differences on real estate 11,868 (947 ) (24,657 ) Amortization of debt/mark to market interest (17,430 ) (18,985 ) (64,676 ) Tax compensation expense less than (in excess of) GAAP (3,828 ) 9,821 (1,244 ) Casualty and impairment (gain) loss, net 6,250 (657 ) (10,542 ) Other adjustments (40,381 ) 11,533 (12,829 ) Taxable net income $ 747,527 $ 839,738 $ 607,190 The following summarizes the tax components of the Company's common dividends declared for the years ended December 31, 2017 , 2016 and 2015 (unaudited): 2017 2016 2015 Ordinary income 75 % 68 % 83 % 20% capital gain 18 % 26 % 12 % Unrecaptured §1250 gain 7 % 6 % 5 % Deferred Financing Costs Deferred financing costs include fees and other expenditures necessary to obtain debt financing and are amortized on a straight-line basis, which approximates the effective interest method, over the shorter of the term of the loan or the related credit enhancement facility, if applicable. Unamortized financing costs are charged to earnings when debt is retired before the maturity date. Accumulated amortization of deferred financing costs related to unsecured notes was $16,984,000 and $14,008,000 as of December 31, 2017 and 2016 , respectively, and related to mortgage notes payable was $4,991,000 and $10,562,000 as of December 31, 2017 and 2016 , respectively. Deferred financing costs, except for costs associated with line-of-credit arrangements, are presented as a direct deduction from the related debt liability. Accumulated amortization of deferred financing costs related to the Company's Credit Facility was $8,299,000 and $6,490,000 as of December 31, 2017 and 2016 , respectively, and was included in prepaid expenses and other assets on the accompanying Consolidated Balance Sheets. Cash, Cash Equivalents and Cash in Escrow Cash and cash equivalents include all cash and liquid investments with an original maturity of three months or less from the date acquired. Cash in escrow includes principal reserve funds that are restricted for the repayment of specified secured financing. The majority of the Company's cash, cash equivalents and cash in escrow are held at major commercial banks. Comprehensive Income Comprehensive income, as reflected on the Consolidated Statements of Comprehensive Income, is defined as all changes in equity during each period except for those resulting from investments by or distributions to shareholders. Accumulated other comprehensive loss, as reflected on the Consolidated Statements of Equity, reflects the effective portion of the cumulative changes in the fair value of derivatives in qualifying cash flow hedge relationships. Earnings per Common Share Basic earnings per share is computed by dividing net income attributable to common stockholders by the weighted average number of shares outstanding during the period. All outstanding unvested restricted share awards contain rights to non-forfeitable dividends and participate in undistributed earnings with common shareholders and, accordingly, are considered participating securities that are included in the two-class method of computing basic earnings per share (“EPS”). Both the unvested restricted shares and other potentially dilutive common shares, and the related impact to earnings, are considered when calculating earnings per share on a diluted basis. The Company's earnings per common share are determined as follows (dollars in thousands, except per share data): For the year ended 12/31/17 12/31/16 12/31/15 Basic and diluted shares outstanding Weighted average common shares—basic 137,523,771 136,928,251 133,565,711 Weighted average DownREIT units outstanding 7,500 7,500 7,500 Effect of dilutive securities 535,415 525,886 1,019,966 Weighted average common shares—diluted 138,066,686 137,461,637 134,593,177 Calculation of Earnings per Share—basic Net income attributable to common stockholders $ 876,921 $ 1,034,002 $ 742,038 Net income allocated to unvested restricted shares (2,463 ) (2,610 ) (1,774 ) Net income attributable to common stockholders, adjusted $ 874,458 $ 1,031,392 $ 740,264 Weighted average common shares—basic 137,523,771 136,928,251 133,565,711 Earnings per common share—basic $ 6.36 $ 7.53 $ 5.54 Calculation of Earnings per Share—diluted Net income attributable to common stockholders $ 876,921 $ 1,034,002 $ 742,038 Add: noncontrolling interests of DownREIT unitholders in consolidated partnerships, including discontinued operations 42 41 38 Adjusted net income attributable to common stockholders $ 876,963 $ 1,034,043 $ 742,076 Weighted average common shares—diluted 138,066,686 137,461,637 134,593,177 Earnings per common share—diluted $ 6.35 $ 7.52 $ 5.51 Dividends per common share $ 5.68 $ 5.40 $ 5.00 All options to purchase shares of common stock outstanding as of December 31, 2017 , 2016 and 2015 are included in the computation of diluted earnings per share. As discussed under "Recently Issued and Adopted Accounting Standards," as of January 1, 2017, the Company adopted the provisions of ASU 2016-09 using the modified retrospective approach to recognize forfeitures as they occur. Prior to the adoption of this standard, the Company was required to estimate the forfeiture of stock options and recognized compensation cost net of the estimated forfeitures. The estimated forfeitures included in compensation cost were adjusted to reflect actual forfeitures at the end of the vesting period. This change in accounting principle had no impact on the Company's financial position and no adjustment to retained earnings or the Company's diluted shares outstanding, as prescribed under the modified retrospective approach. Refer to "Change in Accounting Principle" for discussion of the impact to the accompanying Consolidated Statements of Cash Flows. Abandoned Pursuit Costs and Impairment of Long-Lived Assets The Company capitalizes pre-development costs incurred in pursuit of new development opportunities for which the Company currently believes future development is probable (“Development Rights”). Future development of these Development Rights is dependent upon various factors, including zoning and regulatory approval, rental market conditions, construction costs and the availability of capital. Initial pre-development costs incurred for pursuits for which future development is not yet considered probable are expensed as incurred. In addition, if the status of a Development Right changes, making future development by the Company no longer probable, any capitalized pre-development costs are expensed. The Company expensed costs related to the abandonment of Development Rights, as well as costs incurred in pursuing the acquisition or disposition of assets for which such acquisition and disposition activity did not occur, in the amounts of $2,370,000 , $4,183,000 and $3,016,000 during the years ended December 31, 2017 , 2016 and 2015 , respectively. These costs are included in expensed acquisition, development and other pursuit costs, net of recoveries on the accompanying Consolidated Statements of Comprehensive Income. Abandoned pursuit costs can vary greatly, and the costs incurred in any given period may be significantly different in future periods. The Company evaluates its real estate and other long-lived assets for impairment when potential indicators of impairment exist. Such assets are stated at cost, less accumulated depreciation and amortization, unless the carrying amount of the asset is not recoverable. If events or circumstances indicate that the carrying amount of a property or long-lived asset may not be recoverable, the Company assesses its recoverability by comparing the carrying amount of the property or long-lived asset to its estimated undiscounted future cash flows. If the carrying amount exceeds the aggregate undiscounted future cash flows, the Company recognizes an impairment loss to the extent the carrying amount exceeds the estimated fair value of the property or long-lived asset. Based on periodic tests of recoverability of long-lived assets, for the years ended December 31, 2017 , 2016 and 2015 , the Company did not recognize any impairment losses for wholly-owned operating real estate assets, and did not record any impairment losses other than those related to the impairment on land held for investment and casualty gains and losses from property damage as discussed below. The Company assesses its portfolio of land held for both development and investment for impairment if the intent of the Company changes with respect to either the development of, or the expected holding period for, the land. During the year ended December 31, 2017 , the Company recognized an impairment charge of $9,350,000 related to a land parcel the Company had acquired for development in 2004 and sold during 2017. During the year ended December 31, 2016 , the Company recognized $10,500,000 of aggregate impairment charges related to three ancillary land parcels for which the Company has either sold or intends to sell. These charges were determined as the excess of the Company's carrying basis over the expected sales price for each parcel, and is included in casualty and impairment loss (gain), net on the accompanying Consolidated Statements of Comprehensive Income. The Company did not recognize any material impairment charges on its investment in land during the year ended December 31, 2015 . The Company evaluates its unconsolidated investments for other than temporary impairment, considering both the extent and amount by which the carrying value of the investment exceeds the fair value, and the Company’s intent and ability to hold the investment to recover its carrying value. The Company also evaluates its proportionate share of any impairment of assets held by unconsolidated investments. There were no other than temporary impairment losses recognized by any of the Company's investments in unconsolidated real estate entities during the years ended December 31, 2017 , 2016 or 2015 . Casualty Gains and Losses In February 2017, a fire occurred at the Company's Avalon Maplewood Development Community, located in Maplewood, NJ, which was under construction and not yet occupied. The Company has commenced reconstruction of the damaged and destroyed portions of the community. See Note 7, “Commitments and Contingencies,” for additional discussion of the related casualty loss. During the year ended December 31, 2017 , the Company recorded a casualty loss of $19,481,000 composed of a charge of $16,361,000 to write-off the net book value of the fixed assets destroyed in the Maplewood casualty loss and $3,120,000 for demolition and additional incident expenses. The casualty loss was partially offset by $17,143,000 of expected third-party property damage insurance proceeds. The net casualty loss of $2,338,000 for the year ended December 31, 2017 is included in casualty and impairment loss (gain), net on the accompanying Consolidated Statements of Comprehensive Income. During the year ended December 31, 2017 , the Company reached a final insurance settlement for the property damage and lost income for the Maplewood casualty loss of $19,696,000 , after self-insurance and deductibles, of which the Company recognized $3,495,000 as business interruption insurance proceeds. In January 2015, a fire occurred at the Company's Avalon at Edgewater apartment community located in Edgewater, NJ. Edgewater consisted of two residential buildings. One building, containing 240 apartment homes, was destroyed. The second building, containing 168 apartment homes, suffered minimal damage and has been repaired. See Note 7, “Commitments and Contingencies,” for discussion of the related legal matters. During the year ended December 31, 2016 , the Company reached a final insurance settlement for the Company's property damage and lost income for the Edgewater casualty loss, for which it received aggregate insurance proceeds for Edgewater of $73,150,000 , after self-insurance and deductibles, as discussed below. During the year ended December 31, 2015 , the Company received $44,142,000 in insurance proceeds, which were partially offset by casualty charges of $21,844,000 to write off the net book value of the building destroyed by the fire at Edgewater, and $6,760,000 to record demolition and additional incident expenses, resulting in a net casualty gain of $15,538,000 . During the year ended December 31, 2016 , the Company received the final $29,008,000 of insurance proceeds, of which $8,702,000 was recognized as an additional net casualty gain and $20,306,000 as business interruption insurance proceeds. The Company reported the net casualty gains from each of the respective years as casualty and impairment loss (gain), net on the accompanying Consolidated Statements of Comprehensive Income, and reported the business interruption insurance proceeds as a component of rental and other income on the accompanying Consolidated Statements of Comprehensive Income. During the year ended December 31, 2015 , several of the Company's communities in its Northeast markets incurred property and casualty damages from severe winter storms, for which the Company recorded an impairment due to a casualty loss of $4,195,000 . During the year ended December 31, 2016 , the Company recorded a net casualty gain related to the 2015 severe winter storms of $5,732,000 , which is comprised of $8,493,000 in third-party insurance proceeds received, partially offset by incremental costs of $2,761,000 . These amounts are included in casualty and impairment loss (gain), net on the accompanying Consolidated Statements of Comprehensive Income. A casualty loss may also result in lost operating income from one or more communities that is covered by the Company’s business interruption insurance policies. The Company recognizes income for amounts received under its business interruption insurance policies as a component of rental and other income in the Consolidated Statements of Comprehensive Income. Revenue is recognized upon resolution of all contingencies related to the receipt, typically upon written confirmation by the insurer or receipt of the actual proceeds. The Company recognized $3,498,000 , $20,564,000 and $1,509,000 in income r

Interest Capitalized

Interest Capitalized	12 Months Ended
	Dec. 31, 2017
Interest Capitalized
Interest Capitalized	Interest Capitalized The Company capitalizes interest during the development and redevelopment of real estate assets. Capitalized interest associated with the Company's development or redevelopment activities totaled $64,420,000 , $78,872,000 and $79,834,000 for years ended December 31, 2017 , 2016 and 2015 , respectively.

Mortgage Notes Payable, Unsecur

Mortgage Notes Payable, Unsecured Notes and Credit Facility	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Mortgage Notes Payable, Unsecured Notes and Credit Facility	Mortgage Notes Payable, Unsecured Notes and Credit Facility The Company's mortgage notes payable, unsecured notes, variable rate unsecured term loans (the “Term Loans”) and Credit Facility, as defined below, as of December 31, 2017 and 2016 are summarized below. The following amounts and discussion do not include the mortgage notes related to the communities classified as held for sale, if any, as of December 31, 2017 and 2016 , as shown on the Consolidated Balance Sheets (dollars in thousands) (see Note 6, “Real Estate Disposition Activities”). 12/31/17 12/31/16 Fixed rate unsecured notes (1) $ 5,350,000 $ 4,200,000 Variable rate unsecured notes (1) 300,000 — Term Loans (1) 250,000 300,000 Fixed rate mortgage notes payable—conventional and tax-exempt (2) 593,987 1,668,496 Variable rate mortgage notes payable—conventional and tax-exempt (2) 910,326 908,262 Total mortgage notes payable and unsecured notes and Term Loans 7,404,313 7,076,758 Credit Facility — — Total mortgage notes payable, unsecured notes, Term Loans and Credit Facility $ 7,404,313 $ 7,076,758 _________________________________ (1) Balances at December 31, 2017 and 2016 exclude $10,850 and $8,930 , respectively, of debt discount, and $36,386 and $27,768 , respectively, of deferred financing costs, as reflected in unsecured notes, net on the accompanying Consolidated Balance Sheets. (2) Balances at December 31, 2017 and 2016 exclude $16,351 of debt discount and $1,866 of debt premium, respectively, and $11,256 and $11,046 , respectively, of deferred financing costs, as reflected in mortgage notes payable, net on the accompanying Consolidated Balance Sheets. The following debt activity occurred during the year ended December 31, 2017 : • In February 2017, the Company repaid $17,300,000 of variable rate debt secured by Avalon Mountain View at par at its scheduled maturity date. • In February 2017, the Company entered into a $250,000,000 variable rate unsecured term loan (the " $250 million Term Loan"), of which $100,000,000 matures in February 2022 with stated pricing of LIBOR plus 0.90% , and $150,000,000 matures in February 2024 with stated pricing of LIBOR plus 1.50% . In April 2017, the Company borrowed the $250,000,000 available under the $250 million Term Loan. • In May 2017, the Company repaid $670,590,000 aggregate principal amount of 6.26% fixed rate secured notes secured by 11 communities, representing the majority of the Fannie Mae pool 2 secured indebtedness assumed as part of the Archstone Acquisition, which had a contractual maturity date of November 2017 but opened for prepayment at par on April 30, 2017. In conjunction with the repayment, the Company recognized a gain of $10,839,000 , primarily composed of the write-off of unamortized premium. The Company refinanced the secured borrowings for three of these communities for an aggregate principal amount of $185,100,000 , with a contractual fixed interest rate of 3.61% and maturity dates of June 2027 . • In May 2017, the Company issued $400,000,000 principal amount of unsecured notes in a public offering under its existing shelf registration statement for net proceeds of approximately $396,016,000 . The notes mature in May 2027 and were issued at a 3.35% interest rate. • In June 2017, the Company issued $300,000,000 principal amount of unsecured notes in a public offering under its existing shelf registration statement for net proceeds of approximately $297,372,000 . The notes mature in July 2047 and were issued at a 4.15% interest rate. • In June 2017, the Company repaid $556,313,000 aggregate principal amount of 5.86% fixed rate secured notes secured by 12 wholly-owned operating communities, representing the remaining debt in the Company's Freddie Mac cross-collateralized pool financing originated in 2009, in advance of their May 2019 maturity date. In conjunction with the repayment, the Company recognized a charge of $34,965,000 , consisting of prepayment penalties of $33,515,000 and the non-cash write-off of deferred financing costs of $1,450,000 . • In October 2017, the Company refinanced the secured borrowing for Archstone Lexington for a principal balance of $21,700,000 , with a variable interest rate of LIBOR plus 1.35% and maturity date of October 2020 . • In November 2017, the Company issued $300,000,000 principal amount of floating rate unsecured notes in a public offering under its existing shelf registration statement for net proceeds of approximately $298,800,000 . The notes mature in January 2021 and were issued at three month LIBOR plus 0.43% . • In November 2017, the Company issued $450,000,000 principal amount of unsecured notes in a public offering under its existing shelf registration statement for net proceeds of approximately $445,271,000 . The notes mature in January 2028 and were issued at a 3.20% coupon. • In November 2017, the Company repaid its $300,000,000 variable rate unsecured term loan (the " $300 million Term Loan") entered into in March 2014. In conjunction with the repayment, the Company recognized a charge of $1,367,000 for the non-cash write-off of deferred financing costs. At December 31, 2017 , the Company has a $1,500,000,000 revolving variable rate unsecured credit facility with a syndicate of banks (the "Credit Facility") which matures in April 2020. The Company may extend the maturity for up to nine months , provided the Company is not in default and upon payment of a $1,500,000 extension fee. The Credit Facility bears interest at varying levels based on the London Interbank Offered Rate (“LIBOR”), rating levels achieved on the Company's unsecured notes and on a maturity schedule selected by the Company. The current stated pricing is LIBOR plus 0.825% per annum ( 2.39% at December 31, 2017 ), assuming a one month borrowing rate. The annual facility fee is 0.125% (or approximately $1,875,000 annually based on the $1,500,000,000 facility size and based on the Company's current credit rating). The Company had no borrowings outstanding under the Credit Facility and had $47,315,000 and $46,711,000 outstanding in letters of credit that reduced the borrowing capacity as of December 31, 2017 and 2016 , respectively. In the aggregate, secured notes payable mature at various dates from April 2018 through July 2066, and are secured by certain apartment communities (with a net carrying value of $2,293,583,000 , excluding communities classified as held for sale, as of December 31, 2017 ). As of December 31, 2017 , the Company has guaranteed a $100,000,000 secured note payable held by a wholly-owned subsidiary; such secured note payable is consolidated for financial reporting purposes. The weighted average interest rate of the Company's fixed rate secured notes payable (conventional and tax-exempt) was 4.0% and 4.4% at December 31, 2017 and 2016 , respectively. The weighted average interest rate of the Company's variable rate secured notes payable (conventional and tax exempt), the Term Loans and its Credit Facility, including the effect of certain financing related fees, was 3.0% and 2.3% at December 31, 2017 and 2016 , respectively. Scheduled payments and maturities of mortgage notes payable and unsecured notes outstanding at December 31, 2017 are as follows (dollars in thousands): Year Secured notes payments Secured notes maturities Unsecured notes maturities Stated interest rate of unsecured notes 2018 7,258 76,663 — N/A 2019 4,696 114,721 — N/A 2020 3,624 140,429 250,000 6.100 % 400,000 3.625 % 2021 3,551 27,844 250,000 3.950 % 300,000 LIBOR + 0.43% 2022 3,795 — 450,000 2.950 % 100,000 LIBOR + .90% 2023 4,040 — 350,000 4.200 % 250,000 2.850 % 2024 4,310 — 300,000 3.500 % 150,000 LIBOR + 1.50% 2025 4,585 84,835 525,000 3.450 % 300,000 3.500 % 2026 4,894 — 475,000 2.950 % 300,000 2.900 % 2027 3,083 185,100 400,000 3.350 % Thereafter 148,468 682,417 350,000 3.900 % 300,000 4.150 % 450,000 3.200 % $ 192,304 $ 1,312,009 $ 5,900,000 The Company's unsecured notes are redeemable at the Company's option, in whole or in part, generally at a redemption price equal to the greater of (i) 100% of their principal amount or (ii) the sum of the present value of the remaining scheduled payments of principal and interest discounted at a rate equal to the yield on U.S. Treasury securities with a comparable maturity plus a spread between 20 and 45 basis points depending on the specific series of unsecured notes, plus accrued and unpaid interest to the redemption date. The indenture under which the Company's unsecured notes were issued, the Company's Credit Facility agreement and the Company's Term Loan agreement contain limitations on the amount of debt the Company can incur or the amount of assets that can be used to secure other financing transactions, and other customary financial and other covenants, with which the Company was in compliance at December 31, 2017 .

Equity

Equity	12 Months Ended
	Dec. 31, 2017
Stockholders' Equity Note [Abstract]
Equity	Equity As of December 31, 2017 and 2016 , the Company's charter had authorized for issuance a total of 280,000,000 shares of common stock and 50,000,000 shares of preferred stock. During the year ended December 31, 2017 , the Company: i. issued 42,123 shares of common stock in connection with stock options exercised; ii. issued 3,058 common shares through the Company's dividend reinvestment plan; iii. issued 201,824 common shares in connection with restricted stock grants and the conversion of performance awards to restricted shares; iv. issued 568,424 shares under CEP IV as discussed below; v. withheld 60,319 common shares to satisfy employees' tax withholding and other liabilities; vi. issued 11,528 shares through the Employee Stock Purchase Plan; and vii. canceled 3,388 shares of restricted stock upon forfeiture. Any deferred compensation related to the Company’s stock option, restricted stock and performance award grants during the year ended December 31, 2017 is not reflected on the accompanying Consolidated Balance Sheet as of December 31, 2017 , and will not be reflected until recognized as compensation cost. In December 2015, the Company commenced a fourth continuous equity program (“CEP IV”) under which the Company may sell (and/or enter into forward agreements for) up to $1,000,000,000 of its common stock from time to time. Actual sales will depend on a variety of factors to be determined by the Company, including market conditions, the trading price of the Company's common stock and determinations by the Company of the appropriate sources of funding for the Company. In conjunction with CEP IV, the Company engaged sales agents who will receive compensation of up to 2.0% of the gross sales price for shares sold. The Company expects that, if entered into, it will physically settle each forward sale agreement on one or more dates specified by the Company on or prior to the maturity date of that particular forward sale agreement, in which case the Company will expect to receive aggregate net cash proceeds at settlement equal to the number of shares underlying the particular forward agreement multiplied by the relevant forward sale price. However, the Company may also elect to cash settle or net share settle a forward sale agreement. In connection with each forward sale agreement, the Company will pay the relevant forward seller, in the form of a reduced initial forward sale price, commission of up to 2.0% of the sales prices of all borrowed shares of common stock sold. As of December 31, 2017 , there are no outstanding forward sales agreements. In 2017 , the Company sold 568,424 shares at an average sales price of $188.39 per share, for net proceeds of $105,478,000 . As of December 31, 2017 , the Company had $892,915,000 of shares remaining authorized for issuance under this program.

Investments in Real Estate Enti

Investments in Real Estate Entities	12 Months Ended
	Dec. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Investments in Real Estate Entities	Investments in Real Estate Entities Investments in Unconsolidated Real Estate Entities The Company accounts for its investments in unconsolidated real estate entities under the equity method of accounting, as discussed in Note 1, “Organization, Basis of Presentation and Significant Accounting Policies,” under Principles of Consolidation . The significant accounting policies of the Company's unconsolidated real estate entities are consistent with those of the Company in all material respects. As of December 31, 2017 , the Company had investments in the following real estate entities: • AvalonBay Value Added Fund II, L.P. (“Fund II”) —In September 2008, the Company formed Fund II, a private, discretionary real estate investment vehicle which acquired and operates communities in the Company's markets. Fund II served as the exclusive vehicle through which the Company acquired investment interests in apartment communities, subject to certain exceptions, through the close of its investment period in August 2011. During 2017 , Fund II sold its final three communities, and the Company expects to complete the dissolution of Fund II in 2018. Fund II has six institutional investors, including the Company. One of the Company's wholly owned subsidiaries is the general partner of Fund II and at December 31, 2017, and the Company has an equity investment of $2,576,000 (net of distributions), representing a 31.3% combined general partner and limited partner equity interest. During 2017 , Fund II sold its final three communities containing an aggregate of 1,366 apartment homes: • Eaves Gaithersburg, located in Gaithersburg, MD, for $117,000,000 , • Briarwood Apartments, located in Owings Mills, MD, for $64,750,000 , and • Avalon Watchung, located in Watchung, NJ, for $90,300,000 . The Company's proportionate share of the gain in accordance with GAAP for the three dispositions was $26,322,000 . In conjunction with the disposition of these communities during 2017 , Fund II repaid the remaining $127,179,000 of related secured indebtedness at par in advance of the scheduled maturity dates. The Company has an equity interest of 31.3% in Fund II, and upon achievement of a threshold return the Company has a right to incentive distributions for its promoted interest based on current returns earned by Fund II which currently represents 40.0% of further Fund II distributions, which is in addition to its proportionate share of the remaining 60.0% of distributions. During the year ended December 31, 2017 , the Company recognized income of $26,742,000 for its promoted interest, which is reported as a component of equity in income of unconsolidated real estate entities on the accompanying Consolidated Statements of Comprehensive Income. • Archstone Multifamily Partners AC LP (the “U.S. Fund”) —The U.S. Fund was formed in July 2011 and is fully invested. The U.S. Fund has a term that expires in July 2023, assuming the exercise of two , one -year extension options. The U.S. Fund has six institutional investors, including the Company. The Company is the general partner of the U.S. Fund and, at December 31, 2017 excluding costs incurred in excess of equity in the underlying net assets of the U.S. Fund, the Company has an equity investment of $39,896,000 (net of distributions), representing a 28.6% combined general partner and limited partner equity interest. The Company acquired its interest in the U.S. Fund as part of the Archstone Acquisition. During 2017 , the U.S. Fund sold Eaves Sunnyvale, located in Sunnyvale, CA, containing 192 apartment homes for $107,000,000 . The Company's proportionate share of the gain in accordance with GAAP was $13,788,000 . In conjunction with the disposition of this community, the U.S. Fund repaid $32,542,000 of related secured indebtedness in advance of its scheduled maturity date. This resulted in a charge for a prepayment penalty and the write-off of deferred financing costs, of which the Company’s portion was $406,000 , which is reported as a reduction of equity in income of unconsolidated real estate entities on the accompanying Consolidated Statements of Comprehensive Income. Subsidiaries of the U.S. Fund have six loans secured by individual assets with aggregate amounts outstanding of $237,469,000 , with maturity dates that vary from February 2019 to November 2022 . The mortgage loans are payable by the subsidiaries of the U.S. Fund with operating cash flow or disposition proceeds from the underlying real estate. The Company has not guaranteed the debt of the U.S. Fund, nor does the Company have any obligation to fund this debt should the U.S. Fund be unable to do so. • Multifamily Partners AC JV LP (the “AC JV”) —The AC JV is a joint venture that was formed in 2011 and has four institutional investors, including the Company. Excluding costs incurred in excess of equity in the underlying net assets of the AC JV, at December 31, 2017 the Company has an equity investment of $49,492,000 (net of distributions), representing a 20.0% equity interest. The Company acquired its interest in the AC JV as part of the Archstone Acquisition. The AC JV partnership agreement contains provisions that require the Company to provide a right of first offer (“ROFO”) to the AC JV in connection with additional opportunities to acquire or develop additional interests in multifamily real estate assets within a specified geographic radius of the existing assets, generally one mile or less. The ROFO restriction expires in 2019. As of December 31, 2017 , subsidiaries of the AC JV have eight unsecured loans outstanding in the aggregate of $162,300,000 which mature in August 2021, and which were made by the equity investors in the venture, including the Company, in proportion to the investors' respective equity ownership interest. The unsecured loans are payable by the subsidiaries of the AC JV with operating cash flow from the venture. The Company has not guaranteed the debt of the AC JV, nor does the Company have any obligation to fund this debt should the AC JV be unable to do so. • MVP I, LLC —In December 2004, the Company entered into a joint venture agreement with an unrelated third-party for the development of Avalon at Mission Bay II. Construction of Avalon at Mission Bay II, a 313 apartment-home community located in San Francisco, California, was completed in December 2006. The Company holds a 25.0% equity interest in the venture. The Company is responsible for the day-to-day operations of the community and is the management agent subject to the terms of a management agreement. The Company has not guaranteed the debt of MVP I, LLC, nor does the Company have any obligation to fund this debt should MVP I, LLC be unable to do so. During 2015, the Company received $20,680,000 from the joint venture partner associated with MVP I, LLC, upon agreement with the partner to modify the joint venture agreement to eliminate the Company's promoted interest from associated distributions for future return calculations. Before this modification to the joint venture agreement, the Company had the right to 45.0% of distributions after achievement of a threshold return, which was achieved in 2015, up to the date the joint venture agreement was modified during 2015. Subsequent to the modification, earnings and distributions are based on the Company's 25.0% equity interest in the venture. • Brandywine Apartments of Maryland, LLC (“Brandywine”) —Brandywine owns a 305 apartment home community located in Washington, D.C. The community is managed by a third party. Brandywine is comprised of five members who hold various interests in the joint venture. The Company holds a 28.7% equity interest in Brandywine. Brandywine has an outstanding $22,760,000 fixed rate mortgage loan that is payable by the venture. The Company has not guaranteed the debt of Brandywine, nor does the Company have any obligation to fund this debt should Brandywine be unable to do so. • Residual JV —Through subsidiaries, the Company and Equity Residential entered into three limited liability company agreements (collectively, the “Residual JV”) through which the Company and Equity Residential acquired (i) certain assets of Archstone that the Company and Equity Residential have substantially divested (the “Residual Assets”), and (ii) various liabilities of Archstone that the Company and Equity Residential agreed to assume in conjunction with the Archstone Acquisition (the “Residual Liabilities”). The Residual Assets included a 20.0% interest in Lake Mendota Investments, LLC and Subsidiaries (“SWIB”), a joint venture which disposed the last of its communities in 2015, as well as various licenses, insurance policies, contracts, office leases and other miscellaneous assets. The Residual Liabilities include most existing or future litigation and claims related to Archstone’s operations for periods before the close of the Archstone Acquisition, except for (i) claims that principally relate to the physical condition of the assets acquired directly by the Company or Equity Residential, which generally remain the sole responsibility of the Company or Equity Residential, as applicable, and (ii) certain tax and other litigation between Archstone and various equity holders in Archstone related to periods before the close of the Archstone Acquisition, and claims which may arise due to changes in the capital structure of Archstone that occurred prior to closing, for which the seller has agreed to indemnify the Company and Equity Residential. The Company and Equity Residential jointly control the Residual JV and the Company holds a 40.0% economic interest in the Residual JV. • Legacy JV —As part of the Archstone Acquisition the Company entered into a limited liability company agreement with Equity Residential, through which it assumed obligations of Archstone in the form of preferred interests, some of which are governed by tax protection arrangements (the “Legacy JV”). The Company has a 40.0% interest in the Legacy JV. During the years ended December 31, 2017 , 2016 and 2015 , the Legacy JV redeemed certain of the preferred interests and paid accrued dividends, of which the Company's portion was $2,000,000 , $1,960,000 and $14,410,000 , respectively. At December 31, 2017 , the remaining preferred interests had an aggregate liquidation value of $37,579,000 , the Company's share of which is included in accrued expenses and other liabilities in the accompanying Consolidated Balance Sheets. • Sudbury Development, LLC —During 2015, the Company entered into a joint venture agreement to purchase land and pursue entitlements and pre-development activity for a mixed-use development project in Sudbury, MA, including multifamily apartment homes, retail, senior housing and age-restricted housing. The Company has a 60.0% ownership interest in the venture. The venture is considered a VIE, though the Company is not considered to be the primary beneficiary because the Company and its third party partner share control of the joint venture as approval from both parties is required for all significant aspects of the venture's activities including, but not limited to, changes in the ownership or capital structure of the partnership, acquisitions or dispositions by the venture and decisions about the pre-development and related activities to be performed by the venture. During the year ended December 31, 2017 , the Company and its venture partner each acquired their respective portion of the real estate held by the venture, with the Company's portion consisting of a parcel of land acquired for an investment of $19,200,000 . The Company and its venture partner retained continuing involvement with the venture to fund the completion of the planned infrastructure and site work. At December 31, 2017 , the Company has recorded an obligation of $4,340,000 , representing the Company's share of costs for the venture to complete this work. • North Point II JV, LP —During 2016, the Company entered into a joint venture to develop, own, and operate AVA North Point, an apartment community located in Cambridge, MA, which is currently under construction and expected to contain 265 apartment homes upon completion. The Company owns a 55.0% interest in the venture, and the venture partner owns the remaining 45.0% interest. The venture is considered to be a VIE, though the Company is not considered to be the primary beneficiary because the Company and its third party partner share control of the venture. The Company and its venture partner share decision making authority for all significant aspects of the venture's activities including, but not limited to, changes in the ownership or capital structure, the original capital budget and any changes to the budget to construct AVA North Point and the future operating budget for the community upon completion. AVA North Point is the third phase of a master planned development, the other phases of which are owned through the AC JV. During 2016, the Company provided the partners of the AC JV the opportunity to acquire the AVA North Point land parcel owned by the Company as required in the ROFO provisions for the AC JV. After certain partners of the AC JV declined to participate, the Company entered into the new joint venture and sold the land parcel to the venture in exchange for a cash payment and a capital account credit, and is overseeing the development in exchange for a developer fee. Upon sale of the land parcel, the Company recognized a gain of $10,621,000 during the year ended December 31, 2016, included in (loss) gain on other real estate transactions on the accompanying Consolidated Statements of Comprehensive Income. At December 31, 2017 , excluding costs incurred in excess of equity in the underlying net assets of North Point II JV, LP, the Company has an equity investment of $36,370,000 . The following is a combined summary of the financial position of the entities accounted for using the equity method as of the dates presented, excluding amounts associated with development joint ventures, the Residual JV and Legacy JV (dollars in thousands): 12/31/17 12/31/16 Assets: Real estate, net $ 695,077 $ 954,493 Other assets 39,976 49,519 Total assets $ 735,053 $ 1,004,012 Liabilities and partners' capital: Mortgage notes payable, net and credit facility $ 523,815 $ 689,573 Other liabilities 10,540 16,537 Partners' capital 200,698 297,902 Total liabilities and partners' capital $ 735,053 $ 1,004,012 The following is a combined summary of the operating results of the entities accounted for using the equity method, for the years presented, excluding amounts associated with development joint ventures, Avalon Clarendon, the Residual JV and Legacy JV (dollars in thousands): For the year ended 12/31/17 12/31/16 12/31/15 Rental and other income $ 101,615 $ 131,901 $ 173,578 Operating and other expenses (38,566 ) (50,945 ) (67,962 ) Gain on sale of communities 136,333 196,749 98,899 Interest expense, net (1) (27,104 ) (45,886 ) (45,517 ) Depreciation expense (25,914 ) (34,471 ) (45,324 ) Net income $ 146,364 $ 197,348 $ 113,674 _________________________________ (1) Amounts for the years ended December 31, 2017 , 2016 and 2015 includes charges for prepayment penalties and write-offs of deferred financing costs of $1,591 , $12,659 and $4,481 , respectively. In conjunction with the formation of Fund II and AVA North Point, and the acquisition of the U.S. Fund, AC JV and Brandywine, the Company incurred costs in excess of its equity in the underlying net assets of the respective investments. These costs represent $35,402,000 and $38,015,000 at December 31, 2017 and 2016 , respectively, of the respective investment balances. These amounts are being amortized over the lives of the underlying assets as a component of equity in income of unconsolidated real estate entities on the accompanying Consolidated Statements of Comprehensive Income. The following is a summary of the Company's equity in income of unconsolidated real estate entities for the years presented (dollars in thousands): For the year ended 12/31/17 12/31/16 12/31/15 Fund I (1) $ — $ 87 $ 871 Fund II (2) 53,961 49,882 32,211 U.S. Fund (3) 14,773 15,635 2,052 AC JV 1,388 1,445 511 MVP I, LLC (4) 1,833 1,627 22,453 Brandywine 106 10 (1,474 ) CVP I, LLC (5) — 9 1,812 Residual JV (1,223 ) (1,374 ) 11,582 Avalon Clarendon (6) — (2,359 ) — North Point II JV, LP (122 ) — — Sudbury Development, LLC 28 — — Total $ 70,744 $ 64,962 $ 70,018 _________________________________ (1) The Company's equity in income for this entity represents its residual profits from the sale of the community, or liquidation of the venture. (2) Equity in income for the years ended December 31, 2017 , 2016 and 2015 includes the Company's proportionate share of the gain on the sale of Fund II assets of $26,322 , $41,501 , and $29,726 respectively. In addition, equity in income for the years ended December 31, 2017 and 2016 include $26,742 and $7,985 , respectively, relating to the Company's recognition of its promoted interest. (3) Equity in income for the years ended December 31, 2017 and 2016 include the Company's proportionate share of the gain on the sale of U.S. Fund assets of $13,788 and $16,568 , respectively. (4) Equity in income for the year ended December 31, 2015 includes $21,340 relating to the Company's recognition of its promoted interest, of which $20,680 was from the joint venture partner upon agreement to modify the joint venture agreement to eliminate the Company's promoted interest from associated distribution for future return calculations. (5) Equity in income for the year ended December 31, 2015 includes $1,289 relating to the Company's recognition of its promoted interest. (6) In 2016, the Company and its venture partner established separate legal ownership of Avalon Clarendon, after which the Company reported the operating results of Avalon Clarendon as part of its consolidated operations. Investments in Consolidated Real Estate Entities During the year ended December 31, 2017 , the Company acquired three consolidated communities: • The Lodge Denver West, located in Lakewood, CO, contains 252 apartment homes and was acquired for a purchase price of $76,750,000 . • Avalon Dunn Loring, located in Vienna, VA, contains 440 apartment homes and 27,000 square feet of retail space and was acquired for a purchase price of $151,000,000 . • 850 Boca, located in Boca Raton, FL, contains 370 apartment homes and was acquired for a purchase price of $138,000,000 . The Company accounted for these as asset acquisitions and recorded the acquired assets and assumed liabilities, including identifiable intangibles, at their relative fair values based on the purchase price and acquisition costs incurred. Expensed transaction costs associated with the acquisitions made by the Company in 2016 and 2015 , all of which were accounted for as business combinations prior to the adoption of ASU 2017-01 on October 1, 2016, totaled $5,139,000 and $3,806,000 , respectively. These amounts are reported as a component of expensed acquisition, development and other pursuit costs, net of recoveries on the accompanying Consolidated Statements of Comprehensive Income. To the extent the Company received amounts related to acquired communities for periods prior to their acquisition, the Company reported these receipts, net with expensed acquisition costs. On February 27, 2013, pursuant to an asset purchase agreement dated November 26, 2012, the Company, together with Equity Residential, acquired, directly or indirectly, all of the assets owned by Archstone Enterprise LP (“Archstone,” which has since changed its name to Jupiter Enterprise LP), including all of the ownership interests in joint ventures and other entities owned by Archstone, and assumed Archstone’s liabilities, both known and unknown, with certain limited exceptions. Under the terms of the purchase agreement, the Company acquired approximately 40.0% of Archstone's assets and liabilities and Equity Residential acquired approximately 60.0% of Archstone’s assets and liabilities (the “Archstone Acquisition”). In conjunction with the development of Avalon Brooklyn Bay, the Company entered into a joint venture agreement to construct a mixed-use building that will contain rental apartments, for-sale residential condominium units and related common elements. The Company owns a 70.0% interest in the venture and will have all of the rights and obligations associated with the rental apartments, and the venture partner owns the remaining 30.0% interest and will have all of the rights and obligations associated with the for-sale residential condominium units. The Company is responsible for the development and construction of the structure, and is providing a loan to the venture partner for the venture partner's share of costs. As of December 31, 2017 , the Company has a receivable from the venture partner in the form of a variable rate mortgage note, secured by the for-sale residential condominium units under construction in the amount of $44,831,000 for outstanding principal and interest, reported as a component of prepaid expenses and other assets on the accompanying Consolidated Balance Sheets. The Company recognizes interest income on the accrual basis. The loan will be repaid by the venture partner with the proceeds the partner receives from the sales of the residential condominium units which are expected to occur during 2018. The venture is considered a VIE, and the Company consolidates its interest in the rental apartments and common areas, which are included in total real estate, net on the accompanying Consolidated Balance Sheets.

Real Estate Disposition Activit

Real Estate Disposition Activities	12 Months Ended
	Dec. 31, 2017
Discontinued Operations and Disposal Groups [Abstract]
Real Estate Disposition Activities	Real Estate Disposition Activities During 2017 , the Company sold six wholly-owned operating communities, containing an aggregate of 1,624 apartment homes for an aggregate sales price of $475,500,000 and an aggregate gain of $251,163,000 . In addition during 2017 , the Company sold other real estate, including three undeveloped land parcels, one of which the Company recorded an impairment during 2017 as discussed in Note 1, “Organization, Basis of Presentation and Significant Accounting Policies,” for an aggregate sales price of $39,154,000 , resulting in an aggregate gain of $1,682,000 . Details regarding the real estate sales are summarized in the following table (dollars in thousands): Community Name Location Period of sale Apartment homes Debt Gross sales price Net cash proceeds Avalon Pines (1) Coram, NY Q117 450 $ — $ 140,000 $ 138,689 AVA University District Seattle, WA Q217 283 — 112,500 108,511 Avalon Danbury Danbury, CT Q317 234 — 52,000 51,000 Avalon Run East Lawrenceville, NJ Q417 312 — 87,500 85,033 Avalon Huntington Shelton, CT Q417 99 — 33,000 32,173 Avalon Milford Milford, CT Q417 246 — 50,500 49,161 Other real estate dispositions (2) multiple Q1-Q417 N/A — 39,154 38,472 Total of 2017 asset sales 1,624 $ — $ 514,654 $ 503,039 Total of 2016 asset sales 2,051 $ — $ 564,028 $ 532,717 Total of 2015 asset sales 851 $ — $ 289,320 $ 282,163 _________________________________ (1) Includes the sale of the adjacent golf course. (2) Primarily composed of the sale of two undeveloped land parcels, located in Newcastle, WA, that are adjacent to a completed Development Community, 421-a tax certificates representing the right to qualify for certain property tax exemptions in New York City and one undeveloped land parcel, located in Vienna, VA. As of December 31, 2017 , the Company had no real estate assets that qualified as held for sale.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Employment Agreements and Arrangements At December 31, 2017 , the Company does not have any employment agreements with executive officers. The standard restricted stock and option agreements used by the Company in its compensation program provide that upon an employee's termination without cause or the employee's Retirement (as defined in the agreement), all outstanding stock options and restricted shares of stock held by the employee will vest, and the employee will have up to 12 months or until the fifth anniversary of the grant date, if later, or until the option expiration date, if earlier, to exercise any options then held. Under the agreements, Retirement generally means a termination of employment and other business relationships, other than for cause, after attainment of age 50 , provided that (i) the employee has worked for the Company for at least 10 years, (ii) the employee's age at Retirement plus years of employment with the Company equals at least 70 , (iii) the employee provides at least six months written notice of his intent to retire, and (iv) the employee enters into a one year non-compete and employee non-solicitation agreement. The Company also has an Officer Severance Program (the “Program”). Under the Program, in the event an officer who is not otherwise covered by a severance arrangement is terminated (other than for cause), or chooses to terminate his or her employment for good reason (as defined), in either case within 18 months following a sale event (as defined) of the Company, such officer will generally receive a cash lump sum payment equal to a multiple of the officer's covered compensation (base salary plus annual cash bonus). The multiple is one times for vice presidents and senior vice presidents, two times for executive vice presidents and three times for the chief executive officer. The officer's restricted stock and options would also vest. Costs related to the Program are deferred and recognized over the requisite service period when considered by management to be probable and estimable. Legal Contingencies The Company accounts for recoveries from legal matters as a reduction in the legal and related costs incurred associated with the matter, with recoveries in excess of these costs reported as a gain or, where appropriate, a reduction in the net cost basis of a community to which the suit related. During the years ended December 31, 2017 and 2016 , the Company recognized $6,118,000 and $417,000 in legal recoveries. There were no material receipts during the year ended December 31, 2015 , excluding amounts for the Residual JV. Amounts recognized during the year ended December 31, 2017 include $5,438,000 in legal settlement proceeds relating to construction defects at a community acquired as part of the Archstone Acquisition, reported as a component of casualty and impairment loss (gain), net on the accompanying Consolidated Statements of Comprehensive Income. Maplewood Casualty Loss In February 2017, a fire occurred at the Company's Avalon Maplewood Development Community, located in Maplewood, NJ, which was under construction and not yet occupied. The Company believes that liabilities to third parties resulting from the fire will not be material and will, in any event, be substantially covered by insurance subject to a deductible. The Company has commenced reconstruction of the damaged and destroyed portions of the community. See Note 1, "Organization, Basis of Presentation and Significant Accounting Policies," for further discussion of the casualty gains and losses associated with the Maplewood casualty loss. Edgewater Casualty Loss In conjunction with legal matters associated with the Edgewater casualty loss, the Company has established protocols for processing claims from third parties who suffered losses as a result of the fire, and many third parties have contacted the Company's insurance carrier and settled their claims. See Note 1, "Organization, Basis of Presentation and Significant Accounting Policies," for further discussion of the casualty gains and losses associated with the Edgewater casualty loss. Three class action lawsuits have been filed against the Company on behalf of occupants of the destroyed building and consolidated in the United States District Court for the District of New Jersey. The Company has agreed with class counsel to the terms of a settlement which provides a claims process (with agreed upon protocols for instructing the adjuster as to how to evaluate claims) and, if needed, an arbitration process to determine damage amounts to be paid to individual claimants covered by the class settlement. In July 2017 the District Court granted final approval of the settlement and all claims have been submitted to the independent claims adjuster. A total of 66 units (consisting of residents who did not previously settle their claims and who did not opt out of the class settlement) are included in the class action settlement and bound by its terms. However, only 44 units submitted claims. The independent claims adjuster is currently reviewing the claims submitted, which total approximately $6,900,000 . To date, this claims adjuster has issued awards of behalf of three units and it is expected that the remaining awards should be determined and issued within the next two months. A fourth class action, being heard in the same federal court, was filed against the Company on behalf of residents of the second Edgewater building that suffered minimal damage. In addition to the class action lawsuits described above, 18 of the 19 lawsuits representing approximately 143 individual plaintiffs filed in the Superior Court of New Jersey Bergen County - Law Division were previously scheduled for trial on January 2, 2018. In advance of this date, the Company was able to resolve all of these claims in principle which included approximately 50 units. The Company previously resolved litigated claims with another 10 units. There is currently one remaining lawsuit which was recently filed in the Superior Court of New Jersey Bergen County - Law Division on behalf of one apartment unit. The Company believes it has meritorious defenses to the extent of damages claimed in that suit. There are also seven subrogation lawsuits that have been filed against the Company by insurers of Edgewater residents who obtained renters insurance; it is the Company's position that in the majority of the applicable leases the residents waived subrogation rights. One of these lawsuits has been dismissed on that basis, one is pending in the Superior Court of New Jersey, Bergen County - Law Division, one has been amicably resolved in principle and the other four have been consolidated and are currently pending in the United States District Court for the District of New Jersey. The District Court denied the Company's motions seeking dismissal on this basis. The Company will reassess the viability of this defense after conducting additional discovery. Having settled many third party claims through the insurance claims process, the Company currently believes that any potential remaining liability to third parties (including any potential liability to third parties determined in accordance with the class settlement described above) will not be material to the Company and will in any event be substantially covered by the Company's insurance policies. However, the Company can give no assurances in this regard and continues to evaluate this matter. The Company is involved in various other claims and/or administrative proceedings unrelated to the Edgewater casualty loss that arise in the ordinary course of its business. While no assurances can be given, the Company does not currently believe that any of these other outstanding litigation matters, individually or in the aggregate, will have a material adverse effect on its financial condition or results of operations. Lease Obligations The Company owns 13 apartment communities, one under development and two commercial properties, located on land subject to land leases expiring between October 2026 and March 2142 . The ground leases for 13 apartment communities, of which two represent dual-branded communities with one underlying land lease, and the two commercial properties, are accounted for as operating leases recognizing rental expense on a straight-line basis over the lease term. These leases have varying escalation terms, primarily based on variables determined at future dates such as changes in the Consumer Price Index, and five of these leases have purchase options exercisable through 2095. The Company incurred costs of $23,431,000 , $23,343,000 and $21,295,000 in the years ended December 31, 2017 , 2016 and 2015 , respectively, related to operating leases. One apartment community is located on land subject to a land lease which is accounted for as a capital lease and has the option for the Company to purchase the land at some point during the lease term which expires in 2046. In addition, the Company is party to a lease for a portion of the parking garage adjacent to a lease-up community, accounted for as a capital lease and subject to the Company's real estate accounting policies discussed in Note 1, “Organization, Basis of Presentation and Significant Accounting Policies.” The Company has a total lease obligation of $20,118,000 reported as a component of accrued expenses and other liabilities. In addition, the Company is party to 14 leases for its corporate and regional offices with varying terms through 2031, all of which are accounted for as operating leases. During the year ended December 31, 2017 , the Company acquired the land encumbered by the ground lease for Avalon Morningside Park for $95,000,000 , recognizing a non-cash write-off of prepaid rent of $11,153,000 associated with the ground lease termination, reported as a component of (loss) gain on other real estate transactions on the accompanying Consolidated Statements of Comprehensive Income. Also during the year ended December 31, 2017 , the Company exercised its purchase option under a capital lease, acquiring the land encumbered by the ground lease for Avalon at Assembly Row and AVA Somerville for $17,285,000 . The following table details the future minimum lease payments under the Company's current leases (dollars in thousands): Payments due by period 2018 2019 2020 2021 2022 Thereafter Operating Lease Obligations $ 21,051 $ 21,064 $ 18,781 $ 20,162 $ 20,057 $ 1,052,808 Capital Lease Obligations (1) (2) 1,073 1,075 1,077 1,080 1,082 43,976 $ 22,124 $ 22,139 $ 19,858 $ 21,242 $ 21,139 $ 1,096,784 _________________________________ (1) Aggregate capital lease payments include $25,961 in interest costs, with the timing of certain lease payments for capital land leases determined by completion of the construction of the associated apartment community. (2) Capital lease assets of $19,737 and $39,015 as of December 31, 2017 and 2016 , respectively, are included as a component of land and improvements or building and improvements on the accompanying Consolidated Balance Sheets.

Segment Reporting

Segment Reporting	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Segment Reporting	Segment Reporting The Company's reportable operating segments include Established Communities, Other Stabilized Communities and Development/Redevelopment Communities. Annually as of January 1, the Company determines which of its communities fall into each of these categories and generally maintains that classification throughout the year for the purpose of reporting segment operations, unless disposition or redevelopment plans regarding a community change. • Established Communities (also known as Same Store Communities) are consolidated communities where a comparison of operating results from the prior year to the current year is meaningful, as these communities were owned and had stabilized occupancy as of the beginning of the prior year. The Established Communities for the year ended December 31, 2017 , are communities that are consolidated for financial reporting purposes, had stabilized occupancy as of January 1, 2016 , are not conducting or planning to conduct substantial redevelopment activities and are not held for sale or planned for disposition within the current year. A community is considered to have stabilized occupancy at the earlier of (i) attainment of 95% physical occupancy or (ii) the one -year anniversary of completion of development or redevelopment. • Other Stabilized Communities includes all other consolidated completed communities that have stabilized occupancy, as defined above. Other Stabilized Communities do not include communities that are conducting or planning to conduct substantial redevelopment activities within the current year. • Development/Redevelopment Communities consists of consolidated communities that are under construction and have not received a certificate of occupancy for the entire community, and where substantial redevelopment is in progress or is planned to begin during the current year and communities under lease-up that had not reached stabilized occupancy, as defined above, as of January 1, 2017 . In addition, the Company owns land for future development and has other corporate assets that are not allocated to an operating segment. The Company's segment disclosures present the measure(s) used by the chief operating decision maker for purposes of assessing each segment's performance. The Company's chief operating decision maker is comprised of several members of its executive management team who use net operating income (“NOI”) as the primary financial measure for Established Communities and Other Stabilized Communities. NOI is defined by the Company as total property revenue less direct property operating expenses (including property taxes), and excluding corporate-level income (including management, development and other fees), corporate-level property management and other indirect operating expenses, investments and investment management expenses, expensed acquisition, development and other pursuit costs, net of recoveries, interest expense, net, loss (gain) on extinguishment of debt, net, general and administrative expense, equity in income of unconsolidated real estate entities, depreciation expense, corporate income tax expense, casualty and impairment loss (gain), net, gain on sale of communities, loss (gain) on other real estate transactions and net operating income from real estate assets sold or held for sale. Although the Company considers NOI a useful measure of a community's or communities' operating performance, NOI should not be considered an alternative to net income or net cash flow from operating activities, as determined in accordance with GAAP. NOI excludes a number of income and expense categories as detailed in the reconciliation of NOI to net income. A reconciliation of NOI to net income for years ended December 31, 2017 , 2016 and 2015 is as follows (dollars in thousands): For the year ended 12/31/17 12/31/16 12/31/15 Net income $ 876,660 $ 1,033,708 $ 741,733 Indirect operating expenses, net of corporate income 65,398 61,403 56,973 Investments and investment management expense 5,936 4,822 4,370 Expensed acquisition, development and other pursuit costs, net of recoveries 2,736 9,922 6,822 Interest expense, net 199,661 187,510 175,615 Loss (gain) on extinguishment of debt, net 25,472 7,075 (26,736 ) General and administrative expense 50,673 45,771 42,774 Equity in income of unconsolidated real estate entities (70,744 ) (64,962 ) (70,018 ) Depreciation expense 584,150 531,434 477,923 Income tax expense 141 305 1,483 Casualty and impairment loss (gain), net 6,250 (3,935 ) (10,542 ) Gain on sale of communities (252,599 ) (374,623 ) (115,625 ) Loss (gain) on other real estate transactions 10,907 (10,224 ) (9,647 ) Net operating income from real estate assets sold or held for sale (14,573 ) (44,263 ) (59,383 ) Net operating income $ 1,490,068 $ 1,383,943 $ 1,215,742 The following is a summary of NOI from real estate assets sold or held for sale for the periods presented (dollars in thousands): For the year ended 12/31/2017 12/31/2016 12/31/2015 Rental income from real estate assets sold or held for sale $ 23,457 $ 70,273 $ 96,297 Operating expenses from real estate assets sold or held for sale (8,884 ) (26,010 ) (36,914 ) Net operating income from real estate assets sold or held for sale $ 14,573 $ 44,263 $ 59,383 The primary performance measure for communities under development or redevelopment depends on the stage of completion. While under development, management monitors actual construction costs against budgeted costs as well as lease-up pace and rent levels compared to budget. The following table provides details of the Company's segment information as of the dates specified (dollars in thousands). The segments are classified based on the individual community's status at the beginning of the given calendar year. Therefore, each year the composition of communities within each business segment is adjusted. Accordingly, the amounts between years are not directly comparable. Segment information for total revenue and NOI the years ended December 31, 2017 , 2016 and 2015 has been adjusted to exclude the real estate assets that were sold from January 1, 2015 through December 31, 2017 , or otherwise qualify as held for sale as of December 31, 2017 , as described in Note 6, “Real Estate Disposition Activities.” Segment information for gross real estate as of December 31, 2017 , 2016 and 2015 has not been adjusted to exclude real estate assets that were sold or otherwise qualified as held for sale subsequent to their respective balance sheet dates. Total revenue NOI % NOI change from prior year Gross real estate (1) For the year ended December 31, 2017 Established New England $ 233,091 $ 150,253 2.1 % $ 1,852,676 Metro NY/NJ 362,273 247,720 2.1 % 3,069,690 Mid-Atlantic 221,064 153,750 1.5 % 2,056,066 Pacific Northwest 84,189 61,527 6.3 % 738,532 Northern California 336,767 257,673 1.6 % 2,830,963 Southern California 337,876 241,549 3.9 % 3,017,836 Total Established (2) 1,575,260 1,112,472 2.5 % 13,565,763 Other Stabilized 278,868 196,733 N/A 3,189,393 Development / Redevelopment (3) 276,896 180,863 N/A 5,015,094 Land Held for Future Development N/A N/A N/A 68,364 Non-allocated (4) 4,147 N/A N/A 97,322 Total $ 2,135,171 $ 1,490,068 7.7 % $ 21,935,936 For the year ended December 31, 2016 Established New England $ 226,727 $ 145,671 4.8 % $ 1,888,524 Metro NY/NJ 359,373 245,654 1.2 % 3,212,220 Mid-Atlantic 233,711 162,243 1.3 % 2,339,395 Pacific Northwest 72,475 52,434 7.4 % 737,289 Northern California 319,121 244,458 7.0 % 2,661,258 Southern California 291,567 207,537 9.1 % 2,672,691 Total Established (2) 1,502,974 1,057,997 4.8 % 13,511,377 Other Stabilized (5) 232,977 165,130 N/A 2,330,503 Development / Redevelopment 233,432 160,816 N/A 4,755,315 Land Held for Future Development N/A N/A N/A 84,293 Non-allocated (4) 5,599 N/A N/A 74,292 Total $ 1,974,982 $ 1,383,943 13.8 % $ 20,755,780 For the year ended December 31, 2015 Established New England $ 170,287 $ 107,189 3.0 % $ 1,460,746 Metro NY/NJ 342,768 244,280 3.6 % 3,152,361 Mid-Atlantic 209,012 145,497 0.2 % 2,177,823 Pacific Northwest 67,900 48,833 8.5 % 721,040 Northern California 273,432 210,226 11.9 % 2,414,184 Southern California 252,530 173,919 9.4 % 2,465,432 Total Established (2) 1,315,929 929,944 6.0 % 12,391,586 Other Stabilized 211,633 140,167 N/A 2,040,269 Development / Redevelopment 222,222 145,631 N/A 4,238,967 Land Held for Future Development N/A N/A N/A 484,377 Non-allocated (4) 9,947 N/A N/A 73,372 Total $ 1,759,731 $ 1,215,742 13.0 % $ 19,228,571 _________________________________ (1) Does not include gross real estate assets held for sale of $20,846 and $39,528 as of December 31, 2016 and 2015 , respectively. (2) Gross real estate for the Company's Established Communities includes capitalized additions of approximately $78,241 , $85,676 and $74,982 in 2017 , 2016 and 2015 , respectively. (3) Total revenue and NOI for the year ended December 31, 2017 includes $3,495 in business interruption insurance proceeds related to the Maplewood casualty loss. (4) Revenue represents third-party management, accounting, and developer fees and miscellaneous income which are not allocated to a reportable segment. (5) Total revenue and NOI for the year ended December 31, 2016 includes $20,306 in business interruption insurance proceeds related to the Edgewater casualty loss.

Stock-Based Compensation Plans

Stock-Based Compensation Plans	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation Plans	Stock-Based Compensation Plans The Company's Second Amended and Restated 2009 Equity Incentive Plan (the “2009 Plan”) includes an authorization to issue shares of the Company's common stock, par value $0.01 per share. At December 31, 2017 , the Company has 7,994,292 shares remaining available to issue under the 2009 Plan, exclusive of shares that may be issued to satisfy currently outstanding awards such as stock options or performance awards. In addition, any awards that were outstanding under the Company's 1994 Stock Option and Incentive Plan (the “1994 Plan”) on May 21, 2009, the date the Company adopted the 2009 Plan, that are subsequently forfeited, canceled, surrendered or terminated (other than by exercise) will become available for awards under the 2009 Plan. The 2009 Plan provides for various types of equity awards to associates, officers, non-employee directors and other key personnel of the Company and its subsidiaries. The types of awards that may be granted under the 2009 Plan include restricted stock, restricted stock units, stock options that qualify as incentive stock options (“ISOs”) under Section 422 of the Code, non-qualified stock options, stock appreciation rights and performance awards, among others. The 2009 Plan will expire on May 15, 2027. Information with respect to stock options granted under the 2009 and 1994 Plans is as follows: 2009 Plan shares Weighted average exercise price per share 1994 Plan shares Weighted average exercise price per share Options Outstanding, December 31, 2014 340,062 $ 122.67 272,402 $ 104.96 Exercised (90,884 ) 124.01 (190,207 ) 105.70 Granted — — — — Forfeited — — — — Options Outstanding, December 31, 2015 249,178 $ 122.17 82,195 $ 103.27 Exercised (71,845 ) 117.04 (59,654 ) 112.85 Granted — — — — Forfeited — — — — Options Outstanding, December 31, 2016 177,333 $ 124.25 22,541 $ 77.91 Exercised (27,360 ) 110.47 (14,763 ) 93.35 Granted — — — — Forfeited — — — — Options Outstanding, December 31, 2017 (1) 149,973 $ 126.77 7,778 $ 48.60 Options Exercisable: December 31, 2015 188,081 $ 119.98 82,195 $ 103.27 December 31, 2016 177,333 $ 124.25 22,541 $ 77.91 December 31, 2017 149,973 $ 126.77 7,778 $ 48.60 _________________________________ (1) All options outstanding are exercisable as of December 31, 2017 . The following summarizes the exercise prices and contractual lives of options outstanding as of December 31, 2017 : 2009 Plan Number of Options Range—Exercise Price Weighted Average Remaining Contractual Term (in years) 5,158 $70.00 - $79.99 2.1 15,762 $110.00 - $119.99 3.1 29,862 $120.00 - $129.99 5.2 99,191 $130.00 - $139.99 4.6 149,973 1994 Plan Number of Options Range—Exercise Price Weighted Average Remaining Contractual Term (in years) 7,778 $40.00 - $49.99 1.1 Options outstanding and exercisable under the 2009 and 1994 Plans at December 31, 2017 had an intrinsic value of $7,745,000 and $1,010,000 , respectively. Options exercisable under the 2009 and 1994 Plans had a weighted average contractual life of 4.6 years and 1.1 years, respectively. The intrinsic value of options exercised during 2017 , 2016 and 2015 was $3,592,000 , $9,187,000 and $18,080,000 , respectively. There were no stock options granted in 2017 , 2016 and 2015 . The Company has a compensation framework under which share-based compensation granted is composed of annual restricted stock awards for which one third of the award vests annually over a three year period, and multi-year long term incentive performance awards. Under the Company's multi-year long term incentive compensation framework, the Company grants a target number of performance awards, with the ultimate award determined by the total shareholder return of the Company's common stock and/or operating performance metrics, measured in each case over a measurement period of up to three years. Performance awards granted in 2017 or earlier are earned in the form of time-vesting restricted stock following the end of the three-year performance period, provided that the predetermined goals have been achieved. Under the single-year long term incentive framework, awards are granted in the form of time-vesting restricted stock. For both the earned performance awards and time-vesting restricted stock, the recipient may elect to receive up to 25% of the award value in the form of stock options, for which one third of the award vests annually over a three year period. In general, performance awards are forfeited if the employee's employment terminates for any reason prior to the measurement date. However, for performance awards with performance periods beginning on or after January 1, 2015, after the first year of the performance period, if the employee's employment terminates on account of death, disability, retirement, or termination without cause at a time when the employee meets the age and service requirements for retirement, the employee shall vest in a pro rata portion of the award (based on the employee's service time during the performance period), with such vested portion to be earned and converted into shares at the end of the performance period based on actual achievement under the performance award. Information with respect to performance awards granted is as follows: Performance awards Weighted average grant date fair value per award Outstanding at December 31, 2014 239,902 $ 95.20 Granted (1) 85,636 148.49 Change in awards based on performance (2) 14,697 78.50 Converted to restricted stock (95,826 ) 78.50 Forfeited (6,143 ) 110.34 Outstanding at December 31, 2015 238,266 $ 119.65 Granted (3) 94,054 141.92 Change in awards based on performance (2) 36,091 101.52 Converted to restricted stock (115,618 ) 94.67 Forfeited (1,630 ) 141.98 Outstanding at December 31, 2016 251,163 $ 136.74 Granted (4) 81,708 176.59 Change in awards based on performance (2) 49,323 119.26 Converted to restricted stock (128,482 ) 118.75 Forfeited (1,942 ) 159.39 Outstanding at December 31, 2017 251,770 $ 155.25 _________________________________ (1) The amount of restricted stock that ultimately may be earned is based on the total shareholder return metrics related to the Company’s common stock for 55,162 performance awards and financial metrics related to operating performance and leverage metrics of the Company for 30,474 performance awards. (2) Represents the change in the number of performance awards earned based on performance achievement for the performance period. (3) The amount of restricted stock that ultimately may be earned is based on the total shareholder return metrics related to the Company’s common stock for 61,039 performance awards and financial metrics related to operating performance and leverage metrics of the Company for 33,015 performance awards. (4) The amount of restricted stock that ultimately may be earned is based on the total shareholder return metrics related to the Company’s common stock for 49,374 performance awards and financial metrics related to operating performance and leverage metrics of the Company for 32,334 performance awards. The Company used a Monte Carlo model to assess the compensation cost associated with the portion of the performance awards granted for which achievement will be determined by using total shareholder return measures. The assumptions used are as follows: 2017 2016 2015 Dividend yield 3.2% 3.3% 3.0% Estimated volatility over the life of the plan (1) 15.3% - 19.7% 15.2% - 22.8% 12.0% - 17.3% Risk free rate 0.69% - 1.61% 0.44% - 0.88% 0.07% - 1.09% Estimated performance award value based on total shareholder return measure $175.86 $131.24 $139.18 _________________________________ (1) Estimated volatility of the life of the plan is using 50% historical volatility and 50% implied volatility. For the portion of the performance awards granted for which achievement is determined by using financial metrics, the compensation cost was based on a weighted average grant date value of $179.07 , $161.66 and $166.23 , for the years ended December 31, 2017 , 2016 and 2015 , respectively, and the Company's estimate of corporate achievement for the financial metrics. Information with respect to restricted stock granted is as follows: Restricted stock shares Restricted stock shares weighted average grant date fair value per share Restricted stock shares converted from performance awards Outstanding at December 31, 2014 179,307 $ 129.06 10,933 Granted - restricted stock shares 61,953 173.04 95,826 Vested - restricted stock shares (91,847 ) 130.75 (8,412 ) Forfeited (1,529 ) 151.86 — Outstanding at December 31, 2015 147,884 $ 146.21 98,347 Granted - restricted stock shares 81,400 162.38 115,618 Vested - restricted stock shares (88,712 ) 141.38 (36,872 ) Forfeited (3,867 ) 162.43 (395 ) Outstanding at December 31, 2016 136,705 $ 158.51 176,698 Granted - restricted stock shares 73,342 179.58 128,482 Vested - restricted stock shares (73,683 ) 153.86 (70,595 ) Forfeited (2,731 ) 173.42 (657 ) Outstanding at December 31, 2017 133,633 $ 172.33 233,928 Total employee stock-based compensation cost recognized in income was $17,085,000 , $14,666,000 and $14,703,000 for the years ended December 31, 2017 , 2016 and 2015 , respectively, and total capitalized stock-based compensation cost was $9,474,000 , $9,266,000 and $9,667,000 for the years ended December 31, 2017 , 2016 and 2015 , respectively. At December 31, 2017 , there was a total unrecognized compensation cost of $26,305,000 for unvested restricted stock and performance awards, which does not include forfeitures, and is expected to be recognized over a weighted average period of 3.6 years. As of January 1, 2017 the Company adopted the provisions of ASU 2016-09, electing to account for forfeitures as they occur. Prior to the adoption of ASU 2016-09, the Company was required to estimate the forfeiture of stock options and recognized compensation cost net of the estimated forfeitures. The estimated forfeitures included in compensation cost were adjusted to reflect actual forfeitures at the end of the vesting period. The actual forfeiture rate for the year ended December 31, 2017 was 0.7% . The application of estimated forfeitures did not materially impact compensation expense for the years ended December 31, 2016 and 2015 . Employee Stock Purchase Plan In October 1996, the Company adopted the 1996 Non-Qualified Employee Stock Purchase Plan (as amended, the “ESPP”). Initially 1,000,000 shares of common stock were reserved for issuance under this plan. There are currently 681,284 shares remaining available for issuance under the ESPP. Full-time employees of the Company generally are eligible to participate in the ESPP if, as of the last day of the applicable election period, they have been employed by the Company for at least one month. All other employees of the Company are eligible to participate provided that, as of the applicable election period, they have been employed by the Company for 12 months. Under the ESPP, eligible employees are permitted to acquire shares of the Company's common stock through payroll deductions, subject to maximum purchase limitations, during two purchase periods. The first purchase period begins January 1 and ends June 10, and the second purchase period begins July 1 and ends December 10. The purchase price for common stock purchased under the plan is 85% of the lesser of the fair market value of the Company's common stock on the first day of the applicable purchase period or the last day of the applicable purchase period. The offering dates, purchase dates and duration of purchase periods may be changed if the change is announced prior to the beginning of the affected date or purchase period. The Company issued 11,528 , 11,348 and 10,667 shares and recognized compensation expense of $418,000 , $289,000 and $321,000 under the ESPP for the years ended December 31, 2017 , 2016 and 2015 , respectively. The Company accounts for transactions under the ESPP using the fair value method prescribed by accounting guidance applicable to entities that use employee share purchase plans.

Related Party Arrangements

Related Party Arrangements	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
Related Party Arrangements	Related Party Arrangements Unconsolidated Entities The Company manages unconsolidated real estate entities for which it receives asset management, property management, development and redevelopment fee revenue. From these entities, the Company earned fees of $4,147,000 , $5,599,000 and $9,947,000 in the years ended December 31, 2017 , 2016 and 2015 , respectively. These fees are recognized on an accrual basis when earned in accordance with the accounting guidance applicable to revenue recognition, and are included in management, development and other fees on the accompanying Consolidated Statements of Comprehensive Income. In addition, the Company has outstanding receivables associated with its property and construction management role of $2,449,000 and $5,239,000 as of December 31, 2017 and 2016 , respectively. Director Compensation Directors of the Company who are also employees receive no additional compensation for their services as a director. Following each annual meeting of stockholders, non-employee directors receive (i) a number of shares of restricted stock (or deferred stock units) having a value of $135,000 and (ii) a cash payment of $80,000 , payable in equal quarterly installments of $20,000 . The number of shares of restricted stock (or deferred stock units) is calculated based on the closing price on the day of the award. Non-employee directors may elect to receive all or a portion of cash payments in the form of deferred stock units. Additionally, the Lead Independent Director receives in the aggregate an additional annual fee of $30,000 payable in equal quarterly installments of $7,500 , non-employee directors serving as the chairperson of the Audit or Compensation Committees receive additional cash compensation of $20,000 per year payable in equal quarterly installments of $5,000 , and the Nominating and Corporate Governance and Investment and Finance Committee chairpersons receive an additional annual fee of $15,000 payable in equal quarterly installments of $3,750 . The Company recorded non-employee director compensation expense relating to restricted stock grants and deferred stock awards in the amount of $1,524,000 , $1,216,000 and $1,135,000 for the years ended December 31, 2017 , 2016 and 2015 , respectively, as a component of general and administrative expense. Deferred compensation relating to these restricted stock grants and deferred stock awards to non-employee directors was $525,000 , $531,000 and $488,000 on December 31, 2017 , 2016 and 2015 , respectively.

Fair Value

Fair Value	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value	Fair Value Financial Instruments Carried at Fair Value Derivative Financial Instruments Currently, the Company uses interest rate swap and interest rate cap agreements to manage its interest rate risk. These instruments are carried at fair value in the Company's financial statements. In adjusting the fair value of its derivative contracts for the effect of counterparty nonperformance risk, the Company has considered the impact of its net position with a given counterparty, as well as any applicable credit enhancements, such as collateral postings, thresholds, mutual puts and guarantees. The Company minimizes its credit risk on these transactions by dealing with major, creditworthy financial institutions which have an A or better credit rating by the Standard & Poor's Ratings Group. As part of its on-going control procedures, the Company monitors the credit ratings of counterparties and the exposure of the Company to any single entity, thus reducing credit risk concentration. The Company believes the likelihood of realizing losses from counterparty nonperformance is remote. Although the Company has determined that the majority of the inputs used to value its derivatives fall within Level 2 of the fair value hierarchy, such as interest rate, term to maturity and volatility, the credit valuation adjustments associated with its derivatives use Level 3 inputs, such as estimates of current credit spreads, to evaluate the likelihood of default by itself and its counterparties. As of December 31, 2017 , the Company assessed the significance of the impact of the credit valuation adjustments on the overall valuation of its derivative positions and has determined it is not significant. As a result, the Company has determined that its derivative valuations are classified in Level 2 of the fair value hierarchy. The Company recognized a gain of $753,000 for hedge ineffectiveness for the year ended December 31, 2017 , included as a component of interest expense, net on the accompanying Consolidated Statements of Comprehensive Income. Hedge ineffectiveness did not have a material impact on earnings of the Company for any prior period. The following table summarizes the consolidated derivative positions at December 31, 2017 (dollars in thousands): Non-designated Hedges Interest Rate Caps Cash Flow Hedges Interest Rate Caps Cash Flow Interest Rate Swaps Notional balance $ 689,059 $ 35,039 $ 300,000 Weighted average interest rate (1) 3.3 % 3.5 % N/A Weighted average swapped/capped interest rate 6.5 % 5.9 % 2.4 % Earliest maturity date August 2018 April 2019 May 2018 Latest maturity date September 2022 April 2019 May 2018 _________________________________ (1) For interest rate caps, represents the weighted average interest rate on the hedged debt. In 2017 , the Company entered into $300,000,000 of forward interest rate swap agreements executed to reduce the impact of variability in interest rates on a portion of the Company's expected debt issuance activity in 2018. As of December 31, 2017 , the Company has $300,000,000 in aggregate outstanding forward interest rate swap agreements. At maturity of the remaining outstanding swap agreements, the Company expects to cash settle the contracts and either pay or receive cash for the then current fair value. Assuming that the Company issues the debt as expected, the hedging impact from these positions will then be recognized over the life of the issued debt as a yield adjustment. In addition, during 2017 , the Company settled an aggregate of $800,000,000 of forward interest rate swap agreements, receiving net aggregate payments of $391,000 . which consisted of the following activity: • in conjunction with the refinancing of three secured borrowings in May 2017, in April 2017, the Company settled $185,100,000 of forward interest rate swap agreements designated as cash flow hedges of the interest rate variability of the secured notes, making a payment of $2,326,000 ; • in conjunction with the Company's May 2017 unsecured note issuance, the Company settled $400,000,000 of forward interest rate swap agreements designated as cash flow hedges of the interest rate variability on the forecasted issuance of the unsecured notes, making a payment of $1,361,000 ; and • in conjunction with the Company's June 2017 unsecured note issuance, the Company settled $214,900,000 of forward interest rate swap agreements designated as cash flow hedges of the interest rate variability on the forecasted issuance of the unsecured notes, receiving a payment of $4,078,000 . The Company has deferred $376,000 , the effective portion of the fair value change of these swaps, in accumulated other comprehensive loss on the accompanying Consolidated Balance Sheets, and will recognize the impact as a component of interest expense, net, over the 10 year period of interest payments hedged. The Company had seven derivatives designated as cash flow hedges and 14 derivatives not designated as hedges at December 31, 2017 . Fair value changes for derivatives not in qualifying hedge relationships for the years ended December 31, 2017 and 2016 , were not material. During 2017 , the Company deferred $13,979,000 of losses for cash flow hedges reported as a component of other comprehensive income (loss). The following table summarizes the deferred losses reclassified from accumulated other comprehensive income as a component of interest expense, net (dollars in thousands): For the year ended 12/31/17 12/31/16 12/31/15 Cash flow hedge losses reclassified to earnings $ 7,070 $ 6,433 $ 5,774 The Company anticipates reclassifying approximately $7,012,000 of hedging losses from accumulated other comprehensive loss into earnings within the next 12 months to offset the variability of cash flows of the hedged item during this period. The Company did not have any derivatives designated as fair value hedges as of December 31, 2017 and 2016 . Redeemable Noncontrolling Interests The Company provided redemption options (the “Puts”) that allow joint venture partners of the Company to require the Company to purchase their interests in the investment at a guaranteed minimum amount related to three ventures. The Puts are payable in cash. The Company determines the fair value of the Puts based on unobservable inputs considering the assumptions that market participants would make in pricing the obligations, applying a guaranteed rate of return to the joint venture partners' net capital contribution balances as of period end. Given the significance of the unobservable inputs, the valuations are classified in Level 3 of the fair value hierarchy. The Company issued units of limited partnership interest in DownREITs which provide the DownREIT limited partners the ability to present all or some of their units for redemption for cash as determined by the partnership agreement. Under the DownREIT agreements, for each limited partnership unit, the limited partner is entitled to receive cash in the amount equal to the fair value of the Company's common stock on or about the date of redemption. In lieu of cash redemption, the Company may elect to exchange such units for an equal number of shares of the Company's common stock. The limited partnership units in the DownREITs are valued using the market price of the Company's common stock, a Level 1 price under the fair value hierarchy. Financial Instruments Not Carried at Fair Value Cash and Cash Equivalents Cash and cash equivalent balances are held with various financial institutions, within principal protected accounts. The Company monitors credit ratings of these financial institutions and the concentration of cash and cash equivalent balances with any one financial institution and believes the likelihood of realizing material losses related to cash and cash equivalent balances is remote. Cash and cash equivalents are carried at their face amounts, which reasonably approximate their fair values and are Level 1 within the fair value hierarchy. Other Financial Instruments Rents and other receivables and prepaids, accounts and construction payable and accrued expenses and other liabilities are carried at their face amounts, which reasonably approximate their fair values. The Company values its unsecured notes using quoted market prices, a Level 1 price within the fair value hierarchy. The Company values its notes payable and outstanding amounts under the Credit Facility and Term Loan using a discounted cash flow analysis on the expected cash flows of each instrument. This analysis reflects the contractual terms of the instrument, including the period to maturity, and uses observable market-based inputs, including interest rate curves. The process also considers credit valuation adjustments to appropriately reflect the Company’s nonperformance risk. The Company has concluded that the value of its notes payable and amounts outstanding under its Credit Facility and Term Loan are Level 2 prices as the majority of the inputs used to value its positions fall within Level 2 of the fair value hierarchy. Financial Instruments Measured/Disclosed at Fair Value on a Recurring Basis The following table summarizes the classification between the three levels of the fair value hierarchy of the Company's financial instruments measured/disclosed at fair value on a recurring basis (dollars in thousands): Description Total Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) 12/31/2017 Non Designated Hedges Interest Rate Caps $ 2 $ — $ 2 $ — Cash Flow Hedges Interest Rate Swaps - Assets 2,270 — 2,270 — Interest Rate Swaps - Liabilities (1,171 ) — (1,171 ) — Puts (3,245 ) — — (3,245 ) DownREIT units (1,338 ) (1,338 ) — — Indebtedness Unsecured notes (5,446,604 ) (5,446,604 ) — — Secured notes payable and unsecured term loans (1,849,851 ) — (1,849,851 ) — Total $ (7,299,937 ) $ (5,447,942 ) $ (1,848,750 ) $ (3,245 ) 12/31/2016 Non Designated Hedges Interest Rate Caps $ 79 $ — $ 79 $ — Cash Flow Hedges Interest Rate Caps 2 — 2 — Interest Rate Swaps 14,775 — 14,775 — Puts (6,002 ) — — (6,002 ) DownREIT units (1,329 ) (1,329 ) — — Indebtedness Unsecured notes (4,218,627 ) (4,218,627 ) — — Secured notes payable and unsecured term loans (2,744,462 ) — (2,744,462 ) — Total $ (6,955,564 ) $ (4,219,956 ) $ (2,729,606 ) $ (6,002 )

Quarterly Financial Information

Quarterly Financial Information	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Information	Quarterly Financial Information The following summary represents the unaudited quarterly results of operations for the years ended December 31, 2017 and 2016 (dollars in thousands, except per share data): For the three months ended (1) 3/31/17 6/30/17 9/30/17 12/31/17 Total revenue $ 522,326 $ 530,512 $ 550,500 $ 555,292 Net income $ 235,781 $ 165,194 $ 238,199 $ 237,486 Net income attributable to common stockholders $ 235,875 $ 165,225 $ 238,248 $ 237,573 Net income per common share - basic $ 1.72 $ 1.20 $ 1.73 $ 1.72 Net income per common share - diluted $ 1.72 $ 1.20 $ 1.72 $ 1.72 For the three months ended (1) 3/31/16 6/30/16 9/30/16 12/31/16 Total revenue $ 508,498 $ 502,307 $ 516,211 $ 518,240 Net income $ 237,877 $ 197,319 $ 356,329 $ 242,183 Net income attributable to common stockholders $ 237,931 $ 197,444 $ 356,392 $ 242,235 Net income per common share - basic $ 1.73 $ 1.44 $ 2.60 $ 1.76 Net income per common share - diluted $ 1.73 $ 1.44 $ 2.59 $ 1.76 _________________________________ (1) Amounts may not equal full year results due to rounding.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2017
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events The Company has evaluated subsequent events through the date on which this Form 10-K was filed, the date on which these financial statements were issued, and identified the items below for discussion. In January and February 2018, the Company acquired four parcels of land for development for an aggregate investment of $76,758,000 . In February 2018, the Company repaid $15,174,000 of 6.60% fixed rate debt secured by Avalon Oaks West in advance of its maturity date, incurring a prepayment penalty of $152,000 .

REAL ESTATE AND ACCUMULATED DEP

REAL ESTATE AND ACCUMULATED DEPRECIATION	12 Months Ended
	Dec. 31, 2017
SEC Schedule III, Real Estate and Accumulated Depreciation Disclosure [Abstract]
REAL ESTATE AND ACCUMULATED DEPRECIATION	2017 2016 2017 Initial Cost Total Cost Community City and state # of homes Land and improvements Building / Costs Land and improvements Building / Total Accumulated Total Cost, Total Cost, Encumbrances Year of ESTABLISHED COMMUNITIES NEW ENGLAND Boston, MA Avalon at Lexington Lexington, MA 198 $ 2,124 $ 12,567 $ 10,093 $ 2,124 $ 22,660 $ 24,784 $ 14,080 $ 10,704 $ 11,290 $ — 1994 Avalon Oaks Wilmington, MA 204 2,129 17,567 5,488 2,129 23,055 25,184 13,755 11,429 12,153 — 1999 Eaves Quincy Quincy, MA 245 1,743 14,662 10,184 1,743 24,846 26,589 14,456 12,133 12,799 — 1986/1995 Avalon Oaks West Wilmington, MA 120 3,318 13,465 1,224 3,318 14,689 18,007 8,054 9,953 10,442 15,213 2002 Avalon Orchards Marlborough, MA 156 2,983 17,970 2,702 2,983 20,672 23,655 11,463 12,192 12,865 15,579 2002 Avalon at Newton Highlands Newton, MA 294 11,039 45,547 5,196 11,039 50,743 61,782 25,369 36,413 37,670 — 2003 Avalon at The Pinehills Plymouth, MA 192 6,876 30,401 721 6,876 31,122 37,998 11,155 26,843 27,716 — 2004 Eaves Peabody Peabody, MA 286 4,645 18,919 13,420 4,645 32,339 36,984 13,190 23,794 24,329 — 1962/2004 Avalon at Bedford Center Bedford, MA 139 4,258 20,551 1,457 4,258 22,008 26,266 8,923 17,343 17,570 — 2006 Avalon at Lexington Hills Lexington, MA 387 8,691 79,121 4,158 8,691 83,279 91,970 28,415 63,555 66,241 — 2008 Avalon Acton Acton, MA 380 13,124 48,695 3,504 13,124 52,199 65,323 17,459 47,864 49,275 45,000 2008 Avalon at the Hingham Shipyard Hingham, MA 235 12,218 41,656 2,412 12,218 44,068 56,286 13,882 42,404 43,641 — 2009 Avalon Sharon Sharon, MA 156 4,719 25,478 892 4,719 26,370 31,089 8,759 22,330 22,960 — 2008 Avalon Northborough Northborough, MA 382 8,144 52,184 1,691 8,144 53,875 62,019 14,899 47,120 48,460 — 2009 Avalon Blue Hills Randolph, MA 276 11,110 34,580 1,549 11,110 36,129 47,239 10,781 36,458 37,314 — 2009 Avalon Cohasset Cohasset, MA 220 8,802 46,166 259 8,802 46,425 55,227 9,890 45,337 46,935 — 2012 Avalon Andover Andover, MA 115 4,276 21,871 210 4,276 22,081 26,357 4,527 21,830 22,625 13,498 2012 Avalon Exeter (1) Boston, MA 187 16,313 110,028 214 16,313 110,242 126,555 13,672 112,883 116,744 — 2014 Avalon Natick Natick, MA 407 15,645 64,845 34 15,645 64,879 80,524 10,430 70,094 72,419 48,870 2013 Avalon at Assembly Row Somerville, MA 195 8,599 52,494 26 8,599 52,520 61,119 6,780 54,339 56,030 — 2015 AVA Somerville Somerville, MA 250 10,945 56,470 12 10,945 56,482 67,427 6,208 61,219 63,066 — 2015 Avalon Prudential Center I (2) Boston, MA 243 8,002 32,370 38,384 8,002 70,754 78,756 28,947 49,809 47,586 — 1968/1998 Eaves Burlington Burlington, MA 203 7,714 32,499 6,512 7,714 39,011 46,725 6,538 40,187 41,107 — 1988/2012 Avalon Canton at Blue Hills Canton, MA 196 6,562 33,956 132 6,562 34,088 40,650 4,503 36,147 37,391 — 2014 Avalon Burlington (2) Burlington, MA 312 15,600 58,499 18,176 15,600 76,675 92,275 13,196 79,079 81,135 — 1989/2013 Eaves North Quincy Quincy, MA 224 11,940 39,400 3,544 11,940 42,944 54,884 9,297 45,587 46,492 — 1977/2013 Avalon at Center Place (1) Providence, RI 225 — 26,816 13,271 — 40,087 40,087 24,342 15,745 15,575 — 1991/1997 Total Boston, MA 6,427 $ 211,519 $ 1,048,777 $ 145,465 $ 211,519 $ 1,194,242 $ 1,405,761 $ 352,970 $ 1,052,791 $ 1,081,830 $ 138,160 2017 2016 2017 Initial Cost Total Cost Community City and state # of homes Land and improvements Building / Costs Land and improvements Building / Total Accumulated Total Cost, Total Cost, Encumbrances Year of Fairfield-New Haven, CT Eaves Stamford Stamford, CT 238 $ 5,956 $ 23,993 $ 13,117 $ 5,956 $ 37,110 $ 43,066 $ 24,215 $ 18,851 $ 20,058 $ — 1991 Avalon Wilton on River Rd Wilton, CT 102 2,116 14,664 6,422 2,116 21,086 23,202 12,077 11,125 11,314 — 1997 Avalon New Canaan New Canaan, CT 104 4,834 22,990 2,163 4,834 25,153 29,987 13,192 16,795 17,589 — 2002 AVA Stamford Stamford, CT 306 13,819 56,499 5,887 13,819 62,386 76,205 32,700 43,505 45,461 — 2002/2002 Avalon Darien Darien, CT 189 6,926 34,558 2,734 6,926 37,292 44,218 18,089 26,129 27,188 — 2004 Avalon Norwalk Norwalk, CT 311 11,320 62,904 887 11,320 63,791 75,111 16,187 58,924 60,986 — 2011 Avalon Wilton on Danbury Rd Wilton, CT 100 6,604 23,758 150 6,604 23,908 30,512 5,573 24,939 25,681 — 2011 Avalon Shelton Shelton, CT 250 7,749 40,264 88 7,749 40,352 48,101 6,697 41,404 42,826 — 2013 Avalon East Norwalk Norwalk, CT 240 10,395 36,245 119 10,395 36,364 46,759 5,670 41,089 42,317 — 2013 Avalon Stratford Stratford, CT 130 2,564 27,157 33 2,564 27,190 29,754 3,274 26,480 27,424 — 2014 Total Fairfield-New Haven, CT 1,970 $ 72,283 $ 343,032 $ 31,600 $ 72,283 $ 374,632 $ 446,915 $ 137,674 $ 309,241 $ 320,844 $ — TOTAL NEW ENGLAND 8,397 $ 283,802 $ 1,391,809 $ 177,065 $ 283,802 $ 1,568,874 $ 1,852,676 $ 490,644 $ 1,362,032 $ 1,402,674 $ 138,160 METRO NY/NJ New York City, NY Avalon Riverview (1) Long Island City, NY 372 $ — $ 94,061 $ 9,867 $ — $ 103,928 $ 103,928 $ 52,510 $ 51,418 $ 54,912 $ — 2002 Avalon Bowery Place I New York, NY 206 18,575 75,009 2,890 18,575 77,899 96,474 30,174 66,300 68,882 93,800 2006 Avalon Bowery Place II New York, NY 90 9,106 47,199 3,811 9,106 51,010 60,116 17,750 42,366 44,607 — 2007 Avalon Morningside Park (3) New York, NY 295 95,465 114,233 1,580 95,465 115,813 211,278 36,625 174,653 83,027 100,000 2009 Avalon Fort Greene Brooklyn, NY 631 83,038 216,802 2,052 83,038 218,854 301,892 57,941 243,951 251,213 — 2010 Avalon West Chelsea (1) (4) New York, NY 305 — 119,882 243 — 120,125 120,125 13,643 106,482 102,820 — 2015 AVA High Line (1) (4) New York, NY 405 — 159,187 33 — 159,220 159,220 20,451 138,769 152,127 — 2015 Avalon Clinton North (2) New York, NY 339 84,069 105,821 11,529 84,069 117,350 201,419 23,412 178,007 180,740 147,000 2008/2013 Avalon Clinton South New York, NY 288 71,421 89,851 6,181 71,421 96,032 167,453 20,089 147,364 150,330 121,500 2007/2013 Total New York City, NY 2,931 $ 361,674 $ 1,022,045 $ 38,186 $ 361,674 $ 1,060,231 $ 1,421,905 $ 272,595 $ 1,149,310 $ 1,088,658 $ 462,300 New York - Suburban Avalon Commons Smithtown, NY 312 $ 4,679 $ 28,286 $ 6,335 $ 4,679 $ 34,621 $ 39,300 $ 22,581 $ 16,719 $ 17,712 $ — 1997 Avalon Green I Elmsford, NY 105 1,820 10,525 7,522 1,820 18,047 19,867 9,870 9,997 10,633 — 1995 Avalon Court Melville, NY 494 9,228 50,063 6,681 9,228 56,744 65,972 35,091 30,881 32,294 — 1997 The Avalon Bronxville, NY 110 2,889 28,324 8,661 2,889 36,985 39,874 19,772 20,102 21,064 — 1999 Avalon at Glen Cove (1) Glen Cove, NY 256 7,871 59,969 4,245 7,871 64,214 72,085 28,810 43,275 44,881 — 2004 2017 2016 2017 Initial Cost Total Cost Community City and state # of homes Land and improvements Building / Costs Land and improvements Building / Total Accumulated Total Cost, Total Cost, Encumbrances Year of Avalon Glen Cove North (1) Glen Cove, NY 111 2,577 37,336 531 2,577 37,867 40,444 13,875 26,569 27,768 — 2007 Avalon White Plains White Plains, NY 407 15,391 137,353 996 15,391 138,349 153,740 41,499 112,241 116,188 — 2009 Avalon Rockville Centre I Rockville Centre, NY 349 32,212 78,806 1,013 32,212 79,819 112,031 17,284 94,747 97,195 — 2012 Avalon Green II Elmsford, NY 444 27,765 77,560 223 27,765 77,783 105,548 15,714 89,834 92,537 — 2012 Avalon Garden City Garden City, NY 204 18,205 49,326 416 18,205 49,742 67,947 9,436 58,511 60,173 — 2013 Avalon Ossining Ossining, NY 168 6,392 30,313 — 6,392 30,313 36,705 4,078 32,627 33,734 — 2014 Avalon Huntington Station Huntington Station, NY 303 21,898 58,457 — 21,898 58,457 80,355 7,224 73,131 75,462 — 2014 Avalon Westbury Westbury, NY 396 69,620 43,781 10,941 69,620 54,722 124,342 15,286 109,056 110,752 78,650 2006/2013 Total New York - Suburban 3,659 $ 220,547 $ 690,099 $ 47,564 $ 220,547 $ 737,663 $ 958,210 $ 240,520 $ 717,690 $ 740,393 $ 78,650 New Jersey Avalon Cove Jersey City, NJ 504 $ 8,760 $ 82,422 $ 22,967 $ 8,760 $ 105,389 $ 114,149 $ 64,885 $ 49,264 $ 51,954 $ — 1997 Eaves Lawrenceville (2) Lawrenceville, NJ 632 14,650 60,486 11,899 14,650 72,385 87,035 32,099 54,936 57,334 — 1994 Avalon Princeton Junction West Windsor, NJ 512 5,585 22,382 21,675 5,585 44,057 49,642 26,010 23,632 24,587 — 1988/1993 Avalon Tinton Falls Tinton Falls, NJ 216 7,939 33,170 520 7,939 33,690 41,629 11,225 30,404 31,528 — 2008 Avalon West Long Branch West Long Branch, NJ 180 2,721 22,925 136 2,721 23,061 25,782 6,054 19,728 20,549 — 2011 Avalon North Bergen North Bergen, NJ 164 8,984 30,994 949 8,984 31,943 40,927 6,495 34,432 35,686 — 2012 Avalon at Wesmont Station I Wood-Ridge, NJ 266 14,682 41,635 1,101 14,682 42,736 57,418 8,365 49,053 49,991 — 2012 Avalon Hackensack at Riverside (1) Hackensack, NJ 226 — 44,619 128 — 44,747 44,747 7,140 37,607 39,099 — 2013 Avalon Somerset Somerset, NJ 384 18,241 58,338 226 18,241 58,564 76,805 9,817 66,988 69,023 — 2013 Avalon at Wesmont Station II Wood-Ridge, NJ 140 6,502 16,865 — 6,502 16,865 23,367 2,865 20,502 21,131 — 2013 Avalon Bloomingdale Bloomingdale, NJ 174 3,006 27,801 71 3,006 27,872 30,878 4,119 26,759 27,635 — 2014 Avalon Wharton Wharton, NJ 247 2,273 48,609 98 2,273 48,707 50,980 5,167 45,813 47,455 — 2015 Avalon Roseland Roseland, NJ 136 11,288 34,928 — 11,288 34,928 46,216 3,260 42,956 44,078 — 2015 Total New Jersey 3,781 $ 104,631 $ 525,174 $ 59,770 $ 104,631 $ 584,944 $ 689,575 $ 187,501 $ 502,074 $ 520,050 $ — TOTAL METRO NY/NJ 10,371 $ 686,852 $ 2,237,318 $ 145,520 $ 686,852 $ 2,382,838 $ 3,069,690 $ 700,616 $ 2,369,074 $ 2,349,101 $ 540,950 2017 2016 2017 Initial Cost Total Cost Community City and state # of homes Land and improvements Building / Costs Land and improvements Building / Total Accumulated Total Cost, Total Cost, Encumbrances Year of MID-ATLANTIC Washington Metro/Baltimore, MD Avalon at Foxhall Washington, D.C. 308 $ 6,848 $ 27,614 $ 15,456 $ 6,848 $ 43,070 $ 49,918 $ 29,439 $ 20,479 $ 20,360 $ — 1982/1994 Avalon at Gallery Place Washington, D.C. 203 8,800 39,658 2,167 8,800 41,825 50,625 21,005 29,620 31,047 — 2003 AVA H Street Washington, D.C. 138 7,425 25,282 44 7,425 25,326 32,751 4,717 28,034 28,998 — 2013 Avalon The Albemarle Washington, D.C. 231 25,140 52,459 6,592 25,140 59,051 84,191 12,774 71,417 72,134 — 1966/2013 Eaves Tunlaw Gardens Washington, D.C. 166 16,430 22,902 2,344 16,430 25,246 41,676 5,727 35,949 36,751 — 1944/2013 The Statesman Washington, D.C. 281 38,140 35,352 4,111 38,140 39,463 77,603 9,916 67,687 68,834 — 1961/2013 Eaves Glover Park Washington, D.C. 120 9,580 26,532 2,408 9,580 28,940 38,520 6,575 31,945 32,944 — 1953/2013 Avalon First and M Washington, D.C. 469 43,700 153,950 3,195 43,700 157,145 200,845 28,554 172,291 177,621 — 2012/2013 Avalon at Fairway Hills Columbia, MD 720 8,603 34,432 16,302 8,603 50,734 59,337 33,393 25,944 27,384 — 1987/1996 Eaves Washingtonian Center North Potomac, MD 288 4,047 18,553 2,784 4,047 21,337 25,384 14,268 11,116 11,258 — 1996 Eaves Columbia Town Center Columbia, MD 392 8,802 35,536 12,155 8,802 47,691 56,493 20,971 35,522 36,814 — 1986/1993 Avalon at Grosvenor Station Bethesda, MD 497 29,159 52,993 2,642 29,159 55,635 84,794 27,043 57,751 59,405 — 2004 Avalon at Traville Rockville, MD 520 14,365 55,398 4,155 14,365 59,553 73,918 27,917 46,001 48,065 — 2004 Avalon Russett Laurel, MD 238 10,200 47,524 3,220 10,200 50,744 60,944 11,037 49,907 51,425 32,200 1999/2013 Eaves Fair Lakes Fairfax, VA 420 6,096 24,400 8,904 6,096 33,304 39,400 21,265 18,135 18,986 — 1989/1996 AVA Ballston Arlington, VA 344 7,291 29,177 16,302 7,291 45,479 52,770 29,144 23,626 25,196 — 1990 Avalon Tysons Corner Tysons Corner, VA 558 13,851 43,397 12,788 13,851 56,185 70,036 32,826 37,210 38,956 — 1996 Avalon Park Crest Tysons Corner, VA 354 13,554 63,526 274 13,554 63,800 77,354 11,932 65,422 67,595 — 2013 Eaves Fairfax Towers (2) Falls Church, VA 415 17,889 74,727 4,446 17,889 79,173 97,062 18,433 78,629 79,263 — 1978/2011 Avalon Mosaic Fairfax, VA 531 33,490 75,802 — 33,490 75,802 109,292 10,461 98,831 101,637 — 2014 Avalon Ballston Place Arlington, VA 383 38,490 123,645 5,049 38,490 128,694 167,184 24,830 142,354 146,479 — 2001/2013 Eaves Tysons Corner Vienna, VA 217 16,030 45,420 2,967 16,030 48,387 64,417 11,140 53,277 54,923 — 1980/2013 Avalon Courthouse Place Arlington, VA 564 56,550 178,032 10,254 56,550 188,286 244,836 37,860 206,976 213,114 — 1999/2013 Avalon Arlington North Arlington, VA 228 21,600 59,076 34 21,600 59,110 80,710 7,797 72,913 74,995 — 2014 Avalon Reston Landing Reston, VA 400 26,710 83,084 6,212 26,710 89,296 116,006 20,027 95,979 98,438 — 2000/2013 TOTAL MID-ATLANTIC 8,985 $ 482,790 $ 1,428,471 $ 144,805 $ 482,790 $ 1,573,276 $ 2,056,066 $ 479,051 $ 1,577,015 $ 1,622,622 $ 32,200 2017 2016 2017 Initial Cost Total Cost Community City and state # of homes Land and improvements Building / Costs Land and improvements Building / Total Accumulated Total Cost, Total Cost, Encumbrances Year of PACIFIC NORTHWEST Seattle, WA Avalon Redmond Place Redmond, WA 222 $ 4,558 $ 18,368 $ 10,501 $ 4,558 $ 28,869 $ 33,427 $ 17,567 $ 15,860 $ 16,642 $ — 1991/1997 Avalon at Bear Creek Redmond, WA 264 6,786 27,641 4,893 6,786 32,534 39,320 21,197 18,123 18,645 — 1998/1998 Avalon Bellevue Bellevue, WA 201 6,664 24,119 2,110 6,664 26,229 32,893 15,292 17,601 18,441 — 2001 Avalon RockMeadow Bothell, WA 206 4,777 19,765 2,930 4,777 22,695 27,472 13,423 14,049 14,457 — 2000/2000 Avalon ParcSquare Redmond, WA 124 3,789 15,139 3,286 3,789 18,425 22,214 10,718 11,496 12,060 — 2000/2000 AVA Belltown Seattle, WA 100 5,644 12,733 1,253 5,644 13,986 19,630 7,940 11,690 12,003 — 2001 Avalon Meydenbauer Bellevue, WA 368 12,697 77,450 1,366 12,697 78,816 91,513 26,487 65,026 67,686 — 2008 Avalon Towers Bellevue (1) Bellevue, WA 397 — 123,029 1,341 — 124,370 124,370 32,339 92,031 95,998 — 2011 AVA Queen Anne Seattle, WA 203 12,081 41,618 431 12,081 42,049 54,130 9,060 45,070 46,642 — 2012 AVA Ballard Seattle, WA 265 16,460 46,926 1,002 16,460 47,928 64,388 8,335 56,053 57,893 — 2013 Avalon Alderwood I Lynnwood, WA 367 12,294 55,626 — 12,294 55,626 67,920 6,553 61,367 63,391 — 2015 Eaves Redmond Campus (2) Redmond, WA 422 22,580 88,001 10,267 22,580 98,268 120,848 21,097 99,751 99,157 — 1991/2013 Archstone Redmond Lakeview Redmond, WA 166 10,250 26,842 3,315 10,250 30,157 40,407 6,852 33,555 34,398 — 1987/2013 TOTAL PACIFIC NORTHWEST 3,305 $ 118,580 $ 577,257 $ 42,695 $ 118,580 $ 619,952 $ 738,532 $ 196,860 $ 541,672 $ 557,413 $ — NORTHERN CALIFORNIA San Jose, CA Avalon Campbell Campbell, CA 348 $ 11,830 $ 47,828 $ 13,561 $ 11,830 $ 61,389 $ 73,219 $ 35,368 $ 37,851 $ 39,955 $ 38,800 1995 Eaves San Jose San Jose, CA 440 12,920 53,047 18,931 12,920 71,978 84,898 36,145 48,753 51,143 — 1985/1996 Avalon Mountain View Mountain View, CA 248 9,755 39,393 10,321 9,755 49,714 59,469 30,458 29,011 30,562 — 1986 Eaves Creekside Mountain View, CA 296 6,546 26,263 21,316 6,546 47,579 54,125 25,798 28,327 29,992 — 1962/1997 Avalon at Cahill Park San Jose, CA 218 4,765 47,600 2,020 4,765 49,620 54,385 26,084 28,301 29,836 — 2002 Avalon Morrison Park San Jose, CA 250 13,837 64,534 72 13,837 64,606 78,443 8,779 69,664 72,002 — 2014 Avalon Willow Glen San Jose, CA 412 46,060 81,957 4,707 46,060 86,664 132,724 19,887 112,837 115,648 — 2002/2013 Eaves West Valley San Jose, CA 873 90,890 132,040 10,251 90,890 142,291 233,181 31,153 202,028 205,771 — 1970/2013 Eaves Mountain View at Middlefield Mountain View, CA 402 64,070 69,018 5,498 64,070 74,516 138,586 17,838 120,748 123,403 — 1969/2013 Total San Jose, CA 3,487 $ 260,673 $ 561,680 $ 86,677 $ 260,673 $ 648,357 $ 909,030 $ 231,510 $ 677,520 $ 698,312 $ 38,800 Oakland - East Bay, CA Avalon Fremont Fremont, CA 308 $ 10,746 $ 43,399 $ 6,656 $ 10,746 $ 50,055 $ 60,801 $ 33,523 $ 27,278 $ 28,098 $ — 1992/1994 Eaves Dublin Dublin, CA 204 5,276 19,642 12,366 5,276 32,008 37,284 $ 17,814 19,470 20,653 — 1989/1997 2017 2016 2017 Initial Cost Total Cost Community City and state # of homes Land and improvements Building / Costs Land and improvements Building / Total Accumulated Total Cost, Total Cost, Encumbrances Year of Eaves Pleasanton Pleasanton, CA 456 11,610 46,552 21,755 11,610 68,307 79,917 40,146 39,771 41,764 — 1988/1994 Eaves Union City Union City, CA 208 4,249 16,820 3,312 4,249 20,132 24,381 13,659 10,722 11,342 — 1973/1996 Eaves Fremont Fremont, CA 235 6,581 26,583 9,992 6,581 36,575 43,156 22,733 20,423 21,385 — 1985/1994 Avalon Union City Union City, CA 439 14,732 104,024 982 14,732 105,006 119,738 30,647 89,091 92,395 — 2009 Avalon Walnut Creek (1) Walnut Creek, CA 422 — 148,370 3,245 — 151,615 151,615 39,014 112,601 115,817 3,557 2010 Avalon Dublin Station Dublin, CA 253 7,772 72,142 599 7,772 72,741 80,513 9,650 70,863 72,802 — 2014 Eaves Walnut Creek (2) Walnut Creek, CA 510 30,320 82,375 16,828 30,320 99,203 129,523 19,294 110,229 111,534 — 1987/2013 Avalon Walnut Ridge II Walnut Creek, CA 360 27,190 57,041 5,864 27,190 62,905 90,095 13,372 76,723 76,821 — 1989/2013 Avalon Berkeley Berkeley, CA 94 4,500 28,622 — 4,500 28,622 33,122 3,523 29,599 30,607 — 2014 Total Oakland - East Bay, CA 3,489 $ 122,976 $ 645,570 $ 81,599 $ 122,976 $ 727,169 $ 850,145 $ 243,375 $ 606,770 $ 623,218 $ 3,557 San Francisco, CA Eaves Daly City Daly City, CA 195 $ 4,230 $ 9,659 $ 19,858 $ 4,230 $ 29,517 $ 33,747 $ 17,704 $ 16,043 $ 16,173 $ — 1972/1997 AVA Nob Hill San Francisco, CA 185 5,403 21,567 7,597 5,403 29,164 34,567 17,103 17,464 17,980 20,800 1990/1995 Eaves San Rafael San Rafael, CA 254 5,982 16,885 24,752 5,982 41,637 47,619 22,224 25,395 26,689 — 1973/1996 Eaves Foster City Foster City, CA 288 7,852 31,445 11,629 7,852 43,074 50,926 25,622 25,304 26,440 — 1973/1994 Eaves Pacifica Pacifica, CA 220 6,125 24,796 3,116 6,125 27,912 34,037 18,647 15,390 16,175 17,600 1971/1995 Avalon Sunset Towers San Francisco, CA 243 3,561 21,321 16,129 3,561 37,450 41,011 19,817 21,194 21,819 — 1961/1996 Eaves Diamond Heights San Francisco, CA 154 4,726 19,130 6,189 4,726 25,319 30,045 15,390 14,655 15,313 — 1972/1994 Avalon at Mission Bay I San Francisco, CA 250 14,029 78,452 3,759 14,029 82,211 96,240 41,915 54,325 56,826 — 2003 Avalon at Mission Bay III San Francisco, CA 260 28,687 119,156 447 28,687 119,603 148,290 35,003 113,287 117,091 — 2009 Avalon Ocean Avenue San Francisco, CA 173 5,544 50,906 1,877 5,544 52,783 58,327 10,581 47,746 49,580 — 2012 AVA 55 Ninth San Francisco, CA 273 20,267 97,321 1,258 20,267 98,579 118,846 13,135 105,711 109,414 — 2014 Avalon Hayes Valley San Francisco, CA 182 12,595 81,232 — 12,595 81,232 93,827 7,855 85,972 88,745 — 2015 Avalon San Bruno I San Bruno, CA 300 40,780 68,684 4,974 40,780 73,658 114,438 15,334 99,104 100,274 64,450 2004/2013 Avalon San Bruno II San Bruno, CA 185 23,787 44,934 1,906 23,787 46,840 70,627 9,205 61,422 62,879 29,533 2007/2013 Avalon San Bruno III San Bruno, CA 187 33,303 62,910 3,028 33,303 65,938 99,241 12,956 86,285 88,243 53,315 2010/2013 Total San Francisco, CA 3,349 $ 216,871 $ 748,398 $ 106,519 $ 216,871 $ 854,917 $ 1,071,788 $ 282,491 $ 789,297 $ 813,641 $ 185,698 TOTAL NORTHERN CALIFORNIA 10,325 $ 600,520 $ 1,955,648 $ 274,795 $ 600,520 $ 2,230,443 $ 2,830,963 $ 757,376 $ 2,073,587 $ 2,135,171 $ 228,055 2017 2016 2017 Initial Cost Total Cost Community City and state # of homes Land and improvements Building / Costs Land and improvements Building / Total Accumulated Total Cost, Total Cost, Encumbrances Year of SOUTHERN CALIFORNIA Los Angeles, CA AVA Burbank Burbank, CA 748 $ 22,483 $ 28,104 $ 48,565 $ 22,483 $ 76,669 $ 99,152 $ 40,761 $ 58,391 $ 60,868 $ — 1961/1997 Avalon Woodland Hills Woodland Hills, CA 663 23,828 40,372 49,385 23,828 89,757 113,585 45,441 68,144 70,434 — 1989/1997 Eaves Warner Center Woodland Hills, CA 227 7,045 12,986 9,609 7,045 22,595 29,640 15,855 13,785 14,591 — 1979/1998 Avalon Glendale (1) Glendale, CA 223 — 42,564 2,070 — 44,634 44,634 21,703 22,931 24,122 — 2003 Avalon Burbank Burbank, CA 400 14,053 56,827 24,724 14,053 81,551 95,604 37,558 58,046 60,327 — 1988/2002 Avalon Camarillo Camarillo, CA 249 8,446 40,290 908 8,446 41,198 49,644 16,389 33,255 34,405 — 2006 Avalon Wilshire Los Angeles, CA 123 5,459 41,182 1,206 5,459 42,388 47,847 15,562 32,285 33,601 — 2007 Avalon Encino Encino, CA 131 12,789 49,073 1,091 12,789 50,164 62,953 15,966 46,987 48,412 — 2008 Avalon Warner Place Canoga Park, CA 210 7,920 44,845 589 7,920 45,434 53,354 15,109 38,245 39,727 — 2008 AVA Little Tokyo Los Angeles, CA 280 14,734 93,985 462 14,734 94,447 109,181 10,574 98,607 101,914 — 2015 Eaves Phillips Ranch Pomona, CA 501 9,796 41,740 1,964 9,796 43,704 53,500 10,314 43,186 44,058 — 1989/2011 Eaves San Dimas San Dimas, CA 102 1,916 7,819 1,389 1,916 9,208 11,124 2,202 8,922 9,214 — 1978/2011 Eaves San Dimas Canyon San Dimas, CA 156 2,953 12,428 736 2,953 13,164 16,117 3,145 12,972 13,289 — 1981/2011 AVA Pasadena Pasadena, CA 84 8,400 11,547 5,522 8,400 17,069 25,469 3,214 22,255 22,879 11,073 1973/2012 Eaves Cerritos Artesia, CA 151 8,305 21,195 1,474 8,305 22,669 30,974 4,391 26,583 27,343 — 1973/2012 Avalon Playa Vista Los Angeles, CA 309 30,900 72,008 2,428 30,900 74,436 105,336 14,228 91,108 93,776 — 2006/2012 Avalon San Dimas San Dimas, CA 156 9,141 30,727 — 9,141 30,727 39,868 3,778 36,090 37,250 — 2014 Avalon Mission Oaks Camarillo, CA 160 9,600 35,842 3,002 9,600 38,844 48,444 5,595 42,849 44,281 — 2014 Avalon Simi Valley Simi Valley, CA 500 42,020 73,361 4,940 42,020 78,301 120,321 17,394 102,927 105,475 — 2007/2013 Avalon Studio City Studio City, CA 276 15,756 78,178 5,778 15,756 83,956 99,712 17,139 82,573 84,242 — 2002/2013 Avalon Calabasas Calabasas, CA 600 42,720 107,642 9,921 42,720 117,563 160,283 27,970 132,313 136,511 96,502 1988/2013 Avalon Oak Creek Agoura Hills, CA 336 43,540 79,974 5,842 43,540 85,816 129,356 21,276 108,080 111,280 — 2004/2013 Avalon Del Mar Station Pasadena, CA 347 20,560 106,556 3,731 20,560 110,287 130,847 20,717 110,130 113,568 — 2006/2013 Eaves Thousand Oaks Thousand Oaks, CA 154 13,950 20,211 2,546 13,950 22,757 36,707 6,158 30,549 31,486 — 1992/2013 Eaves Los Feliz (2) Los Angeles, CA 263 18,940 43,661 4,556 18,940 48,217 67,157 10,545 56,612 57,563 41,400 1989/2013 Eaves Woodland Hills Woodland Hills, CA 883 68,940 90,549 11,203 68,940 101,752 170,692 25,353 145,339 148,867 111,500 1971/2013 Avalon Thousand Oaks Plaza Thousand Oaks, CA 148 12,810 22,581 2,300 12,810 24,881 37,691 6,132 31,559 32,257 — 2002/2013 Total Los Angeles, CA 8,380 $ 477,004 $ 1,306,247 $ 205,941 $ 477,004 $ 1,512,188 $ 1,989,192 $ 434,469 $ 1,554,723 $ 1,601,740 $ 260,475 Orange County, CA AVA Newport Costa Mesa, CA 145 $ 1,975 $ 3,814 $ 9,840 $ 1,975 $ 13,654 $ 15,629 $ 6,995 $ 8,634 $ 9,130 $ — 1956/1996 Eaves Mission Viejo Mission Viejo, CA 166 2,517 9,257 3,580 2,517 12,837 15,354 8,660 6,694 7,145 7,635 1984/1996 2017 2016 2017 Initial Cost Total Cost Community City and state # of homes Land and improvements Building / Costs Land and improvements Building / Total Accumulated Total Cost, Total Cost, Encumbrances Year of Eaves South Coast Costa Mesa, CA 258 4,709 16,063 13,442 4,709 29,505 34,214 16,883 17,331 17,829 — 1973/1996 Eaves Santa Margarita Rancho Santa Margarita, CA 301 4,607 16,911 10,917 4,607 27,828 32,435 15,849 16,586 17,224 — 1990/1997 Eaves Huntington Beach Huntington Beach, CA 304 4,871 19,745 10,267 4,871 30,012 34,883 19,912 14,971 15,964 — 1971/1997 Avalon Anaheim Stadium Anaheim, CA 251 27,874 69,156 1,608 27,874 70,764 98,638 21,751 76,887 78,955 — 2009 Avalon Irvine I Irvine, CA 279 9,911 67,520 776 9,911 68,296 78,207 19,629 58,578 60,694 — 2010 Avalon Irvine II Irvine, CA 179 4,358 40,912 — 4,358 40,912 45,270 7,217 38,053 39,535 — 2013 Eaves Lake Forest Lake Forest, CA 225 5,199 21,134 3,248 5,199 24,382 29,581 5,614 23,967 23,870 — 1975/2011 Avalon Baker Ranch Lake Forest, CA 430 31,689 98,411 — 31,689 98,411 130,100 9,406 120,694 124,442 — 2015 Eaves Seal Beach (2) Seal Beach, CA 549 46,790 99,999 5,640 46,790 105,639 152,429 22,914 129,515 132,659 — 1971/2013 Total Orange County, CA 3,087 $ 144,500 $ 462,922 $ 59,318 $ 144,500 $ 522,240 $ 666,740 $ 154,830 $ 511,910 $ 527,447 $ 7,635 San Diego, CA AVA Pacific Beach San Diego, CA 564 $ 9,922 $ 40,580 $ 40,849 $ 9,922 $ 81,429 $ 91,351 $ 41,108 $ 50,243 $ 53,224 $ — 1969/1997 Eaves Mission Ridge San Diego, CA 200 2,710 10,924 12,128 2,710 23,052 25,762 14,637 11,125 11,696 — 1960/1997 AVA Cortez Hill (1) San Diego, CA 299 2,768 20,134 23,567 2,768 43,701 46,469 23,459 23,010 24,543 — 1973/1998 Avalon Fashion Valley San Diego, CA 161 19,627 44,972 696 19,627 45,668 65,295 14,567 50,728 52,186 — 2008 Eaves Rancho Penasquitos San Diego, CA 250 6,692 27,143 3,242 6,692 30,385 37,077 6,960 30,117 30,727 — 1986/2011 Avalon Vista Vista, CA 221 12,689 43,327 — 12,689 43,327 56,016 4,125 51,891 53,512 — 2015 Eaves La Mesa La Mesa, CA 168 9,490 28,482 1,962 9,490 30,444 39,934 7,189 32,745 33,840 — 1989/2013 Total San Diego, CA 1,863 $ 63,898 $ 215,562 $ 82,444 $ 63,898 $ 298,006 $ 361,904 $ 112,045 $ 249,859 $ 259,728 $ — TOTAL SOUTHERN CALIFORNIA 13,330 $ 685,402 $ 1,984,731 $ 347,703 $ 685,402 $ 2,332,434 $ 3,017,836 $ 701,344 $ 2,316,492 $ 2,388,915 $ 268,110 TOTAL ESTABLISHED COMMUNITIES 54,713 $ 2,857,946 $ 9,575,234 $ 1,132,583 $ 2,857,946 $ 10,707,817 $ 13,565,763 $ 3,325,891 $ 10,239,872 $ 10,455,896 $ 1,207,475 2017 2016 2017 Initial Cost Total Cost Community City and state # of homes Land and improvements Building / Costs Land and improvements Building / Total Accumulated Total Cost, Total Cost, Encumbrances Year of OTHER STABILIZED Avalon Silicon Valley Sunnyvale, CA 710 $ 20,713 $ 99,573 $ 34,963 $ 20,713 $ 134,536 $ 155,249 $ 71,577 $ 83,672 $ 85,041 $ — 1998 Avalon Towers on the Peninsula Mountain View, CA 211 9,560 56,136 14,467 9,560 70,603 80,163 31,563 48,600 45,523 — 2002 Eaves San Marcos San Marcos, CA 184 3,277 13,385 4,557 3,277 17,942 21,219 3,641 17,578 18,302 — 1988/2011 Avalon Glendora Glendora, CA 280 18,311 64,759 100 18,311 64,859 83,170 4,974 78,196 80,358 — 2016 Avalon Irvine III Irvine, CA 156 11,607 43,977 — 11,607 43,977 55,584 2,842 52,742 54,232 — 2016 Avalon Dublin Station II Dublin, CA 252 7,762 76,584 26 7,762 76,610 84,372 4,821 79,551 82,106 — 2016 AVA North Hollywood North Hollywood, CA 156 18,408 49,940 4,089 18,408 54,029 72,437 3,810 68,627 70,816 — 2015/2016 AVA Studio City II Studio City, CA 101 4,626 22,954 5,487 4,626 28,441 33,067 5,160 27,907 24,848 — 1991/2013 Avalon Santa Monica on Main Santa Monica, CA 133 32,000 60,770 13,179 32,000 73,949 105,949 13,764 92,185 94,217 — 2007/2013 Avalon La Jolla Colony San Diego, CA 180 16,760 27,694 12,052 16,760 39,746 56,506 7,968 48,538 50,383 — 1987/2013 Eaves Old Town Pasadena Pasadena, CA 96 9,110 15,371 6,778 9,110 22,149 31,259 4,085 27,174 22,644 — 1972/2013 Avalon Walnut Ridge I Walnut Creek, CA 106 9,860 19,850 5,268 9,860 25,118 34,978 4,802 30,176 30,921 — 2000/2013 Avalon Pasadena Pasadena, CA 120 10,240 31,558 6,679 10,240 38,237 48,477 7,273 41,204 42,580 — 2004/2013 AVA Studio City I Studio City, CA 450 17,658 90,715 32,819 17,658 123,534 141,192 20,681 120,511 116,321 — 1987/2013 The Lodge Denver West Lakewood, CO 252 8,047 63,586 5,284 8,047 68,870 76,917 1,966 74,951 N/A — 2016/2017 850 Boca Boca Raton, FL 370 21,430 108,585 8,717 21,430 117,302 138,732 333 138,399 N/A — 2017/2017 Avalon at Chestnut Hill Chestnut Hill, MA 204 14,572 45,911 10,260 14,572 56,171 70,743 19,293 51,450 45,640 38,097 2007 AVA Back Bay Boston, MA 271 9,034 36,540 47,327 9,034 83,867 92,901 34,038 58,863 60,700 — 1968/1998 AVA Theater District Boston, MA 398 17,070 163,580 40 17,070 163,620 180,690 13,499 167,191 172,387 — 2015 Avalon Marlborough Marlborough, MA 350 15,317 60,397 11 15,317 60,408 75,725 5,353 70,372 72,339 — 2015 Avalon Framingham Framingham, MA 180 9,315 34,632 — 9,315 34,632 43,947 2,731 41,216 42,395 — 2015 Avalon Bear Hill Waltham, MA 324 27,350 94,168 28,764 27,350 122,932 150,282 23,723 126,559 131,023 — 1999/2013 Avalon at Edgewater Edgewater, NJ 168 5,982 24,389 9,182 5,982 33,571 39,553 15,351 24,202 21,123 — 2002 Avalon Bloomfield Station Bloomfield, NJ 224 10,701 39,927 — 10,701 39,927 50,628 3,594 47,034 48,031 — 2015 Avalon Union Union, NJ 202 11,695 36,282 — 11,695 36,282 47,977 2,519 45,458 46,615 — 2016 Avalon Hoboken Hoboken, NJ 217 37,237 87,220 8,327 37,237 95,547 132,784 11,390 121,394 124,435 67,904 2008/2016 Avalon Towers Long Beach, NY 109 3,118 11,973 24,372 3,118 36,345 39,463 16,198 23,265 21,775 — 1990/1995 Avalon Riverview North (1) Long Island City, NY 602 — 165,966 14,176 — 180,142 180,142 59,765 120,377 122,418 — 2008 AVA DoBro Brooklyn, NY 500 77,416 203,827 — 77,416 203,827 281,243 10,586 270,657 294,503 — 2017 Avalon Green III Elmsford, NY 68 4,985 17,300 — 4,985 17,300 22,285 1,248 21,037 21,585 — 2016 Archstone Lexington Flower Mound, TX 222 4,540 25,946 2,073 4,540 28,019 32,559 6,883 25,676 26,669 21,700 2000/2013 2017 2016 2017 Initial Cost Total Cost Community City and state # of homes Land and improvements Building / Costs Land and improvements Building / Total Accumulated Total Cost, Total Cost, Encumbrances Year of Archstone Toscano Houston, TX 474 15,607 72,889 — 15,607 72,889 88,496 11,044 77,452 79,819 — 2014 Memorial Heights Villages Houston, TX 318 9,607 48,448 — 9,607 48,448 58,055 10,516 47,539 48,508 — 2014 Eaves Fairfax City Fairfax, VA 141 2,152 8,907 5,475 2,152 14,382 16,534 8,176 8,358 8,773 — 1988/1997 Avalon at Arlington Square Arlington, VA 842 22,041 90,296 31,555 22,041 121,851 143,892 54,059 89,833 87,446 — 2001 Avalon Potomac Yard Alexandria, VA 323 24,225 77,137 7,648 24,225 84,785 109,010 8,659 100,351 103,333 — 2014/2016 Avalon Clarendon Arlington, VA 300 22,573 91,001 8,521 22,573 99,522 122,095 8,530 113,565 117,845 — 2002/2016 Avalon Columbia Pike Arlington, VA 269 18,830 78,395 6,460 18,830 84,855 103,685 5,993 97,692 100,352 68,637 2009/2016 Avalon Dunn Loring Vienna, VA 440 29,377 107,775 14,301 29,377 122,076 151,453 3,972 147,481 N/A — 2012/2017 Avalon Falls Church Falls Church, VA 384 39,544 66,160 — 39,544 66,160 105,704 5,899 99,805 102,279 — 2016 Oakwood Arlington Arlington, VA 184 18,850 38,545 3,052 18,850 41,597 60,447 8,608 51,839 53,139 — 1987/2013 AVA Capitol Hill Seattle, WA 249 20,613 60,014 — 20,613 60,014 80,627 4,194 76,433 78,906 — 2016 Avalon Alderwood II Redmond, WA 124 5,072 21,369 — 5,072 21,369 26,441 1,104 25,337 26,115 — 2016 TOTAL OTHER STABILIZED 11,844 $ 696,192 $ 2,654,431 $ 376,009 $ 696,192 $ 3,030,440 $ 3,726,632 $ 546,185 $ 3,180,447 $ 2,876,445 $ 196,338 LEASE-UP Avalon West Hollywood West Hollywood, CA 294 $ 35,187 $ 115,385 $ — $ 35,187 $ 115,385 $ 150,572 $ 1,697 $ 148,875 $ 130,173 $ — 2017 Avalon Chino Hills Chino Hills, CA 331 16,615 81,753 — 16,615 81,753 98,368 2,127 96,241 87,406 — 2017 Avalon Huntington Beach Huntington Beach, CA 378 13,055 105,719 222 13,055 105,941 118,996 4,995 114,001 115,269 — 2017 Avalon North Station Boston, MA 503 22,788 245,234 306 22,788 245,540 268,328 5,918 262,410 249,022 — 2017 Avalon Quincy Quincy, MA 395 14,674 78,151 — 14,674 78,151 92,825 2,972 89,853 84,132 — 2017 Avalon Easton Easton, MA 290 3,151 59,245 — 3,151 59,245 62,396 840 61,556 29,074 — 2017 Avalon Hunt Valley Hunt Valley, MD 332 10,842 62,596 — 10,842 62,596 73,438 2,144 71,294 67,019 — 2017 Avalon Laurel Laurel, MD 344 10,122 61,803 — 10,122 61,803 71,925 2,919 69,006 69,532 — 2017 Avalon Princeton Princeton, NJ 280 26,459 68,175 303 26,459 68,478 94,937 2,363 92,574 88,360 — 2017 Avalon Willoughby Square Brooklyn, NY 326 50,475 132,892 — 50,475 132,892 183,367 6,901 176,466 153,310 — 2017 Avalon Great Neck Great Neck, NY 191 14,776 64,459 — 14,776 64,459 79,235 931 78,304 55,671 — 2017 Avalon Rockville Centre II Rockville Centre, NY 165 7,534 49,115 — 7,534 49,115 56,649 267 56,382 26,796 — 2017 Avalon Esterra Park Redmond, WA 482 22,668 112,441 305 22,668 112,746 135,414 4,963 130,451 127,986 — 2017 Avalon Newcastle Commons I Newcastle, WA 378 9,622 109,453 — 9,622 109,453 119,075 1,889 117,186 92,267 — 2017 TOTAL LEASE-UP 4,689 $ 257,968 $ 1,346,421 $ 1,136 $ 257,968 $ 1,347,557 $ 1,605,525 $ 40,926 $ 1,564,599 $ 1,376,017 $ — 2017 2016 2017 Initial Cost Total Cost Community City and state # of homes Land and improvements Building / Costs Land and improvements Building / Total Accumulated Total Cost, Total Cost, Encumbrances Year of REDEVELOPMENT Avalon on the Alameda San Jose, CA 305 $ 6,119 $ 50,225 $ 10,087 $ 6,119 $ 60,312 $ 66,431 $ 33,696 $ 32,735 $ 27,497 $ — 1999 AVA Toluca Hills Los Angeles, CA 1,151 86,450 161,256 37,513 86,450 198,769 285,219 39,361 245,858 227,814 — 1973/2013 AVA Van Ness Washington, D.C. 269 22,890 58,691 9,030 22,890 67,721 90,611 13,443 77,168 74,556 — 1978/2013 Avalon Prudential Center II Boston, MA 266 8,776 35,496 52,864 8,776 88,360 97,136 32,7

Organization, Basis of Presen22

Organization, Basis of Presentation, and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Organization	Organization and Basis of Presentation AvalonBay Communities, Inc. (the “Company,” which term, unless the context otherwise requires, refers to AvalonBay Communities, Inc. together with its subsidiaries), is a Maryland corporation that has elected to be treated as a real estate investment trust (“REIT”) for federal income tax purposes under the Internal Revenue Code of 1986 (the “Code”). The Company focuses on the development, redevelopment, acquisition, ownership and operation of multifamily communities primarily in New England, the New York/New Jersey metro area, the Mid-Atlantic, the Pacific Northwest, and Northern and Southern California. At December 31, 2017 , the Company owned or held a direct or indirect ownership interest in 267 operating apartment communities containing 77,614 apartment homes in 12 states and the District of Columbia, of which nine communities containing 3,752 apartment homes were under redevelopment. In addition, the Company owned or held a direct or indirect ownership interest in 21 communities under development that are expected to contain an aggregate of 6,544 apartment homes (unaudited) when completed. The Company also owned or held a direct or indirect ownership interest in land or rights to land in which the Company expects to develop an additional 29 communities that, if developed as expected, will contain an estimated 9,496 apartment homes (unaudited). Capitalized terms used without definition have meanings provided elsewhere in this Form 10-K
Principles of Consolidation	Principles of Consolidation The accompanying Consolidated Financial Statements include the accounts of the Company and its wholly-owned subsidiaries, certain joint venture partnerships, subsidiary partnerships structured as DownREITs and any variable interest entities that qualify for consolidation. All significant intercompany balances and transactions have been eliminated in consolidation. The Company accounts for joint venture entities and subsidiary partnerships in accordance with the consolidation guidance. The Company evaluates the partnership of each joint venture entity and determines first whether to follow the variable interest entity (“VIE”) or the voting interest entity (“VOE”) model. Once the appropriate consolidation model is identified, the Company then evaluates whether it should consolidate the venture. Under the VIE model, the Company consolidates an investment when it has control to direct the activities of the venture and the obligation to absorb losses or the right to receive benefits that could potentially be significant to the VIE. Under the VOE model, the Company consolidates an investment when 1) it controls the investment through ownership of a majority voting interest if the investment is not a limited partnership or 2) it controls the investment through its ability to remove the other partners in the investment, at its discretion, when the investment is a limited partnership. The Company generally uses the equity method of accounting for its investment in joint ventures, under all other potential scenarios, including where the Company holds a noncontrolling limited partner interest in a joint venture. Any investment in excess of the Company's cost basis at acquisition or formation of an equity method venture, will be recorded as a component of the Company's investment in the joint venture and recognized over the life of the underlying fixed assets of the venture as a reduction to its equity in income from the venture. Investments in which the Company has little or no influence are accounted for using the cost method.
Revenue and Gain Recognition	Revenue and Gain Recognition Rental income related to the Company’s residential and retail leases is recognized on an accrual basis when due from residents and/or retail tenants, as required by the accounting guidance applicable to leases, which provides guidance on classification and recognition. In accordance with the Company's standard residential lease terms, rental payments are generally due on a monthly basis. Any cash concessions given at the inception of the lease are amortized over the approximate life of the lease, which is generally one year.
Real Estate	Real Estate Operating real estate assets are stated at cost and consist of land and improvements, buildings and improvements, furniture, fixtures and equipment, and other costs incurred during their development, redevelopment and acquisition. Significant expenditures which improve or extend the life of an existing asset and that will benefit the Company for periods greater than a year, are capitalized. Expenditures for maintenance and repairs are charged to expense as incurred. The Company generally expenses purchases of personal property made for replacement purposes. Project costs related to the development, construction and redevelopment of real estate projects (including interest and related loan fees, property taxes and other direct costs) are capitalized as a cost of the project. Indirect project costs that relate to several projects are capitalized and allocated to the projects to which they relate. Indirect costs not clearly related to development, construction and redevelopment activity are expensed as incurred. For development, capitalization (i) begins when the Company has determined that development of the future asset is probable, (ii) can be suspended if there is no current development activity underway, but future development is still probable and (iii) ends when the asset, or a portion of an asset, is delivered and is ready for its intended use, or the Company's intended use changes such that capitalization is no longer appropriate. For land parcels improved with operating real estate, for which the Company intends to pursue development, the Company generally manages the current improvements until such time as all tenant obligations have been satisfied or eliminated through negotiation, and construction of new apartment communities is ready to begin. Revenue from incidental operations received from the current improvements on land parcels in excess of any incremental costs are recorded as a reduction of total capitalized costs of the respective Development Right and not as part of net income. Incidental operating costs in excess of incidental operating income are expensed in the period incurred. For redevelopment efforts, the Company capitalizes costs either (i) in advance of taking homes out of service when significant renovation of the common area has begun until the redevelopment is completed, or (ii) when an apartment home is taken out of service for redevelopment until the redevelopment is completed and the apartment home is available for a new resident. Rental income and operating costs incurred during the initial lease-up or post-redevelopment lease-up period are recognized in earnings as incurred. The Company defers external costs associated with originating new leases, recognizing the impact of these costs in earnings over the term of the lease. The adoption of ASU 2017-01 on October 1, 2016, impacted the Company's accounting framework for the acquisition of operating communities. Prior to adoption, the acquisition of an operating community was viewed as an acquisition of a business, and the Company identified and recorded each asset acquired and liability assumed in such transaction at its estimated fair value at the date of acquisition, and expensed all costs incurred related to acquisitions of operating communities. Subsequent to adoption of ASU 2017-01 on October 1, 2016, the Company assesses each acquisition of an operating community to determine if it meets the definition of a business or if it qualifies as an asset acquisition. The Company generally views acquisitions of individual operating communities as asset acquisitions, and results in the capitalization of acquisition costs, and the allocation of purchase price to the assets acquired and liabilities assumed, based on the relative fair value of the respective assets and liabilities. The purchase price allocation to tangible assets, such as land and improvements, buildings and improvements, and furniture, fixtures and equipment, and the in-place lease intangible assets, is as reflected in real estate assets and depreciated over their estimated useful lives. Any purchase price allocation to intangible assets, other than in-place lease intangibles, is included in prepaid expenses and other assets on the accompanying Consolidated Balance Sheets and amortized over the term of the acquired intangible asset. The Company values land based on a market approach, looking to recent sales of similar properties, adjusting for differences due to location, the state of entitlement as well as the shape and size of the parcel. Improvements to land are valued using a replacement cost approach and consider the structures and amenities included for the communities. The approach applied industry standard replacement costs adjusted for geographic specific considerations and reduced by estimated depreciation. The value for furniture, fixtures and equipment is also determined based on a replacement cost approach, considering costs for both items in the apartment homes as well as common areas and was adjusted for estimated depreciation. The fair value of buildings acquired is estimated using the replacement cost approach, assuming the buildings were vacant at acquisition. The replacement cost approach considers the composition of structures acquired, adjusted for an estimate of depreciation. The estimate of depreciation is made considering industry standard information, depreciation curves for the identified asset classes and estimated useful life of the acquired property. The value of the acquired lease-related intangibles considered the estimated cost of leasing the apartment homes as if the acquired building(s) were vacant, as well as the value of the current leases relative to market-rate leases. The in-place lease value is determined using an average total lease-up time, the number of apartment homes and net revenues generated during the lease-up time. The lease-up period for an apartment community is assumed to be 12 months to achieve stabilized occupancy. Net revenues use market rent considering actual leasing and industry rental rate data. The value of current leases relative to a market-rate lease is based on market rents obtained for market comparables, and considered a market derived discount rate. Given the heterogeneous nature of multifamily real estate, the fair values for the land, debt, real estate assets and in-place leases incorporated significant unobservable inputs and therefore are considered to be Level 3 prices within the fair value hierarchy. Consideration for acquisitions is typically in the form of cash unless otherwise disclosed. Depreciation is calculated on buildings and improvements using the straight-line method over their estimated useful lives, which range from seven to 30 years. Furniture, fixtures and equipment are generally depreciated using the straight-line method over their estimated useful lives, which range from three years (primarily computer-related equipment) to seven years.
Income Taxes	Income Taxes The Company elected to be treated as a REIT for U.S. federal income tax purposes for its tax year ended December 31, 1994 and has not revoked such election. A REIT is a corporate entity which holds real estate interests and can deduct from its federally taxable income qualifying dividends it pays if it meets a number of organizational and operational requirements, including a requirement that it currently distribute at least 90% of its adjusted taxable income to stockholders. Therefore, as a REIT, the Company generally will not be subject to corporate level federal income tax on its taxable income if it annually distributes 100% of its taxable income to its stockholders. The states in which the Company operates have similar tax provisions which recognize the Company as a REIT for state income tax purposes. Management believes that all such conditions for the exemption from income taxes on ordinary income have been or will be met for the periods presented. Accordingly, no provision for federal and state income taxes has been made. If the Company fails to qualify as a REIT in any taxable year, it will be subject to federal corporate income taxes at regular corporate rates and may not be able to qualify as a corporate REIT for four subsequent taxable years. Even if the Company qualifies for taxation as a REIT, the Company may be subject to certain state and local taxes on its income and property, and to federal income and excise taxes on its undistributed taxable income and in certain other instances. The Company did not incur any charges or receive refunds of excise taxes related to the years ended December 31, 2017 , 2016 and 2015 . In addition, taxable income from non-REIT activities performed through taxable REIT subsidiaries (“TRS”) is subject to federal, state and local income taxes. The Company incurred income tax expense of $141,000 , $305,000 and $1,483,000 in 2017 , 2016 and 2015 , respectively, associated primarily with activities transacted through a TRS. As of December 31, 2017 and 2016 , the Company did not have any unrecognized tax benefits. The Company does not believe that there will be any material changes in its unrecognized tax positions over the next 12 months. The Company is subject to examination by the respective taxing authorities for the tax years 2014 through 2016 . On December 22, 2017, H.R. 1, the Tax Cuts and Jobs Act (the “TCJA”), was enacted. The TCJA makes major changes to the Code, including lowering the statutory U.S. federal income tax rate from 35% to 21% effective January 1, 2018. The Company has completed its assessment of the Act and does not believe it will have a material impact on its financial position or results of operations. The following reconciles net income attributable to common stockholders to taxable net income for the years ended December 31, 2017 , 2016 and 2015 (unaudited, dollars in thousands): 2017 Estimate 2016 Actual 2015 Actual Net income attributable to common stockholders $ 876,921 $ 1,034,002 $ 742,038 GAAP gain on sale of communities (in excess of) less than tax gain (85,873 ) (195,029 ) (20,900 ) Depreciation/amortization timing differences on real estate 11,868 (947 ) (24,657 ) Amortization of debt/mark to market interest (17,430 ) (18,985 ) (64,676 ) Tax compensation expense less than (in excess of) GAAP (3,828 ) 9,821 (1,244 ) Casualty and impairment (gain) loss, net 6,250 (657 ) (10,542 ) Other adjustments (40,381 ) 11,533 (12,829 ) Taxable net income $ 747,527 $ 839,738 $ 607,190 The following summarizes the tax components of the Company's common dividends declared for the years ended December 31, 2017 , 2016 and 2015 (unaudited): 2017 2016 2015 Ordinary income 75 % 68 % 83 % 20% capital gain 18 % 26 % 12 % Unrecaptured §1250 gain 7 % 6 % 5 %
Deferred Financing Costs	Deferred Financing Costs Deferred financing costs include fees and other expenditures necessary to obtain debt financing and are amortized on a straight-line basis, which approximates the effective interest method, over the shorter of the term of the loan or the related credit enhancement facility, if applicable. Unamortized financing costs are charged to earnings when debt is retired before the maturity date. Accumulated amortization of deferred financing costs related to unsecured notes was $16,984,000 and $14,008,000 as of December 31, 2017 and 2016 , respectively, and related to mortgage notes payable was $4,991,000 and $10,562,000 as of December 31, 2017 and 2016 , respectively. Deferred financing costs, except for costs associated with line-of-credit arrangements, are presented as a direct deduction from the related debt liability. Accumulated amortization of deferred financing costs related to the Company's Credit Facility was $8,299,000 and $6,490,000 as of December 31, 2017 and 2016 , respectively, and was included in prepaid expenses and other assets on the accompanying Consolidated Balance Sheets.
Cash, Cash Equivalents and Cash in Escrow	Cash, Cash Equivalents and Cash in Escrow Cash and cash equivalents include all cash and liquid investments with an original maturity of three months or less from the date acquired. Cash in escrow includes principal reserve funds that are restricted for the repayment of specified secured financing. The majority of the Company's cash, cash equivalents and cash in escrow are held at major commercial banks.
Comprehensive Income	Comprehensive Income Comprehensive income, as reflected on the Consolidated Statements of Comprehensive Income, is defined as all changes in equity during each period except for those resulting from investments by or distributions to shareholders. Accumulated other comprehensive loss, as reflected on the Consolidated Statements of Equity, reflects the effective portion of the cumulative changes in the fair value of derivatives in qualifying cash flow hedge relationships.
Earnings per Common Share	Earnings per Common Share Basic earnings per share is computed by dividing net income attributable to common stockholders by the weighted average number of shares outstanding during the period. All outstanding unvested restricted share awards contain rights to non-forfeitable dividends and participate in undistributed earnings with common shareholders and, accordingly, are considered participating securities that are included in the two-class method of computing basic earnings per share (“EPS”). Both the unvested restricted shares and other potentially dilutive common shares, and the related impact to earnings, are considered when calculating earnings per share on a diluted basis. The Company's earnings per common share are determined as follows (dollars in thousands, except per share data): For the year ended 12/31/17 12/31/16 12/31/15 Basic and diluted shares outstanding Weighted average common shares—basic 137,523,771 136,928,251 133,565,711 Weighted average DownREIT units outstanding 7,500 7,500 7,500 Effect of dilutive securities 535,415 525,886 1,019,966 Weighted average common shares—diluted 138,066,686 137,461,637 134,593,177 Calculation of Earnings per Share—basic Net income attributable to common stockholders $ 876,921 $ 1,034,002 $ 742,038 Net income allocated to unvested restricted shares (2,463 ) (2,610 ) (1,774 ) Net income attributable to common stockholders, adjusted $ 874,458 $ 1,031,392 $ 740,264 Weighted average common shares—basic 137,523,771 136,928,251 133,565,711 Earnings per common share—basic $ 6.36 $ 7.53 $ 5.54 Calculation of Earnings per Share—diluted Net income attributable to common stockholders $ 876,921 $ 1,034,002 $ 742,038 Add: noncontrolling interests of DownREIT unitholders in consolidated partnerships, including discontinued operations 42 41 38 Adjusted net income attributable to common stockholders $ 876,963 $ 1,034,043 $ 742,076 Weighted average common shares—diluted 138,066,686 137,461,637 134,593,177 Earnings per common share—diluted $ 6.35 $ 7.52 $ 5.51 Dividends per common share $ 5.68 $ 5.40 $ 5.00 All options to purchase shares of common stock outstanding as of December 31, 2017 , 2016 and 2015 are included in the computation of diluted earnings per share. As discussed under "Recently Issued and Adopted Accounting Standards," as of January 1, 2017, the Company adopted the provisions of ASU 2016-09 using the modified retrospective approach to recognize forfeitures as they occur. Prior to the adoption of this standard, the Company was required to estimate the forfeiture of stock options and recognized compensation cost net of the estimated forfeitures. The estimated forfeitures included in compensation cost were adjusted to reflect actual forfeitures at the end of the vesting period. This change in accounting principle had no impact on the Company's financial position and no adjustment to retained earnings or the Company's diluted shares outstanding, as prescribed under the modified retrospective approach. Refer to "Change in Accounting Principle" for discussion of the impact to the accompanying Consolidated Statements of Cash Flows.
Abandoned Pursuit Costs, Impairment of Long-Lived Assets and Casualty Loss	Abandoned Pursuit Costs and Impairment of Long-Lived Assets The Company capitalizes pre-development costs incurred in pursuit of new development opportunities for which the Company currently believes future development is probable (“Development Rights”). Future development of these Development Rights is dependent upon various factors, including zoning and regulatory approval, rental market conditions, construction costs and the availability of capital. Initial pre-development costs incurred for pursuits for which future development is not yet considered probable are expensed as incurred. In addition, if the status of a Development Right changes, making future development by the Company no longer probable, any capitalized pre-development costs are expensed. The Company expensed costs related to the abandonment of Development Rights, as well as costs incurred in pursuing the acquisition or disposition of assets for which such acquisition and disposition activity did not occur, in the amounts of $2,370,000 , $4,183,000 and $3,016,000 during the years ended December 31, 2017 , 2016 and 2015 , respectively. These costs are included in expensed acquisition, development and other pursuit costs, net of recoveries on the accompanying Consolidated Statements of Comprehensive Income. Abandoned pursuit costs can vary greatly, and the costs incurred in any given period may be significantly different in future periods. The Company evaluates its real estate and other long-lived assets for impairment when potential indicators of impairment exist. Such assets are stated at cost, less accumulated depreciation and amortization, unless the carrying amount of the asset is not recoverable. If events or circumstances indicate that the carrying amount of a property or long-lived asset may not be recoverable, the Company assesses its recoverability by comparing the carrying amount of the property or long-lived asset to its estimated undiscounted future cash flows. If the carrying amount exceeds the aggregate undiscounted future cash flows, the Company recognizes an impairment loss to the extent the carrying amount exceeds the estimated fair value of the property or long-lived asset. Based on periodic tests of recoverability of long-lived assets, for the years ended December 31, 2017 , 2016 and 2015 , the Company did not recognize any impairment losses for wholly-owned operating real estate assets, and did not record any impairment losses other than those related to the impairment on land held for investment and casualty gains and losses from property damage as discussed below. The Company assesses its portfolio of land held for both development and investment for impairment if the intent of the Company changes with respect to either the development of, or the expected holding period for, the land. During the year ended December 31, 2017 , the Company recognized an impairment charge of $9,350,000 related to a land parcel the Company had acquired for development in 2004 and sold during 2017. During the year ended December 31, 2016 , the Company recognized $10,500,000 of aggregate impairment charges related to three ancillary land parcels for which the Company has either sold or intends to sell. These charges were determined as the excess of the Company's carrying basis over the expected sales price for each parcel, and is included in casualty and impairment loss (gain), net on the accompanying Consolidated Statements of Comprehensive Income. The Company did not recognize any material impairment charges on its investment in land during the year ended December 31, 2015 . The Company evaluates its unconsolidated investments for other than temporary impairment, considering both the extent and amount by which the carrying value of the investment exceeds the fair value, and the Company’s intent and ability to hold the investment to recover its carrying value. The Company also evaluates its proportionate share of any impairment of assets held by unconsolidated investments. There were no other than temporary impairment losses recognized by any of the Company's investments in unconsolidated real estate entities during the years ended December 31, 2017 , 2016 or 2015 . Casualty Gains and Losses In February 2017, a fire occurred at the Company's Avalon Maplewood Development Community, located in Maplewood, NJ, which was under construction and not yet occupied. The Company has commenced reconstruction of the damaged and destroyed portions of the community. See Note 7, “Commitments and Contingencies,” for additional discussion of the related casualty loss. During the year ended December 31, 2017 , the Company recorded a casualty loss of $19,481,000 composed of a charge of $16,361,000 to write-off the net book value of the fixed assets destroyed in the Maplewood casualty loss and $3,120,000 for demolition and additional incident expenses. The casualty loss was partially offset by $17,143,000 of expected third-party property damage insurance proceeds. The net casualty loss of $2,338,000 for the year ended December 31, 2017 is included in casualty and impairment loss (gain), net on the accompanying Consolidated Statements of Comprehensive Income. During the year ended December 31, 2017 , the Company reached a final insurance settlement for the property damage and lost income for the Maplewood casualty loss of $19,696,000 , after self-insurance and deductibles, of which the Company recognized $3,495,000 as business interruption insurance proceeds. In January 2015, a fire occurred at the Company's Avalon at Edgewater apartment community located in Edgewater, NJ. Edgewater consisted of two residential buildings. One building, containing 240 apartment homes, was destroyed. The second building, containing 168 apartment homes, suffered minimal damage and has been repaired. See Note 7, “Commitments and Contingencies,” for discussion of the related legal matters. During the year ended December 31, 2016 , the Company reached a final insurance settlement for the Company's property damage and lost income for the Edgewater casualty loss, for which it received aggregate insurance proceeds for Edgewater of $73,150,000 , after self-insurance and deductibles, as discussed below. During the year ended December 31, 2015 , the Company received $44,142,000 in insurance proceeds, which were partially offset by casualty charges of $21,844,000 to write off the net book value of the building destroyed by the fire at Edgewater, and $6,760,000 to record demolition and additional incident expenses, resulting in a net casualty gain of $15,538,000 . During the year ended December 31, 2016 , the Company received the final $29,008,000 of insurance proceeds, of which $8,702,000 was recognized as an additional net casualty gain and $20,306,000 as business interruption insurance proceeds. The Company reported the net casualty gains from each of the respective years as casualty and impairment loss (gain), net on the accompanying Consolidated Statements of Comprehensive Income, and reported the business interruption insurance proceeds as a component of rental and other income on the accompanying Consolidated Statements of Comprehensive Income. During the year ended December 31, 2015 , several of the Company's communities in its Northeast markets incurred property and casualty damages from severe winter storms, for which the Company recorded an impairment due to a casualty loss of $4,195,000 . During the year ended December 31, 2016 , the Company recorded a net casualty gain related to the 2015 severe winter storms of $5,732,000 , which is comprised of $8,493,000 in third-party insurance proceeds received, partially offset by incremental costs of $2,761,000 . These amounts are included in casualty and impairment loss (gain), net on the accompanying Consolidated Statements of Comprehensive Income. A casualty loss may also result in lost operating income from one or more communities that is covered by the Company’s business interruption insurance policies. The Company recognizes income for amounts received under its business interruption insurance policies as a component of rental and other income in the Consolidated Statements of Comprehensive Income. Revenue is recognized upon resolution of all contingencies related to the receipt, typically upon written confirmation by the insurer or receipt of the actual proceeds. The Company recognized $3,498,000 , $20,564,000 and $1,509,000 in income related business interruption insurance proceeds for the years ended December 31, 2017 , 2016 and 2015 , respectively.
Assets Held for Sale and Discontinued Operations	Assets Held for Sale and Discontinued Operations The Company presents the assets and liabilities of any communities which have been sold, or otherwise qualify as held for sale, separately in the Consolidated Balance Sheets. In addition, the results of operations for those assets that meet the definition of discontinued operations are presented as such in the accompanying Consolidated Statements of Comprehensive Income. Real estate assets held for sale are measured at the lower of the carrying amount or the fair value less the cost to sell. Both the real estate assets and corresponding liabilities are presented separately in the accompanying Consolidated Balance Sheets. Upon the classification of an asset as held for sale, no further depreciation is recorded. Disposals representing a strategic shift in operations (e.g., a disposal of a major geographic area, a major line of business or a major equity method investment) will be presented as discontinued operations, and for those assets qualifying for classification as discontinued operations, the specific components of net income presented as discontinued operations include net operating income, depreciation expense and interest expense, net. For periods prior to the asset qualifying for discontinued operations, the Company reclassifies the results of operations to discontinued operations. In addition, the net gain or loss (including any impairment loss) on the eventual disposal of assets held for sale will be presented as discontinued operations when recognized. A change in presentation for held for sale or discontinued operations has no impact on the Company's financial condition or results of operations. The Company combines the operating, investing and financing portions of cash flows attributable to discontinued operations with the respective cash flows from continuing operations on the accompanying Consolidated Statements of Cash Flows. The Company had no real estate that qualified as held for sale presentation at December 31, 2017 .
Redeemable Noncontrolling Interests	Redeemable Noncontrolling Interests Redeemable noncontrolling interests are comprised of potential future obligations of the Company, which allow the investors holding the noncontrolling interest to require the Company to purchase their interest. The Company classifies obligations under the redeemable noncontrolling interests at fair value, with a corresponding offset for changes in the fair value recorded in accumulated earnings less dividends. Reductions in fair value are recorded only to the extent that the Company has previously recorded increases in fair value above the redeemable noncontrolling interest's initial basis. The redeemable noncontrolling interests are presented outside of permanent equity as settlement in shares of the Company's common stock, where permitted, may not be within the Company's control. The nature and valuation of the Company's redeemable noncontrolling interests are discussed further in Note 11, “Fair Value.
Derivative Instruments and Hedging Activities	Derivative Instruments and Hedging Activities The Company enters into interest rate swap and interest rate cap agreements (collectively, “Hedging Derivatives”) for interest rate risk management purposes and in conjunction with certain variable rate secured debt to satisfy lender requirements. The Company does not enter into Hedging Derivative transactions for trading or other speculative purposes. The Company assesses the effectiveness of qualifying cash flow and fair value hedges, both at inception and on an on-going basis. Hedge ineffectiveness is reported as a component of general and administrative expenses. The fair values of Hedging Derivatives that are in an asset position are recorded in prepaid expenses and other assets. The fair value of Hedging Derivatives that are in a liability position are included in accrued expenses and other liabilities. The Company does not present or disclose the fair value of Hedging Derivatives on a net basis. Fair value changes for derivatives that are not in qualifying hedge relationships are reported as a component of interest expense, net. For the Hedging Derivative positions that the Company has determined qualify as effective cash flow hedges, the Company has recorded the effective portion of cumulative changes in the fair value of Hedging Derivatives in other comprehensive income (loss). Amounts recorded in other comprehensive income (loss) will be reclassified into earnings in the periods in which earnings are affected by the hedged cash flow. The effective portion of the change in fair value of the Hedging Derivatives that the Company has determined qualified as effective fair value hedges is reported as an adjustment to the carrying amount of the corresponding debt being hedged.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make certain estimates and assumptions. These estimates and assumptions affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the dates of the financial statements and the reported amounts of revenue and expenses during the reporting periods. Actual results could differ from those estimates.
Reclassifications	Reclassifications Certain reclassifications have been made to amounts in prior years' notes to financial statements to conform to current year presentations as a result of changes in held for sale classification and disposition activity.
Recently Issued and Adopted Accounting Standards and Change in Accounting Principle	Recently Issued and Adopted Accounting Standards In August 2017, the FASB issued ASU 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities. This ASU expands hedge accounting for both nonfinancial and financial risk components and aligns the recognition and presentation of the effects of the hedging instrument and the hedged item in the financial statements. This update also simplifies the application of hedge accounting guidance and eases the administrative burden of hedge documentation requirements and assessing hedge effectiveness. The guidance will be effective in the first quarter of 2019, allows for early adoption, and will be applied prospectively at adoption. The Company will adopt the guidance as of January 1, 2018 and does not believe it will have a material effect on the Company’s financial position or results of operations. In February 2017, the FASB issued ASU 2017-05, Other Income-Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20): Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets. This ASU (i) clarifies the scope of the nonfinancial asset guidance and the derecognition of certain businesses and nonprofit activities, (ii) eliminates the exception in the financial asset guidance for transfers of investments (including equity method investments) in real estate entities and supersedes the guidance in the Exchanges of a Nonfinancial Asset for a Noncontrolling Ownership Interest and (iii) provides guidance on the accounting of partial sales of nonfinancial assets and contributions of nonfinancial assets to a joint venture or other noncontrolled investee. The new standard allows for either a retrospective or modified retrospective approach. The guidance will be effective in the first quarter of 2018 and allows for early adoption. The Company will adopt the new standard as of January 1, 2018 using the modified retrospective approach, applying the provisions to open contracts as of the date of adoption. See "Revenue and Gain Recognition" above for additional discussion of the impact of adopting the guidance. In November 2016, the FASB issued ASU 2016-18-Statement of Cash Flows (Topic 230): Restricted Cash, which requires statements of cash flows to explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. The new standard requires a retrospective approach. The guidance will be effective in the first quarter of 2018 and allows for early adoption. The Company adopted the guidance as of October 1, 2017 and it did not have a material effect on the Company’s financial position or results of operations. See discussion of the impact to the Company's Consolidated Statements of Cash Flows under "Change in Accounting Principle." In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments. This ASU addresses eight specific cash flow issues including debt prepayment or debt extinguishment costs, proceeds from the settlement of insurance claims, distributions received from equity method investees and separately identifiable cash flows and application of the predominance principle. The new standard requires a retrospective approach. The guidance will be effective in the first quarter of 2018 and allows for early adoption. The Company adopted this guidance as of January 1, 2017. The new standard did not have a material effect on the Company's Consolidated Statements of Cash Flows. In March 2016, the FASB issued ASU 2016-09, Compensation-Stock Compensation: Improvements to Employee Share-Based Payment Accounting, which simplifies several aspects of share-based payment transactions, including income tax consequences, classification of awards as equity or liability, statement of cash flows classification and policy election options for forfeitures. The Company adopted this guidance as of January 1, 2017 which did not have a material effect on the Company's financial position, results of operations or earnings per share as discussed in "Earnings per Common Share." Upon adoption of the standard, the Company elected to account for forfeitures when they occur instead of estimating the forfeitures. See discussion of the impact to the Company's Consolidated Statements of Cash Flows under "Change in Accounting Principle." In February 2016, the FASB issued ASU 2016-02, Leases, amending the existing accounting standards for lease accounting, including requiring lessees to recognize most leases on their balance sheets and making targeted changes to lessor accounting. The guidance will be effective in the first quarter of 2019 and allows for early adoption. The new standard requires a modified retrospective transition approach for all leases existing at the date of initial application, with an option to use certain transition relief. ASU 2016-02 provides for transition relief, which includes not electing to (i) reassess whether any expired or existing contract is a lease or contains a lease, (ii) reassess the lease classification of any expired or existing leases and (iii) expense any capitalized initial direct costs for any existing leases. The Company anticipates adoption of the standard to have a material impact on its financial position resulting from the recognition of the right to use asset and corresponding lease obligation for its long-term ground leases, currently accounted for as operating leases. The Company will continue to assess the impact of the new standard. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers and in August 2015, the FASB issued ASU 2015-14, Revenue from Contracts with Customers-Deferral of the Effective Date, which defers the effective date of the new revenue recognition standard until the first quarter of 2018. Subsequently, the FASB has issued multiple ASUs clarifying ASU 2014-09 and ASU 2015-14. Under the new standard, revenue is recognized when persuasive evidence of an arrangement exists, delivery has occurred, the fee is fixed or determinable, and collectability is probable. Revenue is generally recognized net of allowances and any taxes collected from customers and subsequently remitted to governmental authorities. The majority of the Company's revenue is derived from rental income, which is scoped out from this standard and will be accounted for under ASU 2016-02, Leases, discussed above. The Company's other revenue streams, which are being evaluated under this ASU, include but are not limited to management fees, non-recurring rental and non-rental related income, and gains and losses from real estate dispositions. The Company will adopt the new standard as of January 1, 2018 using the modified retrospective approach, applying the provisions to open contracts as of the date of adoption. See "Revenue and Gain Recognition" above for additional discussion of the impact of adopting the guidance. Change in Accounting Principle As of January 1, 2017, the Company adopted ASU 2016-09, Compensation-Stock Compensation: Improvements to Employee Share-Based Payment Accounting, as discussed under "Recently Issued and Adopted Accounting Standards." The guidance requires payments related to tax withholding for share-based compensation to be presented separately as a financing activity on the Consolidated Statements of Cash Flows, and was adopted retrospectively. The prior period amounts that have been impacted by the new guidance and retrospectively adjusted include (i) an increase in accrued expenses, other liability and accrued interest payable (cash provided by operating activities) and (ii) payments related to tax withholding for share-based compensation (cash used in financing activities), located on the Consolidated Statements of Cash Flows. As of October 1, 2017, the Company adopted ASU 2016-18 Statement of Cash Flows (Topic 230): Restricted Cash, as discussed under "Recently Issued and Adopted Accounting Standards." The guidance requires statements of cash flows to explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents, and was adopted retrospectively. The prior period amounts that have been impacted by the new guidance and retrospectively adjusted include (i) an increase in cash in operating escrows (cash provided by operating activities), (ii) an increase in cash in deposit escrows (cash provided by investing activities) and (iii) repayments of mortgage notes payable, including prepayment penalties (cash used in financing activities), located on the Consolidated Statements of Cash Flows. The following tables present the impact of the two changes in accounting principle to the Consolidated Statement of Cash Flows for the years ended December 31, 2016 and 2015 (dollars in thousands): 12/31/2016 (as previously reported) Impact of ASU 2016-09 Impact of ASU 2016-18 12/31/2016 (as adjusted and currently reported) Net cash provided by operating activities 1,143,484 8,562 8,226 1,160,272 Net cash used in investing activities (1,037,352 ) — 5,000 (1,032,352 ) Net cash used in financing activities (291,645 ) (8,562 ) (3,064 ) (303,271 ) Net decrease in cash, cash equivalents (185,513 ) — 185,513 — Net decrease in cash, cash equivalents and restricted cash — — (175,351 ) (175,351 ) Cash, cash equivalents, beginning of period 400,507 — (400,507 ) — Cash, cash equivalents and restricted cash, beginning of period — — 505,328 505,328 Cash, cash equivalents, end of period $ 214,994 — — — Cash, cash equivalents and restricted cash, end of period $ — $ 114,983 $ 329,977 12/31/2015 (as previously reported) Impact of ASU 2016-09 Impact of ASU 2016-18 12/31/2015 (as adjusted and currently reported) Net cash provided by operating activities 1,056,754 6,076 11,837 1,074,667 Net cash used in investing activities (1,199,517 ) — — (1,199,517 ) Net cash provided by (used in) financing activities 33,810 (6,076 ) (2,641 ) 25,093 Net decrease in cash, cash equivalents (108,953 ) — 108,953 — Net decrease in cash, cash equivalents and restricted cash — — (99,757 ) (99,757 ) Cash, cash equivalents, beginning of period 509,460 — (509,460 ) — Cash, cash equivalents and restricted cash, beginning of period — — 605,085 605,085 Cash, cash equivalents, end of period $ 400,507 — — — Cash, cash equivalents and restricted cash, end of period $ — $ 104,821 $ 505,328

Organization, Basis of Presen23

Organization, Basis of Presentation, and Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Schedule of reconciliation of income from book basis to tax basis	The following reconciles net income attributable to common stockholders to taxable net income for the years ended December 31, 2017 , 2016 and 2015 (unaudited, dollars in thousands): 2017 Estimate 2016 Actual 2015 Actual Net income attributable to common stockholders $ 876,921 $ 1,034,002 $ 742,038 GAAP gain on sale of communities (in excess of) less than tax gain (85,873 ) (195,029 ) (20,900 ) Depreciation/amortization timing differences on real estate 11,868 (947 ) (24,657 ) Amortization of debt/mark to market interest (17,430 ) (18,985 ) (64,676 ) Tax compensation expense less than (in excess of) GAAP (3,828 ) 9,821 (1,244 ) Casualty and impairment (gain) loss, net 6,250 (657 ) (10,542 ) Other adjustments (40,381 ) 11,533 (12,829 ) Taxable net income $ 747,527 $ 839,738 $ 607,190
Schedule of tax components of the entity's common dividends declared	The following summarizes the tax components of the Company's common dividends declared for the years ended December 31, 2017 , 2016 and 2015 (unaudited): 2017 2016 2015 Ordinary income 75 % 68 % 83 % 20% capital gain 18 % 26 % 12 % Unrecaptured §1250 gain 7 % 6 % 5 %
Schedule of earnings per common share	The Company's earnings per common share are determined as follows (dollars in thousands, except per share data): For the year ended 12/31/17 12/31/16 12/31/15 Basic and diluted shares outstanding Weighted average common shares—basic 137,523,771 136,928,251 133,565,711 Weighted average DownREIT units outstanding 7,500 7,500 7,500 Effect of dilutive securities 535,415 525,886 1,019,966 Weighted average common shares—diluted 138,066,686 137,461,637 134,593,177 Calculation of Earnings per Share—basic Net income attributable to common stockholders $ 876,921 $ 1,034,002 $ 742,038 Net income allocated to unvested restricted shares (2,463 ) (2,610 ) (1,774 ) Net income attributable to common stockholders, adjusted $ 874,458 $ 1,031,392 $ 740,264 Weighted average common shares—basic 137,523,771 136,928,251 133,565,711 Earnings per common share—basic $ 6.36 $ 7.53 $ 5.54 Calculation of Earnings per Share—diluted Net income attributable to common stockholders $ 876,921 $ 1,034,002 $ 742,038 Add: noncontrolling interests of DownREIT unitholders in consolidated partnerships, including discontinued operations 42 41 38 Adjusted net income attributable to common stockholders $ 876,963 $ 1,034,043 $ 742,076 Weighted average common shares—diluted 138,066,686 137,461,637 134,593,177 Earnings per common share—diluted $ 6.35 $ 7.52 $ 5.51 Dividends per common share $ 5.68 $ 5.40 $ 5.00
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	The following tables present the impact of the two changes in accounting principle to the Consolidated Statement of Cash Flows for the years ended December 31, 2016 and 2015 (dollars in thousands): 12/31/2016 (as previously reported) Impact of ASU 2016-09 Impact of ASU 2016-18 12/31/2016 (as adjusted and currently reported) Net cash provided by operating activities 1,143,484 8,562 8,226 1,160,272 Net cash used in investing activities (1,037,352 ) — 5,000 (1,032,352 ) Net cash used in financing activities (291,645 ) (8,562 ) (3,064 ) (303,271 ) Net decrease in cash, cash equivalents (185,513 ) — 185,513 — Net decrease in cash, cash equivalents and restricted cash — — (175,351 ) (175,351 ) Cash, cash equivalents, beginning of period 400,507 — (400,507 ) — Cash, cash equivalents and restricted cash, beginning of period — — 505,328 505,328 Cash, cash equivalents, end of period $ 214,994 — — — Cash, cash equivalents and restricted cash, end of period $ — $ 114,983 $ 329,977 12/31/2015 (as previously reported) Impact of ASU 2016-09 Impact of ASU 2016-18 12/31/2015 (as adjusted and currently reported) Net cash provided by operating activities 1,056,754 6,076 11,837 1,074,667 Net cash used in investing activities (1,199,517 ) — — (1,199,517 ) Net cash provided by (used in) financing activities 33,810 (6,076 ) (2,641 ) 25,093 Net decrease in cash, cash equivalents (108,953 ) — 108,953 — Net decrease in cash, cash equivalents and restricted cash — — (99,757 ) (99,757 ) Cash, cash equivalents, beginning of period 509,460 — (509,460 ) — Cash, cash equivalents and restricted cash, beginning of period — — 605,085 605,085 Cash, cash equivalents, end of period $ 400,507 — — — Cash, cash equivalents and restricted cash, end of period $ — $ 104,821 $ 505,328

Mortgage Notes Payable, Unsec24

Mortgage Notes Payable, Unsecured Notes and Credit Facility (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Summary of company's mortgage notes payable, unsecured notes, term loan and credit facility	The following amounts and discussion do not include the mortgage notes related to the communities classified as held for sale, if any, as of December 31, 2017 and 2016 , as shown on the Consolidated Balance Sheets (dollars in thousands) (see Note 6, “Real Estate Disposition Activities”). 12/31/17 12/31/16 Fixed rate unsecured notes (1) $ 5,350,000 $ 4,200,000 Variable rate unsecured notes (1) 300,000 — Term Loans (1) 250,000 300,000 Fixed rate mortgage notes payable—conventional and tax-exempt (2) 593,987 1,668,496 Variable rate mortgage notes payable—conventional and tax-exempt (2) 910,326 908,262 Total mortgage notes payable and unsecured notes and Term Loans 7,404,313 7,076,758 Credit Facility — — Total mortgage notes payable, unsecured notes, Term Loans and Credit Facility $ 7,404,313 $ 7,076,758 _________________________________ (1) Balances at December 31, 2017 and 2016 exclude $10,850 and $8,930 , respectively, of debt discount, and $36,386 and $27,768 , respectively, of deferred financing costs, as reflected in unsecured notes, net on the accompanying Consolidated Balance Sheets. (2) Balances at December 31, 2017 and 2016 exclude $16,351 of debt discount and $1,866 of debt premium, respectively, and $11,256 and $11,046 , respectively, of deferred financing costs, as reflected in mortgage notes payable, net on the accompanying Consolidated Balance Sheets.
Scheduled payments and maturities of mortgage notes payable and unsecured notes outstanding	Scheduled payments and maturities of mortgage notes payable and unsecured notes outstanding at December 31, 2017 are as follows (dollars in thousands): Year Secured notes payments Secured notes maturities Unsecured notes maturities Stated interest rate of unsecured notes 2018 7,258 76,663 — N/A 2019 4,696 114,721 — N/A 2020 3,624 140,429 250,000 6.100 % 400,000 3.625 % 2021 3,551 27,844 250,000 3.950 % 300,000 LIBOR + 0.43% 2022 3,795 — 450,000 2.950 % 100,000 LIBOR + .90% 2023 4,040 — 350,000 4.200 % 250,000 2.850 % 2024 4,310 — 300,000 3.500 % 150,000 LIBOR + 1.50% 2025 4,585 84,835 525,000 3.450 % 300,000 3.500 % 2026 4,894 — 475,000 2.950 % 300,000 2.900 % 2027 3,083 185,100 400,000 3.350 % Thereafter 148,468 682,417 350,000 3.900 % 300,000 4.150 % 450,000 3.200 % $ 192,304 $ 1,312,009 $ 5,900,000

Investments in Real Estate En25

Investments in Real Estate Entities (Tables)	12 Months Ended
	Dec. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Combined summary of the financial position of the entities accounted for using the equity method	The following is a combined summary of the financial position of the entities accounted for using the equity method as of the dates presented, excluding amounts associated with development joint ventures, the Residual JV and Legacy JV (dollars in thousands): 12/31/17 12/31/16 Assets: Real estate, net $ 695,077 $ 954,493 Other assets 39,976 49,519 Total assets $ 735,053 $ 1,004,012 Liabilities and partners' capital: Mortgage notes payable, net and credit facility $ 523,815 $ 689,573 Other liabilities 10,540 16,537 Partners' capital 200,698 297,902 Total liabilities and partners' capital $ 735,053 $ 1,004,012
Combined summary of the operating results of the entities accounted for using the equity method	The following is a combined summary of the operating results of the entities accounted for using the equity method, for the years presented, excluding amounts associated with development joint ventures, Avalon Clarendon, the Residual JV and Legacy JV (dollars in thousands): For the year ended 12/31/17 12/31/16 12/31/15 Rental and other income $ 101,615 $ 131,901 $ 173,578 Operating and other expenses (38,566 ) (50,945 ) (67,962 ) Gain on sale of communities 136,333 196,749 98,899 Interest expense, net (1) (27,104 ) (45,886 ) (45,517 ) Depreciation expense (25,914 ) (34,471 ) (45,324 ) Net income $ 146,364 $ 197,348 $ 113,674
Equity in income of unconsolidated entities	The following is a summary of the Company's equity in income of unconsolidated real estate entities for the years presented (dollars in thousands): For the year ended 12/31/17 12/31/16 12/31/15 Fund I (1) $ — $ 87 $ 871 Fund II (2) 53,961 49,882 32,211 U.S. Fund (3) 14,773 15,635 2,052 AC JV 1,388 1,445 511 MVP I, LLC (4) 1,833 1,627 22,453 Brandywine 106 10 (1,474 ) CVP I, LLC (5) — 9 1,812 Residual JV (1,223 ) (1,374 ) 11,582 Avalon Clarendon (6) — (2,359 ) — North Point II JV, LP (122 ) — — Sudbury Development, LLC 28 — — Total $ 70,744 $ 64,962 $ 70,018 _________________________________ (1) The Company's equity in income for this entity represents its residual profits from the sale of the community, or liquidation of the venture. (2) Equity in income for the years ended December 31, 2017 , 2016 and 2015 includes the Company's proportionate share of the gain on the sale of Fund II assets of $26,322 , $41,501 , and $29,726 respectively. In addition, equity in income for the years ended December 31, 2017 and 2016 include $26,742 and $7,985 , respectively, relating to the Company's recognition of its promoted interest. (3) Equity in income for the years ended December 31, 2017 and 2016 include the Company's proportionate share of the gain on the sale of U.S. Fund assets of $13,788 and $16,568 , respectively. (4) Equity in income for the year ended December 31, 2015 includes $21,340 relating to the Company's recognition of its promoted interest, of which $20,680 was from the joint venture partner upon agreement to modify the joint venture agreement to eliminate the Company's promoted interest from associated distribution for future return calculations. (5) Equity in income for the year ended December 31, 2015 includes $1,289 relating to the Company's recognition of its promoted interest. (6) In 2016, the Company and its venture partner established separate legal ownership of Avalon Clarendon, after which the Company reported the operating results of Avalon Clarendon as part of its consolidated operations.

Real Estate Disposition Activ26

Real Estate Disposition Activities (Tables)	12 Months Ended
	Dec. 31, 2017
Discontinued Operations and Disposal Groups [Abstract]
Details regarding the real estate sales	Details regarding the real estate sales are summarized in the following table (dollars in thousands): Community Name Location Period of sale Apartment homes Debt Gross sales price Net cash proceeds Avalon Pines (1) Coram, NY Q117 450 $ — $ 140,000 $ 138,689 AVA University District Seattle, WA Q217 283 — 112,500 108,511 Avalon Danbury Danbury, CT Q317 234 — 52,000 51,000 Avalon Run East Lawrenceville, NJ Q417 312 — 87,500 85,033 Avalon Huntington Shelton, CT Q417 99 — 33,000 32,173 Avalon Milford Milford, CT Q417 246 — 50,500 49,161 Other real estate dispositions (2) multiple Q1-Q417 N/A — 39,154 38,472 Total of 2017 asset sales 1,624 $ — $ 514,654 $ 503,039 Total of 2016 asset sales 2,051 $ — $ 564,028 $ 532,717 Total of 2015 asset sales 851 $ — $ 289,320 $ 282,163 _________________________________ (1) Includes the sale of the adjacent golf course.

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Future Minimum Lease Payments Under Current Leases	The following table details the future minimum lease payments under the Company's current leases (dollars in thousands): Payments due by period 2018 2019 2020 2021 2022 Thereafter Operating Lease Obligations $ 21,051 $ 21,064 $ 18,781 $ 20,162 $ 20,057 $ 1,052,808 Capital Lease Obligations (1) (2) 1,073 1,075 1,077 1,080 1,082 43,976 $ 22,124 $ 22,139 $ 19,858 $ 21,242 $ 21,139 $ 1,096,784 _________________________________ (1) Aggregate capital lease payments include $25,961 in interest costs, with the timing of certain lease payments for capital land leases determined by completion of the construction of the associated apartment community. (2) Capital lease assets of $19,737 and $39,015 as of December 31, 2017 and 2016 , respectively, are included as a component of land and improvements or building and improvements on the accompanying Consolidated Balance Sheets.

Segment Reporting (Tables)

Segment Reporting (Tables)	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Schedule of reconciliation of NOI to net income	A reconciliation of NOI to net income for years ended December 31, 2017 , 2016 and 2015 is as follows (dollars in thousands): For the year ended 12/31/17 12/31/16 12/31/15 Net income $ 876,660 $ 1,033,708 $ 741,733 Indirect operating expenses, net of corporate income 65,398 61,403 56,973 Investments and investment management expense 5,936 4,822 4,370 Expensed acquisition, development and other pursuit costs, net of recoveries 2,736 9,922 6,822 Interest expense, net 199,661 187,510 175,615 Loss (gain) on extinguishment of debt, net 25,472 7,075 (26,736 ) General and administrative expense 50,673 45,771 42,774 Equity in income of unconsolidated real estate entities (70,744 ) (64,962 ) (70,018 ) Depreciation expense 584,150 531,434 477,923 Income tax expense 141 305 1,483 Casualty and impairment loss (gain), net 6,250 (3,935 ) (10,542 ) Gain on sale of communities (252,599 ) (374,623 ) (115,625 ) Loss (gain) on other real estate transactions 10,907 (10,224 ) (9,647 ) Net operating income from real estate assets sold or held for sale (14,573 ) (44,263 ) (59,383 ) Net operating income $ 1,490,068 $ 1,383,943 $ 1,215,742
Schedule of net operating income from real estate assets sold or held for sale, not classified as discontinued operations	The following is a summary of NOI from real estate assets sold or held for sale for the periods presented (dollars in thousands): For the year ended 12/31/2017 12/31/2016 12/31/2015 Rental income from real estate assets sold or held for sale $ 23,457 $ 70,273 $ 96,297 Operating expenses from real estate assets sold or held for sale (8,884 ) (26,010 ) (36,914 ) Net operating income from real estate assets sold or held for sale $ 14,573 $ 44,263 $ 59,383
Schedule of details of segment information	Total revenue NOI % NOI change from prior year Gross real estate (1) For the year ended December 31, 2017 Established New England $ 233,091 $ 150,253 2.1 % $ 1,852,676 Metro NY/NJ 362,273 247,720 2.1 % 3,069,690 Mid-Atlantic 221,064 153,750 1.5 % 2,056,066 Pacific Northwest 84,189 61,527 6.3 % 738,532 Northern California 336,767 257,673 1.6 % 2,830,963 Southern California 337,876 241,549 3.9 % 3,017,836 Total Established (2) 1,575,260 1,112,472 2.5 % 13,565,763 Other Stabilized 278,868 196,733 N/A 3,189,393 Development / Redevelopment (3) 276,896 180,863 N/A 5,015,094 Land Held for Future Development N/A N/A N/A 68,364 Non-allocated (4) 4,147 N/A N/A 97,322 Total $ 2,135,171 $ 1,490,068 7.7 % $ 21,935,936 For the year ended December 31, 2016 Established New England $ 226,727 $ 145,671 4.8 % $ 1,888,524 Metro NY/NJ 359,373 245,654 1.2 % 3,212,220 Mid-Atlantic 233,711 162,243 1.3 % 2,339,395 Pacific Northwest 72,475 52,434 7.4 % 737,289 Northern California 319,121 244,458 7.0 % 2,661,258 Southern California 291,567 207,537 9.1 % 2,672,691 Total Established (2) 1,502,974 1,057,997 4.8 % 13,511,377 Other Stabilized (5) 232,977 165,130 N/A 2,330,503 Development / Redevelopment 233,432 160,816 N/A 4,755,315 Land Held for Future Development N/A N/A N/A 84,293 Non-allocated (4) 5,599 N/A N/A 74,292 Total $ 1,974,982 $ 1,383,943 13.8 % $ 20,755,780 For the year ended December 31, 2015 Established New England $ 170,287 $ 107,189 3.0 % $ 1,460,746 Metro NY/NJ 342,768 244,280 3.6 % 3,152,361 Mid-Atlantic 209,012 145,497 0.2 % 2,177,823 Pacific Northwest 67,900 48,833 8.5 % 721,040 Northern California 273,432 210,226 11.9 % 2,414,184 Southern California 252,530 173,919 9.4 % 2,465,432 Total Established (2) 1,315,929 929,944 6.0 % 12,391,586 Other Stabilized 211,633 140,167 N/A 2,040,269 Development / Redevelopment 222,222 145,631 N/A 4,238,967 Land Held for Future Development N/A N/A N/A 484,377 Non-allocated (4) 9,947 N/A N/A 73,372 Total $ 1,759,731 $ 1,215,742 13.0 % $ 19,228,571 _________________________________ (1) Does not include gross real estate assets held for sale of $20,846 and $39,528 as of December 31, 2016 and 2015 , respectively. (2) Gross real estate for the Company's Established Communities includes capitalized additions of approximately $78,241 , $85,676 and $74,982 in 2017 , 2016 and 2015 , respectively. (3) Total revenue and NOI for the year ended December 31, 2017 includes $3,495 in business interruption insurance proceeds related to the Maplewood casualty loss. (4) Revenue represents third-party management, accounting, and developer fees and miscellaneous income which are not allocated to a reportable segment. (5) Total revenue and NOI for the year ended December 31, 2016 includes $20,306 in business interruption insurance proceeds related to the Edgewater casualty loss.

Stock-Based Compensation Plans

Stock-Based Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of information with respect to stock options granted	Information with respect to stock options granted under the 2009 and 1994 Plans is as follows: 2009 Plan shares Weighted average exercise price per share 1994 Plan shares Weighted average exercise price per share Options Outstanding, December 31, 2014 340,062 $ 122.67 272,402 $ 104.96 Exercised (90,884 ) 124.01 (190,207 ) 105.70 Granted — — — — Forfeited — — — — Options Outstanding, December 31, 2015 249,178 $ 122.17 82,195 $ 103.27 Exercised (71,845 ) 117.04 (59,654 ) 112.85 Granted — — — — Forfeited — — — — Options Outstanding, December 31, 2016 177,333 $ 124.25 22,541 $ 77.91 Exercised (27,360 ) 110.47 (14,763 ) 93.35 Granted — — — — Forfeited — — — — Options Outstanding, December 31, 2017 (1) 149,973 $ 126.77 7,778 $ 48.60 Options Exercisable: December 31, 2015 188,081 $ 119.98 82,195 $ 103.27 December 31, 2016 177,333 $ 124.25 22,541 $ 77.91 December 31, 2017 149,973 $ 126.77 7,778 $ 48.60
Summary of exercise prices and contractual lives of options outstanding	The following summarizes the exercise prices and contractual lives of options outstanding as of December 31, 2017 : 2009 Plan Number of Options Range—Exercise Price Weighted Average Remaining Contractual Term (in years) 5,158 $70.00 - $79.99 2.1 15,762 $110.00 - $119.99 3.1 29,862 $120.00 - $129.99 5.2 99,191 $130.00 - $139.99 4.6 149,973 1994 Plan Number of Options Range—Exercise Price Weighted Average Remaining Contractual Term (in years) 7,778 $40.00 - $49.99 1.1
Schedule of nonvested performance awards granted	Information with respect to performance awards granted is as follows: Performance awards Weighted average grant date fair value per award Outstanding at December 31, 2014 239,902 $ 95.20 Granted (1) 85,636 148.49 Change in awards based on performance (2) 14,697 78.50 Converted to restricted stock (95,826 ) 78.50 Forfeited (6,143 ) 110.34 Outstanding at December 31, 2015 238,266 $ 119.65 Granted (3) 94,054 141.92 Change in awards based on performance (2) 36,091 101.52 Converted to restricted stock (115,618 ) 94.67 Forfeited (1,630 ) 141.98 Outstanding at December 31, 2016 251,163 $ 136.74 Granted (4) 81,708 176.59 Change in awards based on performance (2) 49,323 119.26 Converted to restricted stock (128,482 ) 118.75 Forfeited (1,942 ) 159.39 Outstanding at December 31, 2017 251,770 $ 155.25 _________________________________ (1) The amount of restricted stock that ultimately may be earned is based on the total shareholder return metrics related to the Company’s common stock for 55,162 performance awards and financial metrics related to operating performance and leverage metrics of the Company for 30,474 performance awards. (2) Represents the change in the number of performance awards earned based on performance achievement for the performance period. (3) The amount of restricted stock that ultimately may be earned is based on the total shareholder return metrics related to the Company’s common stock for 61,039 performance awards and financial metrics related to operating performance and leverage metrics of the Company for 33,015 performance awards. (4) The amount of restricted stock that ultimately may be earned is based on the total shareholder return metrics related to the Company’s common stock for 49,374 performance awards and financial metrics related to operating performance and leverage metrics of the Company for 32,334 performance awards.
Schedule of restricted stock granted	Information with respect to restricted stock granted is as follows: Restricted stock shares Restricted stock shares weighted average grant date fair value per share Restricted stock shares converted from performance awards Outstanding at December 31, 2014 179,307 $ 129.06 10,933 Granted - restricted stock shares 61,953 173.04 95,826 Vested - restricted stock shares (91,847 ) 130.75 (8,412 ) Forfeited (1,529 ) 151.86 — Outstanding at December 31, 2015 147,884 $ 146.21 98,347 Granted - restricted stock shares 81,400 162.38 115,618 Vested - restricted stock shares (88,712 ) 141.38 (36,872 ) Forfeited (3,867 ) 162.43 (395 ) Outstanding at December 31, 2016 136,705 $ 158.51 176,698 Granted - restricted stock shares 73,342 179.58 128,482 Vested - restricted stock shares (73,683 ) 153.86 (70,595 ) Forfeited (2,731 ) 173.42 (657 ) Outstanding at December 31, 2017 133,633 $ 172.33 233,928
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Summary of valuation options	There were no stock options granted in 2017 , 2016 and 2015 .
Performance awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Summary of valuation options	The Company used a Monte Carlo model to assess the compensation cost associated with the portion of the performance awards granted for which achievement will be determined by using total shareholder return measures. The assumptions used are as follows: 2017 2016 2015 Dividend yield 3.2% 3.3% 3.0% Estimated volatility over the life of the plan (1) 15.3% - 19.7% 15.2% - 22.8% 12.0% - 17.3% Risk free rate 0.69% - 1.61% 0.44% - 0.88% 0.07% - 1.09% Estimated performance award value based on total shareholder return measure $175.86 $131.24 $139.18 _________________________________ (1) Estimated volatility of the life of the plan is using 50% historical volatility and 50% implied volatility.

Fair Value (Tables)

Fair Value (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Schedule of summary of consolidated hedging derivatives, excluding derivatives executed to hedge debt on communities classified as held for sale	The following table summarizes the consolidated derivative positions at December 31, 2017 (dollars in thousands): Non-designated Hedges Interest Rate Caps Cash Flow Hedges Interest Rate Caps Cash Flow Interest Rate Swaps Notional balance $ 689,059 $ 35,039 $ 300,000 Weighted average interest rate (1) 3.3 % 3.5 % N/A Weighted average swapped/capped interest rate 6.5 % 5.9 % 2.4 % Earliest maturity date August 2018 April 2019 May 2018 Latest maturity date September 2022 April 2019 May 2018 _________________________________ (1) For interest rate caps, represents the weighted average interest rate on the hedged debt.
Summary of deferred losses reclassified from AOCI	The following table summarizes the deferred losses reclassified from accumulated other comprehensive income as a component of interest expense, net (dollars in thousands): For the year ended 12/31/17 12/31/16 12/31/15 Cash flow hedge losses reclassified to earnings $ 7,070 $ 6,433 $ 5,774
Schedule of summary of classification between the three levels of the fair value hierarchy of the Company's financial instruments measured at fair value on a recurring basis	The following table summarizes the classification between the three levels of the fair value hierarchy of the Company's financial instruments measured/disclosed at fair value on a recurring basis (dollars in thousands): Description Total Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) 12/31/2017 Non Designated Hedges Interest Rate Caps $ 2 $ — $ 2 $ — Cash Flow Hedges Interest Rate Swaps - Assets 2,270 — 2,270 — Interest Rate Swaps - Liabilities (1,171 ) — (1,171 ) — Puts (3,245 ) — — (3,245 ) DownREIT units (1,338 ) (1,338 ) — — Indebtedness Unsecured notes (5,446,604 ) (5,446,604 ) — — Secured notes payable and unsecured term loans (1,849,851 ) — (1,849,851 ) — Total $ (7,299,937 ) $ (5,447,942 ) $ (1,848,750 ) $ (3,245 ) 12/31/2016 Non Designated Hedges Interest Rate Caps $ 79 $ — $ 79 $ — Cash Flow Hedges Interest Rate Caps 2 — 2 — Interest Rate Swaps 14,775 — 14,775 — Puts (6,002 ) — — (6,002 ) DownREIT units (1,329 ) (1,329 ) — — Indebtedness Unsecured notes (4,218,627 ) (4,218,627 ) — — Secured notes payable and unsecured term loans (2,744,462 ) — (2,744,462 ) — Total $ (6,955,564 ) $ (4,219,956 ) $ (2,729,606 ) $ (6,002 )

Quarterly Financial Informati31

Quarterly Financial Information (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	The following summary represents the unaudited quarterly results of operations for the years ended December 31, 2017 and 2016 (dollars in thousands, except per share data): For the three months ended (1) 3/31/17 6/30/17 9/30/17 12/31/17 Total revenue $ 522,326 $ 530,512 $ 550,500 $ 555,292 Net income $ 235,781 $ 165,194 $ 238,199 $ 237,486 Net income attributable to common stockholders $ 235,875 $ 165,225 $ 238,248 $ 237,573 Net income per common share - basic $ 1.72 $ 1.20 $ 1.73 $ 1.72 Net income per common share - diluted $ 1.72 $ 1.20 $ 1.72 $ 1.72 For the three months ended (1) 3/31/16 6/30/16 9/30/16 12/31/16 Total revenue $ 508,498 $ 502,307 $ 516,211 $ 518,240 Net income $ 237,877 $ 197,319 $ 356,329 $ 242,183 Net income attributable to common stockholders $ 237,931 $ 197,444 $ 356,392 $ 242,235 Net income per common share - basic $ 1.73 $ 1.44 $ 2.60 $ 1.76 Net income per common share - diluted $ 1.73 $ 1.44 $ 2.59 $ 1.76 _________________________________ (1) Amounts may not equal full year results due to rounding.

Organization, Basis of Presen32

Organization, Basis of Presentation, and Significant Accounting Policies (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)statecommunityhome	Dec. 31, 2016USD ($)
Organization and Basis of Presentation
Number of Real Estate Properties | community	267
Number of apartment homes included in operating apartment communities owned | home	77,614
Number of states where operating apartment communities owned are located | state	12
Number of communities with apartments under reconstruction | community	9
Number of apartment homes under reconstruction | home	3,752
Number of owned communities under construction | community	21
Expected number of apartment homes under construction | home	6,544
Communities under development rights | community	29
Estimated number of apartment homes in communities to be developed | home	9,496
Period of lease (in years)	1 year
Real Estate
Net operating real estate | $	$ 16,342,893	$ 15,045,593
Buildings and Building Improvements | Minimum
Real Estate
Estimated useful life of buildings and improvements (in years)	7 years
Buildings and Building Improvements | Maximum
Real Estate
Estimated useful life of buildings and improvements (in years)	30 years
Computers and furniture | Minimum
Real Estate
Estimated useful life of buildings and improvements (in years)	3 years
Computers and furniture | Maximum
Real Estate
Estimated useful life of buildings and improvements (in years)	7 years

Organization, Basis of Presen33

Organization, Basis of Presentation, and Significant Accounting Policies (Details 2) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounting Policies [Abstract]
Minimum distribution of adjusted taxable income for deducting dividends from federally taxable income (as a percent)									90.00%
Minimum distribution of REIT taxable income for federal income tax exemption (as a percent)									100.00%
Income Tax Disclosure [Abstract]
Unrecognized tax benefits	$ 0				$ 0				$ 0	$ 0
Excise and Sales Taxes									0	0	$ 0
Excise Tax Refund	0				0				0	0	0
Income tax expense									141	305	1,483
Casualty and impairment loss (gain), net									6,250	(3,935)	(10,542)
Other than Temporary Impairment Losses, Investments									0	0	0
Reconciliation of Income from Book Basis to Tax Basis Adjustment
Net income attributable to common stockholders	237,573	$ 238,248	$ 165,225	$ 235,875	242,235	$ 356,392	$ 197,444	$ 237,931	876,921	1,034,002	742,038
GAAP gain on sale of communities (in excess of) less than tax gain									(85,873)	(195,029)	(20,900)
Depreciation/amortization timing differences on real estate									11,868	(947)	(24,657)
Amortization of debt/mark to market interest									(17,430)	(18,985)	(64,676)
Tax compensation expense less than (in excess of) GAAP									(3,828)	9,821	(1,244)
Casualty and impairment (gain) loss, net									6,250	(657)	(10,542)
Other adjustments									(40,381)	11,533	(12,829)
Taxable net income									$ 747,527	$ 839,738	$ 607,190
Tax components of common stock dividends declared
Ordinary income (as a percent)									75.00%	68.00%	83.00%
20% capital gain (as a percent)									18.00%	26.00%	12.00%
Capital gain tax rate (as a percent)									20.00%	20.00%	20.00%
Unrecaptured 1250 gain (as a percent)									7.00%	6.00%	5.00%
Unsecured notes
Deferred Financing Costs
Accumulated amortization of deferred finance costs	16,984				14,008				$ 16,984	$ 14,008
Secured notes
Deferred Financing Costs
Accumulated amortization of deferred finance costs	4,991				10,562				4,991	10,562
Line of Credit [Member]
Deferred Financing Costs
Accumulated amortization of deferred finance costs	$ 8,299				$ 6,490				8,299	6,490
Land [Member]
Income Tax Disclosure [Abstract]
Casualty and impairment loss (gain), net									$ 9,350		$ 0
New England [Member]
Income Tax Disclosure [Abstract]
Casualty and impairment loss (gain), net										(5,732)
Deferred Financing Costs
Insurance Recoveries										$ 8,493

Organization, Basis of Presen34

Organization, Basis of Presentation, and Significant Accounting Policies (Details 3) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended			15 Months Ended
	Dec. 31, 2017USD ($)communityhomebuilding$ / shares	Sep. 30, 2017USD ($)$ / shares	Jun. 30, 2017USD ($)$ / shares	Mar. 31, 2017USD ($)$ / shares	Dec. 31, 2016USD ($)$ / shares	Sep. 30, 2016USD ($)$ / shares	Jun. 30, 2016USD ($)$ / shares	Mar. 31, 2016USD ($)$ / shares	Dec. 31, 2017USD ($)communityhomebuilding$ / sharesshares	Dec. 31, 2016USD ($)land_parcel$ / sharesshares	Dec. 31, 2015USD ($)$ / sharesshares	Mar. 31, 2016USD ($)
Basic and diluted shares outstanding
Weighted average common shares—basic | shares									137,523,771	136,928,251	133,565,711
Weighted average DownREIT units outstanding (in shares) | shares									7,500	7,500	7,500
Effect of dilutive securities (in shares) | shares									535,415	525,886	1,019,966
Weighted average common shares - diluted (in shares) | shares									138,066,686	137,461,637	134,593,177
Calculation of Earnings per Share—basic
Net income attributable to common stockholders	$ 237,573	$ 238,248	$ 165,225	$ 235,875	$ 242,235	$ 356,392	$ 197,444	$ 237,931	$ 876,921	$ 1,034,002	$ 742,038
Net income allocated to unvested restricted shares									(2,463)	(2,610)	(1,774)
Net income attributable to common stockholders, adjusted									$ 874,458	$ 1,031,392	$ 740,264
Weighted average common shares—basic | shares									137,523,771	136,928,251	133,565,711
Earnings per common share - basic (in dollars per share) | $ / shares	$ 1.72	$ 1.73	$ 1.20	$ 1.72	$ 1.76	$ 2.60	$ 1.44	$ 1.73	$ 6.36	$ 7.53	$ 5.54
Calculation of Earnings per Share—diluted
Net income attributable to common stockholders	$ 237,573	$ 238,248	$ 165,225	$ 235,875	$ 242,235	$ 356,392	$ 197,444	$ 237,931	$ 876,921	$ 1,034,002	$ 742,038
Add: noncontrolling interests of DownREIT unitholders in consolidated partnerships, including discontinued operations									42	41	38
Adjusted net income attributable to common stockholders									$ 876,963	$ 1,034,043	$ 742,076
Weighted average common shares—diluted | shares									138,066,686	137,461,637	134,593,177
Earnings per common share - diluted (in dollars per share) | $ / shares	$ 1.72	$ 1.72	$ 1.20	$ 1.72	$ 1.76	$ 2.59	$ 1.44	$ 1.73	$ 6.35	$ 7.52	$ 5.51
Dividends per common share: (in dollars per share) | $ / shares									$ 5.68	$ 5.4	$ 5
Casualty Loss, Abandoned Pursuit Costs and Impairment of Long-Lived Assets
Abandoned pursuits costs									$ 2,370	$ 4,183	$ 3,016
Casualty and impairment loss (gain), net									6,250	$ (3,935)	(10,542)
Number of Land Parcels Impaired | land_parcel										3
Impairment of investment in unconsolidated entities									0	$ 0	0
Net operating real estate	$ 16,342,893				$ 15,045,593				16,342,893	15,045,593
Gain on Business Interruption Insurance Recovery									$ 3,498	20,564	1,509
Number of Real Estate Properties | community	267								267
Number of Units in Real Estate Property | home	77,614								77,614
Number of Land Parcels Held for Sale | community	0								0
Land [Member]
Casualty Loss, Abandoned Pursuit Costs and Impairment of Long-Lived Assets
Casualty and impairment loss (gain), net									$ 9,350		0
Avalon at Edgewater [Member]
Casualty Loss, Abandoned Pursuit Costs and Impairment of Long-Lived Assets
Casualty and impairment loss (gain), net										(8,702)	(15,538)
Insurance Proceeds										29,008	44,142	$ 73,150
Net operating real estate											21,844
Casualty Loss											6,760
Gain on Business Interruption Insurance Recovery										20,306
Number of Real Estate Properties | building	2								2
Number Of Real Estate Properties, Uninhabitable | building	1								1
Number Of Units In Real Estate Property, Uninhabitable | home	240								240
Number of Units in Real Estate Property | home	168								168
New England [Member]
Casualty Loss, Abandoned Pursuit Costs and Impairment of Long-Lived Assets
Casualty and impairment loss (gain), net										(5,732)
Casualty Loss										2,761
Insurance Recoveries										8,493
Land Parcel [Member]
Casualty Loss, Abandoned Pursuit Costs and Impairment of Long-Lived Assets
Casualty and impairment loss (gain), net										$ 10,500
Avalon Maplewood [Member]
Casualty Loss, Abandoned Pursuit Costs and Impairment of Long-Lived Assets
Casualty and impairment loss (gain), net									$ 2,338
Insurance Proceeds									17,143
Net operating real estate	$ 16,361								16,361
Casualty Loss									19,481
Gain on Business Interruption Insurance Recovery									3,495
Other Nonrecurring Expense									3,120
Insurance Recoveries									$ 19,696
New England [Member]
Casualty Loss, Abandoned Pursuit Costs and Impairment of Long-Lived Assets
Casualty and impairment loss (gain), net											4,195
New England [Member] | Avalon at Edgewater [Member]
Casualty Loss, Abandoned Pursuit Costs and Impairment of Long-Lived Assets
Casualty and impairment loss (gain), net											$ 26,039

Organization, Basis of Presen35

Organization, Basis of Presentation, and Significant Accounting Policies - Schedule of New Accounting Pronouncements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash provided by operating activities	$ 1,256,257	$ 1,160,272	$ 1,074,667
Net cash used in investing activities	(965,381)	(1,032,352)	(1,199,517)
Net cash used in financing activities	(418,947)	(303,271)	25,093
Net decrease in cash, cash equivalents and restricted cash	(128,071)	(175,351)	(99,757)
Cash, cash equivalents, beginning of period	214,994	400,507
Cash and cash equivalents and restricted cash, beginning of year	329,977	505,328	605,085
Cash, cash equivalents, end of period	67,088	214,994	400,507
Cash and cash equivalents and restricted cash, end of year	201,906	329,977	505,328
Scenario, Previously Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash provided by operating activities		1,143,484	1,056,754
Net cash used in investing activities		(1,037,352)	(1,199,517)
Net cash used in financing activities		(291,645)	33,810
Net decrease in cash, cash equivalents		(185,513)	(108,953)
Cash, cash equivalents, beginning of period	214,994	400,507	509,460
Cash, cash equivalents, end of period		214,994	400,507
Impact of ASU 2016-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash provided by operating activities		8,562	6,076
Net cash used in financing activities		(8,562)	(6,076)
Impact of ASU 2016-18
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash provided by operating activities		8,226	11,837
Net cash used in investing activities		5,000	0
Net cash used in financing activities		(3,064)	(2,641)
Net decrease in cash, cash equivalents		185,513	108,953
Net decrease in cash, cash equivalents and restricted cash		(175,351)	(99,757)
Cash, cash equivalents, beginning of period		(400,507)	(509,460)
Cash and cash equivalents and restricted cash, beginning of year	$ 114,983	104,821	605,085
Cash, cash equivalents, end of period			(400,507)
Cash and cash equivalents and restricted cash, end of year		$ 114,983	$ 104,821

Interest Capitalized (Details)

Interest Capitalized (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest Capitalized
Capitalized interest during the development and redevelopment of real estate assets	$ 64,420	$ 78,872	$ 79,834

Mortgage Notes Payable, Unsec37

Mortgage Notes Payable, Unsecured Notes and Credit Facility (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Total mortgage notes payable and unsecured notes and Term Loans	$ 7,404,313	$ 7,076,758
Variable rate unsecured credit facility	0	0
Total mortgage notes payable, unsecured notes, Term Loans and Credit Facility	7,404,313	7,076,758
Unsecured notes
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Fixed rate notes	5,350,000	4,200,000
Variable rate notes	300,000	0
Total mortgage notes payable and unsecured notes and Term Loans	5,900,000
Amount of debt discount	10,850	8,930
Deferred financing costs, net	36,386	27,768
Term loan
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Variable rate notes	250,000	300,000
Mortgage notes payable
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Fixed rate notes	593,987	1,668,496
Variable rate notes	910,326	908,262
Total mortgage notes payable and unsecured notes and Term Loans	1,312,009
Amount of debt discount	16,351
Deferred financing costs, net	$ 11,256	11,046
Amount of debt premium		$ (1,866)

Mortgage Notes Payable, Unsec38

Mortgage Notes Payable, Unsecured Notes and Credit Facility (Details 2)	1 Months Ended					12 Months Ended
	Nov. 30, 2017USD ($)	Oct. 31, 2017USD ($)	Jun. 30, 2017USD ($)community	May 31, 2017USD ($)community	Feb. 28, 2017USD ($)	Dec. 31, 2017USD ($)community	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Apr. 30, 2017USD ($)
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Gains (losses) on extinguishment of debt						$ (25,472,000)	$ (7,075,000)	$ 26,736,000
Number of Real Estate Properties | community						267
Repayments of Unsecured Debt						$ 300,000,000	504,403,000	$ 0
Variable rate unsecured credit facility | LIBOR
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt Instrument, Interest Rate, Effective Percentage						2.39%
Debt instrument, basis spread on variable rate (as a percent)						0.825%
Variable Rate Unsecured Term Loan $250 Million [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Principal amount of notes issued									$ 250,000,000
Variable Rate Unsecured Term Loan $100 Million [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Principal amount of notes issued					$ 100,000,000
Variable Rate Unsecured Term Loan $100 Million [Member] | LIBOR
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, basis spread on variable rate (as a percent)					0.90%
Variable Rate Unsecured Term Loan $150 Million [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Principal amount of notes issued					$ 150,000,000
Variable Rate Unsecured Term Loan $150 Million [Member] | LIBOR
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, basis spread on variable rate (as a percent)					1.50%
Unsecured notes
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Amount drawn						$ 300,000,000	0
Unsecured notes | Variable Rate Unsecured Term Loan $300 Million [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Write off of Deferred Debt Issuance Cost	$ (1,367,000)
Repayments of Unsecured Debt	$ 300,000,000
Unsecured notes | Unsecured Notes 3.20 Percent [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Stated interest rate (as a percent)	3.20%
Unsecured notes | Notes Payable 2.900 Maturities 2026 [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Stated interest rate (as a percent)						2.90%
Unsecured notes | Notes Payable Maturities 2027 [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Stated interest rate (as a percent)						3.35%
Unsecured notes | Notes Payable Maturities 2046 [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Stated interest rate (as a percent)						3.90%
Unsecured notes | Variable Rate Unsecured Term Loan $100 Million [Member] | LIBOR
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, basis spread on variable rate (as a percent)						0.90%
Unsecured notes | Variable Rate Unsecured Term Loan $150 Million [Member] | LIBOR
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, basis spread on variable rate (as a percent)						1.50%
Unsecured notes | Notes Payable 3.350 Maturities 2027 [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Stated interest rate (as a percent)				3.35%
Unsecured notes | Unsecured Notes 4.15 Percent [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Stated interest rate (as a percent)			4.15%
Unsecured Notes 4.15 Percent [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Principal amount of notes issued			$ 300,000,000
Net proceeds from issuance of debt			297,372,000
Mortgage notes payable
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Amount drawn						$ 910,326,000	908,262,000
Mortgage notes payable | Notes Payable Maturities 2019 [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Repayments of secured mortgages			556,313,000
Gains (losses) on extinguishment of debt			$ (34,965,000)
Stated interest rate (as a percent)			5.86%
Number of Real Estate Properties | community			12
Prepayment Penalty			$ (33,515,000)
Write off of Deferred Debt Issuance Cost			$ (1,450,000)
Mortgage notes payable | Notes payable maturing in 2017
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Repayments of secured mortgages				$ 670,590,000	$ 17,300,000
Gains (losses) on extinguishment of debt				$ 10,839,000
Stated interest rate (as a percent)				6.256%
Number of Real Estate Properties | community				11
Mortgage notes payable | Notes Payable Maturities 2027 [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Principal amount of notes issued				$ 185,100,000
Stated interest rate (as a percent)				3.61%
Number of Real Estate Properties | community				3
Unsecured Notes 3.20 Percent [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Principal amount of notes issued	$ 450,000,000
Net proceeds from issuance of debt	$ 445,271,000
Unsecured Notes 3.35 Percent [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Principal amount of notes issued				$ 400,000,000
Net proceeds from issuance of debt				$ 396,016,000
Avalon Hoboken [Member] | Mortgage notes payable | Notes Payable Maturities 2020 [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Assumed principal amount of indebtedness							67,904,000
Avalon Columbia Pike [Member] | Mortgage notes payable | Notes Payable Maturities 2020 [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Assumed principal amount of indebtedness							$ 70,507,000
Archstone Lexington [Member] | Mortgage notes payable | Notes Payable Maturities 2020 [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Amount drawn		$ 21,700,000
Debt instrument, basis spread on variable rate (as a percent)		1.35%

Mortgage Notes Payable, Unsec39

Mortgage Notes Payable, Unsecured Notes and Credit Facility (Details 3) - USD ($)	1 Months Ended			12 Months Ended
	Nov. 30, 2017	Oct. 31, 2017	Feb. 28, 2017	Dec. 31, 2017	Dec. 31, 2016
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Variable rate unsecured credit facility				$ 0	$ 0
Net carrying value of apartment communities and improved land parcels securing debt				2,293,583,000
Mortgage notes payable
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable held by wholly owned subsidiaries guaranteed by the Company				100,000,000
Variable rate unsecured credit facility
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Available borrowing capacity				$ 1,500,000,000
Line of credit facility, extension period				9 months
Extension fee				$ 1,500,000
Annual facility fee				1,875,000
Outstanding balance of letters of credit				$ 47,315,000	$ 46,711,000
Debt Instrument Assumed Period of Borrowing Rate				1 month
Line of Credit Facility, Commitment Fee Percentage				0.125%
Fixed rate mortgage notes payable
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Weighted average interest rate, debt (as a percent)				4.00%	4.40%
Variable rate mortgage notes payable, unsecured term loan and Credit Facility
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Weighted average interest rate, debt (as a percent)				3.00%	2.30%
Variable Rate Unsecured Term Loan $100 Million [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt Instrument, Face Amount			$ 100,000,000
Variable Rate Unsecured Term Loan $150 Million [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt Instrument, Face Amount			$ 150,000,000
Floating Rate Unsecured Notes 300 Million [Member] | Unsecured notes
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt Instrument, Face Amount	$ 300,000,000
Net proceeds from issuance of debt	$ 298,800,000
LIBOR | Variable rate unsecured credit facility
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, basis spread on variable rate (as a percent)				0.825%
Debt Instrument, Interest Rate, Effective Percentage				2.39%
LIBOR | Variable Rate Unsecured Term Loan $100 Million [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, basis spread on variable rate (as a percent)			0.90%
LIBOR | Variable Rate Unsecured Term Loan $100 Million [Member] | Unsecured notes
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, basis spread on variable rate (as a percent)				0.90%
LIBOR | Variable Rate Unsecured Term Loan $150 Million [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, basis spread on variable rate (as a percent)			1.50%
LIBOR | Variable Rate Unsecured Term Loan $150 Million [Member] | Unsecured notes
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, basis spread on variable rate (as a percent)				1.50%
LIBOR | Floating Rate Unsecured Notes 300 Million [Member] | Unsecured notes
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, basis spread on variable rate (as a percent)	0.43%			0.43%
Minimum [Member] | Unsecured notes
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, basis spread on variable rate (as a percent)				0.20%
Maximum | Unsecured notes
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, basis spread on variable rate (as a percent)				0.45%
Archstone Lexington [Member] | Notes Payable Maturities 2020 [Member] | Mortgage notes payable
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, basis spread on variable rate (as a percent)		1.35%

Mortgage Notes Payable, Unsec40

Mortgage Notes Payable, Unsecured Notes and Credit Facility (Details 4) - USD ($) $ in Thousands	1 Months Ended		12 Months Ended
	Nov. 30, 2017	Feb. 28, 2017	Dec. 31, 2017	Jun. 30, 2017	May 31, 2017	Dec. 31, 2016
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes			$ 7,404,313			$ 7,076,758
Percentage of principle amount at which the entity may redeem some or all of the notes			100.00%
Variable Rate Unsecured Term Loan $100 Million [Member] | LIBOR
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, basis spread on variable rate (as a percent)		0.90%
Variable Rate Unsecured Term Loan $150 Million [Member] | LIBOR
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, basis spread on variable rate (as a percent)		1.50%
Unsecured notes
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes			$ 5,900,000
Unsecured notes | Minimum
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, basis spread on variable rate (as a percent)			0.20%
Unsecured notes | Maximum
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, basis spread on variable rate (as a percent)			0.45%
Unsecured notes | Notes Payable 6.100 Percent Maturities 2020
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes			$ 250,000
Stated interest rate of unsecured notes (as a percent)			6.10%
Unsecured notes | Notes Payable 3.625 Percent Maturities 2020
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes			$ 400,000
Stated interest rate of unsecured notes (as a percent)			3.625%
Unsecured notes | Notes payable maturing in 2021
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes			$ 250,000
Stated interest rate of unsecured notes (as a percent)			3.95%
Unsecured notes | Floating Rate Unsecured Notes 300 Million [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes			$ 300,000
Unsecured notes | Floating Rate Unsecured Notes 300 Million [Member] | LIBOR
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, basis spread on variable rate (as a percent)	0.43%		0.43%
Unsecured notes | Notes payable maturing in 2022
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes			$ 450,000
Stated interest rate of unsecured notes (as a percent)			2.95%
Unsecured notes | Variable Rate Unsecured Term Loan $100 Million [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes			$ 100,000
Unsecured notes | Variable Rate Unsecured Term Loan $100 Million [Member] | LIBOR
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, basis spread on variable rate (as a percent)			0.90%
Unsecured notes | Notes Payable 4.200 Maturities 2023
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes			$ 350,000
Stated interest rate of unsecured notes (as a percent)			4.20%
Unsecured notes | Notes Payable 2.850 Maturities 2023
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes			$ 250,000
Stated interest rate of unsecured notes (as a percent)			2.85%
Unsecured notes | Notes Payable 2024
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes			$ 300,000
Stated interest rate of unsecured notes (as a percent)			3.50%
Unsecured notes | Variable Rate Unsecured Term Loan $150 Million [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes			$ 150,000
Unsecured notes | Variable Rate Unsecured Term Loan $150 Million [Member] | LIBOR
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, basis spread on variable rate (as a percent)			1.50%
Unsecured notes | Notes Payable 3.450 Maturities 2025 [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes			$ 525,000
Stated interest rate of unsecured notes (as a percent)			3.45%
Unsecured notes | Notes Payable 3.500 Maturities 2025 [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes			$ 300,000
Stated interest rate of unsecured notes (as a percent)			3.50%
Unsecured notes | Notes Payable 2.950 Maturities 2026 [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes			$ 475,000
Stated interest rate of unsecured notes (as a percent)			2.95%
Unsecured notes | Notes Payable 2.900 Maturities 2026 [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes			$ 300,000
Stated interest rate of unsecured notes (as a percent)			2.90%
Unsecured notes | Notes Payable Maturities 2027 [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes			$ 400,000
Stated interest rate of unsecured notes (as a percent)			3.35%
Unsecured notes | Notes Payable Maturities 2046 [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes			$ 350,000
Stated interest rate of unsecured notes (as a percent)			3.90%
Unsecured notes | Notes Payable Maturities 2047 [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes			$ 300,000
Stated interest rate of unsecured notes (as a percent)			4.15%
Unsecured notes | Notes Payable Maturities 2028 [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes			$ 450,000
Stated interest rate of unsecured notes (as a percent)			3.20%
Secured notes
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Secured notes payments			$ 192,304
Mortgage notes payable and unsecured notes			1,312,009
Secured notes | Notes payable maturing in 2017
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Stated interest rate of unsecured notes (as a percent)					6.256%
Secured notes | Notes payable maturing in 2018
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Secured notes payments			7,258
Mortgage notes payable and unsecured notes			76,663
Secured notes | Notes payable maturing in 2019
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Secured notes payments			4,696
Mortgage notes payable and unsecured notes			114,721
Stated interest rate of unsecured notes (as a percent)				5.86%
Secured notes | Notes Payable Maturities 2020 [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Secured notes payments			3,624
Mortgage notes payable and unsecured notes			140,429
Secured notes | Notes payable maturing in 2021
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Secured notes payments			3,551
Mortgage notes payable and unsecured notes			27,844
Secured notes | Notes payable maturing in 2022
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Secured notes payments			3,795
Secured notes | Notes Payable Maturities 2023 [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Secured notes payments			4,040
Secured notes | Notes Payable 2024
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Secured notes payments			4,310
Secured notes | Notes Payable Maturities 2025 [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Secured notes payments			4,585
Mortgage notes payable and unsecured notes			84,835
Secured notes | Notes Payable Maturities 2026 [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Secured notes payments			4,894
Secured notes | Notes Payable Maturities 2027 [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Secured notes payments			3,083
Mortgage notes payable and unsecured notes			185,100
Stated interest rate of unsecured notes (as a percent)					3.61%
Secured notes | Notes Payable Maturities Thereafter [Member]
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Secured notes payments			148,468
Mortgage notes payable and unsecured notes			$ 682,417

Equity (Details)

Equity (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Class of Stock [Line Items]
Common stock, shares authorized	280,000,000	280,000,000
Preferred stock, shares authorized	50,000,000	50,000,000
Common stock shares issued in connection with stock options exercised	42,123
Common stock shares issued through dividend reinvestment plan	3,058	2,396	2,142
Number of shares of stock grants withheld	60,319	53,453	45,090
Common shares issued under Employee Stock Purchase Plan	11,528
Number of shares forfeited	3,388
Issuance of common stock, net	$ 111,093,000	$ 15,526,000	$ 690,184,000
Continuous Equity Program CEP IV [Member]
Class of Stock [Line Items]
Maximum value of shares of common stock that can be sold	$ 1,000,000,000
Percentage of compensation received by sales agent	2.00%
Issuance of common stock, net of withholdings (in shares)	568,424
Shares issued, weighted average price per share (in dollars per share)	$ 188.39
Issuance of common stock, net	$ 105,478,000
Common stock value, remaining to be authorized under continuous equity program	$ 892,915,000
Maximum [Member] | Continuous Equity Program CEP IV [Member]
Class of Stock [Line Items]
Percentage of compensation received by sales agent	2.00%
Restricted Stock Converted From Performance Shares [Member]
Class of Stock [Line Items]
Common stock shares issued in connection with stock grants	201,824	197,018	157,779

Investments in Real Estate En42

Investments in Real Estate Entities (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)communityhomeloanextensionagreementinvestorft²mi	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Feb. 27, 2013
Schedule of Equity Method Investments [Line Items]
(Loss) gain on other real estate transactions	$ (10,907)	$ 10,224	$ 9,647
Gain on sale of communities	$ 136,333	196,749	98,899
Number of Communities Acquired | community	3
Payments to Acquire Other Real Estate	$ 462,317	393,316	0
Loss (gain) on extinguishment of debt, net	$ 25,472	7,075	(26,736)
Number of Apartment Homes in Communities Owned | home	81,517
Preferred interest obligation redemption and dividends	$ (2,000)	(1,960)	(14,410)
Investments in unconsolidated real estate entities	163,475	175,116
Equity Method Investment, Difference Between Carrying Amount and Underlying Equity	35,402	38,015
Expensed acquisition, development and other pursuit costs, net of recoveries	2,736	9,922	6,822
The Lodge Denver West [Member]
Schedule of Equity Method Investments [Line Items]
Payments to Acquire Other Real Estate	$ 76,750
Number of Apartment Homes, Acquired | home	252
Avalon Dunn Loring [Member]
Schedule of Equity Method Investments [Line Items]
Payments to Acquire Other Real Estate	$ 151,000
Number of Apartment Homes, Acquired | home	440
Retail square feet acquired | ft²	27,000
850 Boca [Member]
Schedule of Equity Method Investments [Line Items]
Payments to Acquire Other Real Estate	$ 138,000
Number of Apartment Homes, Acquired | home	370
Acquired Real Estate [Member]
Schedule of Equity Method Investments [Line Items]
Expensed acquisition, development and other pursuit costs, net of recoveries		5,139	3,806
Archstone Enterprise LP
Schedule of Equity Method Investments [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired				40.00%
Equity Residential and its Operating Partnership and ERP Operating Limited Partnership [Member] | Archstone Enterprise LP
Schedule of Equity Method Investments [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired				60.00%
Fund II
Schedule of Equity Method Investments [Line Items]
Number of Institutional Investors | investor	6
Real Estate Investments, Joint Ventures	$ 2,576
Equity Method Investment, Ownership Percentage	31.30%
Number of apartment communities sold | community	3
Apartment homes | home	1,366
Gain on sale of communities	$ 26,322	41,501	29,726
Repayments of secured mortgages	$ 127,179
Percentage of Right of Distribution	40.00%
Percentage of Right of Remaining Distribution	60.00%
Equity in income of unconsolidated entities relating to the Company's recognition of promoted interest	$ 26,742	7,985
Fund II | Eaves Gaithersburg [Member]
Schedule of Equity Method Investments [Line Items]
Proceeds from Sale of Real Estate	117,000
Fund II | Briarwood Apartments [Member]
Schedule of Equity Method Investments [Line Items]
Proceeds from Sale of Real Estate	64,750
Fund II | Avalon Watchung [Member]
Schedule of Equity Method Investments [Line Items]
Proceeds from Sale of Real Estate	$ 90,300
US Fund
Schedule of Equity Method Investments [Line Items]
Number of Institutional Investors | investor	6
Real Estate Investments, Joint Ventures	$ 39,896
Equity Method Investment, Ownership Percentage	28.60%
Gain on sale of communities	$ 13,788	$ 16,568
Number of loans secured by individual assets | loan	6
Debt outstanding	$ 237,469
Number of extension options | extension	2
Period of extension (in years)	1 year
US Fund | Eaves Sunnyvale [Member]
Schedule of Equity Method Investments [Line Items]
Apartment homes | home	192
Proceeds from Sale of Real Estate	$ 107,000
Repayments of secured mortgages	32,542
Loss (gain) on extinguishment of debt, net	$ 406
ACJV
Schedule of Equity Method Investments [Line Items]
Number of Institutional Investors | investor	4
Real Estate Investments, Joint Ventures	$ 49,492
Equity Method Investment, Ownership Percentage	20.00%
Maximum geographic radius for existing assets within considered for right of first offer | mi	1
Number of loans secured by individual assets | loan	8
Debt outstanding	$ 162,300
MVPI LLC
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	25.00%
Percentage of Right of Distribution		45.00%
Equity in income of unconsolidated entities relating to the Company's recognition of promoted interest			21,340
Number of Apartment Homes in Communities Owned | home	313
MVPI LLC | Joint Venture Agreement Modification [Member]
Schedule of Equity Method Investments [Line Items]
Payments for (Proceeds from) Other Real Estate Partnerships			$ 20,680
Brandywine [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	28.70%
Debt outstanding	$ 22,760
Number of Apartment Homes in Communities Owned | home	305
Number of Members who Hold Various Interests in Joint Venture | investor	5
SWIB [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	20.00%
Residual JV
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	40.00%
Number of Limited Liability Company Agreements | agreement	3
Legacy JV [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	40.00%
Preferred Interest Obligation Liquidation Value	$ 37,579
Sudbury [Member]
Schedule of Equity Method Investments [Line Items]
Real Estate Investments, Joint Ventures	$ (4,340)
Equity Method Investment, Ownership Percentage	60.00%
Land	$ 19,200
AVA North Point [Member]
Schedule of Equity Method Investments [Line Items]
Real Estate Investments, Joint Ventures	$ 36,370
Equity Method Investment, Ownership Percentage	55.00%
(Loss) gain on other real estate transactions	$ 10,621
Number of Apartment Homes in Communities Owned | home	265
AVA North Point [Member] | Joint Venture Partner [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	45.00%
Avalon Brooklyn Bay [Member]
Schedule of Equity Method Investments [Line Items]
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage	70.00%
Variable Interest Entity, Ownership Interest by Partner	30.00%
Due from Related Parties	$ 44,831

Investments in Real Estate En43

Investments in Real Estate Entities (Details 2) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets:
Real estate, net	$ 695,077	$ 954,493
Other assets	39,976	49,519
Total assets	735,053	1,004,012
Liabilities and partners' capital:
Mortgage notes payable, net and credit facility	523,815	689,573
Other liabilities	10,540	16,537
Partners' capital	200,698	297,902
Total liabilities and partners' capital	$ 735,053	$ 1,004,012

Investments in Real Estate En44

Investments in Real Estate Entities (Details 3) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Combined summary of the operating results of the accounted for using the equity method
Rental and other income	$ 101,615	$ 131,901	$ 173,578
Operating and other expenses	(38,566)	(50,945)	(67,962)
Gain on sale of communities	136,333	196,749	98,899
Interest expense, net	(27,104)	(45,886)	(45,517)
Depreciation expense	(25,914)	(34,471)	(45,324)
Net income	146,364	197,348	113,674
Schedule of Equity Method Investments [Line Items]
Loss (gain) on extinguishment of debt, net	25,472	7,075	(26,736)
Funds [Member]
Schedule of Equity Method Investments [Line Items]
Loss (gain) on extinguishment of debt, net	1,591	12,659	4,481
Fund II
Combined summary of the operating results of the accounted for using the equity method
Gain on sale of communities	26,322	41,501	$ 29,726
Equity in income of unconsolidated entities relating to the Company's recognition of promoted interest	$ 26,742	$ 7,985

Investments in Real Estate En45

Investments in Real Estate Entities (Details 4) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Summary of the Company's equity in income of unconsolidated entities
Equity in income of unconsolidated real estate entities	$ 70,744	$ 64,962	$ 70,018
Gain on sale of communities	136,333	196,749	98,899
Fund I
Summary of the Company's equity in income of unconsolidated entities
Equity in income of unconsolidated real estate entities	0	87	871
Fund II
Summary of the Company's equity in income of unconsolidated entities
Equity in income of unconsolidated real estate entities	53,961	49,882	32,211
Equity in income of unconsolidated entities relating to the Company's recognition of promoted interest	26,742	7,985
Gain on sale of communities	26,322	41,501	29,726
US Fund
Summary of the Company's equity in income of unconsolidated entities
Equity in income of unconsolidated real estate entities	14,773	15,635	2,052
Gain on sale of communities	13,788	16,568
ACJV
Summary of the Company's equity in income of unconsolidated entities
Equity in income of unconsolidated real estate entities	1,388	1,445	511
MVPI LLC
Summary of the Company's equity in income of unconsolidated entities
Equity in income of unconsolidated real estate entities	1,833	1,627	22,453
Equity in income of unconsolidated entities relating to the Company's recognition of promoted interest			21,340
MVPI LLC | Joint Venture Agreement Modification [Member]
Summary of the Company's equity in income of unconsolidated entities
Payments for (Proceeds from) Other Real Estate Partnerships			20,680
Brandywine [Member]
Summary of the Company's equity in income of unconsolidated entities
Equity in income of unconsolidated real estate entities	106	10	(1,474)
CVP I, LLC
Summary of the Company's equity in income of unconsolidated entities
Equity in income of unconsolidated real estate entities	0	9	1,812
Equity in income of unconsolidated entities relating to the Company's recognition of promoted interest			1,289
Residual JV
Summary of the Company's equity in income of unconsolidated entities
Equity in income of unconsolidated real estate entities	(1,223)	(1,374)	11,582
Avalon Clarendon [Member]
Summary of the Company's equity in income of unconsolidated entities
Equity in income of unconsolidated real estate entities	0	(2,359)	0
AVA North Point [Member]
Summary of the Company's equity in income of unconsolidated entities
Equity in income of unconsolidated real estate entities	(122)	0	0
Sudbury [Member]
Summary of the Company's equity in income of unconsolidated entities
Equity in income of unconsolidated real estate entities	$ 28	$ 0	$ 0

Real Estate Disposition Activ46

Real Estate Disposition Activities (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)communityland_parcelhome	Dec. 31, 2016USD ($)home	Dec. 31, 2015USD ($)home
Summary of income from discontinued operations
Gain on sale of communities	$ 252,599	$ 374,623	$ 115,625
Number of Land Parcels Sold | land_parcel	3
(Loss) gain on other real estate transactions	$ (10,907)	$ 10,224	$ 9,647
Avalon Pines [Member]
Summary of income from discontinued operations
Apartment homes | home	450
Gross sales price	$ 140,000
Net cash proceeds	$ 138,689
AVA University District [Member]
Summary of income from discontinued operations
Apartment homes | home	283
Gross sales price	$ 112,500
Net cash proceeds	$ 108,511
Avalon Danbury [Member]
Summary of income from discontinued operations
Apartment homes | home	234
Gross sales price	$ 52,000
Net cash proceeds	$ 51,000
Avalon Run East [Member]
Summary of income from discontinued operations
Apartment homes | home	312
Gross sales price	$ 87,500
Net cash proceeds	$ 85,033
Avalon Huntington [Member]
Summary of income from discontinued operations
Apartment homes | home	99
Gross sales price	$ 33,000
Net cash proceeds	$ 32,173
Avalon Milford [Member]
Summary of income from discontinued operations
Apartment homes | home	246
Gross sales price	$ 50,500
Net cash proceeds	49,161
Other Real Estate Sales [Member]
Summary of income from discontinued operations
(Loss) gain on other real estate transactions	1,682
Gross sales price	39,154
Net cash proceeds	$ 38,472
Newcastle Land [Member]
Summary of income from discontinued operations
Number of Land Parcels Sold | land_parcel	2
Tysons West Land [Member]
Summary of income from discontinued operations
Number of Land Parcels Sold | land_parcel	1
Wholly Owned Properties
Summary of income from discontinued operations
Number of apartment communities sold | community	6
Sale of Communities Gross Sales Price	$ 475,500
Gain on sale of communities	$ 251,163
Apartment homes | home	1,624	2,051	851
Repayments of secured mortgages	$ 0	$ 0	$ 0
Gross sales price	514,654	564,028	289,320
Net cash proceeds	$ 503,039	$ 532,717	$ 282,163

Commitments and Contingencies47

Commitments and Contingencies (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)communitypropertyClaimmultiplierLeaseplaintiff	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Employment Agreements and Arrangements [Abstract]
Proceeds from legal recoveries | $	$ 6,118	$ 0	$ 417
Capital Leased Assets, Gross | $	19,737	39,015
Lease Obligations [Abstract]
Cost related to operating lease | $	$ 23,431	23,343	21,295
Number of Office Leases | Lease	14
Payments to Acquire Other Real Estate | $	$ 462,317	393,316	0
(Loss) gain on other real estate transactions | $	(10,907)	10,224	9,647
Repayments of Long-term Capital Lease Obligations | $	$ 18,951	$ 0	$ 0
Properties on Land Subject to Land Leases
Lease Obligations [Abstract]
Number of apartment communities | community	13
Number of Operating Apartment Communities Under Construction | community	1
Number of commercial properties owned | property	2
Number of leased properties accounted for as operating leases | community	13
Number of Dual Branded Properties with Operating Land Leases | community	2
Land Subject to Ground Leases | Lease	1
Number of leased properties with purchase options | property	5
Assets Held under Capital Leases
Lease Obligations [Abstract]
Number of apartment communities | community	1
Capital lease obligations | $	$ 20,118
Restricted stock and stock options
Employment Agreements and Arrangements [Abstract]
Retirement age (in years)	50 years
Period of the non-compete agreement (in years)	1 year
Restricted stock and stock options | Minimum
Employment Agreements and Arrangements [Abstract]
Service period (in years)	10 years
Employee's age at retirement plus years of employment (in years)	70 years
Written notice period (in years)	6 months
Restricted stock and stock options | Maximum
Employment Agreements and Arrangements [Abstract]
Options exercise period upon termination without cause or retirement (in months)	12 months
Officer Severance Program | Vice President and Senior Vice President
Employment Agreements and Arrangements [Abstract]
Compensation multiplier | multiplier	1
Officer Severance Program | Executive Vice Presidents
Employment Agreements and Arrangements [Abstract]
Compensation multiplier | multiplier	2
Officer Severance Program | Chief Executive Officer [Member]
Employment Agreements and Arrangements [Abstract]
Compensation multiplier | multiplier	3
Officer Severance Program | Maximum
Employment Agreements and Arrangements [Abstract]
Termination period following a sale event (in years)	18 months
Memorial Heights Villages [Member]
Employment Agreements and Arrangements [Abstract]
Proceeds from legal recoveries | $	$ 5,438
Avalon at Edgewater [Member]
Employment Agreements and Arrangements [Abstract]
Loss Contingency New Class Action Claims Filed Number	3
Loss Contingency Class Action Claims Filed, Additional, Number	4
Loss Contingency, Claims Filed, Number, Consolidated	18
Loss Contingency, New Claims Filed, Number	19
Loss Contingency, Number of Plaintiffs | plaintiff	143
Loss Contingency Class Action Claims Filed, Number of Apartments in Settlement Resolved	50
Loss Contingency Class Action Claims Filed, Number of Apartments in Settlement Previously Resolved	10
Loss Contingency Class Action Claims Filed, Number of Apartments in Settlement, Number of Lawsuits Remaining	1
Loss Contingency New Subrogation Claims Filed Number	7
Loss Contingency Subrogation Claims Filed Dismissed Number	1
Loss Contingency Subrogation Claims Filed Pending Not Dismissed Number	1
Loss Contingency Subrogation Claims Filed Resolved Number	1
Loss Contingency Subrogation Claims Filed Pending Number	4
Lease Obligations [Abstract]
Loss Contingency Class Action Claims Filed, Number of Apartments Included in Settlement	66
Loss Contingency Class Action Claims Filed, Number of Apartments Included in Settlement Remaining	1
Loss Contingency Class Action Claims Filed, Number of Apartments Included in Settlement Submitted	44
Loss Contingency Class Action Claims Filed, Number of Apartments Included in Settlement Submitted Amount | $	$ 6,900
Loss Contingency Class Action Claims Filed, Number of Apartments Issued Awards By Claims Adjuster	3
Avalon Morningside Park [Member]
Lease Obligations [Abstract]
Payments to Acquire Other Real Estate | $	$ 95,000
(Loss) gain on other real estate transactions | $	(11,153)
Avalon at Assembly Row and AVA Somerville [Member]
Lease Obligations [Abstract]
Repayments of Long-term Capital Lease Obligations | $	$ 17,285

Commitments and Contingencies48

Commitments and Contingencies (Details 2) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Future minimum lease payments under the Company's current leases
2,018	$ 22,124
2,019	22,139
2,020	19,858
2,021	21,242
2,022	21,139
Thereafter	1,096,784
Operating Lease Obligations
2,018	21,051
2,019	21,064
2,020	18,781
2,021	20,162
2,022	20,057
Thereafter	1,052,808
Capital lease obligations
2,018	1,073
2,019	1,075
2,020	1,077
2,021	1,080
2,022	1,082
Thereafter	43,976
Imputed interest on capital leases	25,961
Capital Leased Assets, Gross	$ 19,737	$ 39,015

Segment Reporting (Details)

Segment Reporting (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Percentage of physical occupancy									95.00%
Anniversary of Completion of Development or Redevelopment (in years)									1 year
Reconciliation of NOI to net income
Net income	$ 237,486	$ 238,199	$ 165,194	$ 235,781	$ 242,183	$ 356,329	$ 197,319	$ 237,877	$ 876,660	$ 1,033,708	$ 741,733
Indirect operating expenses, net of corporate income									65,398	61,403	56,973
Investments and investment management expense									5,936	4,822	4,370
Expensed acquisition, development and other pursuit costs, net of recoveries									2,736	9,922	6,822
Interest expense, net									199,661	187,510	175,615
Loss (gain) on extinguishment of debt, net									25,472	7,075	(26,736)
General and administrative expense									50,673	45,771	42,774
Equity in income of unconsolidated real estate entities									(70,744)	(64,962)	(70,018)
Depreciation expense									584,150	531,434	477,923
Income tax expense									141	305	1,483
Casualty and impairment loss (gain), net									6,250	(3,935)	(10,542)
Gain on sale of communities									(252,599)	(374,623)	(115,625)
(Loss) gain on other real estate transactions									10,907	(10,224)	(9,647)
Net operating income from real estate assets sold or held for sale									(14,573)	(44,263)	(59,383)
Net operating income									$ 1,490,068	$ 1,383,943	$ 1,215,742

Segment Reporting Segment Repor

Segment Reporting Segment Reporting (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting [Abstract]
Rental income from real estate assets sold or held for sale	$ 23,457	$ 70,273	$ 96,297
Operating expenses from real estate assets sold or held for sale	(8,884)	(26,010)	(36,914)
Net operating income from real estate assets sold or held for sale	$ 14,573	$ 44,263	$ 59,383

Segment Reporting (Details 3)

Segment Reporting (Details 3) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting
Total revenue	$ 555,292	$ 550,500	$ 530,512	$ 522,326	$ 518,240	$ 516,211	$ 502,307	$ 508,498	$ 2,158,628	$ 2,045,255	$ 1,856,028
NOI									$ 1,490,068	$ 1,383,943	$ 1,215,742
% NOI change from prior year (percent)									7.70%	13.80%	13.00%
Gross real estate	21,935,936				20,755,780				$ 21,935,936	$ 20,755,780	$ 19,228,571
Gross real estate assets held for sale					20,846					20,846	39,528
Gain on Business Interruption Insurance Recovery									3,498	20,564	1,509
Established
Segment Reporting
Real estate capitalized additions	78,241				85,676				78,241	85,676	74,982
Operating segment | Established
Segment Reporting
Total revenue									1,575,260	1,502,974	1,315,929
NOI									$ 1,112,472	$ 1,057,997	$ 929,944
% NOI change from prior year (percent)									2.50%	4.80%	6.00%
Gross real estate	13,565,763				13,511,377				$ 13,565,763	$ 13,511,377	$ 12,391,586
Operating segment | Established | New England
Segment Reporting
Total revenue									233,091	226,727	170,287
NOI									$ 150,253	$ 145,671	$ 107,189
% NOI change from prior year (percent)									2.10%	4.80%	3.00%
Gross real estate	1,852,676				1,888,524				$ 1,852,676	$ 1,888,524	$ 1,460,746
Operating segment | Established | Metro NY/NJ
Segment Reporting
Total revenue									362,273	359,373	342,768
NOI									$ 247,720	$ 245,654	$ 244,280
% NOI change from prior year (percent)									2.10%	1.20%	3.60%
Gross real estate	3,069,690				3,212,220				$ 3,069,690	$ 3,212,220	$ 3,152,361
Operating segment | Established | Mid-Atlantic
Segment Reporting
Total revenue									221,064	233,711	209,012
NOI									$ 153,750	$ 162,243	$ 145,497
% NOI change from prior year (percent)									1.50%	1.30%	0.20%
Gross real estate	2,056,066				2,339,395				$ 2,056,066	$ 2,339,395	$ 2,177,823
Operating segment | Established | Pacific Northwest
Segment Reporting
Total revenue									84,189	72,475	67,900
NOI									$ 61,527	$ 52,434	$ 48,833
% NOI change from prior year (percent)									6.30%	7.40%	8.50%
Gross real estate	738,532				737,289				$ 738,532	$ 737,289	$ 721,040
Operating segment | Established | Northern California
Segment Reporting
Total revenue									336,767	319,121	273,432
NOI									$ 257,673	$ 244,458	$ 210,226
% NOI change from prior year (percent)									1.60%	7.00%	11.90%
Gross real estate	2,830,963				2,661,258				$ 2,830,963	$ 2,661,258	$ 2,414,184
Operating segment | Established | Southern California
Segment Reporting
Total revenue									337,876	291,567	252,530
NOI									$ 241,549	$ 207,537	$ 173,919
% NOI change from prior year (percent)									3.90%	9.10%	9.40%
Gross real estate	3,017,836				2,672,691				$ 3,017,836	$ 2,672,691	$ 2,465,432
Operating segment | Other Stabilized
Segment Reporting
Total revenue									278,868	232,977	211,633
NOI									196,733	165,130	140,167
Gross real estate	3,189,393				2,330,503				3,189,393	2,330,503	2,040,269
Operating segment | Development / Redevelopment
Segment Reporting
Total revenue									276,896	233,432	222,222
NOI									180,863	160,816	145,631
Gross real estate	5,015,094				4,755,315				5,015,094	4,755,315	4,238,967
Segment Reconciling Items [Member]
Segment Reporting
Gross real estate	68,364				84,293				68,364	84,293	484,377
Non-allocated
Segment Reporting
Total revenue									4,147	5,599	9,947
Gross real estate	$ 97,322				$ 74,292				97,322	74,292	73,372
Continuing Operations
Segment Reporting
Total revenue									2,135,171	1,974,982	$ 1,759,731
Avalon Maplewood [Member]
Segment Reporting
Gain on Business Interruption Insurance Recovery									$ 3,495
Avalon at Edgewater [Member]
Segment Reporting
Gain on Business Interruption Insurance Recovery										$ 20,306

Stock-Based Compensation Plan52

Stock-Based Compensation Plans (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Stock-Based Compensation Plans
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Shares
Exercised (in shares)	(42,123)
2009 Plan
Stock-Based Compensation Plans
Common stock, par value (in dollars per share)	$ 0.01
Common stock shares available for grant	7,994,292
2009 Plan | Stock Options
Shares
Options outstanding at the beginning of the period (in shares)	177,333	249,178	340,062
Exercised (in shares)	(27,360)	(71,845)	(90,884)
Granted (in shares)	0	0	0
Forfeited (in shares)	0	0	0
Options outstanding at the end of the period (in shares)	149,973	177,333	249,178
Options exercisable at the end of the period (in shares)	149,973	177,333	188,081
Weighted average exercise price per share
Options outstanding at the beginning of the period (in dollars per share)	$ 124.25	$ 122.17	$ 122.67
Exercised (in dollars per share)	110.47	117.04	124.01
Granted (in dollars per share)	0	0	0
Forfeited (in dollars per share)	0	0	0
Options outstanding at the end of the period (in dollars per share)	126.77	124.25	122.17
Options exercisable at the end of the period (in dollars per share)	$ 126.77	$ 124.25	$ 119.98
1994 Plan | Stock Options
Shares
Options outstanding at the beginning of the period (in shares)	22,541	82,195	272,402
Exercised (in shares)	(14,763)	(59,654)	(190,207)
Granted (in shares)	0	0	0
Forfeited (in shares)	0	0	0
Options outstanding at the end of the period (in shares)	7,778	22,541	82,195
Options exercisable at the end of the period (in shares)	7,778	22,541	82,195
Weighted average exercise price per share
Options outstanding at the beginning of the period (in dollars per share)	$ 77.91	$ 103.27	$ 104.96
Exercised (in dollars per share)	93.35	112.85	105.70
Granted (in dollars per share)	0	0	0
Forfeited (in dollars per share)	0	0	0
Options outstanding at the end of the period (in dollars per share)	48.60	77.91	103.27
Options exercisable at the end of the period (in dollars per share)	$ 48.60	$ 77.91	$ 103.27

Stock-Based Compensation Plan53

Stock-Based Compensation Plans (Details 2) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Stock Options
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Intrinsic value of options exercised	$ 3,592	$ 9,187	$ 18,080
2009 Plan
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding intrinsic value	7,745
Options exercisable intrinsic value	$ 7,745
Options exercisable weighted average contractual life (in years)	4 years 7 months 6 days
2009 Plan | Stock Options
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Options (in shares)	149,973
1994 Plan
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding intrinsic value	$ 1,010
Options exercisable intrinsic value	$ 1,010
Options exercisable weighted average contractual life (in years)	1 year 1 month 6 days
40.00 - 49.99 | 1994 Plan | Stock Options
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Options (in shares)	7,778
Exercise Price, lower limit (in dollars per share)	$ 40
Exercise Price, upper limit (in dollars per share)	$ 49.99
Weighted Average Remaining Contractual Term	1 year 1 month 6 days
70.00 - 79.99 | 2009 Plan | Stock Options
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Options (in shares)	5,158
Exercise Price, lower limit (in dollars per share)	$ 70
Exercise Price, upper limit (in dollars per share)	$ 79.99
Weighted Average Remaining Contractual Term	2 years 1 month 6 days
110.00 - 119.99 | 2009 Plan | Stock Options
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Options (in shares)	15,762
Exercise Price, lower limit (in dollars per share)	$ 110
Exercise Price, upper limit (in dollars per share)	$ 119.99
Weighted Average Remaining Contractual Term	3 years 1 month 6 days
120.00 - 129.99 | 2009 Plan | Stock Options
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Options (in shares)	29,862
Exercise Price, lower limit (in dollars per share)	$ 120
Exercise Price, upper limit (in dollars per share)	$ 129.99
Weighted Average Remaining Contractual Term	5 years 2 months 12 days
130.00 - 139.99 | 2009 Plan | Stock Options
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Options (in shares)	99,191
Exercise Price, lower limit (in dollars per share)	$ 130
Exercise Price, upper limit (in dollars per share)	$ 139.99
Weighted Average Remaining Contractual Term	4 years 7 months 6 days

Stock-Based Compensation Plan54

Stock-Based Compensation Plans (Details 3) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)periodshares	Dec. 31, 2016USD ($)shares	Dec. 31, 2015USD ($)shares	Oct. 31, 1996shares
Additional disclosures
Stock-based compensation expense	$ 17,085	$ 14,666	$ 14,703
Capitalized stock-based compensation cost	$ 9,474	9,266	9,667
Employee Stock Purchase Plan [Abstract]
Shares issued under Employee Stock Purchase Plan | shares	11,528
Stock-based compensation expense	$ 17,085	14,666	14,703
Stock Options
Additional disclosures
Forfeiture rate (as a percent)	0.70%
Performance awards
Additional disclosures
Maximum Measurement Period (in years)	3 years
Award vesting period (in years)	3 years
Performance awards | Maximum
Additional disclosures
Percentage of stock based compensation elected to be received in the form of stock options upon the election of the recipient	25.00%
Restricted Stock and Restricted Stock Units [Member]
Additional disclosures
Unrecognized compensation cost for unvested stock options	$ 26,305
Weighted average period for recognition of unrecognized compensation cost	3 years 7 months 6 days
Non Qualified Employee Stock Purchase Plan [Member]
Additional disclosures
Stock-based compensation expense	$ 418	$ 289	$ 321
Employee Stock Purchase Plan [Abstract]
Employee stock purchase plan, shares of common stock reserved for issuance | shares				1,000,000
Employee stock purchase plan, remaining shares of common stock available for issuance | shares	681,284
Employment period of full-time employees for becoming eligible to participate in the plan (in months)	1 month
Employment period of other employees for becoming eligible to participate in the plan (in months)	12 months
Number of purchase periods | period	2
Employee stock purchase plan, discounted stock price percentage	85.00%
Shares issued under Employee Stock Purchase Plan | shares	11,528	11,348	10,667
Stock-based compensation expense	$ 418	$ 289	$ 321

Stock-Based Compensation Plan55

Stock-Based Compensation Plans (Details 4) - Performance awards - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Performance awards
Outstanding at the beginning of the period (in shares)	251,163	238,266	239,902
Granted (in shares)	81,708	94,054	85,636
Increase (decrease) in awards based on performance (in shares)	49,323	36,091	14,697
Converted to restricted stock (in shares)	(128,482)	(115,618)	(95,826)
Forfeited (in shares)	(1,942)	(1,630)	(6,143)
Outstanding at the ending of the period (in shares)	251,770	251,163	238,266
Weighted average grant date fair value per award
Outstanding at the beginning of the period (in dollars per share)	$ 136.74	$ 119.65	$ 95.20
Granted (in dollars per share)	176.59	141.92	148.49
Change in awards based on performance (in dollars per share)	119.26	101.52	78.50
Converted to restricted stock (in dollars per share)	118.75	94.67	78.50
Forfeited (in dollars per share)	159.39	141.98	110.34
Outstanding at the ending of the period (in dollars per share)	$ 155.25	$ 136.74	$ 119.65
Grants in period based on shareholder metrics (in shares)	49,374	61,039	55,162
Grants in period based on financial metrics (in shares)	32,334	33,015	30,474

Stock-Based Compensation Plan56

Stock-Based Compensation Plans (Details 5) - Performance awards - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Dividend yield (as a percent)	3.20%	3.30%	3.00%
Estimated volatility, minimum (as a percent)	15.30%	15.20%	12.00%
Estimated volatility, maximum (as a percent)	19.70%	22.80%	17.30%
Risk-free interest rate, minimum (as a percent)	0.69%	0.44%	0.07%
Risk-free interest rate, maximum (as a percent)	1.61%	0.88%	1.09%
Estimated performance award value based on total shareholder return measure (in dollars per share)	$ 175.86	$ 131.24	$ 139.18
Historical volatility (as a percent)	50.00%	50.00%	50.00%
Implied volatility (as a percent)	50.00%	50.00%	50.00%
Market closing price (in dollars per share)	$ 179.07	$ 161.66	$ 166.23

Stock-Based Compensation Plan57

Stock-Based Compensation Plans (Details 6) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restricted stock
Restricted stock shares
Outstanding at the beginning of the period (in shares)	136,705	147,884	179,307
Granted (in shares)	73,342	81,400	61,953
Vested (in shares)	(73,683)	(88,712)	(91,847)
Forfeited (in shares)	(2,731)	(3,867)	(1,529)
Outstanding at the ending of the period (in shares)	133,633	136,705	147,884
Restricted stock shares weighted average grant date fair value per share
Outstanding at the beginning of the period (in dollars per share)	$ 158.51	$ 146.21	$ 129.06
Granted (in dollars per share)	179.58	162.38	173.04
Vested (in dollars per share)	153.86	141.38	130.75
Forfeited (in dollars per share)	173.42	162.43	151.86
Outstanding at the ending of the period (in dollars per share)	$ 172.33	$ 158.51	$ 146.21
Restricted stock converted from performance shares
Restricted stock shares
Outstanding at the beginning of the period (in shares)	176,698	98,347	10,933
Granted (in shares)	128,482	115,618	95,826
Vested (in shares)	(70,595)	(36,872)	(8,412)
Forfeited (in shares)	(657)	(395)	0
Outstanding at the ending of the period (in shares)	233,928	176,698	98,347

Related Party Arrangements (Det

Related Party Arrangements (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Related Party Arrangements
Management fees revenue	$ 4,147,000	$ 5,599,000	$ 9,947,000
Compensation expense	17,085,000	14,666,000	14,703,000
Unconsolidated real estate entities
Related Party Arrangements
Outstanding receivables	2,449,000	5,239,000
Non-employee directors
Related Party Arrangements
Payable to related parties	80,000
Payable to related parties in quarterly installments	20,000
Non-employee directors | Restricted stock and deferred stock awards
Related Party Arrangements
Payable to related parties	135,000
Compensation expense	1,524,000	1,216,000	1,135,000
Amount of deferred compensation	525,000	$ 531,000	$ 488,000
Lead Independent Director
Related Party Arrangements
Payable to related parties	30,000
Payable to related parties in quarterly installments	7,500
Non-employees directors serving as a chairperson
Related Party Arrangements
Payable to related parties	20,000
Payable to related parties in quarterly installments	5,000
Non Employee Director Serving As A Chairperson of the Nominating and Corporate Governance or Investment and Finance Committees [Member]
Related Party Arrangements
Payable to related parties	15,000
Payable to related parties in quarterly installments	$ 3,750

Fair Value (Details)

Fair Value (Details)	1 Months Ended			12 Months Ended
	Jun. 30, 2017USD ($)	May 31, 2017USD ($)community	Apr. 30, 2017USD ($)	Dec. 31, 2017USD ($)communityderivativeventure	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Derivative instruments and Hedging Activities
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred				$ 376,000
Number of Real Estate Properties | community				267
Gain on Fair Value Hedge Ineffectiveness				$ 753,000
Amortization Period of Deferred Gain (Loss) on Discontinuation of Interest Rate Fair Value Hedge				10 years
Derivative, Notional Amounts Settled During Period	$ 214,900,000	$ 400,000,000	$ 185,100,000	$ 800,000,000
Receipts (payments) for termination of forward interest rate swaps	$ (4,078,000)	$ 1,361,000	$ 2,326,000	(391,000)	$ 14,847,000	$ 0
Income (loss) on cash flow hedges				$ (13,979,000)	$ (5,556,000)	$ 5,354,000
Cash Flow Hedges Interest Rate Caps
Derivative instruments and Hedging Activities
Number of derivative instruments held | derivative				7
Puts
Derivative instruments and Hedging Activities
Number of ventures in which entity is required to purchase interest in investment at guaranteed minimum amount | venture				3
Interest Rate Caps | Cash Flow Hedges Interest Rate Caps
Derivative instruments and Hedging Activities
Notional balance				$ 35,039,000
Weighted average interest rate (as a percent)				3.50%
Weighted average capped interest rate (as a percent)				5.90%
Interest Rate Swap [Member] | Cash Flow Hedges Interest Rate Caps
Derivative instruments and Hedging Activities
Notional balance				$ 300,000,000
Weighted average capped interest rate (as a percent)				2.40%
Derivative, Notional Amounts Entered into During Period				$ 300,000,000
Non-designated Hedges Interest Rate Caps
Derivative instruments and Hedging Activities
Number of derivative instruments held | derivative				14
Non-designated Hedges Interest Rate Caps | Interest Rate Caps
Derivative instruments and Hedging Activities
Notional balance				$ 689,059,000
Weighted average interest rate (as a percent)				3.30%
Weighted average capped interest rate (as a percent)				6.50%
Notes Payable Maturities 2027 [Member] | Secured notes
Derivative instruments and Hedging Activities
Number of Real Estate Properties | community		3
Reclassification out of Accumulated Other Comprehensive Income [Member]
Derivative instruments and Hedging Activities
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred				$ 7,012,000

Fair Value (Details 2)

Fair Value (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Cash flow hedge losses reclassified to earnings	$ 7,070	$ 6,433	$ 5,774

Fair Value (Details 3)

Fair Value (Details 3) $ in Thousands	Dec. 31, 2017USD ($)derivative	Dec. 31, 2016USD ($)
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial Instruments Measured/Discussed at Fair Value
DownREIT units	$ (1,338)	$ (1,329)
Total	(5,447,942)	(4,219,956)
Recurring basis | Significant Other Observable Inputs (Level 2)
Financial Instruments Measured/Discussed at Fair Value
Total	(1,848,750)	(2,729,606)
Recurring basis | Significant Unobservable Inputs (Level 3)
Financial Instruments Measured/Discussed at Fair Value
Total	(3,245)	(6,002)
Recurring basis | Significant Unobservable Inputs (Level 3) | Puts
Financial Instruments Measured/Discussed at Fair Value
Fair value of remaining outstanding Puts	$ (3,245)	(6,002)
Cash Flow Hedges Interest Rate Caps
Financial Instruments Measured/Discussed at Fair Value
Derivative, Number of Instruments Held | derivative	7
Cash Flow Hedges Interest Rate Caps | Recurring basis | Significant Other Observable Inputs (Level 2) | Interest Rate Caps
Financial Instruments Measured/Discussed at Fair Value
Derivative assets		2
Cash Flow Hedges Interest Rate Caps | Recurring basis | Significant Other Observable Inputs (Level 2) | Interest Rate Swap [Member]
Financial Instruments Measured/Discussed at Fair Value
Derivative assets	$ 2,270	14,775
Derivative Liability	(1,171)
Total Fair Value | Recurring basis
Financial Instruments Measured/Discussed at Fair Value
DownREIT units	(1,338)	(1,329)
Total	(7,299,937)	(6,955,564)
Total Fair Value | Recurring basis | Puts
Financial Instruments Measured/Discussed at Fair Value
Fair value of remaining outstanding Puts	(3,245)	(6,002)
Total Fair Value | Cash Flow Hedges Interest Rate Caps | Recurring basis | Interest Rate Caps
Financial Instruments Measured/Discussed at Fair Value
Derivative assets		2
Total Fair Value | Cash Flow Hedges Interest Rate Caps | Recurring basis | Interest Rate Swap [Member]
Financial Instruments Measured/Discussed at Fair Value
Derivative assets	2,270	14,775
Derivative Liability	$ (1,171)
Non-designated Hedges Interest Rate Caps
Financial Instruments Measured/Discussed at Fair Value
Derivative, Number of Instruments Held | derivative	14
Non-designated Hedges Interest Rate Caps | Recurring basis | Significant Other Observable Inputs (Level 2) | Interest Rate Caps
Financial Instruments Measured/Discussed at Fair Value
Derivative assets	$ 2	79
Non-designated Hedges Interest Rate Caps | Total Fair Value | Recurring basis | Interest Rate Caps
Financial Instruments Measured/Discussed at Fair Value
Derivative assets	2	79
Secured Debt and Variable Rate Unsecured Term Loan [Member] | Recurring basis | Significant Other Observable Inputs (Level 2)
Financial Instruments Measured/Discussed at Fair Value
Indebtedness	(1,849,851)	(2,744,462)
Secured Debt and Variable Rate Unsecured Term Loan [Member] | Total Fair Value | Recurring basis
Financial Instruments Measured/Discussed at Fair Value
Indebtedness	(1,849,851)	(2,744,462)
Unsecured notes | Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial Instruments Measured/Discussed at Fair Value
Indebtedness	(5,446,604)	(4,218,627)
Unsecured notes | Total Fair Value | Recurring basis
Financial Instruments Measured/Discussed at Fair Value
Indebtedness	$ (5,446,604)	$ (4,218,627)

Quarterly Financial Informati62

Quarterly Financial Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Total revenue	$ 555,292	$ 550,500	$ 530,512	$ 522,326	$ 518,240	$ 516,211	$ 502,307	$ 508,498	$ 2,158,628	$ 2,045,255	$ 1,856,028
Net income	237,486	238,199	165,194	235,781	242,183	356,329	197,319	237,877	876,660	1,033,708	741,733
Net income attributable to common stockholders	$ 237,573	$ 238,248	$ 165,225	$ 235,875	$ 242,235	$ 356,392	$ 197,444	$ 237,931	$ 876,921	$ 1,034,002	$ 742,038
Net income per common share - basic (in dollars per share)	$ 1.72	$ 1.73	$ 1.20	$ 1.72	$ 1.76	$ 2.60	$ 1.44	$ 1.73	$ 6.36	$ 7.53	$ 5.54
Net income per common share - diluted (in dollars per share)	$ 1.72	$ 1.72	$ 1.20	$ 1.72	$ 1.76	$ 2.59	$ 1.44	$ 1.73	$ 6.35	$ 7.52	$ 5.51

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent event $ in Thousands	1 Months Ended	2 Months Ended
	Feb. 23, 2018USD ($)	Feb. 23, 2018USD ($)land_parcel
Subsequent events
Number of Land Parcels Acquired | land_parcel		4
Payments to Acquire Land		$ 76,758
Secured notes | Notes Payable Maturities 2043 [Member]
Subsequent events
Repayments of secured mortgages	$ 15,174
Stated interest rate (as a percent)	6.60%	6.60%
Prepayment Penalty	$ 152

REAL ESTATE AND ACCUMULATED D64

REAL ESTATE AND ACCUMULATED DEPRECIATION (Details) $ in Thousands	Dec. 31, 2017USD ($)home	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	81,517
Initial Cost
Land and improvements	$ 4,305,682
Building / Construction in Progress & Improvements	14,684,237
Costs Subsequent to Acquisition / Construction	2,946,017
Total Cost
Land	4,305,682
Building / Construction in Progress & Improvements	17,630,254
Total	21,935,936	$ 20,776,626	$ 19,268,099	$ 17,849,316
Accumulated Depreciation	4,218,379	3,743,632	$ 3,325,790	$ 2,913,576
Total Cost, Net of Accumulated Depreciation	17,717,557	17,032,994
Encumbrances	$ 7,404,313
Current Communities
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	75,238
Initial Cost
Land and improvements	$ 4,175,565
Building / Construction in Progress & Improvements	14,353,940
Costs Subsequent to Acquisition / Construction	1,711,986
Total Cost
Land	4,175,565
Building / Construction in Progress & Improvements	16,065,926
Total	20,241,491
Accumulated Depreciation	4,169,850
Total Cost, Net of Accumulated Depreciation	16,071,641	15,721,244
Encumbrances	$ 1,504,313
Current Communities | Avalon at Lexington [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	198
Initial Cost
Land and improvements	$ 2,124
Building / Construction in Progress & Improvements	12,567
Costs Subsequent to Acquisition / Construction	10,093
Total Cost
Land	2,124
Building / Construction in Progress & Improvements	22,660
Total	24,784
Accumulated Depreciation	14,080
Total Cost, Net of Accumulated Depreciation	10,704	11,290
Encumbrances	$ 0
Current Communities | Avalon Oaks [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	204
Initial Cost
Land and improvements	$ 2,129
Building / Construction in Progress & Improvements	17,567
Costs Subsequent to Acquisition / Construction	5,488
Total Cost
Land	2,129
Building / Construction in Progress & Improvements	23,055
Total	25,184
Accumulated Depreciation	13,755
Total Cost, Net of Accumulated Depreciation	11,429	12,153
Encumbrances	$ 0
Current Communities | Eaves Quincy [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	245
Initial Cost
Land and improvements	$ 1,743
Building / Construction in Progress & Improvements	14,662
Costs Subsequent to Acquisition / Construction	10,184
Total Cost
Land	1,743
Building / Construction in Progress & Improvements	24,846
Total	26,589
Accumulated Depreciation	14,456
Total Cost, Net of Accumulated Depreciation	12,133	12,799
Encumbrances	$ 0
Current Communities | Avalon Oaks West [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	120
Initial Cost
Land and improvements	$ 3,318
Building / Construction in Progress & Improvements	13,465
Costs Subsequent to Acquisition / Construction	1,224
Total Cost
Land	3,318
Building / Construction in Progress & Improvements	14,689
Total	18,007
Accumulated Depreciation	8,054
Total Cost, Net of Accumulated Depreciation	9,953	10,442
Encumbrances	$ 15,213
Current Communities | Avalon Orchards [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	156
Initial Cost
Land and improvements	$ 2,983
Building / Construction in Progress & Improvements	17,970
Costs Subsequent to Acquisition / Construction	2,702
Total Cost
Land	2,983
Building / Construction in Progress & Improvements	20,672
Total	23,655
Accumulated Depreciation	11,463
Total Cost, Net of Accumulated Depreciation	12,192	12,865
Encumbrances	$ 15,579
Current Communities | Avalon at Newton Highlands [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	294
Initial Cost
Land and improvements	$ 11,039
Building / Construction in Progress & Improvements	45,547
Costs Subsequent to Acquisition / Construction	5,196
Total Cost
Land	11,039
Building / Construction in Progress & Improvements	50,743
Total	61,782
Accumulated Depreciation	25,369
Total Cost, Net of Accumulated Depreciation	36,413	37,670
Encumbrances	$ 0
Current Communities | Avalon at the Pinehills [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	192
Initial Cost
Land and improvements	$ 6,876
Building / Construction in Progress & Improvements	30,401
Costs Subsequent to Acquisition / Construction	721
Total Cost
Land	6,876
Building / Construction in Progress & Improvements	31,122
Total	37,998
Accumulated Depreciation	11,155
Total Cost, Net of Accumulated Depreciation	26,843	27,716
Encumbrances	$ 0
Current Communities | Eaves Peabody [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	286
Initial Cost
Land and improvements	$ 4,645
Building / Construction in Progress & Improvements	18,919
Costs Subsequent to Acquisition / Construction	13,420
Total Cost
Land	4,645
Building / Construction in Progress & Improvements	32,339
Total	36,984
Accumulated Depreciation	13,190
Total Cost, Net of Accumulated Depreciation	23,794	24,329
Encumbrances	$ 0
Current Communities | Avalon at Bedford Center [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	139
Initial Cost
Land and improvements	$ 4,258
Building / Construction in Progress & Improvements	20,551
Costs Subsequent to Acquisition / Construction	1,457
Total Cost
Land	4,258
Building / Construction in Progress & Improvements	22,008
Total	26,266
Accumulated Depreciation	8,923
Total Cost, Net of Accumulated Depreciation	17,343	17,570
Encumbrances	$ 0
Current Communities | Avalon at Lexington Hills [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	387
Initial Cost
Land and improvements	$ 8,691
Building / Construction in Progress & Improvements	79,121
Costs Subsequent to Acquisition / Construction	4,158
Total Cost
Land	8,691
Building / Construction in Progress & Improvements	83,279
Total	91,970
Accumulated Depreciation	28,415
Total Cost, Net of Accumulated Depreciation	63,555	66,241
Encumbrances	$ 0
Current Communities | Avalon Acton [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	380
Initial Cost
Land and improvements	$ 13,124
Building / Construction in Progress & Improvements	48,695
Costs Subsequent to Acquisition / Construction	3,504
Total Cost
Land	13,124
Building / Construction in Progress & Improvements	52,199
Total	65,323
Accumulated Depreciation	17,459
Total Cost, Net of Accumulated Depreciation	47,864	49,275
Encumbrances	$ 45,000
Current Communities | Avalon at the Hingham Shipyard [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	235
Initial Cost
Land and improvements	$ 12,218
Building / Construction in Progress & Improvements	41,656
Costs Subsequent to Acquisition / Construction	2,412
Total Cost
Land	12,218
Building / Construction in Progress & Improvements	44,068
Total	56,286
Accumulated Depreciation	13,882
Total Cost, Net of Accumulated Depreciation	42,404	43,641
Encumbrances	$ 0
Current Communities | Avalon Sharon [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	156
Initial Cost
Land and improvements	$ 4,719
Building / Construction in Progress & Improvements	25,478
Costs Subsequent to Acquisition / Construction	892
Total Cost
Land	4,719
Building / Construction in Progress & Improvements	26,370
Total	31,089
Accumulated Depreciation	8,759
Total Cost, Net of Accumulated Depreciation	22,330	22,960
Encumbrances	$ 0
Current Communities | Avalon Northborough [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	382
Initial Cost
Land and improvements	$ 8,144
Building / Construction in Progress & Improvements	52,184
Costs Subsequent to Acquisition / Construction	1,691
Total Cost
Land	8,144
Building / Construction in Progress & Improvements	53,875
Total	62,019
Accumulated Depreciation	14,899
Total Cost, Net of Accumulated Depreciation	47,120	48,460
Encumbrances	$ 0
Current Communities | Avalon Blue Hills [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	276
Initial Cost
Land and improvements	$ 11,110
Building / Construction in Progress & Improvements	34,580
Costs Subsequent to Acquisition / Construction	1,549
Total Cost
Land	11,110
Building / Construction in Progress & Improvements	36,129
Total	47,239
Accumulated Depreciation	10,781
Total Cost, Net of Accumulated Depreciation	36,458	37,314
Encumbrances	$ 0
Current Communities | Avalon Cohasset [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	220
Initial Cost
Land and improvements	$ 8,802
Building / Construction in Progress & Improvements	46,166
Costs Subsequent to Acquisition / Construction	259
Total Cost
Land	8,802
Building / Construction in Progress & Improvements	46,425
Total	55,227
Accumulated Depreciation	9,890
Total Cost, Net of Accumulated Depreciation	45,337	46,935
Encumbrances	$ 0
Current Communities | Avalon Andover [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	115
Initial Cost
Land and improvements	$ 4,276
Building / Construction in Progress & Improvements	21,871
Costs Subsequent to Acquisition / Construction	210
Total Cost
Land	4,276
Building / Construction in Progress & Improvements	22,081
Total	26,357
Accumulated Depreciation	4,527
Total Cost, Net of Accumulated Depreciation	21,830	22,625
Encumbrances	$ 13,498
Current Communities | Avalon Exeter [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	187
Initial Cost
Land and improvements	$ 16,313
Building / Construction in Progress & Improvements	110,028
Costs Subsequent to Acquisition / Construction	214
Total Cost
Land	16,313
Building / Construction in Progress & Improvements	110,242
Total	126,555
Accumulated Depreciation	13,672
Total Cost, Net of Accumulated Depreciation	112,883	116,744
Encumbrances	$ 0
Current Communities | Avalon Natick [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	407
Initial Cost
Land and improvements	$ 15,645
Building / Construction in Progress & Improvements	64,845
Costs Subsequent to Acquisition / Construction	34
Total Cost
Land	15,645
Building / Construction in Progress & Improvements	64,879
Total	80,524
Accumulated Depreciation	10,430
Total Cost, Net of Accumulated Depreciation	70,094	72,419
Encumbrances	$ 48,870
Current Communities | Avalon at Assembly Row [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	195
Initial Cost
Land and improvements	$ 8,599
Building / Construction in Progress & Improvements	52,494
Costs Subsequent to Acquisition / Construction	26
Total Cost
Land	8,599
Building / Construction in Progress & Improvements	52,520
Total	61,119
Accumulated Depreciation	6,780
Total Cost, Net of Accumulated Depreciation	54,339	56,030
Encumbrances	$ 0
Current Communities | AVA Somerville [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	250
Initial Cost
Land and improvements	$ 10,945
Building / Construction in Progress & Improvements	56,470
Costs Subsequent to Acquisition / Construction	12
Total Cost
Land	10,945
Building / Construction in Progress & Improvements	56,482
Total	67,427
Accumulated Depreciation	6,208
Total Cost, Net of Accumulated Depreciation	61,219	63,066
Encumbrances	$ 0
Current Communities | Avalon at Prudential Center I [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	243
Initial Cost
Land and improvements	$ 8,002
Building / Construction in Progress & Improvements	32,370
Costs Subsequent to Acquisition / Construction	38,384
Total Cost
Land	8,002
Building / Construction in Progress & Improvements	70,754
Total	78,756
Accumulated Depreciation	28,947
Total Cost, Net of Accumulated Depreciation	49,809	47,586
Encumbrances	$ 0
Current Communities | Eaves Burlington [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	203
Initial Cost
Land and improvements	$ 7,714
Building / Construction in Progress & Improvements	32,499
Costs Subsequent to Acquisition / Construction	6,512
Total Cost
Land	7,714
Building / Construction in Progress & Improvements	39,011
Total	46,725
Accumulated Depreciation	6,538
Total Cost, Net of Accumulated Depreciation	40,187	41,107
Encumbrances	$ 0
Current Communities | Avalon Canton at Blue Hills [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	196
Initial Cost
Land and improvements	$ 6,562
Building / Construction in Progress & Improvements	33,956
Costs Subsequent to Acquisition / Construction	132
Total Cost
Land	6,562
Building / Construction in Progress & Improvements	34,088
Total	40,650
Accumulated Depreciation	4,503
Total Cost, Net of Accumulated Depreciation	36,147	37,391
Encumbrances	$ 0
Current Communities | Avalon Burlington [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	312
Initial Cost
Land and improvements	$ 15,600
Building / Construction in Progress & Improvements	58,499
Costs Subsequent to Acquisition / Construction	18,176
Total Cost
Land	15,600
Building / Construction in Progress & Improvements	76,675
Total	92,275
Accumulated Depreciation	13,196
Total Cost, Net of Accumulated Depreciation	79,079	81,135
Encumbrances	$ 0
Current Communities | Eaves North Quincy [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	224
Initial Cost
Land and improvements	$ 11,940
Building / Construction in Progress & Improvements	39,400
Costs Subsequent to Acquisition / Construction	3,544
Total Cost
Land	11,940
Building / Construction in Progress & Improvements	42,944
Total	54,884
Accumulated Depreciation	9,297
Total Cost, Net of Accumulated Depreciation	45,587	46,492
Encumbrances	$ 0
Current Communities | Avalon at Center Place [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	225
Initial Cost
Land and improvements	$ 0
Building / Construction in Progress & Improvements	26,816
Costs Subsequent to Acquisition / Construction	13,271
Total Cost
Land	0
Building / Construction in Progress & Improvements	40,087
Total	40,087
Accumulated Depreciation	24,342
Total Cost, Net of Accumulated Depreciation	15,745	15,575
Encumbrances	$ 0
Current Communities | Eaves Stamford [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	238
Initial Cost
Land and improvements	$ 5,956
Building / Construction in Progress & Improvements	23,993
Costs Subsequent to Acquisition / Construction	13,117
Total Cost
Land	5,956
Building / Construction in Progress & Improvements	37,110
Total	43,066
Accumulated Depreciation	24,215
Total Cost, Net of Accumulated Depreciation	18,851	20,058
Encumbrances	$ 0
Current Communities | Avalon Wilton on River Rd [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	102
Initial Cost
Land and improvements	$ 2,116
Building / Construction in Progress & Improvements	14,664
Costs Subsequent to Acquisition / Construction	6,422
Total Cost
Land	2,116
Building / Construction in Progress & Improvements	21,086
Total	23,202
Accumulated Depreciation	12,077
Total Cost, Net of Accumulated Depreciation	11,125	11,314
Encumbrances	$ 0
Current Communities | Avalon New Canaan [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	104
Initial Cost
Land and improvements	$ 4,834
Building / Construction in Progress & Improvements	22,990
Costs Subsequent to Acquisition / Construction	2,163
Total Cost
Land	4,834
Building / Construction in Progress & Improvements	25,153
Total	29,987
Accumulated Depreciation	13,192
Total Cost, Net of Accumulated Depreciation	16,795	17,589
Encumbrances	$ 0
Current Communities | AVA Stamford [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	306
Initial Cost
Land and improvements	$ 13,819
Building / Construction in Progress & Improvements	56,499
Costs Subsequent to Acquisition / Construction	5,887
Total Cost
Land	13,819
Building / Construction in Progress & Improvements	62,386
Total	76,205
Accumulated Depreciation	32,700
Total Cost, Net of Accumulated Depreciation	43,505	45,461
Encumbrances	$ 0
Current Communities | Avalon Darien [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	189
Initial Cost
Land and improvements	$ 6,926
Building / Construction in Progress & Improvements	34,558
Costs Subsequent to Acquisition / Construction	2,734
Total Cost
Land	6,926
Building / Construction in Progress & Improvements	37,292
Total	44,218
Accumulated Depreciation	18,089
Total Cost, Net of Accumulated Depreciation	26,129	27,188
Encumbrances	$ 0
Current Communities | Avalon Norwalk [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	311
Initial Cost
Land and improvements	$ 11,320
Building / Construction in Progress & Improvements	62,904
Costs Subsequent to Acquisition / Construction	887
Total Cost
Land	11,320
Building / Construction in Progress & Improvements	63,791
Total	75,111
Accumulated Depreciation	16,187
Total Cost, Net of Accumulated Depreciation	58,924	60,986
Encumbrances	$ 0
Current Communities | Avalon Wilton on Danbury Rd [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	100
Initial Cost
Land and improvements	$ 6,604
Building / Construction in Progress & Improvements	23,758
Costs Subsequent to Acquisition / Construction	150
Total Cost
Land	6,604
Building / Construction in Progress & Improvements	23,908
Total	30,512
Accumulated Depreciation	5,573
Total Cost, Net of Accumulated Depreciation	24,939	25,681
Encumbrances	$ 0
Current Communities | Avalon Shelton [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	250
Initial Cost
Land and improvements	$ 7,749
Building / Construction in Progress & Improvements	40,264
Costs Subsequent to Acquisition / Construction	88
Total Cost
Land	7,749
Building / Construction in Progress & Improvements	40,352
Total	48,101
Accumulated Depreciation	6,697
Total Cost, Net of Accumulated Depreciation	41,404	42,826
Encumbrances	$ 0
Current Communities | Avalon East Norwalk [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	240
Initial Cost
Land and improvements	$ 10,395
Building / Construction in Progress & Improvements	36,245
Costs Subsequent to Acquisition / Construction	119
Total Cost
Land	10,395
Building / Construction in Progress & Improvements	36,364
Total	46,759
Accumulated Depreciation	5,670
Total Cost, Net of Accumulated Depreciation	41,089	42,317
Encumbrances	$ 0
Current Communities | Avalon at Stratford [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	130
Initial Cost
Land and improvements	$ 2,564
Building / Construction in Progress & Improvements	27,157
Costs Subsequent to Acquisition / Construction	33
Total Cost
Land	2,564
Building / Construction in Progress & Improvements	27,190
Total	29,754
Accumulated Depreciation	3,274
Total Cost, Net of Accumulated Depreciation	26,480	27,424
Encumbrances	$ 0
Current Communities | Avalon Riverview [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	372
Initial Cost
Land and improvements	$ 0
Building / Construction in Progress & Improvements	94,061
Costs Subsequent to Acquisition / Construction	9,867
Total Cost
Land	0
Building / Construction in Progress & Improvements	103,928
Total	103,928
Accumulated Depreciation	52,510
Total Cost, Net of Accumulated Depreciation	51,418	54,912
Encumbrances	$ 0
Current Communities | Avalon Bowery Place I [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	206
Initial Cost
Land and improvements	$ 18,575
Building / Construction in Progress & Improvements	75,009
Costs Subsequent to Acquisition / Construction	2,890
Total Cost
Land	18,575
Building / Construction in Progress & Improvements	77,899
Total	96,474
Accumulated Depreciation	30,174
Total Cost, Net of Accumulated Depreciation	66,300	68,882
Encumbrances	$ 93,800
Current Communities | Avalon Bowery Place II [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	90
Initial Cost
Land and improvements	$ 9,106
Building / Construction in Progress & Improvements	47,199
Costs Subsequent to Acquisition / Construction	3,811
Total Cost
Land	9,106
Building / Construction in Progress & Improvements	51,010
Total	60,116
Accumulated Depreciation	17,750
Total Cost, Net of Accumulated Depreciation	42,366	44,607
Encumbrances	$ 0
Current Communities | Avalon Morningside Park [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	295
Initial Cost
Land and improvements	$ 95,465
Building / Construction in Progress & Improvements	114,233
Costs Subsequent to Acquisition / Construction	1,580
Total Cost
Land	95,465
Building / Construction in Progress & Improvements	115,813
Total	211,278
Accumulated Depreciation	36,625
Total Cost, Net of Accumulated Depreciation	174,653	83,027
Encumbrances	$ 100,000
Current Communities | Avalon Fort Greene [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	631
Initial Cost
Land and improvements	$ 83,038
Building / Construction in Progress & Improvements	216,802
Costs Subsequent to Acquisition / Construction	2,052
Total Cost
Land	83,038
Building / Construction in Progress & Improvements	218,854
Total	301,892
Accumulated Depreciation	57,941
Total Cost, Net of Accumulated Depreciation	243,951	251,213
Encumbrances	$ 0
Current Communities | Avalon West Chelsea [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	305
Initial Cost
Land and improvements	$ 0
Building / Construction in Progress & Improvements	119,882
Costs Subsequent to Acquisition / Construction	243
Total Cost
Land	0
Building / Construction in Progress & Improvements	120,125
Total	120,125
Accumulated Depreciation	13,643
Total Cost, Net of Accumulated Depreciation	106,482	102,820
Encumbrances	$ 0
Current Communities | AVA High Line [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	405
Initial Cost
Land and improvements	$ 0
Building / Construction in Progress & Improvements	159,187
Costs Subsequent to Acquisition / Construction	33
Total Cost
Land	0
Building / Construction in Progress & Improvements	159,220
Total	159,220
Accumulated Depreciation	20,451
Total Cost, Net of Accumulated Depreciation	138,769	152,127
Encumbrances	$ 0
Current Communities | Avalon Clinton North [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	339
Initial Cost
Land and improvements	$ 84,069
Building / Construction in Progress & Improvements	105,821
Costs Subsequent to Acquisition / Construction	11,529
Total Cost
Land	84,069
Building / Construction in Progress & Improvements	117,350
Total	201,419
Accumulated Depreciation	23,412
Total Cost, Net of Accumulated Depreciation	178,007	180,740
Encumbrances	$ 147,000
Current Communities | Avalon Clinton South [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	288
Initial Cost
Land and improvements	$ 71,421
Building / Construction in Progress & Improvements	89,851
Costs Subsequent to Acquisition / Construction	6,181
Total Cost
Land	71,421
Building / Construction in Progress & Improvements	96,032
Total	167,453
Accumulated Depreciation	20,089
Total Cost, Net of Accumulated Depreciation	147,364	150,330
Encumbrances	$ 121,500
Current Communities | Avalon Commons [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	312
Initial Cost
Land and improvements	$ 4,679
Building / Construction in Progress & Improvements	28,286
Costs Subsequent to Acquisition / Construction	6,335
Total Cost
Land	4,679
Building / Construction in Progress & Improvements	34,621
Total	39,300
Accumulated Depreciation	22,581
Total Cost, Net of Accumulated Depreciation	16,719	17,712
Encumbrances	$ 0
Current Communities | Avalon Green I [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	105
Initial Cost
Land and improvements	$ 1,820
Building / Construction in Progress & Improvements	10,525
Costs Subsequent to Acquisition / Construction	7,522
Total Cost
Land	1,820
Building / Construction in Progress & Improvements	18,047
Total	19,867
Accumulated Depreciation	9,870
Total Cost, Net of Accumulated Depreciation	9,997	10,633
Encumbrances	$ 0
Current Communities | Avalon Court [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	494
Initial Cost
Land and improvements	$ 9,228
Building / Construction in Progress & Improvements	50,063
Costs Subsequent to Acquisition / Construction	6,681
Total Cost
Land	9,228
Building / Construction in Progress & Improvements	56,744
Total	65,972
Accumulated Depreciation	35,091
Total Cost, Net of Accumulated Depreciation	30,881	32,294
Encumbrances	$ 0
Current Communities | The Avalon [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	110
Initial Cost
Land and improvements	$ 2,889
Building / Construction in Progress & Improvements	28,324
Costs Subsequent to Acquisition / Construction	8,661
Total Cost
Land	2,889
Building / Construction in Progress & Improvements	36,985
Total	39,874
Accumulated Depreciation	19,772
Total Cost, Net of Accumulated Depreciation	20,102	21,064
Encumbrances	$ 0
Current Communities | Avalon at Glen Cove [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	256
Initial Cost
Land and improvements	$ 7,871
Building / Construction in Progress & Improvements	59,969
Costs Subsequent to Acquisition / Construction	4,245
Total Cost
Land	7,871
Building / Construction in Progress & Improvements	64,214
Total	72,085
Accumulated Depreciation	28,810
Total Cost, Net of Accumulated Depreciation	43,275	44,881
Encumbrances	$ 0
Current Communities | Avalon Glen Cove North [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	111
Initial Cost
Land and improvements	$ 2,577
Building / Construction in Progress & Improvements	37,336
Costs Subsequent to Acquisition / Construction	531
Total Cost
Land	2,577
Building / Construction in Progress & Improvements	37,867
Total	40,444
Accumulated Depreciation	13,875
Total Cost, Net of Accumulated Depreciation	26,569	27,768
Encumbrances	$ 0
Current Communities | Avalon White Plains [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	407
Initial Cost
Land and improvements	$ 15,391
Building / Construction in Progress & Improvements	137,353
Costs Subsequent to Acquisition / Construction	996
Total Cost
Land	15,391
Building / Construction in Progress & Improvements	138,349
Total	153,740
Accumulated Depreciation	41,499
Total Cost, Net of Accumulated Depreciation	112,241	116,188
Encumbrances	$ 0
Current Communities | Avalon Rockville Centre I [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	349
Initial Cost
Land and improvements	$ 32,212
Building / Construction in Progress & Improvements	78,806
Costs Subsequent to Acquisition / Construction	1,013
Total Cost
Land	32,212
Building / Construction in Progress & Improvements	79,819
Total	112,031
Accumulated Depreciation	17,284
Total Cost, Net of Accumulated Depreciation	94,747	97,195
Encumbrances	$ 0
Current Communities | Avalon Green II [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	444
Initial Cost
Land and improvements	$ 27,765
Building / Construction in Progress & Improvements	77,560
Costs Subsequent to Acquisition / Construction	223
Total Cost
Land	27,765
Building / Construction in Progress & Improvements	77,783
Total	105,548
Accumulated Depreciation	15,714
Total Cost, Net of Accumulated Depreciation	89,834	92,537
Encumbrances	$ 0
Current Communities | Avalon Garden City [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	204
Initial Cost
Land and improvements	$ 18,205
Building / Construction in Progress & Improvements	49,326
Costs Subsequent to Acquisition / Construction	416
Total Cost
Land	18,205
Building / Construction in Progress & Improvements	49,742
Total	67,947
Accumulated Depreciation	9,436
Total Cost, Net of Accumulated Depreciation	58,511	60,173
Encumbrances	$ 0
Current Communities | Avalon Ossining [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	168
Initial Cost
Land and improvements	$ 6,392
Building / Construction in Progress & Improvements	30,313
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	6,392
Building / Construction in Progress & Improvements	30,313
Total	36,705
Accumulated Depreciation	4,078
Total Cost, Net of Accumulated Depreciation	32,627	33,734
Encumbrances	$ 0
Current Communities | Avalon Huntington Station [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	303
Initial Cost
Land and improvements	$ 21,898
Building / Construction in Progress & Improvements	58,457
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	21,898
Building / Construction in Progress & Improvements	58,457
Total	80,355
Accumulated Depreciation	7,224
Total Cost, Net of Accumulated Depreciation	73,131	75,462
Encumbrances	$ 0
Current Communities | Avalon Westbury [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	396
Initial Cost
Land and improvements	$ 69,620
Building / Construction in Progress & Improvements	43,781
Costs Subsequent to Acquisition / Construction	10,941
Total Cost
Land	69,620
Building / Construction in Progress & Improvements	54,722
Total	124,342
Accumulated Depreciation	15,286
Total Cost, Net of Accumulated Depreciation	109,056	110,752
Encumbrances	$ 78,650
Current Communities | Avalon Cove [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	504
Initial Cost
Land and improvements	$ 8,760
Building / Construction in Progress & Improvements	82,422
Costs Subsequent to Acquisition / Construction	22,967
Total Cost
Land	8,760
Building / Construction in Progress & Improvements	105,389
Total	114,149
Accumulated Depreciation	64,885
Total Cost, Net of Accumulated Depreciation	49,264	51,954
Encumbrances	$ 0
Current Communities | Eaves Lawrenceville [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	632
Initial Cost
Land and improvements	$ 14,650
Building / Construction in Progress & Improvements	60,486
Costs Subsequent to Acquisition / Construction	11,899
Total Cost
Land	14,650
Building / Construction in Progress & Improvements	72,385
Total	87,035
Accumulated Depreciation	32,099
Total Cost, Net of Accumulated Depreciation	54,936	57,334
Encumbrances	$ 0
Current Communities | Avalon Princeton Junction [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	512
Initial Cost
Land and improvements	$ 5,585
Building / Construction in Progress & Improvements	22,382
Costs Subsequent to Acquisition / Construction	21,675
Total Cost
Land	5,585
Building / Construction in Progress & Improvements	44,057
Total	49,642
Accumulated Depreciation	26,010
Total Cost, Net of Accumulated Depreciation	23,632	24,587
Encumbrances	$ 0
Current Communities | Avalon Tinton Falls [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	216
Initial Cost
Land and improvements	$ 7,939
Building / Construction in Progress & Improvements	33,170
Costs Subsequent to Acquisition / Construction	520
Total Cost
Land	7,939
Building / Construction in Progress & Improvements	33,690
Total	41,629
Accumulated Depreciation	11,225
Total Cost, Net of Accumulated Depreciation	30,404	31,528
Encumbrances	$ 0
Current Communities | Avalon West Long Branch [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	180
Initial Cost
Land and improvements	$ 2,721
Building / Construction in Progress & Improvements	22,925
Costs Subsequent to Acquisition / Construction	136
Total Cost
Land	2,721
Building / Construction in Progress & Improvements	23,061
Total	25,782
Accumulated Depreciation	6,054
Total Cost, Net of Accumulated Depreciation	19,728	20,549
Encumbrances	$ 0
Current Communities | Avalon North Bergen [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	164
Initial Cost
Land and improvements	$ 8,984
Building / Construction in Progress & Improvements	30,994
Costs Subsequent to Acquisition / Construction	949
Total Cost
Land	8,984
Building / Construction in Progress & Improvements	31,943
Total	40,927
Accumulated Depreciation	6,495
Total Cost, Net of Accumulated Depreciation	34,432	35,686
Encumbrances	$ 0
Current Communities | Avalon at Wesmont Station I [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	266
Initial Cost
Land and improvements	$ 14,682
Building / Construction in Progress & Improvements	41,635
Costs Subsequent to Acquisition / Construction	1,101
Total Cost
Land	14,682
Building / Construction in Progress & Improvements	42,736
Total	57,418
Accumulated Depreciation	8,365
Total Cost, Net of Accumulated Depreciation	49,053	49,991
Encumbrances	$ 0
Current Communities | Avalon Hackensack at Riverside [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	226
Initial Cost
Land and improvements	$ 0
Building / Construction in Progress & Improvements	44,619
Costs Subsequent to Acquisition / Construction	128
Total Cost
Land	0
Building / Construction in Progress & Improvements	44,747
Total	44,747
Accumulated Depreciation	7,140
Total Cost, Net of Accumulated Depreciation	37,607	39,099
Encumbrances	$ 0
Current Communities | Avalon Somerset [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	384
Initial Cost
Land and improvements	$ 18,241
Building / Construction in Progress & Improvements	58,338
Costs Subsequent to Acquisition / Construction	226
Total Cost
Land	18,241
Building / Construction in Progress & Improvements	58,564
Total	76,805
Accumulated Depreciation	9,817
Total Cost, Net of Accumulated Depreciation	66,988	69,023
Encumbrances	$ 0
Current Communities | Avalon at Wesmont Station II [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	140
Initial Cost
Land and improvements	$ 6,502
Building / Construction in Progress & Improvements	16,865
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	6,502
Building / Construction in Progress & Improvements	16,865
Total	23,367
Accumulated Depreciation	2,865
Total Cost, Net of Accumulated Depreciation	20,502	21,131
Encumbrances	$ 0
Current Communities | Avalon Bloomingdale [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	174
Initial Cost
Land and improvements	$ 3,006
Building / Construction in Progress & Improvements	27,801
Costs Subsequent to Acquisition / Construction	71
Total Cost
Land	3,006
Building / Construction in Progress & Improvements	27,872
Total	30,878
Accumulated Depreciation	4,119
Total Cost, Net of Accumulated Depreciation	26,759	27,635
Encumbrances	$ 0
Current Communities | Avalon Wharton [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	247
Initial Cost
Land and improvements	$ 2,273
Building / Construction in Progress & Improvements	48,609
Costs Subsequent to Acquisition / Construction	98
Total Cost
Land	2,273
Building / Construction in Progress & Improvements	48,707
Total	50,980
Accumulated Depreciation	5,167
Total Cost, Net of Accumulated Depreciation	45,813	47,455
Encumbrances	$ 0
Current Communities | Avalon Roseland [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	136
Initial Cost
Land and improvements	$ 11,288
Building / Construction in Progress & Improvements	34,928
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	11,288
Building / Construction in Progress & Improvements	34,928
Total	46,216
Accumulated Depreciation	3,260
Total Cost, Net of Accumulated Depreciation	42,956	44,078
Encumbrances	$ 0
Current Communities | Avalon at Foxhall [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	308
Initial Cost
Land and improvements	$ 6,848
Building / Construction in Progress & Improvements	27,614
Costs Subsequent to Acquisition / Construction	15,456
Total Cost
Land	6,848
Building / Construction in Progress & Improvements	43,070
Total	49,918
Accumulated Depreciation	29,439
Total Cost, Net of Accumulated Depreciation	20,479	20,360
Encumbrances	$ 0
Current Communities | Avalon at Gallery Place [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	203
Initial Cost
Land and improvements	$ 8,800
Building / Construction in Progress & Improvements	39,658
Costs Subsequent to Acquisition / Construction	2,167
Total Cost
Land	8,800
Building / Construction in Progress & Improvements	41,825
Total	50,625
Accumulated Depreciation	21,005
Total Cost, Net of Accumulated Depreciation	29,620	31,047
Encumbrances	$ 0
Current Communities | AVA H Street [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	138
Initial Cost
Land and improvements	$ 7,425
Building / Construction in Progress & Improvements	25,282
Costs Subsequent to Acquisition / Construction	44
Total Cost
Land	7,425
Building / Construction in Progress & Improvements	25,326
Total	32,751
Accumulated Depreciation	4,717
Total Cost, Net of Accumulated Depreciation	28,034	28,998
Encumbrances	$ 0
Current Communities | Avalon The Albemarle [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	231
Initial Cost
Land and improvements	$ 25,140
Building / Construction in Progress & Improvements	52,459
Costs Subsequent to Acquisition / Construction	6,592
Total Cost
Land	25,140
Building / Construction in Progress & Improvements	59,051
Total	84,191
Accumulated Depreciation	12,774
Total Cost, Net of Accumulated Depreciation	71,417	72,134
Encumbrances	$ 0
Current Communities | Eaves Tunlaw Gardens [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	166
Initial Cost
Land and improvements	$ 16,430
Building / Construction in Progress & Improvements	22,902
Costs Subsequent to Acquisition / Construction	2,344
Total Cost
Land	16,430
Building / Construction in Progress & Improvements	25,246
Total	41,676
Accumulated Depreciation	5,727
Total Cost, Net of Accumulated Depreciation	35,949	36,751
Encumbrances	$ 0
Current Communities | The Statesman [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	281
Initial Cost
Land and improvements	$ 38,140
Building / Construction in Progress & Improvements	35,352
Costs Subsequent to Acquisition / Construction	4,111
Total Cost
Land	38,140
Building / Construction in Progress & Improvements	39,463
Total	77,603
Accumulated Depreciation	9,916
Total Cost, Net of Accumulated Depreciation	67,687	68,834
Encumbrances	$ 0
Current Communities | Eaves Glover Park [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	120
Initial Cost
Land and improvements	$ 9,580
Building / Construction in Progress & Improvements	26,532
Costs Subsequent to Acquisition / Construction	2,408
Total Cost
Land	9,580
Building / Construction in Progress & Improvements	28,940
Total	38,520
Accumulated Depreciation	6,575
Total Cost, Net of Accumulated Depreciation	31,945	32,944
Encumbrances	$ 0
Current Communities | Avalon First and M [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	469
Initial Cost
Land and improvements	$ 43,700
Building / Construction in Progress & Improvements	153,950
Costs Subsequent to Acquisition / Construction	3,195
Total Cost
Land	43,700
Building / Construction in Progress & Improvements	157,145
Total	200,845
Accumulated Depreciation	28,554
Total Cost, Net of Accumulated Depreciation	172,291	177,621
Encumbrances	$ 0
Current Communities | Avalon at Fairway Hills [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	720
Initial Cost
Land and improvements	$ 8,603
Building / Construction in Progress & Improvements	34,432
Costs Subsequent to Acquisition / Construction	16,302
Total Cost
Land	8,603
Building / Construction in Progress & Improvements	50,734
Total	59,337
Accumulated Depreciation	33,393
Total Cost, Net of Accumulated Depreciation	25,944	27,384
Encumbrances	$ 0
Current Communities | Eaves Washingtonian Center [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	288
Initial Cost
Land and improvements	$ 4,047
Building / Construction in Progress & Improvements	18,553
Costs Subsequent to Acquisition / Construction	2,784
Total Cost
Land	4,047
Building / Construction in Progress & Improvements	21,337
Total	25,384
Accumulated Depreciation	14,268
Total Cost, Net of Accumulated Depreciation	11,116	11,258
Encumbrances	$ 0
Current Communities | Eaves Columbia Town Center [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	392
Initial Cost
Land and improvements	$ 8,802
Building / Construction in Progress & Improvements	35,536
Costs Subsequent to Acquisition / Construction	12,155
Total Cost
Land	8,802
Building / Construction in Progress & Improvements	47,691
Total	56,493
Accumulated Depreciation	20,971
Total Cost, Net of Accumulated Depreciation	35,522	36,814
Encumbrances	$ 0
Current Communities | Avalon at Grosvenor Station [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	497
Initial Cost
Land and improvements	$ 29,159
Building / Construction in Progress & Improvements	52,993
Costs Subsequent to Acquisition / Construction	2,642
Total Cost
Land	29,159
Building / Construction in Progress & Improvements	55,635
Total	84,794
Accumulated Depreciation	27,043
Total Cost, Net of Accumulated Depreciation	57,751	59,405
Encumbrances	$ 0
Current Communities | Avalon at Traville [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	520
Initial Cost
Land and improvements	$ 14,365
Building / Construction in Progress & Improvements	55,398
Costs Subsequent to Acquisition / Construction	4,155
Total Cost
Land	14,365
Building / Construction in Progress & Improvements	59,553
Total	73,918
Accumulated Depreciation	27,917
Total Cost, Net of Accumulated Depreciation	46,001	48,065
Encumbrances	$ 0
Current Communities | Avalon Russett [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	238
Initial Cost
Land and improvements	$ 10,200
Building / Construction in Progress & Improvements	47,524
Costs Subsequent to Acquisition / Construction	3,220
Total Cost
Land	10,200
Building / Construction in Progress & Improvements	50,744
Total	60,944
Accumulated Depreciation	11,037
Total Cost, Net of Accumulated Depreciation	49,907	51,425
Encumbrances	$ 32,200
Current Communities | Eaves Fair Lakes [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	420
Initial Cost
Land and improvements	$ 6,096
Building / Construction in Progress & Improvements	24,400
Costs Subsequent to Acquisition / Construction	8,904
Total Cost
Land	6,096
Building / Construction in Progress & Improvements	33,304
Total	39,400
Accumulated Depreciation	21,265
Total Cost, Net of Accumulated Depreciation	18,135	18,986
Encumbrances	$ 0
Current Communities | AVA Ballston [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	344
Initial Cost
Land and improvements	$ 7,291
Building / Construction in Progress & Improvements	29,177
Costs Subsequent to Acquisition / Construction	16,302
Total Cost
Land	7,291
Building / Construction in Progress & Improvements	45,479
Total	52,770
Accumulated Depreciation	29,144
Total Cost, Net of Accumulated Depreciation	23,626	25,196
Encumbrances	$ 0
Current Communities | Avalon Tysons Corner [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	558
Initial Cost
Land and improvements	$ 13,851
Building / Construction in Progress & Improvements	43,397
Costs Subsequent to Acquisition / Construction	12,788
Total Cost
Land	13,851
Building / Construction in Progress & Improvements	56,185
Total	70,036
Accumulated Depreciation	32,826
Total Cost, Net of Accumulated Depreciation	37,210	38,956
Encumbrances	$ 0
Current Communities | Avalon Park Crest [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	354
Initial Cost
Land and improvements	$ 13,554
Building / Construction in Progress & Improvements	63,526
Costs Subsequent to Acquisition / Construction	274
Total Cost
Land	13,554
Building / Construction in Progress & Improvements	63,800
Total	77,354
Accumulated Depreciation	11,932
Total Cost, Net of Accumulated Depreciation	65,422	67,595
Encumbrances	$ 0
Current Communities | Eaves Fairfax Towers [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	415
Initial Cost
Land and improvements	$ 17,889
Building / Construction in Progress & Improvements	74,727
Costs Subsequent to Acquisition / Construction	4,446
Total Cost
Land	17,889
Building / Construction in Progress & Improvements	79,173
Total	97,062
Accumulated Depreciation	18,433
Total Cost, Net of Accumulated Depreciation	78,629	79,263
Encumbrances	$ 0
Current Communities | Avalon Mosaic [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	531
Initial Cost
Land and improvements	$ 33,490
Building / Construction in Progress & Improvements	75,802
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	33,490
Building / Construction in Progress & Improvements	75,802
Total	109,292
Accumulated Depreciation	10,461
Total Cost, Net of Accumulated Depreciation	98,831	101,637
Encumbrances	$ 0
Current Communities | Avalon Ballston Place [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	383
Initial Cost
Land and improvements	$ 38,490
Building / Construction in Progress & Improvements	123,645
Costs Subsequent to Acquisition / Construction	5,049
Total Cost
Land	38,490
Building / Construction in Progress & Improvements	128,694
Total	167,184
Accumulated Depreciation	24,830
Total Cost, Net of Accumulated Depreciation	142,354	146,479
Encumbrances	$ 0
Current Communities | Eaves Tysons Corner [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	217
Initial Cost
Land and improvements	$ 16,030
Building / Construction in Progress & Improvements	45,420
Costs Subsequent to Acquisition / Construction	2,967
Total Cost
Land	16,030
Building / Construction in Progress & Improvements	48,387
Total	64,417
Accumulated Depreciation	11,140
Total Cost, Net of Accumulated Depreciation	53,277	54,923
Encumbrances	$ 0
Current Communities | Avalon Courthouse Place [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	564
Initial Cost
Land and improvements	$ 56,550
Building / Construction in Progress & Improvements	178,032
Costs Subsequent to Acquisition / Construction	10,254
Total Cost
Land	56,550
Building / Construction in Progress & Improvements	188,286
Total	244,836
Accumulated Depreciation	37,860
Total Cost, Net of Accumulated Depreciation	206,976	213,114
Encumbrances	$ 0
Current Communities | Avalon Arlington North [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	228
Initial Cost
Land and improvements	$ 21,600
Building / Construction in Progress & Improvements	59,076
Costs Subsequent to Acquisition / Construction	34
Total Cost
Land	21,600
Building / Construction in Progress & Improvements	59,110
Total	80,710
Accumulated Depreciation	7,797
Total Cost, Net of Accumulated Depreciation	72,913	74,995
Encumbrances	$ 0
Current Communities | Avalon Reston Landing [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	400
Initial Cost
Land and improvements	$ 26,710
Building / Construction in Progress & Improvements	83,084
Costs Subsequent to Acquisition / Construction	6,212
Total Cost
Land	26,710
Building / Construction in Progress & Improvements	89,296
Total	116,006
Accumulated Depreciation	20,027
Total Cost, Net of Accumulated Depreciation	95,979	98,438
Encumbrances	$ 0
Current Communities | Avalon Redmond Place [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	222
Initial Cost
Land and improvements	$ 4,558
Building / Construction in Progress & Improvements	18,368
Costs Subsequent to Acquisition / Construction	10,501
Total Cost
Land	4,558
Building / Construction in Progress & Improvements	28,869
Total	33,427
Accumulated Depreciation	17,567
Total Cost, Net of Accumulated Depreciation	15,860	16,642
Encumbrances	$ 0
Current Communities | Avalon at Bear Creek [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	264
Initial Cost
Land and improvements	$ 6,786
Building / Construction in Progress & Improvements	27,641
Costs Subsequent to Acquisition / Construction	4,893
Total Cost
Land	6,786
Building / Construction in Progress & Improvements	32,534
Total	39,320
Accumulated Depreciation	21,197
Total Cost, Net of Accumulated Depreciation	18,123	18,645
Encumbrances	$ 0
Current Communities | Avalon Bellevue [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	201
Initial Cost
Land and improvements	$ 6,664
Building / Construction in Progress & Improvements	24,119
Costs Subsequent to Acquisition / Construction	2,110
Total Cost
Land	6,664
Building / Construction in Progress & Improvements	26,229
Total	32,893
Accumulated Depreciation	15,292
Total Cost, Net of Accumulated Depreciation	17,601	18,441
Encumbrances	$ 0
Current Communities | Avalon RockMeadow [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	206
Initial Cost
Land and improvements	$ 4,777
Building / Construction in Progress & Improvements	19,765
Costs Subsequent to Acquisition / Construction	2,930
Total Cost
Land	4,777
Building / Construction in Progress & Improvements	22,695
Total	27,472
Accumulated Depreciation	13,423
Total Cost, Net of Accumulated Depreciation	14,049	14,457
Encumbrances	$ 0
Current Communities | Avalon ParcSquare [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	124
Initial Cost
Land and improvements	$ 3,789
Building / Construction in Progress & Improvements	15,139
Costs Subsequent to Acquisition / Construction	3,286
Total Cost
Land	3,789
Building / Construction in Progress & Improvements	18,425
Total	22,214
Accumulated Depreciation	10,718
Total Cost, Net of Accumulated Depreciation	11,496	12,060
Encumbrances	$ 0
Current Communities | AVA Belltown [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	100
Initial Cost
Land and improvements	$ 5,644
Building / Construction in Progress & Improvements	12,733
Costs Subsequent to Acquisition / Construction	1,253
Total Cost
Land	5,644
Building / Construction in Progress & Improvements	13,986
Total	19,630
Accumulated Depreciation	7,940
Total Cost, Net of Accumulated Depreciation	11,690	12,003
Encumbrances	$ 0
Current Communities | Avalon Meydenbauer [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	368
Initial Cost
Land and improvements	$ 12,697
Building / Construction in Progress & Improvements	77,450
Costs Subsequent to Acquisition / Construction	1,366
Total Cost
Land	12,697
Building / Construction in Progress & Improvements	78,816
Total	91,513
Accumulated Depreciation	26,487
Total Cost, Net of Accumulated Depreciation	65,026	67,686
Encumbrances	$ 0
Current Communities | Avalon Towers Bellevue [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	397
Initial Cost
Land and improvements	$ 0
Building / Construction in Progress & Improvements	123,029
Costs Subsequent to Acquisition / Construction	1,341
Total Cost
Land	0
Building / Construction in Progress & Improvements	124,370
Total	124,370
Accumulated Depreciation	32,339
Total Cost, Net of Accumulated Depreciation	92,031	95,998
Encumbrances	$ 0
Current Communities | AVA Queen Anne [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	203
Initial Cost
Land and improvements	$ 12,081
Building / Construction in Progress & Improvements	41,618
Costs Subsequent to Acquisition / Construction	431
Total Cost
Land	12,081
Building / Construction in Progress & Improvements	42,049
Total	54,130
Accumulated Depreciation	9,060
Total Cost, Net of Accumulated Depreciation	45,070	46,642
Encumbrances	$ 0
Current Communities | AVA Ballard [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	265
Initial Cost
Land and improvements	$ 16,460
Building / Construction in Progress & Improvements	46,926
Costs Subsequent to Acquisition / Construction	1,002
Total Cost
Land	16,460
Building / Construction in Progress & Improvements	47,928
Total	64,388
Accumulated Depreciation	8,335
Total Cost, Net of Accumulated Depreciation	56,053	57,893
Encumbrances	$ 0
Current Communities | Avalon Alderwood I [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	367
Initial Cost
Land and improvements	$ 12,294
Building / Construction in Progress & Improvements	55,626
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	12,294
Building / Construction in Progress & Improvements	55,626
Total	67,920
Accumulated Depreciation	6,553
Total Cost, Net of Accumulated Depreciation	61,367	63,391
Encumbrances	$ 0
Current Communities | Eaves Redmond Campus [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	422
Initial Cost
Land and improvements	$ 22,580
Building / Construction in Progress & Improvements	88,001
Costs Subsequent to Acquisition / Construction	10,267
Total Cost
Land	22,580
Building / Construction in Progress & Improvements	98,268
Total	120,848
Accumulated Depreciation	21,097
Total Cost, Net of Accumulated Depreciation	99,751	99,157
Encumbrances	$ 0
Current Communities | Archstone Redmond Lakeview [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	166
Initial Cost
Land and improvements	$ 10,250
Building / Construction in Progress & Improvements	26,842
Costs Subsequent to Acquisition / Construction	3,315
Total Cost
Land	10,250
Building / Construction in Progress & Improvements	30,157
Total	40,407
Accumulated Depreciation	6,852
Total Cost, Net of Accumulated Depreciation	33,555	34,398
Encumbrances	$ 0
Current Communities | Avalon Campbell [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	348
Initial Cost
Land and improvements	$ 11,830
Building / Construction in Progress & Improvements	47,828
Costs Subsequent to Acquisition / Construction	13,561
Total Cost
Land	11,830
Building / Construction in Progress & Improvements	61,389
Total	73,219
Accumulated Depreciation	35,368
Total Cost, Net of Accumulated Depreciation	37,851	39,955
Encumbrances	$ 38,800
Current Communities | Eaves San Jose [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	440
Initial Cost
Land and improvements	$ 12,920
Building / Construction in Progress & Improvements	53,047
Costs Subsequent to Acquisition / Construction	18,931
Total Cost
Land	12,920
Building / Construction in Progress & Improvements	71,978
Total	84,898
Accumulated Depreciation	36,145
Total Cost, Net of Accumulated Depreciation	48,753	51,143
Encumbrances	$ 0
Current Communities | Avalon Mountain View [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	248
Initial Cost
Land and improvements	$ 9,755
Building / Construction in Progress & Improvements	39,393
Costs Subsequent to Acquisition / Construction	10,321
Total Cost
Land	9,755
Building / Construction in Progress & Improvements	49,714
Total	59,469
Accumulated Depreciation	30,458
Total Cost, Net of Accumulated Depreciation	29,011	30,562
Encumbrances	$ 0
Current Communities | Eaves Creekside [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	296
Initial Cost
Land and improvements	$ 6,546
Building / Construction in Progress & Improvements	26,263
Costs Subsequent to Acquisition / Construction	21,316
Total Cost
Land	6,546
Building / Construction in Progress & Improvements	47,579
Total	54,125
Accumulated Depreciation	25,798
Total Cost, Net of Accumulated Depreciation	28,327	29,992
Encumbrances	$ 0
Current Communities | Avalon at Cahill Park [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	218
Initial Cost
Land and improvements	$ 4,765
Building / Construction in Progress & Improvements	47,600
Costs Subsequent to Acquisition / Construction	2,020
Total Cost
Land	4,765
Building / Construction in Progress & Improvements	49,620
Total	54,385
Accumulated Depreciation	26,084
Total Cost, Net of Accumulated Depreciation	28,301	29,836
Encumbrances	$ 0
Current Communities | Avalon Morrison Park [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	250
Initial Cost
Land and improvements	$ 13,837
Building / Construction in Progress & Improvements	64,534
Costs Subsequent to Acquisition / Construction	72
Total Cost
Land	13,837
Building / Construction in Progress & Improvements	64,606
Total	78,443
Accumulated Depreciation	8,779
Total Cost, Net of Accumulated Depreciation	69,664	72,002
Encumbrances	$ 0
Current Communities | Avalon Willow Glen [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	412
Initial Cost
Land and improvements	$ 46,060
Building / Construction in Progress & Improvements	81,957
Costs Subsequent to Acquisition / Construction	4,707
Total Cost
Land	46,060
Building / Construction in Progress & Improvements	86,664
Total	132,724
Accumulated Depreciation	19,887
Total Cost, Net of Accumulated Depreciation	112,837	115,648
Encumbrances	$ 0
Current Communities | Eaves West Valley [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	873
Initial Cost
Land and improvements	$ 90,890
Building / Construction in Progress & Improvements	132,040
Costs Subsequent to Acquisition / Construction	10,251
Total Cost
Land	90,890
Building / Construction in Progress & Improvements	142,291
Total	233,181
Accumulated Depreciation	31,153
Total Cost, Net of Accumulated Depreciation	202,028	205,771
Encumbrances	$ 0
Current Communities | Eaves Mountain View at Middlefield [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	402
Initial Cost
Land and improvements	$ 64,070
Building / Construction in Progress & Improvements	69,018
Costs Subsequent to Acquisition / Construction	5,498
Total Cost
Land	64,070
Building / Construction in Progress & Improvements	74,516
Total	138,586
Accumulated Depreciation	17,838
Total Cost, Net of Accumulated Depreciation	120,748	123,403
Encumbrances	$ 0
Current Communities | Avalon Fremont [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	308
Initial Cost
Land and improvements	$ 10,746
Building / Construction in Progress & Improvements	43,399
Costs Subsequent to Acquisition / Construction	6,656
Total Cost
Land	10,746
Building / Construction in Progress & Improvements	50,055
Total	60,801
Accumulated Depreciation	33,523
Total Cost, Net of Accumulated Depreciation	27,278	28,098
Encumbrances	$ 0
Current Communities | Eaves Dublin [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	204
Initial Cost
Land and improvements	$ 5,276
Building / Construction in Progress & Improvements	19,642
Costs Subsequent to Acquisition / Construction	12,366
Total Cost
Land	5,276
Building / Construction in Progress & Improvements	32,008
Total	37,284
Accumulated Depreciation	17,814
Total Cost, Net of Accumulated Depreciation	19,470	20,653
Encumbrances	$ 0
Current Communities | Eaves Pleasanton [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	456
Initial Cost
Land and improvements	$ 11,610
Building / Construction in Progress & Improvements	46,552
Costs Subsequent to Acquisition / Construction	21,755
Total Cost
Land	11,610
Building / Construction in Progress & Improvements	68,307
Total	79,917
Accumulated Depreciation	40,146
Total Cost, Net of Accumulated Depreciation	39,771	41,764
Encumbrances	$ 0
Current Communities | Eaves Union City [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	208
Initial Cost
Land and improvements	$ 4,249
Building / Construction in Progress & Improvements	16,820
Costs Subsequent to Acquisition / Construction	3,312
Total Cost
Land	4,249
Building / Construction in Progress & Improvements	20,132
Total	24,381
Accumulated Depreciation	13,659
Total Cost, Net of Accumulated Depreciation	10,722	11,342
Encumbrances	$ 0
Current Communities | Eaves Fremont [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	235
Initial Cost
Land and improvements	$ 6,581
Building / Construction in Progress & Improvements	26,583
Costs Subsequent to Acquisition / Construction	9,992
Total Cost
Land	6,581
Building / Construction in Progress & Improvements	36,575
Total	43,156
Accumulated Depreciation	22,733
Total Cost, Net of Accumulated Depreciation	20,423	21,385
Encumbrances	$ 0
Current Communities | Avalon Union City [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	439
Initial Cost
Land and improvements	$ 14,732
Building / Construction in Progress & Improvements	104,024
Costs Subsequent to Acquisition / Construction	982
Total Cost
Land	14,732
Building / Construction in Progress & Improvements	105,006
Total	119,738
Accumulated Depreciation	30,647
Total Cost, Net of Accumulated Depreciation	89,091	92,395
Encumbrances	$ 0
Current Communities | Avalon Walnut Creek [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	422
Initial Cost
Land and improvements	$ 0
Building / Construction in Progress & Improvements	148,370
Costs Subsequent to Acquisition / Construction	3,245
Total Cost
Land	0
Building / Construction in Progress & Improvements	151,615
Total	151,615
Accumulated Depreciation	39,014
Total Cost, Net of Accumulated Depreciation	112,601	115,817
Encumbrances	$ 3,557
Current Communities | Avalon Dublin Station [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	253
Initial Cost
Land and improvements	$ 7,772
Building / Construction in Progress & Improvements	72,142
Costs Subsequent to Acquisition / Construction	599
Total Cost
Land	7,772
Building / Construction in Progress & Improvements	72,741
Total	80,513
Accumulated Depreciation	9,650
Total Cost, Net of Accumulated Depreciation	70,863	72,802
Encumbrances	$ 0
Current Communities | Eaves Walnut Creek [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	510
Initial Cost
Land and improvements	$ 30,320
Building / Construction in Progress & Improvements	82,375
Costs Subsequent to Acquisition / Construction	16,828
Total Cost
Land	30,320
Building / Construction in Progress & Improvements	99,203
Total	129,523
Accumulated Depreciation	19,294
Total Cost, Net of Accumulated Depreciation	110,229	111,534
Encumbrances	$ 0
Current Communities | Avalon Walnut Ridge II [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	360
Initial Cost
Land and improvements	$ 27,190
Building / Construction in Progress & Improvements	57,041
Costs Subsequent to Acquisition / Construction	5,864
Total Cost
Land	27,190
Building / Construction in Progress & Improvements	62,905
Total	90,095
Accumulated Depreciation	13,372
Total Cost, Net of Accumulated Depreciation	76,723	76,821
Encumbrances	$ 0
Current Communities | Avalon Berkeley [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	94
Initial Cost
Land and improvements	$ 4,500
Building / Construction in Progress & Improvements	28,622
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	4,500
Building / Construction in Progress & Improvements	28,622
Total	33,122
Accumulated Depreciation	3,523
Total Cost, Net of Accumulated Depreciation	29,599	30,607
Encumbrances	$ 0
Current Communities | Eaves Daly City [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	195
Initial Cost
Land and improvements	$ 4,230
Building / Construction in Progress & Improvements	9,659
Costs Subsequent to Acquisition / Construction	19,858
Total Cost
Land	4,230
Building / Construction in Progress & Improvements	29,517
Total	33,747
Accumulated Depreciation	17,704
Total Cost, Net of Accumulated Depreciation	16,043	16,173
Encumbrances	$ 0
Current Communities | AVA Nob Hill [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	185
Initial Cost
Land and improvements	$ 5,403
Building / Construction in Progress & Improvements	21,567
Costs Subsequent to Acquisition / Construction	7,597
Total Cost
Land	5,403
Building / Construction in Progress & Improvements	29,164
Total	34,567
Accumulated Depreciation	17,103
Total Cost, Net of Accumulated Depreciation	17,464	17,980
Encumbrances	$ 20,800
Current Communities | Eaves San Rafael [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	254
Initial Cost
Land and improvements	$ 5,982
Building / Construction in Progress & Improvements	16,885
Costs Subsequent to Acquisition / Construction	24,752
Total Cost
Land	5,982
Building / Construction in Progress & Improvements	41,637
Total	47,619
Accumulated Depreciation	22,224
Total Cost, Net of Accumulated Depreciation	25,395	26,689
Encumbrances	$ 0
Current Communities | Eaves Foster City [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	288
Initial Cost
Land and improvements	$ 7,852
Building / Construction in Progress & Improvements	31,445
Costs Subsequent to Acquisition / Construction	11,629
Total Cost
Land	7,852
Building / Construction in Progress & Improvements	43,074
Total	50,926
Accumulated Depreciation	25,622
Total Cost, Net of Accumulated Depreciation	25,304	26,440
Encumbrances	$ 0
Current Communities | Eaves Pacifica [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	220
Initial Cost
Land and improvements	$ 6,125
Building / Construction in Progress & Improvements	24,796
Costs Subsequent to Acquisition / Construction	3,116
Total Cost
Land	6,125
Building / Construction in Progress & Improvements	27,912
Total	34,037
Accumulated Depreciation	18,647
Total Cost, Net of Accumulated Depreciation	15,390	16,175
Encumbrances	$ 17,600
Current Communities | Avalon Sunset Towers [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	243
Initial Cost
Land and improvements	$ 3,561
Building / Construction in Progress & Improvements	21,321
Costs Subsequent to Acquisition / Construction	16,129
Total Cost
Land	3,561
Building / Construction in Progress & Improvements	37,450
Total	41,011
Accumulated Depreciation	19,817
Total Cost, Net of Accumulated Depreciation	21,194	21,819
Encumbrances	$ 0
Current Communities | Eaves Diamond Heights [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	154
Initial Cost
Land and improvements	$ 4,726
Building / Construction in Progress & Improvements	19,130
Costs Subsequent to Acquisition / Construction	6,189
Total Cost
Land	4,726
Building / Construction in Progress & Improvements	25,319
Total	30,045
Accumulated Depreciation	15,390
Total Cost, Net of Accumulated Depreciation	14,655	15,313
Encumbrances	$ 0
Current Communities | Avalon at Mission Bay I [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	250
Initial Cost
Land and improvements	$ 14,029
Building / Construction in Progress & Improvements	78,452
Costs Subsequent to Acquisition / Construction	3,759
Total Cost
Land	14,029
Building / Construction in Progress & Improvements	82,211
Total	96,240
Accumulated Depreciation	41,915
Total Cost, Net of Accumulated Depreciation	54,325	56,826
Encumbrances	$ 0
Current Communities | Avalon at Mission Bay III [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	260
Initial Cost
Land and improvements	$ 28,687
Building / Construction in Progress & Improvements	119,156
Costs Subsequent to Acquisition / Construction	447
Total Cost
Land	28,687
Building / Construction in Progress & Improvements	119,603
Total	148,290
Accumulated Depreciation	35,003
Total Cost, Net of Accumulated Depreciation	113,287	117,091
Encumbrances	$ 0
Current Communities | Avalon Ocean Avenue [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	173
Initial Cost
Land and improvements	$ 5,544
Building / Construction in Progress & Improvements	50,906
Costs Subsequent to Acquisition / Construction	1,877
Total Cost
Land	5,544
Building / Construction in Progress & Improvements	52,783
Total	58,327
Accumulated Depreciation	10,581
Total Cost, Net of Accumulated Depreciation	47,746	49,580
Encumbrances	$ 0
Current Communities | AVA 55 Ninth [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	273
Initial Cost
Land and improvements	$ 20,267
Building / Construction in Progress & Improvements	97,321
Costs Subsequent to Acquisition / Construction	1,258
Total Cost
Land	20,267
Building / Construction in Progress & Improvements	98,579
Total	118,846
Accumulated Depreciation	13,135
Total Cost, Net of Accumulated Depreciation	105,711	109,414
Encumbrances	$ 0
Current Communities | Avalon Hayes Valley [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	182
Initial Cost
Land and improvements	$ 12,595
Building / Construction in Progress & Improvements	81,232
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	12,595
Building / Construction in Progress & Improvements	81,232
Total	93,827
Accumulated Depreciation	7,855
Total Cost, Net of Accumulated Depreciation	85,972	88,745
Encumbrances	$ 0
Current Communities | Avalon San Bruno I [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	300
Initial Cost
Land and improvements	$ 40,780
Building / Construction in Progress & Improvements	68,684
Costs Subsequent to Acquisition / Construction	4,974
Total Cost
Land	40,780
Building / Construction in Progress & Improvements	73,658
Total	114,438
Accumulated Depreciation	15,334
Total Cost, Net of Accumulated Depreciation	99,104	100,274
Encumbrances	$ 64,450
Current Communities | Avalon San Bruno II [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	185
Initial Cost
Land and improvements	$ 23,787
Building / Construction in Progress & Improvements	44,934
Costs Subsequent to Acquisition / Construction	1,906
Total Cost
Land	23,787
Building / Construction in Progress & Improvements	46,840
Total	70,627
Accumulated Depreciation	9,205
Total Cost, Net of Accumulated Depreciation	61,422	62,879
Encumbrances	$ 29,533
Current Communities | Avalon San Bruno III [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	187
Initial Cost
Land and improvements	$ 33,303
Building / Construction in Progress & Improvements	62,910
Costs Subsequent to Acquisition / Construction	3,028
Total Cost
Land	33,303
Building / Construction in Progress & Improvements	65,938
Total	99,241
Accumulated Depreciation	12,956
Total Cost, Net of Accumulated Depreciation	86,285	88,243
Encumbrances	$ 53,315
Current Communities | AVA Burbank [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	748
Initial Cost
Land and improvements	$ 22,483
Building / Construction in Progress & Improvements	28,104
Costs Subsequent to Acquisition / Construction	48,565
Total Cost
Land	22,483
Building / Construction in Progress & Improvements	76,669
Total	99,152
Accumulated Depreciation	40,761
Total Cost, Net of Accumulated Depreciation	58,391	60,868
Encumbrances	$ 0
Current Communities | Avalon Woodland Hills [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	663
Initial Cost
Land and improvements	$ 23,828
Building / Construction in Progress & Improvements	40,372
Costs Subsequent to Acquisition / Construction	49,385
Total Cost
Land	23,828
Building / Construction in Progress & Improvements	89,757
Total	113,585
Accumulated Depreciation	45,441
Total Cost, Net of Accumulated Depreciation	68,144	70,434
Encumbrances	$ 0
Current Communities | Eaves Warner Center [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	227
Initial Cost
Land and improvements	$ 7,045
Building / Construction in Progress & Improvements	12,986
Costs Subsequent to Acquisition / Construction	9,609
Total Cost
Land	7,045
Building / Construction in Progress & Improvements	22,595
Total	29,640
Accumulated Depreciation	15,855
Total Cost, Net of Accumulated Depreciation	13,785	14,591
Encumbrances	$ 0
Current Communities | Avalon Glendale [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	223
Initial Cost
Land and improvements	$ 0
Building / Construction in Progress & Improvements	42,564
Costs Subsequent to Acquisition / Construction	2,070
Total Cost
Land	0
Building / Construction in Progress & Improvements	44,634
Total	44,634
Accumulated Depreciation	21,703
Total Cost, Net of Accumulated Depreciation	22,931	24,122
Encumbrances	$ 0
Current Communities | Avalon Burbank [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	400
Initial Cost
Land and improvements	$ 14,053
Building / Construction in Progress & Improvements	56,827
Costs Subsequent to Acquisition / Construction	24,724
Total Cost
Land	14,053
Building / Construction in Progress & Improvements	81,551
Total	95,604
Accumulated Depreciation	37,558
Total Cost, Net of Accumulated Depreciation	58,046	60,327
Encumbrances	$ 0
Current Communities | Avalon Camarillo [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	249
Initial Cost
Land and improvements	$ 8,446
Building / Construction in Progress & Improvements	40,290
Costs Subsequent to Acquisition / Construction	908
Total Cost
Land	8,446
Building / Construction in Progress & Improvements	41,198
Total	49,644
Accumulated Depreciation	16,389
Total Cost, Net of Accumulated Depreciation	33,255	34,405
Encumbrances	$ 0
Current Communities | Avalon Wilshire [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	123
Initial Cost
Land and improvements	$ 5,459
Building / Construction in Progress & Improvements	41,182
Costs Subsequent to Acquisition / Construction	1,206
Total Cost
Land	5,459
Building / Construction in Progress & Improvements	42,388
Total	47,847
Accumulated Depreciation	15,562
Total Cost, Net of Accumulated Depreciation	32,285	33,601
Encumbrances	$ 0
Current Communities | Avalon Encino [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	131
Initial Cost
Land and improvements	$ 12,789
Building / Construction in Progress & Improvements	49,073
Costs Subsequent to Acquisition / Construction	1,091
Total Cost
Land	12,789
Building / Construction in Progress & Improvements	50,164
Total	62,953
Accumulated Depreciation	15,966
Total Cost, Net of Accumulated Depreciation	46,987	48,412
Encumbrances	$ 0
Current Communities | Avalon Warner Place [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	210
Initial Cost
Land and improvements	$ 7,920
Building / Construction in Progress & Improvements	44,845
Costs Subsequent to Acquisition / Construction	589
Total Cost
Land	7,920
Building / Construction in Progress & Improvements	45,434
Total	53,354
Accumulated Depreciation	15,109
Total Cost, Net of Accumulated Depreciation	38,245	39,727
Encumbrances	$ 0
Current Communities | AVA Little Tokyo [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	280
Initial Cost
Land and improvements	$ 14,734
Building / Construction in Progress & Improvements	93,985
Costs Subsequent to Acquisition / Construction	462
Total Cost
Land	14,734
Building / Construction in Progress & Improvements	94,447
Total	109,181
Accumulated Depreciation	10,574
Total Cost, Net of Accumulated Depreciation	98,607	101,914
Encumbrances	$ 0
Current Communities | Eaves Phillips Ranch [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	501
Initial Cost
Land and improvements	$ 9,796
Building / Construction in Progress & Improvements	41,740
Costs Subsequent to Acquisition / Construction	1,964
Total Cost
Land	9,796
Building / Construction in Progress & Improvements	43,704
Total	53,500
Accumulated Depreciation	10,314
Total Cost, Net of Accumulated Depreciation	43,186	44,058
Encumbrances	$ 0
Current Communities | Eaves San Dimas [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	102
Initial Cost
Land and improvements	$ 1,916
Building / Construction in Progress & Improvements	7,819
Costs Subsequent to Acquisition / Construction	1,389
Total Cost
Land	1,916
Building / Construction in Progress & Improvements	9,208
Total	11,124
Accumulated Depreciation	2,202
Total Cost, Net of Accumulated Depreciation	8,922	9,214
Encumbrances	$ 0
Current Communities | Eaves San Dimas Canyon [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	156
Initial Cost
Land and improvements	$ 2,953
Building / Construction in Progress & Improvements	12,428
Costs Subsequent to Acquisition / Construction	736
Total Cost
Land	2,953
Building / Construction in Progress & Improvements	13,164
Total	16,117
Accumulated Depreciation	3,145
Total Cost, Net of Accumulated Depreciation	12,972	13,289
Encumbrances	$ 0
Current Communities | AVA Pasadena [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	84
Initial Cost
Land and improvements	$ 8,400
Building / Construction in Progress & Improvements	11,547
Costs Subsequent to Acquisition / Construction	5,522
Total Cost
Land	8,400
Building / Construction in Progress & Improvements	17,069
Total	25,469
Accumulated Depreciation	3,214
Total Cost, Net of Accumulated Depreciation	22,255	22,879
Encumbrances	$ 11,073
Current Communities | Eaves Cerritos [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	151
Initial Cost
Land and improvements	$ 8,305
Building / Construction in Progress & Improvements	21,195
Costs Subsequent to Acquisition / Construction	1,474
Total Cost
Land	8,305
Building / Construction in Progress & Improvements	22,669
Total	30,974
Accumulated Depreciation	4,391
Total Cost, Net of Accumulated Depreciation	26,583	27,343
Encumbrances	$ 0
Current Communities | Avalon Playa Vista [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	309
Initial Cost
Land and improvements	$ 30,900
Building / Construction in Progress & Improvements	72,008
Costs Subsequent to Acquisition / Construction	2,428
Total Cost
Land	30,900
Building / Construction in Progress & Improvements	74,436
Total	105,336
Accumulated Depreciation	14,228
Total Cost, Net of Accumulated Depreciation	91,108	93,776
Encumbrances	$ 0
Current Communities | Avalon San Dimas [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	156
Initial Cost
Land and improvements	$ 9,141
Building / Construction in Progress & Improvements	30,727
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	9,141
Building / Construction in Progress & Improvements	30,727
Total	39,868
Accumulated Depreciation	3,778
Total Cost, Net of Accumulated Depreciation	36,090	37,250
Encumbrances	$ 0
Current Communities | Avalon Mission Oaks [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	160
Initial Cost
Land and improvements	$ 9,600
Building / Construction in Progress & Improvements	35,842
Costs Subsequent to Acquisition / Construction	3,002
Total Cost
Land	9,600
Building / Construction in Progress & Improvements	38,844
Total	48,444
Accumulated Depreciation	5,595
Total Cost, Net of Accumulated Depreciation	42,849	44,281
Encumbrances	$ 0
Current Communities | Avalon Simi Valley [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	500
Initial Cost
Land and improvements	$ 42,020
Building / Construction in Progress & Improvements	73,361
Costs Subsequent to Acquisition / Construction	4,940
Total Cost
Land	42,020
Building / Construction in Progress & Improvements	78,301
Total	120,321
Accumulated Depreciation	17,394
Total Cost, Net of Accumulated Depreciation	102,927	105,475
Encumbrances	$ 0
Current Communities | Avalon Studio City [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	276
Initial Cost
Land and improvements	$ 15,756
Building / Construction in Progress & Improvements	78,178
Costs Subsequent to Acquisition / Construction	5,778
Total Cost
Land	15,756
Building / Construction in Progress & Improvements	83,956
Total	99,712
Accumulated Depreciation	17,139
Total Cost, Net of Accumulated Depreciation	82,573	84,242
Encumbrances	$ 0
Current Communities | Avalon Calabasas [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	600
Initial Cost
Land and improvements	$ 42,720
Building / Construction in Progress & Improvements	107,642
Costs Subsequent to Acquisition / Construction	9,921
Total Cost
Land	42,720
Building / Construction in Progress & Improvements	117,563
Total	160,283
Accumulated Depreciation	27,970
Total Cost, Net of Accumulated Depreciation	132,313	136,511
Encumbrances	$ 96,502
Current Communities | Avalon Oak Creek [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	336
Initial Cost
Land and improvements	$ 43,540
Building / Construction in Progress & Improvements	79,974
Costs Subsequent to Acquisition / Construction	5,842
Total Cost
Land	43,540
Building / Construction in Progress & Improvements	85,816
Total	129,356
Accumulated Depreciation	21,276
Total Cost, Net of Accumulated Depreciation	108,080	111,280
Encumbrances	$ 0
Current Communities | Avalon Del Mar Station [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	347
Initial Cost
Land and improvements	$ 20,560
Building / Construction in Progress & Improvements	106,556
Costs Subsequent to Acquisition / Construction	3,731
Total Cost
Land	20,560
Building / Construction in Progress & Improvements	110,287
Total	130,847
Accumulated Depreciation	20,717
Total Cost, Net of Accumulated Depreciation	110,130	113,568
Encumbrances	$ 0
Current Communities | Eaves Thousand Oaks [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	154
Initial Cost
Land and improvements	$ 13,950
Building / Construction in Progress & Improvements	20,211
Costs Subsequent to Acquisition / Construction	2,546
Total Cost
Land	13,950
Building / Construction in Progress & Improvements	22,757
Total	36,707
Accumulated Depreciation	6,158
Total Cost, Net of Accumulated Depreciation	30,549	31,486
Encumbrances	$ 0
Current Communities | Eaves Los Feliz [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	263
Initial Cost
Land and improvements	$ 18,940
Building / Construction in Progress & Improvements	43,661
Costs Subsequent to Acquisition / Construction	4,556
Total Cost
Land	18,940
Building / Construction in Progress & Improvements	48,217
Total	67,157
Accumulated Depreciation	10,545
Total Cost, Net of Accumulated Depreciation	56,612	57,563
Encumbrances	$ 41,400
Current Communities | Eaves Woodland Hills [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	883
Initial Cost
Land and improvements	$ 68,940
Building / Construction in Progress & Improvements	90,549
Costs Subsequent to Acquisition / Construction	11,203
Total Cost
Land	68,940
Building / Construction in Progress & Improvements	101,752
Total	170,692
Accumulated Depreciation	25,353
Total Cost, Net of Accumulated Depreciation	145,339	148,867
Encumbrances	$ 111,500
Current Communities | Avalon Thousand Oaks Plaza [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	148
Initial Cost
Land and improvements	$ 12,810
Building / Construction in Progress & Improvements	22,581
Costs Subsequent to Acquisition / Construction	2,300
Total Cost
Land	12,810
Building / Construction in Progress & Improvements	24,881
Total	37,691
Accumulated Depreciation	6,132
Total Cost, Net of Accumulated Depreciation	31,559	32,257
Encumbrances	$ 0
Current Communities | AVA Newport [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	145
Initial Cost
Land and improvements	$ 1,975
Building / Construction in Progress & Improvements	3,814
Costs Subsequent to Acquisition / Construction	9,840
Total Cost
Land	1,975
Building / Construction in Progress & Improvements	13,654
Total	15,629
Accumulated Depreciation	6,995
Total Cost, Net of Accumulated Depreciation	8,634	9,130
Encumbrances	$ 0
Current Communities | Eaves Mission Viejo [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	166
Initial Cost
Land and improvements	$ 2,517
Building / Construction in Progress & Improvements	9,257
Costs Subsequent to Acquisition / Construction	3,580
Total Cost
Land	2,517
Building / Construction in Progress & Improvements	12,837
Total	15,354
Accumulated Depreciation	8,660
Total Cost, Net of Accumulated Depreciation	6,694	7,145
Encumbrances	$ 7,635
Current Communities | Eaves South Coast [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	258
Initial Cost
Land and improvements	$ 4,709
Building / Construction in Progress & Improvements	16,063
Costs Subsequent to Acquisition / Construction	13,442
Total Cost
Land	4,709
Building / Construction in Progress & Improvements	29,505
Total	34,214
Accumulated Depreciation	16,883
Total Cost, Net of Accumulated Depreciation	17,331	17,829
Encumbrances	$ 0
Current Communities | Eaves Santa Margarita [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	301
Initial Cost
Land and improvements	$ 4,607
Building / Construction in Progress & Improvements	16,911
Costs Subsequent to Acquisition / Construction	10,917
Total Cost
Land	4,607
Building / Construction in Progress & Improvements	27,828
Total	32,435
Accumulated Depreciation	15,849
Total Cost, Net of Accumulated Depreciation	16,586	17,224
Encumbrances	$ 0
Current Communities | Eaves Huntington Beach [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	304
Initial Cost
Land and improvements	$ 4,871
Building / Construction in Progress & Improvements	19,745
Costs Subsequent to Acquisition / Construction	10,267
Total Cost
Land	4,871
Building / Construction in Progress & Improvements	30,012
Total	34,883
Accumulated Depreciation	19,912
Total Cost, Net of Accumulated Depreciation	14,971	15,964
Encumbrances	$ 0
Current Communities | Avalon Anaheim Stadium [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	251
Initial Cost
Land and improvements	$ 27,874
Building / Construction in Progress & Improvements	69,156
Costs Subsequent to Acquisition / Construction	1,608
Total Cost
Land	27,874
Building / Construction in Progress & Improvements	70,764
Total	98,638
Accumulated Depreciation	21,751
Total Cost, Net of Accumulated Depreciation	76,887	78,955
Encumbrances	$ 0
Current Communities | Avalon Irvine I [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	279
Initial Cost
Land and improvements	$ 9,911
Building / Construction in Progress & Improvements	67,520
Costs Subsequent to Acquisition / Construction	776
Total Cost
Land	9,911
Building / Construction in Progress & Improvements	68,296
Total	78,207
Accumulated Depreciation	19,629
Total Cost, Net of Accumulated Depreciation	58,578	60,694
Encumbrances	$ 0
Current Communities | Avalon Irvine II [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	179
Initial Cost
Land and improvements	$ 4,358
Building / Construction in Progress & Improvements	40,912
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	4,358
Building / Construction in Progress & Improvements	40,912
Total	45,270
Accumulated Depreciation	7,217
Total Cost, Net of Accumulated Depreciation	38,053	39,535
Encumbrances	$ 0
Current Communities | Eaves Lake Forest [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	225
Initial Cost
Land and improvements	$ 5,199
Building / Construction in Progress & Improvements	21,134
Costs Subsequent to Acquisition / Construction	3,248
Total Cost
Land	5,199
Building / Construction in Progress & Improvements	24,382
Total	29,581
Accumulated Depreciation	5,614
Total Cost, Net of Accumulated Depreciation	23,967	23,870
Encumbrances	$ 0
Current Communities | Avalon Baker Ranch [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	430
Initial Cost
Land and improvements	$ 31,689
Building / Construction in Progress & Improvements	98,411
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	31,689
Building / Construction in Progress & Improvements	98,411
Total	130,100
Accumulated Depreciation	9,406
Total Cost, Net of Accumulated Depreciation	120,694	124,442
Encumbrances	$ 0
Current Communities | Eaves Seal Beach [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	549
Initial Cost
Land and improvements	$ 46,790
Building / Construction in Progress & Improvements	99,999
Costs Subsequent to Acquisition / Construction	5,640
Total Cost
Land	46,790
Building / Construction in Progress & Improvements	105,639
Total	152,429
Accumulated Depreciation	22,914
Total Cost, Net of Accumulated Depreciation	129,515	132,659
Encumbrances	$ 0
Current Communities | AVA Pacific Beach [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	564
Initial Cost
Land and improvements	$ 9,922
Building / Construction in Progress & Improvements	40,580
Costs Subsequent to Acquisition / Construction	40,849
Total Cost
Land	9,922
Building / Construction in Progress & Improvements	81,429
Total	91,351
Accumulated Depreciation	41,108
Total Cost, Net of Accumulated Depreciation	50,243	53,224
Encumbrances	$ 0
Current Communities | Eaves Mission Ridge [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	200
Initial Cost
Land and improvements	$ 2,710
Building / Construction in Progress & Improvements	10,924
Costs Subsequent to Acquisition / Construction	12,128
Total Cost
Land	2,710
Building / Construction in Progress & Improvements	23,052
Total	25,762
Accumulated Depreciation	14,637
Total Cost, Net of Accumulated Depreciation	11,125	11,696
Encumbrances	$ 0
Current Communities | AVA Cortez Hill [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	299
Initial Cost
Land and improvements	$ 2,768
Building / Construction in Progress & Improvements	20,134
Costs Subsequent to Acquisition / Construction	23,567
Total Cost
Land	2,768
Building / Construction in Progress & Improvements	43,701
Total	46,469
Accumulated Depreciation	23,459
Total Cost, Net of Accumulated Depreciation	23,010	24,543
Encumbrances	$ 0
Current Communities | Avalon Fashion Valley [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	161
Initial Cost
Land and improvements	$ 19,627
Building / Construction in Progress & Improvements	44,972
Costs Subsequent to Acquisition / Construction	696
Total Cost
Land	19,627
Building / Construction in Progress & Improvements	45,668
Total	65,295
Accumulated Depreciation	14,567
Total Cost, Net of Accumulated Depreciation	50,728	52,186
Encumbrances	$ 0
Current Communities | Eaves Rancho Penasquitos [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	250
Initial Cost
Land and improvements	$ 6,692
Building / Construction in Progress & Improvements	27,143
Costs Subsequent to Acquisition / Construction	3,242
Total Cost
Land	6,692
Building / Construction in Progress & Improvements	30,385
Total	37,077
Accumulated Depreciation	6,960
Total Cost, Net of Accumulated Depreciation	30,117	30,727
Encumbrances	$ 0
Current Communities | Avalon Vista [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	221
Initial Cost
Land and improvements	$ 12,689
Building / Construction in Progress & Improvements	43,327
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	12,689
Building / Construction in Progress & Improvements	43,327
Total	56,016
Accumulated Depreciation	4,125
Total Cost, Net of Accumulated Depreciation	51,891	53,512
Encumbrances	$ 0
Current Communities | Eaves La Mesa [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	168
Initial Cost
Land and improvements	$ 9,490
Building / Construction in Progress & Improvements	28,482
Costs Subsequent to Acquisition / Construction	1,962
Total Cost
Land	9,490
Building / Construction in Progress & Improvements	30,444
Total	39,934
Accumulated Depreciation	7,189
Total Cost, Net of Accumulated Depreciation	32,745	33,840
Encumbrances	$ 0
Current Communities | Avalon Silicon Valley [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	710
Initial Cost
Land and improvements	$ 20,713
Building / Construction in Progress & Improvements	99,573
Costs Subsequent to Acquisition / Construction	34,963
Total Cost
Land	20,713
Building / Construction in Progress & Improvements	134,536
Total	155,249
Accumulated Depreciation	71,577
Total Cost, Net of Accumulated Depreciation	83,672	85,041
Encumbrances	$ 0
Current Communities | Avalon Towers on the Peninsula [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	211
Initial Cost
Land and improvements	$ 9,560
Building / Construction in Progress & Improvements	56,136
Costs Subsequent to Acquisition / Construction	14,467
Total Cost
Land	9,560
Building / Construction in Progress & Improvements	70,603
Total	80,163
Accumulated Depreciation	31,563
Total Cost, Net of Accumulated Depreciation	48,600	45,523
Encumbrances	$ 0
Current Communities | Eaves San Marcos [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	184
Initial Cost
Land and improvements	$ 3,277
Building / Construction in Progress & Improvements	13,385
Costs Subsequent to Acquisition / Construction	4,557
Total Cost
Land	3,277
Building / Construction in Progress & Improvements	17,942
Total	21,219
Accumulated Depreciation	3,641
Total Cost, Net of Accumulated Depreciation	17,578	18,302
Encumbrances	$ 0
Current Communities | Avalon Glendora [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	280
Initial Cost
Land and improvements	$ 18,311
Building / Construction in Progress & Improvements	64,759
Costs Subsequent to Acquisition / Construction	100
Total Cost
Land	18,311
Building / Construction in Progress & Improvements	64,859
Total	83,170
Accumulated Depreciation	4,974
Total Cost, Net of Accumulated Depreciation	78,196	80,358
Encumbrances	$ 0
Current Communities | Avalon Irvine III [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	156
Initial Cost
Land and improvements	$ 11,607
Building / Construction in Progress & Improvements	43,977
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	11,607
Building / Construction in Progress & Improvements	43,977
Total	55,584
Accumulated Depreciation	2,842
Total Cost, Net of Accumulated Depreciation	52,742	54,232
Encumbrances	$ 0
Current Communities | Avalon Dublin Station II [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	252
Initial Cost
Land and improvements	$ 7,762
Building / Construction in Progress & Improvements	76,584
Costs Subsequent to Acquisition / Construction	26
Total Cost
Land	7,762
Building / Construction in Progress & Improvements	76,610
Total	84,372
Accumulated Depreciation	4,821
Total Cost, Net of Accumulated Depreciation	79,551	82,106
Encumbrances	$ 0
Current Communities | AVA North Hollywood [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	156
Initial Cost
Land and improvements	$ 18,408
Building / Construction in Progress & Improvements	49,940
Costs Subsequent to Acquisition / Construction	4,089
Total Cost
Land	18,408
Building / Construction in Progress & Improvements	54,029
Total	72,437
Accumulated Depreciation	3,810
Total Cost, Net of Accumulated Depreciation	68,627	70,816
Encumbrances	$ 0
Current Communities | AVA Studio City II [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	101
Initial Cost
Land and improvements	$ 4,626
Building / Construction in Progress & Improvements	22,954
Costs Subsequent to Acquisition / Construction	5,487
Total Cost
Land	4,626
Building / Construction in Progress & Improvements	28,441
Total	33,067
Accumulated Depreciation	5,160
Total Cost, Net of Accumulated Depreciation	27,907	24,848
Encumbrances	$ 0
Current Communities | Avalon Santa Monica on Main [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	133
Initial Cost
Land and improvements	$ 32,000
Building / Construction in Progress & Improvements	60,770
Costs Subsequent to Acquisition / Construction	13,179
Total Cost
Land	32,000
Building / Construction in Progress & Improvements	73,949
Total	105,949
Accumulated Depreciation	13,764
Total Cost, Net of Accumulated Depreciation	92,185	94,217
Encumbrances	$ 0
Current Communities | Avalon La Jolla Colony [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	180
Initial Cost
Land and improvements	$ 16,760
Building / Construction in Progress & Improvements	27,694
Costs Subsequent to Acquisition / Construction	12,052
Total Cost
Land	16,760
Building / Construction in Progress & Improvements	39,746
Total	56,506
Accumulated Depreciation	7,968
Total Cost, Net of Accumulated Depreciation	48,538	50,383
Encumbrances	$ 0
Current Communities | Eaves Old Town Pasadena [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	96
Initial Cost
Land and improvements	$ 9,110
Building / Construction in Progress & Improvements	15,371
Costs Subsequent to Acquisition / Construction	6,778
Total Cost
Land	9,110
Building / Construction in Progress & Improvements	22,149
Total	31,259
Accumulated Depreciation	4,085
Total Cost, Net of Accumulated Depreciation	27,174	22,644
Encumbrances	$ 0
Current Communities | Avalon Walnut Ridge I [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	106
Initial Cost
Land and improvements	$ 9,860
Building / Construction in Progress & Improvements	19,850
Costs Subsequent to Acquisition / Construction	5,268
Total Cost
Land	9,860
Building / Construction in Progress & Improvements	25,118
Total	34,978
Accumulated Depreciation	4,802
Total Cost, Net of Accumulated Depreciation	30,176	30,921
Encumbrances	$ 0
Current Communities | Avalon Pasadena [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	120
Initial Cost
Land and improvements	$ 10,240
Building / Construction in Progress & Improvements	31,558
Costs Subsequent to Acquisition / Construction	6,679
Total Cost
Land	10,240
Building / Construction in Progress & Improvements	38,237
Total	48,477
Accumulated Depreciation	7,273
Total Cost, Net of Accumulated Depreciation	41,204	42,580
Encumbrances	$ 0
Current Communities | AVA Studio City I [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	450
Initial Cost
Land and improvements	$ 17,658
Building / Construction in Progress & Improvements	90,715
Costs Subsequent to Acquisition / Construction	32,819
Total Cost
Land	17,658
Building / Construction in Progress & Improvements	123,534
Total	141,192
Accumulated Depreciation	20,681
Total Cost, Net of Accumulated Depreciation	120,511	116,321
Encumbrances	$ 0
Current Communities | The Lodge Denver West [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	252
Initial Cost
Land and improvements	$ 8,047
Building / Construction in Progress & Improvements	63,586
Costs Subsequent to Acquisition / Construction	5,284
Total Cost
Land	8,047
Building / Construction in Progress & Improvements	68,870
Total	76,917
Accumulated Depreciation	1,966
Total Cost, Net of Accumulated Depreciation	74,951
Encumbrances	$ 0
Current Communities | 850 Boca [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	370
Initial Cost
Land and improvements	$ 21,430
Building / Construction in Progress & Improvements	108,585
Costs Subsequent to Acquisition / Construction	8,717
Total Cost
Land	21,430
Building / Construction in Progress & Improvements	117,302
Total	138,732
Accumulated Depreciation	333
Total Cost, Net of Accumulated Depreciation	138,399
Encumbrances	$ 0
Current Communities | Avalon Chestnut Hill [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	204
Initial Cost
Land and improvements	$ 14,572
Building / Construction in Progress & Improvements	45,911
Costs Subsequent to Acquisition / Construction	10,260
Total Cost
Land	14,572
Building / Construction in Progress & Improvements	56,171
Total	70,743
Accumulated Depreciation	19,293
Total Cost, Net of Accumulated Depreciation	51,450	45,640
Encumbrances	$ 38,097
Current Communities | AVA Back Bay [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	271
Initial Cost
Land and improvements	$ 9,034
Building / Construction in Progress & Improvements	36,540
Costs Subsequent to Acquisition / Construction	47,327
Total Cost
Land	9,034
Building / Construction in Progress & Improvements	83,867
Total	92,901
Accumulated Depreciation	34,038
Total Cost, Net of Accumulated Depreciation	58,863	60,700
Encumbrances	$ 0
Current Communities | AVA Theater District [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	398
Initial Cost
Land and improvements	$ 17,070
Building / Construction in Progress & Improvements	163,580
Costs Subsequent to Acquisition / Construction	40
Total Cost
Land	17,070
Building / Construction in Progress & Improvements	163,620
Total	180,690
Accumulated Depreciation	13,499
Total Cost, Net of Accumulated Depreciation	167,191	172,387
Encumbrances	$ 0
Current Communities | Avalon Marlborough [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	350
Initial Cost
Land and improvements	$ 15,317
Building / Construction in Progress & Improvements	60,397
Costs Subsequent to Acquisition / Construction	11
Total Cost
Land	15,317
Building / Construction in Progress & Improvements	60,408
Total	75,725
Accumulated Depreciation	5,353
Total Cost, Net of Accumulated Depreciation	70,372	72,339
Encumbrances	$ 0
Current Communities | Avalon Framingham [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	180
Initial Cost
Land and improvements	$ 9,315
Building / Construction in Progress & Improvements	34,632
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	9,315
Building / Construction in Progress & Improvements	34,632
Total	43,947
Accumulated Depreciation	2,731
Total Cost, Net of Accumulated Depreciation	41,216	42,395
Encumbrances	$ 0
Current Communities | Avalon Bear Hill [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	324
Initial Cost
Land and improvements	$ 27,350
Building / Construction in Progress & Improvements	94,168
Costs Subsequent to Acquisition / Construction	28,764
Total Cost
Land	27,350
Building / Construction in Progress & Improvements	122,932
Total	150,282
Accumulated Depreciation	23,723
Total Cost, Net of Accumulated Depreciation	126,559	131,023
Encumbrances	$ 0
Current Communities | Avalon at Edgewater [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	168
Initial Cost
Land and improvements	$ 5,982
Building / Construction in Progress & Improvements	24,389
Costs Subsequent to Acquisition / Construction	9,182
Total Cost
Land	5,982
Building / Construction in Progress & Improvements	33,571
Total	39,553
Accumulated Depreciation	15,351
Total Cost, Net of Accumulated Depreciation	24,202	21,123
Encumbrances	$ 0
Current Communities | Avalon Bloomfield Station
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	224
Initial Cost
Land and improvements	$ 10,701
Building / Construction in Progress & Improvements	39,927
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	10,701
Building / Construction in Progress & Improvements	39,927
Total	50,628
Accumulated Depreciation	3,594
Total Cost, Net of Accumulated Depreciation	47,034	48,031
Encumbrances	$ 0
Current Communities | Avalon Union [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	202
Initial Cost
Land and improvements	$ 11,695
Building / Construction in Progress & Improvements	36,282
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	11,695
Building / Construction in Progress & Improvements	36,282
Total	47,977
Accumulated Depreciation	2,519
Total Cost, Net of Accumulated Depreciation	45,458	46,615
Encumbrances	$ 0
Current Communities | Avalon Hoboken [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	217
Initial Cost
Land and improvements	$ 37,237
Building / Construction in Progress & Improvements	87,220
Costs Subsequent to Acquisition / Construction	8,327
Total Cost
Land	37,237
Building / Construction in Progress & Improvements	95,547
Total	132,784
Accumulated Depreciation	11,390
Total Cost, Net of Accumulated Depreciation	121,394	124,435
Encumbrances	$ 67,904
Current Communities | Avalon Towers [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	109
Initial Cost
Land and improvements	$ 3,118
Building / Construction in Progress & Improvements	11,973
Costs Subsequent to Acquisition / Construction	24,372
Total Cost
Land	3,118
Building / Construction in Progress & Improvements	36,345
Total	39,463
Accumulated Depreciation	16,198
Total Cost, Net of Accumulated Depreciation	23,265	21,775
Encumbrances	$ 0
Current Communities | Avalon Riverview North [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	602
Initial Cost
Land and improvements	$ 0
Building / Construction in Progress & Improvements	165,966
Costs Subsequent to Acquisition / Construction	14,176
Total Cost
Land	0
Building / Construction in Progress & Improvements	180,142
Total	180,142
Accumulated Depreciation	59,765
Total Cost, Net of Accumulated Depreciation	120,377	122,418
Encumbrances	$ 0
Current Communities | AVA DoBro [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	500
Initial Cost
Land and improvements	$ 77,416
Building / Construction in Progress & Improvements	203,827
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	77,416
Building / Construction in Progress & Improvements	203,827
Total	281,243
Accumulated Depreciation	10,586
Total Cost, Net of Accumulated Depreciation	270,657	294,503
Encumbrances	$ 0
Current Communities | Avalon Green III [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	68
Initial Cost
Land and improvements	$ 4,985
Building / Construction in Progress & Improvements	17,300
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	4,985
Building / Construction in Progress & Improvements	17,300
Total	22,285
Accumulated Depreciation	1,248
Total Cost, Net of Accumulated Depreciation	21,037	21,585
Encumbrances	$ 0
Current Communities | Archstone Lexington [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	222
Initial Cost
Land and improvements	$ 4,540
Building / Construction in Progress & Improvements	25,946
Costs Subsequent to Acquisition / Construction	2,073
Total Cost
Land	4,540
Building / Construction in Progress & Improvements	28,019
Total	32,559
Accumulated Depreciation	6,883
Total Cost, Net of Accumulated Depreciation	25,676	26,669
Encumbrances	$ 21,700
Current Communities | Archstone Toscano [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	474
Initial Cost
Land and improvements	$ 15,607
Building / Construction in Progress & Improvements	72,889
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	15,607
Building / Construction in Progress & Improvements	72,889
Total	88,496
Accumulated Depreciation	11,044
Total Cost, Net of Accumulated Depreciation	77,452	79,819
Encumbrances	$ 0
Current Communities | Memorial Heights Villages [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	318
Initial Cost
Land and improvements	$ 9,607
Building / Construction in Progress & Improvements	48,448
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	9,607
Building / Construction in Progress & Improvements	48,448
Total	58,055
Accumulated Depreciation	10,516
Total Cost, Net of Accumulated Depreciation	47,539	48,508
Encumbrances	$ 0
Current Communities | Eaves Fairfax City [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	141
Initial Cost
Land and improvements	$ 2,152
Building / Construction in Progress & Improvements	8,907
Costs Subsequent to Acquisition / Construction	5,475
Total Cost
Land	2,152
Building / Construction in Progress & Improvements	14,382
Total	16,534
Accumulated Depreciation	8,176
Total Cost, Net of Accumulated Depreciation	8,358	8,773
Encumbrances	$ 0
Current Communities | Avalon at Arlington Square [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	842
Initial Cost
Land and improvements	$ 22,041
Building / Construction in Progress & Improvements	90,296
Costs Subsequent to Acquisition / Construction	31,555
Total Cost
Land	22,041
Building / Construction in Progress & Improvements	121,851
Total	143,892
Accumulated Depreciation	54,059
Total Cost, Net of Accumulated Depreciation	89,833	87,446
Encumbrances	$ 0
Current Communities | Avalon Potomac Yard [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	323
Initial Cost
Land and improvements	$ 24,225
Building / Construction in Progress & Improvements	77,137
Costs Subsequent to Acquisition / Construction	7,648
Total Cost
Land	24,225
Building / Construction in Progress & Improvements	84,785
Total	109,010
Accumulated Depreciation	8,659
Total Cost, Net of Accumulated Depreciation	100,351	103,333
Encumbrances	$ 0
Current Communities | Avalon Clarendon [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	300
Initial Cost
Land and improvements	$ 22,573
Building / Construction in Progress & Improvements	91,001
Costs Subsequent to Acquisition / Construction	8,521
Total Cost
Land	22,573
Building / Construction in Progress & Improvements	99,522
Total	122,095
Accumulated Depreciation	8,530
Total Cost, Net of Accumulated Depreciation	113,565	117,845
Encumbrances	$ 0
Current Communities | Avalon Columbia Pike [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	269
Initial Cost
Land and improvements	$ 18,830
Building / Construction in Progress & Improvements	78,395
Costs Subsequent to Acquisition / Construction	6,460
Total Cost
Land	18,830
Building / Construction in Progress & Improvements	84,855
Total	103,685
Accumulated Depreciation	5,993
Total Cost, Net of Accumulated Depreciation	97,692	100,352
Encumbrances	$ 68,637
Current Communities | Avalon Dunn Loring [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	440
Initial Cost
Land and improvements	$ 29,377
Building / Construction in Progress & Improvements	107,775
Costs Subsequent to Acquisition / Construction	14,301
Total Cost
Land	29,377
Building / Construction in Progress & Improvements	122,076
Total	151,453
Accumulated Depreciation	3,972
Total Cost, Net of Accumulated Depreciation	147,481
Encumbrances	$ 0
Current Communities | Avalon Falls Church [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	384
Initial Cost
Land and improvements	$ 39,544
Building / Construction in Progress & Improvements	66,160
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	39,544
Building / Construction in Progress & Improvements	66,160
Total	105,704
Accumulated Depreciation	5,899
Total Cost, Net of Accumulated Depreciation	99,805	102,279
Encumbrances	$ 0
Current Communities | Oakwood Arlington [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	184
Initial Cost
Land and improvements	$ 18,850
Building / Construction in Progress & Improvements	38,545
Costs Subsequent to Acquisition / Construction	3,052
Total Cost
Land	18,850
Building / Construction in Progress & Improvements	41,597
Total	60,447
Accumulated Depreciation	8,608
Total Cost, Net of Accumulated Depreciation	51,839	53,139
Encumbrances	$ 0
Current Communities | AVA Capitol Hill [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	249
Initial Cost
Land and improvements	$ 20,613
Building / Construction in Progress & Improvements	60,014
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	20,613
Building / Construction in Progress & Improvements	60,014
Total	80,627
Accumulated Depreciation	4,194
Total Cost, Net of Accumulated Depreciation	76,433	78,906
Encumbrances	$ 0
Current Communities | Avalon Alderwood II [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	124
Initial Cost
Land and improvements	$ 5,072
Building / Construction in Progress & Improvements	21,369
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	5,072
Building / Construction in Progress & Improvements	21,369
Total	26,441
Accumulated Depreciation	1,104
Total Cost, Net of Accumulated Depreciation	25,337	26,115
Encumbrances	$ 0
Current Communities | Avalon West Hollywood [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	294
Initial Cost
Land and improvements	$ 35,187
Building / Construction in Progress & Improvements	115,385
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	35,187
Building / Construction in Progress & Improvements	115,385
Total	150,572
Accumulated Depreciation	1,697
Total Cost, Net of Accumulated Depreciation	148,875	130,173
Encumbrances	$ 0
Current Communities | Avalon Chino Hills [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	331
Initial Cost
Land and improvements	$ 16,615
Building / Construction in Progress & Improvements	81,753
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	16,615
Building / Construction in Progress & Improvements	81,753
Total	98,368
Accumulated Depreciation	2,127
Total Cost, Net of Accumulated Depreciation	96,241	87,406
Encumbrances	$ 0
Current Communities | Avalon Huntington Beach [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	378
Initial Cost
Land and improvements	$ 13,055
Building / Construction in Progress & Improvements	105,719
Costs Subsequent to Acquisition / Construction	222
Total Cost
Land	13,055
Building / Construction in Progress & Improvements	105,941
Total	118,996
Accumulated Depreciation	4,995
Total Cost, Net of Accumulated Depreciation	114,001	115,269
Encumbrances	$ 0
Current Communities | Avalon North Station [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	503
Initial Cost
Land and improvements	$ 22,788
Building / Construction in Progress & Improvements	245,234
Costs Subsequent to Acquisition / Construction	306
Total Cost
Land	22,788
Building / Construction in Progress & Improvements	245,540
Total	268,328
Accumulated Depreciation	5,918
Total Cost, Net of Accumulated Depreciation	262,410	249,022
Encumbrances	$ 0
Current Communities | Avalon Quincy [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	395
Initial Cost
Land and improvements	$ 14,674
Building / Construction in Progress & Improvements	78,151
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	14,674
Building / Construction in Progress & Improvements	78,151
Total	92,825
Accumulated Depreciation	2,972
Total Cost, Net of Accumulated Depreciation	89,853	84,132
Encumbrances	$ 0
Current Communities | Avalon Easton [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	290
Initial Cost
Land and improvements	$ 3,151
Building / Construction in Progress & Improvements	59,245
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	3,151
Building / Construction in Progress & Improvements	59,245
Total	62,396
Accumulated Depreciation	840
Total Cost, Net of Accumulated Depreciation	61,556	29,074
Encumbrances	$ 0
Current Communities | Avalon Hunt Valley [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	332
Initial Cost
Land and improvements	$ 10,842
Building / Construction in Progress & Improvements	62,596
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	10,842
Building / Construction in Progress & Improvements	62,596
Total	73,438
Accumulated Depreciation	2,144
Total Cost, Net of Accumulated Depreciation	71,294	67,019
Encumbrances	$ 0
Current Communities | Avalon Laurel [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	344
Initial Cost
Land and improvements	$ 10,122
Building / Construction in Progress & Improvements	61,803
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	10,122
Building / Construction in Progress & Improvements	61,803
Total	71,925
Accumulated Depreciation	2,919
Total Cost, Net of Accumulated Depreciation	69,006	69,532
Encumbrances	$ 0
Current Communities | Avalon Princeton [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	280
Initial Cost
Land and improvements	$ 26,459
Building / Construction in Progress & Improvements	68,175
Costs Subsequent to Acquisition / Construction	303
Total Cost
Land	26,459
Building / Construction in Progress & Improvements	68,478
Total	94,937
Accumulated Depreciation	2,363
Total Cost, Net of Accumulated Depreciation	92,574	88,360
Encumbrances	$ 0
Current Communities | Avalon Willoughby Square [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	326
Initial Cost
Land and improvements	$ 50,475
Building / Construction in Progress & Improvements	132,892
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	50,475
Building / Construction in Progress & Improvements	132,892
Total	183,367
Accumulated Depreciation	6,901
Total Cost, Net of Accumulated Depreciation	176,466	153,310
Encumbrances	$ 0
Current Communities | Avalon Great Neck [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	191
Initial Cost
Land and improvements	$ 14,776
Building / Construction in Progress & Improvements	64,459
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	14,776
Building / Construction in Progress & Improvements	64,459
Total	79,235
Accumulated Depreciation	931
Total Cost, Net of Accumulated Depreciation	78,304	55,671
Encumbrances	$ 0
Current Communities | Avalon Rockville Centre II [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	165
Initial Cost
Land and improvements	$ 7,534
Building / Construction in Progress & Improvements	49,115
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	7,534
Building / Construction in Progress & Improvements	49,115
Total	56,649
Accumulated Depreciation	267
Total Cost, Net of Accumulated Depreciation	56,382	26,796
Encumbrances	$ 0
Current Communities | Avalon Esterra Park [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	482
Initial Cost
Land and improvements	$ 22,668
Building / Construction in Progress & Improvements	112,441
Costs Subsequent to Acquisition / Construction	305
Total Cost
Land	22,668
Building / Construction in Progress & Improvements	112,746
Total	135,414
Accumulated Depreciation	4,963
Total Cost, Net of Accumulated Depreciation	130,451	127,986
Encumbrances	$ 0
Current Communities | Avalon Newcastle Commons I [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	378
Initial Cost
Land and improvements	$ 9,622
Building / Construction in Progress & Improvements	109,453
Costs Subsequent to Acquisition / Construction	0
Total Cost
Land	9,622
Building / Construction in Progress & Improvements	109,453
Total	119,075
Accumulated Depreciation	1,889
Total Cost, Net of Accumulated Depreciation	117,186	92,267
Encumbrances	$ 0
Current Communities | Avalon on the Alameda [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	305
Initial Cost
Land and improvements	$ 6,119
Building / Construction in Progress & Improvements	50,225
Costs Subsequent to Acquisition / Construction	10,087
Total Cost
Land	6,119
Building / Construction in Progress & Improvements	60,312
Total	66,431
Accumulated Depreciation	33,696
Total Cost, Net of Accumulated Depreciation	32,735	27,497
Encumbrances	$ 0
Current Communities | AVA Toluca Hills [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	1,151
Initial Cost
Land and improvements	$ 86,450
Building / Construction in Progress & Improvements	161,256
Costs Subsequent to Acquisition / Construction	37,513
Total Cost
Land	86,450
Building / Construction in Progress & Improvements	198,769
Total	285,219
Accumulated Depreciation	39,361
Total Cost, Net of Accumulated Depreciation	245,858	227,814
Encumbrances	$ 0
Current Communities | AVA Van Ness [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	269
Initial Cost
Land and improvements	$ 22,890
Building / Construction in Progress & Improvements	58,691
Costs Subsequent to Acquisition / Construction	9,030
Total Cost
Land	22,890
Building / Construction in Progress & Improvements	67,721
Total	90,611
Accumulated Depreciation	13,443
Total Cost, Net of Accumulated Depreciation	77,168	74,556
Encumbrances	$ 0
Current Communities | Avalon at Prudential Center II [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	266
Initial Cost
Land and improvements	$ 8,776
Building / Construction in Progress & Improvements	35,496
Costs Subsequent to Acquisition / Construction	52,864
Total Cost
Land	8,776
Building / Construction in Progress & Improvements	88,360
Total	97,136
Accumulated Depreciation	32,748
Total Cost, Net of Accumulated Depreciation	64,388	59,218
Encumbrances	$ 0
Current Communities | Avalon at Florham Park [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	270
Initial Cost
Land and improvements	$ 6,647
Building / Construction in Progress & Improvements	34,906
Costs Subsequent to Acquisition / Construction	7,083
Total Cost
Land	6,647
Building / Construction in Progress & Improvements	41,989
Total	48,636
Accumulated Depreciation	22,468
Total Cost, Net of Accumulated Depreciation	26,168	23,830
Encumbrances	$ 0
Current Communities | Avalon at Edgewater II [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	240
Initial Cost
Land and improvements	$ 0
Building / Construction in Progress & Improvements	299
Costs Subsequent to Acquisition / Construction	37,003
Total Cost
Land	0
Building / Construction in Progress & Improvements	37,302
Total	37,302
Accumulated Depreciation	0
Total Cost, Net of Accumulated Depreciation	37,302
Encumbrances	$ 0
Current Communities | Avalon Willow [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	227
Initial Cost
Land and improvements	$ 6,207
Building / Construction in Progress & Improvements	40,791
Costs Subsequent to Acquisition / Construction	9,010
Total Cost
Land	6,207
Building / Construction in Progress & Improvements	49,801
Total	56,008
Accumulated Depreciation	26,424
Total Cost, Net of Accumulated Depreciation	29,584	24,153
Encumbrances	$ 0
Current Communities | Avalon Midtown West [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	550
Initial Cost
Land and improvements	$ 154,730
Building / Construction in Progress & Improvements	180,253
Costs Subsequent to Acquisition / Construction	23,290
Total Cost
Land	154,730
Building / Construction in Progress & Improvements	203,543
Total	358,273
Accumulated Depreciation	41,452
Total Cost, Net of Accumulated Depreciation	316,821	313,096
Encumbrances	$ 100,500
Current Communities | Avalon Ballston Square [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	714
Initial Cost
Land and improvements	$ 71,640
Building / Construction in Progress & Improvements	215,937
Costs Subsequent to Acquisition / Construction	16,378
Total Cost
Land	71,640
Building / Construction in Progress & Improvements	232,315
Total	303,955
Accumulated Depreciation	47,256
Total Cost, Net of Accumulated Depreciation	256,699	262,722
Encumbrances	$ 0
Boston, MA [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	6,427
Initial Cost
Land and improvements	$ 211,519
Building / Construction in Progress & Improvements	1,048,777
Costs Subsequent to Acquisition / Construction	145,465
Total Cost
Land	211,519
Building / Construction in Progress & Improvements	1,194,242
Total	1,405,761
Accumulated Depreciation	352,970
Total Cost, Net of Accumulated Depreciation	1,052,791	1,081,830
Encumbrances	$ 138,160
Fairfield-New Haven, CT [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	1,970
Initial Cost
Land and improvements	$ 72,283
Building / Construction in Progress & Improvements	343,032
Costs Subsequent to Acquisition / Construction	31,600
Total Cost
Land	72,283
Building / Construction in Progress & Improvements	374,632
Total	446,915
Accumulated Depreciation	137,674
Total Cost, Net of Accumulated Depreciation	309,241	320,844
Encumbrances	$ 0
New England
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	8,397
Initial Cost
Land and improvements	$ 283,802
Building / Construction in Progress & Improvements	1,391,809
Costs Subsequent to Acquisition / Construction	177,065
Total Cost
Land	283,802
Building / Construction in Progress & Improvements	1,568,874
Total	1,852,676
Accumulated Depreciation	490,644
Total Cost, Net of Accumulated Depreciation	1,362,032	1,402,674
Encumbrances	$ 138,160
New York City, NY [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	2,931
Initial Cost
Land and improvements	$ 361,674
Building / Construction in Progress & Improvements	1,022,045
Costs Subsequent to Acquisition / Construction	38,186
Total Cost
Land	361,674
Building / Construction in Progress & Improvements	1,060,231
Total	1,421,905
Accumulated Depreciation	272,595
Total Cost, Net of Accumulated Depreciation	1,149,310	1,088,658
Encumbrances	$ 462,300
New York - Suburban [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	3,659
Initial Cost
Land and improvements	$ 220,547
Building / Construction in Progress & Improvements	690,099
Costs Subsequent to Acquisition / Construction	47,564
Total Cost
Land	220,547
Building / Construction in Progress & Improvements	737,663
Total	958,210
Accumulated Depreciation	240,520
Total Cost, Net of Accumulated Depreciation	717,690	740,393
Encumbrances	$ 78,650
New Jersey [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	3,781
Initial Cost
Land and improvements	$ 104,631
Building / Construction in Progress & Improvements	525,174
Costs Subsequent to Acquisition / Construction	59,770
Total Cost
Land	104,631
Building / Construction in Progress & Improvements	584,944
Total	689,575
Accumulated Depreciation	187,501
Total Cost, Net of Accumulated Depreciation	502,074	520,050
Encumbrances	$ 0
Metro NY/NJ
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	10,371
Initial Cost
Land and improvements	$ 686,852
Building / Construction in Progress & Improvements	2,237,318
Costs Subsequent to Acquisition / Construction	145,520
Total Cost
Land	686,852
Building / Construction in Progress & Improvements	2,382,838
Total	3,069,690
Accumulated Depreciation	700,616
Total Cost, Net of Accumulated Depreciation	2,369,074	2,349,101
Encumbrances	$ 540,950
Mid-Atlantic
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	8,985
Initial Cost
Land and improvements	$ 482,790
Building / Construction in Progress & Improvements	1,428,471
Costs Subsequent to Acquisition / Construction	144,805
Total Cost
Land	482,790
Building / Construction in Progress & Improvements	1,573,276
Total	2,056,066
Accumulated Depreciation	479,051
Total Cost, Net of Accumulated Depreciation	1,577,015	1,622,622
Encumbrances	$ 32,200
Pacific Northwest
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	3,305
Initial Cost
Land and improvements	$ 118,580
Building / Construction in Progress & Improvements	577,257
Costs Subsequent to Acquisition / Construction	42,695
Total Cost
Land	118,580
Building / Construction in Progress & Improvements	619,952
Total	738,532
Accumulated Depreciation	196,860
Total Cost, Net of Accumulated Depreciation	541,672	557,413
Encumbrances	$ 0
San Jose, CA [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	3,487
Initial Cost
Land and improvements	$ 260,673
Building / Construction in Progress & Improvements	561,680
Costs Subsequent to Acquisition / Construction	86,677
Total Cost
Land	260,673
Building / Construction in Progress & Improvements	648,357
Total	909,030
Accumulated Depreciation	231,510
Total Cost, Net of Accumulated Depreciation	677,520	698,312
Encumbrances	$ 38,800
Oakland - East Bay, CA [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	3,489
Initial Cost
Land and improvements	$ 122,976
Building / Construction in Progress & Improvements	645,570
Costs Subsequent to Acquisition / Construction	81,599
Total Cost
Land	122,976
Building / Construction in Progress & Improvements	727,169
Total	850,145
Accumulated Depreciation	243,375
Total Cost, Net of Accumulated Depreciation	606,770	623,218
Encumbrances	$ 3,557
San Francisco, CA [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	3,349
Initial Cost
Land and improvements	$ 216,871
Building / Construction in Progress & Improvements	748,398
Costs Subsequent to Acquisition / Construction	106,519
Total Cost
Land	216,871
Building / Construction in Progress & Improvements	854,917
Total	1,071,788
Accumulated Depreciation	282,491
Total Cost, Net of Accumulated Depreciation	789,297	813,641
Encumbrances	$ 185,698
Northern California
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	10,325
Initial Cost
Land and improvements	$ 600,520
Building / Construction in Progress & Improvements	1,955,648
Costs Subsequent to Acquisition / Construction	274,795
Total Cost
Land	600,520
Building / Construction in Progress & Improvements	2,230,443
Total	2,830,963
Accumulated Depreciation	757,376
Total Cost, Net of Accumulated Depreciation	2,073,587	2,135,171
Encumbrances	$ 228,055
Los Angeles, CA [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	8,380
Initial Cost
Land and improvements	$ 477,004
Building / Construction in Progress & Improvements	1,306,247
Costs Subsequent to Acquisition / Construction	205,941
Total Cost
Land	477,004
Building / Construction in Progress & Improvements	1,512,188
Total	1,989,192
Accumulated Depreciation	434,469
Total Cost, Net of Accumulated Depreciation	1,554,723	1,601,740
Encumbrances	$ 260,475
Orange County, CA [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	3,087
Initial Cost
Land and improvements	$ 144,500
Building / Construction in Progress & Improvements	462,922
Costs Subsequent to Acquisition / Construction	59,318
Total Cost
Land	144,500
Building / Construction in Progress & Improvements	522,240
Total	666,740
Accumulated Depreciation	154,830
Total Cost, Net of Accumulated Depreciation	511,910	527,447
Encumbrances	$ 7,635
San Diego, CA [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	1,863
Initial Cost
Land and improvements	$ 63,898
Building / Construction in Progress & Improvements	215,562
Costs Subsequent to Acquisition / Construction	82,444
Total Cost
Land	63,898
Building / Construction in Progress & Improvements	298,006
Total	361,904
Accumulated Depreciation	112,045
Total Cost, Net of Accumulated Depreciation	249,859	259,728
Encumbrances	$ 0
Southern California
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	13,330
Initial Cost
Land and improvements	$ 685,402
Building / Construction in Progress & Improvements	1,984,731
Costs Subsequent to Acquisition / Construction	347,703
Total Cost
Land	685,402
Building / Construction in Progress & Improvements	2,332,434
Total	3,017,836
Accumulated Depreciation	701,344
Total Cost, Net of Accumulated Depreciation	2,316,492	2,388,915
Encumbrances	$ 268,110
Established [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	54,713
Initial Cost
Land and improvements	$ 2,857,946
Building / Construction in Progress & Improvements	9,575,234
Costs Subsequent to Acquisition / Construction	1,132,583
Total Cost
Land	2,857,946
Building / Construction in Progress & Improvements	10,707,817
Total	13,565,763
Accumulated Depreciation	3,325,891
Total Cost, Net of Accumulated Depreciation	10,239,872	10,455,896
Encumbrances	$ 1,207,475
Lease-Up Communities [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	4,689
Initial Cost
Land and improvements	$ 257,968
Building / Construction in Progress & Improvements	1,346,421
Costs Subsequent to Acquisition / Construction	1,136
Total Cost
Land	257,968
Building / Construction in Progress & Improvements	1,347,557
Total	1,605,525
Accumulated Depreciation	40,926
Total Cost, Net of Accumulated Depreciation	1,564,599	1,376,017
Encumbrances	$ 0
Redevelopment Communities [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	3,992
Initial Cost
Land and improvements	$ 363,459
Building / Construction in Progress & Improvements	777,854
Costs Subsequent to Acquisition / Construction	202,258
Total Cost
Land	363,459
Building / Construction in Progress & Improvements	980,112
Total	1,343,571
Accumulated Depreciation	256,848
Total Cost, Net of Accumulated Depreciation	1,086,723	1,012,886
Encumbrances	$ 100,500
Other Stabilized
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	11,844
Initial Cost
Land and improvements	$ 696,192
Building / Construction in Progress & Improvements	2,654,431
Costs Subsequent to Acquisition / Construction	376,009
Total Cost
Land	696,192
Building / Construction in Progress & Improvements	3,030,440
Total	3,726,632
Accumulated Depreciation	546,185
Total Cost, Net of Accumulated Depreciation	3,180,447	2,876,445
Encumbrances	$ 196,338
Development Communities [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	6,279
Initial Cost
Land and improvements	$ 47,713
Building / Construction in Progress & Improvements	319,551
Costs Subsequent to Acquisition / Construction	1,156,842
Total Cost
Land	47,713
Building / Construction in Progress & Improvements	1,476,393
Total	1,524,106
Accumulated Depreciation	3,699
Total Cost, Net of Accumulated Depreciation	1,520,407	930,496
Encumbrances	$ 0
Development Communities [Member] | Avalon Dogpatch [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	326
Initial Cost
Land and improvements	$ 9,494
Building / Construction in Progress & Improvements	73,702
Costs Subsequent to Acquisition / Construction	99,991
Total Cost
Land	9,494
Building / Construction in Progress & Improvements	173,693
Total	183,187
Accumulated Depreciation	621
Total Cost, Net of Accumulated Depreciation	182,566	108,565
Encumbrances	$ 0
Development Communities [Member] | Avalon Public Market [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	289
Initial Cost
Land and improvements	$ 0
Building / Construction in Progress & Improvements	83
Costs Subsequent to Acquisition / Construction	55,789
Total Cost
Land	0
Building / Construction in Progress & Improvements	55,872
Total	55,872
Accumulated Depreciation	0
Total Cost, Net of Accumulated Depreciation	55,872	29,698
Encumbrances	$ 0
Development Communities [Member] | AVA Hollywood [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	695
Initial Cost
Land and improvements	$ 0
Building / Construction in Progress & Improvements	275
Costs Subsequent to Acquisition / Construction	168,732
Total Cost
Land	0
Building / Construction in Progress & Improvements	169,007
Total	169,007
Accumulated Depreciation	0
Total Cost, Net of Accumulated Depreciation	169,007	123,267
Encumbrances	$ 0
Development Communities [Member] | Avalon Walnut Creek II [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	200
Initial Cost
Land and improvements	$ 0
Building / Construction in Progress & Improvements	0
Costs Subsequent to Acquisition / Construction	8,812
Total Cost
Land	0
Building / Construction in Progress & Improvements	8,812
Total	8,812
Accumulated Depreciation	0
Total Cost, Net of Accumulated Depreciation	8,812
Encumbrances	$ 0
Development Communities [Member] | AVA NoMa [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	438
Initial Cost
Land and improvements	$ 18,831
Building / Construction in Progress & Improvements	91,621
Costs Subsequent to Acquisition / Construction	27,007
Total Cost
Land	18,831
Building / Construction in Progress & Improvements	118,628
Total	137,459
Accumulated Depreciation	1,592
Total Cost, Net of Accumulated Depreciation	135,867	109,200
Encumbrances	$ 0
Development Communities [Member] | Avalon at the Hingham Shipyard II [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	190
Initial Cost
Land and improvements	$ 0
Building / Construction in Progress & Improvements	0
Costs Subsequent to Acquisition / Construction	23,792
Total Cost
Land	0
Building / Construction in Progress & Improvements	23,792
Total	23,792
Accumulated Depreciation	0
Total Cost, Net of Accumulated Depreciation	23,792
Encumbrances	$ 0
Development Communities [Member] | Avalon Sudbury [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	250
Initial Cost
Land and improvements	$ 0
Building / Construction in Progress & Improvements	0
Costs Subsequent to Acquisition / Construction	33,595
Total Cost
Land	0
Building / Construction in Progress & Improvements	33,595
Total	33,595
Accumulated Depreciation	0
Total Cost, Net of Accumulated Depreciation	33,595
Encumbrances	$ 0
Development Communities [Member] | AVA Wheaton [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	319
Initial Cost
Land and improvements	$ 2,624
Building / Construction in Progress & Improvements	29,826
Costs Subsequent to Acquisition / Construction	38,017
Total Cost
Land	2,624
Building / Construction in Progress & Improvements	67,843
Total	70,467
Accumulated Depreciation	279
Total Cost, Net of Accumulated Depreciation	70,188	35,361
Encumbrances	$ 0
Development Communities [Member] | Avalon Towson [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	371
Initial Cost
Land and improvements	$ 0
Building / Construction in Progress & Improvements	0
Costs Subsequent to Acquisition / Construction	3,985
Total Cost
Land	0
Building / Construction in Progress & Improvements	3,985
Total	3,985
Accumulated Depreciation	0
Total Cost, Net of Accumulated Depreciation	3,985
Encumbrances	$ 0
Development Communities [Member] | Avalon Maplewood [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	235
Initial Cost
Land and improvements	$ 3,230
Building / Construction in Progress & Improvements	13,019
Costs Subsequent to Acquisition / Construction	45,009
Total Cost
Land	3,230
Building / Construction in Progress & Improvements	58,028
Total	61,258
Accumulated Depreciation	56
Total Cost, Net of Accumulated Depreciation	61,202	48,453
Encumbrances	$ 0
Development Communities [Member] | Avalon Boonton [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	350
Initial Cost
Land and improvements	$ 0
Building / Construction in Progress & Improvements	124
Costs Subsequent to Acquisition / Construction	29,830
Total Cost
Land	0
Building / Construction in Progress & Improvements	29,954
Total	29,954
Accumulated Depreciation	0
Total Cost, Net of Accumulated Depreciation	29,954	8,292
Encumbrances	$ 0
Development Communities [Member] | Avalon Teaneck [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	248
Initial Cost
Land and improvements	$ 0
Building / Construction in Progress & Improvements	42
Costs Subsequent to Acquisition / Construction	18,567
Total Cost
Land	0
Building / Construction in Progress & Improvements	18,609
Total	18,609
Accumulated Depreciation	0
Total Cost, Net of Accumulated Depreciation	18,609	14,034
Encumbrances	$ 0
Development Communities [Member] | Avalon Piscataway [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	360
Initial Cost
Land and improvements	$ 0
Building / Construction in Progress & Improvements	248
Costs Subsequent to Acquisition / Construction	28,055
Total Cost
Land	0
Building / Construction in Progress & Improvements	28,303
Total	28,303
Accumulated Depreciation	0
Total Cost, Net of Accumulated Depreciation	28,303
Encumbrances	$ 0
Development Communities [Member] | Avalon Brooklyn Bay [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	180
Initial Cost
Land and improvements	$ 8,830
Building / Construction in Progress & Improvements	76,690
Costs Subsequent to Acquisition / Construction	5,004
Total Cost
Land	8,830
Building / Construction in Progress & Improvements	81,694
Total	90,524
Accumulated Depreciation	781
Total Cost, Net of Accumulated Depreciation	89,743	58,833
Encumbrances	$ 0
Development Communities [Member] | Avalon Somers [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	152
Initial Cost
Land and improvements	$ 4,704
Building / Construction in Progress & Improvements	33,404
Costs Subsequent to Acquisition / Construction	4,046
Total Cost
Land	4,704
Building / Construction in Progress & Improvements	37,450
Total	42,154
Accumulated Depreciation	370
Total Cost, Net of Accumulated Depreciation	41,784	16,586
Encumbrances	$ 0
Development Communities [Member] | 11 West 61st Street [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	172
Initial Cost
Land and improvements	$ 0
Building / Construction in Progress & Improvements	339
Costs Subsequent to Acquisition / Construction	440,373
Total Cost
Land	0
Building / Construction in Progress & Improvements	440,712
Total	440,712
Accumulated Depreciation	0
Total Cost, Net of Accumulated Depreciation	440,712	348,821
Encumbrances	$ 0
Development Communities [Member] | Avalon Yonkers [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	590
Initial Cost
Land and improvements	$ 0
Building / Construction in Progress & Improvements	0
Costs Subsequent to Acquisition / Construction	23,300
Total Cost
Land	0
Building / Construction in Progress & Improvements	23,300
Total	23,300
Accumulated Depreciation	0
Total Cost, Net of Accumulated Depreciation	23,300
Encumbrances	$ 0
Development Communities [Member] | Avalon Belltown Towers [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	275
Initial Cost
Land and improvements	$ 0
Building / Construction in Progress & Improvements	55
Costs Subsequent to Acquisition / Construction	50,581
Total Cost
Land	0
Building / Construction in Progress & Improvements	50,636
Total	50,636
Accumulated Depreciation	0
Total Cost, Net of Accumulated Depreciation	50,636	29,386
Encumbrances	$ 0
Development Communities [Member] | AVA Esterra Park [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	323
Initial Cost
Land and improvements	$ 0
Building / Construction in Progress & Improvements	123
Costs Subsequent to Acquisition / Construction	36,925
Total Cost
Land	0
Building / Construction in Progress & Improvements	37,048
Total	37,048
Accumulated Depreciation	0
Total Cost, Net of Accumulated Depreciation	37,048
Encumbrances	$ 0
Development Communities [Member] | Avalon North Creek [Member]
Real Estate and Accumulated Depreciation
Number of Apartment Homes in Communities Owned | home	316
Initial Cost
Land and improvements	$ 0
Building / Construction in Progress & Improvements	0
Costs Subsequent to Acquisition / Construction	15,432
Total Cost
Land	0
Building / Construction in Progress & Improvements	15,432
Total	15,432
Accumulated Depreciation	0
Total Cost, Net of Accumulated Depreciation	15,432
Encumbrances	0
Land Held for Development
Initial Cost
Land and improvements	68,364
Total Cost
Land	68,364
Total	68,364
Total Cost, Net of Accumulated Depreciation	68,364	84,293
Corporate overhead
Initial Cost
Land and improvements	14,040
Building / Construction in Progress & Improvements	10,746
Costs Subsequent to Acquisition / Construction	77,189
Total Cost
Land	14,040
Building / Construction in Progress & Improvements	87,935
Total	101,975
Accumulated Depreciation	44,830
Total Cost, Net of Accumulated Depreciation	57,145	53,309
Encumbrances	$ 5,900,000
2017 Disposals [Member]
Total Cost
Total Cost, Net of Accumulated Depreciation		$ 243,652

REAL ESTATE AND ACCUMULATED D65

REAL ESTATE AND ACCUMULATED DEPRECIATION (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Estimated useful lives
Aggregate cost of total real estate for federal income tax purposes	$ 21,271
Changes in total real estate assets
Balance, beginning of period	20,776,626	$ 19,268,099	$ 17,849,316
Acquisitions, construction costs and improvements	1,526,516	1,788,515	1,667,989
Dispositions, including impairment loss on planned dispositions	(367,206)	(279,988)	(249,206)
Balance, end of period	21,935,936	20,776,626	19,268,099
Changes in accumulated depreciation
Balance, beginning of period	3,743,632	3,325,790	2,913,576
Depreciation, including discontinued operations	584,150	531,434	477,923
Dispositions	(109,403)	(113,592)	(65,709)
Balance, end of period	$ 4,218,379	$ 3,743,632	$ 3,325,790
Building
Estimated useful lives
Estimated useful lives of assets (in years)	30 years
Improvements, upgrades and FF&E
Estimated useful lives
Estimated useful lives of assets (in years)	7 years