Federal Realty Investment Trust (FRT) 10-K 11 Feb 21 2020 FY Annual report Financial data

Cover Page

Cover Page - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2020	Feb. 08, 2021	Jun. 30, 2020
Entity Information [Line Items]
Document Annual Report	true
Document Transition Report	false
Entity Incorporation, State or Country Code	MD
Entity Registrant Name	FEDERAL REALTY INVESTMENT TRUST
Entity Central Index Key	0000034903
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		76,747,943
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 6.4
Entity File Number	1-07533
Entity Tax Identification Number	52-0782497
Entity Address, Address Line One	909 Rose Avenue, Suite 200
Entity Address, City or Town	North Bethesda
Entity Address, State or Province	MD
Entity Address, Postal Zip Code	20852
City Area Code	301)
Local Phone Number	998-8100
Entity Interactive Data Current	Yes
New York Stock Exchange, Inc. | Common Shares Of Beneficial Interest
Entity Information [Line Items]
Title of 12(b) Security	Common Shares of Beneficial Interest
Trading Symbol	FRT
Security Exchange Name	NYSE
New York Stock Exchange, Inc. | Depositary Shares
Entity Information [Line Items]
Title of 12(b) Security	Depositary Shares, each representing 1/1000 of a share
Trading Symbol	FRT-C
Security Exchange Name	NYSE

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
ASSETS
Operating (including $1,703,202 and $1,676,866 of consolidated variable interest entities, respectively)	$ 7,771,981	$ 7,535,983
Construction-in-progress (including $44,896 and $102,583 of consolidated variable interest entities, respectively)	810,889	760,420
Assets held for sale	0	1,729
Real estate, at cost, total	8,582,870	8,298,132
Less accumulated depreciation and amortization (including $335,735 and $296,165 of consolidated variable interest entities, respectively)	(2,357,692)	(2,215,413)
Net real estate	6,225,178	6,082,719
Cash and cash equivalents	798,329	127,432
Accounts and notes receivable	159,780	152,572
Mortgage notes receivable, net	39,892	30,429
Investment in partnerships	22,128	28,604
Operating lease right of use assets	92,248	93,774
Finance lease right of use assets	51,116	52,402
Prepaid expenses and other assets	218,953	227,060
TOTAL ASSETS	7,607,624	6,794,992
Liabilities
Mortgages payable, net (including $413,681 and $469,184 of consolidated variable interest entities, respectively)	484,111	545,679
Notes payable	402,776	3,781
Senior notes and debentures, net	3,404,488	2,807,134
Accounts payable and accrued expenses	228,641	255,503
Dividends payable	83,839	81,676
Security deposits payable	20,388	21,701
Operating lease liabilities	72,441	73,628
Finance lease liabilities	72,049	72,062
Other liabilities and deferred credits	152,424	157,938
Total liabilities	4,921,157	4,019,102
Commitments and contingencies (Note 7)
Redeemable noncontrolling interests	137,720	139,758
Shareholders’ equity
Common shares of beneficial interest, $.01 par, 100,000,000 shares authorized, 76,727,394 and 75,540,804 shares issued and outstanding, respectively	771	759
Additional paid-in capital	3,297,305	3,166,522
Accumulated dividends in excess of net income	(988,272)	(791,124)
Accumulated other comprehensive loss	(5,644)	(813)
Total shareholders’ equity of the Trust	2,464,157	2,535,341
Noncontrolling interests	84,590	100,791
Total shareholders’ equity	2,548,747	2,636,132
TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY	7,607,624	6,794,992
5.0% Series C Cumulative Redeemable Preferred Shares, (stated at liquidation preference $25,000 per share), 6,000 shares issued and outstanding
Shareholders’ equity
Preferred shares, authorized 15,000,000 shares, $.01 par:	150,000	150,000
5.417% Series 1 Cumulative Convertible Preferred Shares, (stated at liquidation preference $25 per share), 399,896 shares issued and outstanding
Shareholders’ equity
Preferred shares, authorized 15,000,000 shares, $.01 par:	$ 9,997	$ 9,997

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Operating real estate, consolidated variable interest entities	$ 1,703,202	$ 1,676,866
Construction-in-progress, consolidated variable interest entities	44,896	102,583
Accumulated depreciation and amortization, consolidated variable interest entities	335,735	296,165
Mortgages payable, consolidated variable interest entities	$ 413,681	$ 469,184
Preferred shares, authorized	15,000,000	15,000,000
Preferred shares, par value	$ 0.01	$ 0.01
Preferred shares, percentage	5.00%	5.00%
Common shares of beneficial interest, par value	$ 0.01	$ 0.01
Common shares of beneficial interest, shares authorized	100,000,000	100,000,000
Common shares of beneficial interest, shares issued	76,727,394	75,540,804
Common shares of beneficial interest, shares outstanding	76,727,394	75,540,804
5.417% Series 1 Cumulative Convertible Preferred Shares, (stated at liquidation preference $25 per share), 399,896 shares issued and outstanding
Preferred shares, par value	$ 0.01	$ 0.01
Preferred shares, percentage	5.417%	5.417%
Preferred Shares, liquidation preference per share	$ 25	$ 25
Preferred shares, shares issued	399,896	399,896
Preferred shares, shares outstanding	399,896	399,896
5.0% Series C Cumulative Redeemable Preferred Shares, (stated at liquidation preference $25,000 per share), 6,000 shares issued and outstanding
Preferred shares, par value	$ 0.01	$ 0.01
Preferred shares, percentage	5.00%	5.00%
Preferred Shares, liquidation preference per share	$ 25,000	$ 25,000
Preferred shares, shares issued	6,000	6,000
Preferred shares, shares outstanding	6,000	6,000

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
REVENUE
Rental Income	$ 832,171	$ 932,738	$ 912,287
Mortgage interest income	3,323	3,050	3,149
Total revenue	835,494	935,788	915,436
EXPENSES
Rental expenses	170,920	187,831	173,094
Real estate taxes	119,242	110,927	114,776
General and administrative	41,680	42,754	33,600
Depreciation and amortization	255,027	239,758	244,245
Total operating expenses	586,869	581,270	565,715
Impairment charge	(57,218)	0	0
Gain on sale of real estate, net of tax	98,117	116,393	11,915
OPERATING INCOME	289,524	470,911	361,636
Other interest income	1,894	1,266	942
Interest expense	(136,289)	(109,623)	(110,154)
Early extinguishment of debt	(11,179)	0	0
(Loss) income from real estate partnerships	(8,062)	(2,012)	(3,398)
Net income	135,888	360,542	249,026
Net income attributable to noncontrolling interests	(4,182)	(6,676)	(7,119)
NET INCOME ATTRIBUTABLE TO THE TRUST	131,706	353,866	241,907
Dividends on preferred shares	(8,042)	(8,042)	(8,042)
NET INCOME AVAILABLE FOR COMMON SHAREHOLDERS	$ 123,664	$ 345,824	$ 233,865
EARNINGS PER COMMON SHARE, BASIC
Net income available for common shareholders	$ 1.62	$ 4.61	$ 3.18
Weighted average common shares outstanding, basic	75,515	74,766	73,274
EARNINGS PER COMMON SHARE, DILUTED
Net income available for common shareholders	$ 1.62	$ 4.61	$ 3.18
Weighted average number of common shares	75,515	74,766	73,302
Comprehensive Income
Net income	$ 135,888	$ 360,542	$ 249,026
Other comprehensive loss - change in value of interest rate swaps	(5,302)	(397)	(438)
COMPREHENSIVE INCOME	130,586	360,145	248,588
Comprehensive income attributable to noncontrolling interests	(3,711)	(6,676)	(7,119)
COMPREHENSIVE INCOME ATTRIBUTABLE TO THE TRUST	$ 126,875	$ 353,469	$ 241,469

Consolidated Statement Of Share

Consolidated Statement Of Shareholders' Equity - USD ($) $ in Thousands	Total	Preferred Shares	Common shares	Additional Paid-in Capital	Accumulated Dividends in Excess of Net Income	Accumulated Other Comprehensive Income/(Loss)	Noncontrolling Interests
Beginning balance (in shares) at Dec. 31, 2017		405,896	73,090,877
Beginning balance at Dec. 31, 2017	$ 2,391,514	$ 159,997	$ 733	$ 2,855,321	$ (749,367)	$ 22	$ 124,808
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of new accounting standard	(6,028)				(6,028)
Net income, excluding amount attributable to redeemable noncontrolling interests	245,161				241,907		3,254
Other comprehensive loss - change in value of interest rate swaps	(438)					(438)
Dividends declared to common shareholders ($4.14 per share)	(297,347)				(297,347)
Dividends declared to preferred shareholders	(8,042)				(8,042)
Distributions declared to noncontrolling interests	(5,175)						(5,175)
Shares issued (in shares)			987,461
Shares issued	126,071		$ 10	126,061
Exercise of stock options (in shares)			105,803
Exercise of stock options	$ 4,572		$ 1	4,571
Shares issued under dividend reinvestment plan (in shares)	17,952		17,952
Shares issued under dividend reinvestment plan	$ 2,159			2,159
Share-based compensation expense, net of forfeitures (in shares)			55,223
Share-based compensation expense, net of forfeitures	12,736		$ 1	12,735
Shares withheld for employee taxes (in shares)			(8,432)
Shares withheld for employee taxes	(958)			(958)
Conversion and redemption of OP units (in shares)			749
Conversion and redemption of OP units	(6,012)		$ 0	(544)			(5,468)
Contributions from noncontrolling interests	4,020						4,020
Adjustment to redeemable noncontrolling interests	5,097			5,097
Ending balance (in shares) at Dec. 31, 2018		405,896	74,249,633
Ending balance at Dec. 31, 2018	2,467,330	$ 159,997	$ 745	3,004,442	(818,877)	(416)	121,439
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of new accounting standard	(7,098)				(7,098)
Net income, excluding amount attributable to redeemable noncontrolling interests	357,112				353,866		3,246
Other comprehensive loss - change in value of interest rate swaps	(397)					(397)
Dividends declared to common shareholders ($4.14 per share)	(310,973)				(310,973)
Dividends declared to preferred shareholders	(8,042)				(8,042)
Distributions declared to noncontrolling interests	(9,961)						(9,961)
Shares issued (in shares)			1,069,740
Shares issued	$ 142,716		$ 11	142,705
Shares issued under dividend reinvestment plan (in shares)	15,909		15,909
Shares issued under dividend reinvestment plan	$ 2,095			2,095
Share-based compensation expense, net of forfeitures (in shares)			111,555
Share-based compensation expense, net of forfeitures	13,330		$ 1	13,329
Shares withheld for employee taxes (in shares)			(34,320)
Shares withheld for employee taxes	(4,626)			(4,626)
Conversion and redemption of OP units (in shares)			128,287
Conversion and redemption of OP units	(72)		$ 2	14,102			(14,176)
Contributions from noncontrolling interests	243						243
Adjustment to redeemable noncontrolling interests	(5,525)			(5,525)
Ending balance (in shares) at Dec. 31, 2019		405,896	75,540,804
Ending balance at Dec. 31, 2019	2,636,132	$ 159,997	$ 759	3,166,522	(791,124)	(813)	100,791
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of new accounting standard	(510)				(510)
Net income, excluding amount attributable to redeemable noncontrolling interests	133,660				131,706		1,954
Other Comprehensive Income (loss), net of portion attributable to noncontrolling interest	(4,831)					(4,831)
Other comprehensive loss - change in value of interest rate swaps	(5,302)
Dividends declared to common shareholders ($4.14 per share)	(320,302)				(320,302)
Dividends declared to preferred shareholders	(8,042)				(8,042)
Distributions declared to noncontrolling interests	(8,874)						(8,874)
Shares issued (in shares)			1,080,882
Shares issued	$ 98,839		$ 11	98,828
Exercise of stock options (in shares)	0
Shares issued under dividend reinvestment plan (in shares)	24,491		24,491
Shares issued under dividend reinvestment plan	$ 2,072			2,072
Share-based compensation expense, net of forfeitures (in shares)			114,251
Share-based compensation expense, net of forfeitures	13,243		$ 1	13,242
Shares withheld for employee taxes (in shares)			(33,034)
Shares withheld for employee taxes	(4,052)			(4,052)
Conversion and redemption of OP units (in shares)			0
Conversion and redemption of OP units	(3,320)		$ 0	(30)			(3,290)
Contributions from noncontrolling interests	120						120
Purchase of noncontrolling interest	(7,321)			(1,210)			(6,111)
Adjustment to redeemable noncontrolling interests	21,933			21,933
Ending balance (in shares) at Dec. 31, 2020		405,896	76,727,394
Ending balance at Dec. 31, 2020	$ 2,548,747	$ 159,997	$ 771	$ 3,297,305	$ (988,272)	$ (5,644)	$ 84,590

Consolidated Statement Of Sha_2

Consolidated Statement Of Shareholders' Equity (Parenthetical) - USD ($) $ in Thousands	Nov. 05, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Stockholders' Equity [Abstract]
Amounts attributable to redeemable noncontrolling interest		$ 2,228	$ 3,430	$ 3,865
Other comprehensive loss - change in value of interest rate swaps, attributable to redeemable noncontrolling interests		$ (471)	$ 0	$ 0
Dividends declared to common shareholders	$ 1.06	$ 4.220	$ 4.140	$ 4.040

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
OPERATING ACTIVITIES
Net income	$ 135,888	$ 360,542	$ 249,026
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	255,027	239,758	244,245
Impairment charge	57,218	0	0
Gain on sale of real estate, net of tax	(98,117)	(116,393)	(11,915)
Early extinguishment of debt	11,179	0	0
Loss from partnerships	8,062	2,012	3,398
Other, net	6,142	169	4,147
Changes in assets and liabilities, net of effects of acquisitions and dispositions:
Proceeds from new market tax credit transaction, net of deferred costs	0	0	12,353
(Increase) decrease in accounts receivable, net	(6,032)	(16,128)	917
Increase in prepaid expenses and other assets	(3,260)	(10,253)	(2,070)
Increase in accounts payable and accrued expenses	5,621	2,327	2,650
(Decrease) increase in security deposits and other liabilities	(1,799)	(115)	13,937
Net cash provided by operating activities	369,929	461,919	516,688
INVESTING ACTIVITIES
Acquisition of real estate	(9,589)	(204,516)	(13,503)
Capital expenditures - development and redevelopment	(433,872)	(327,074)	(302,120)
Capital expenditures other	(68,064)	(82,836)	(66,138)
Costs associated with property sold under threat of condemnation, net	(12,924)	0	0
Proceeds from sale of real estate	183,461	321,997	177,775
Proceeds from partnership formation	0	0	37,998
Investment in partnerships	(3,348)	(1,052)	(1,037)
Distribution from partnerships in excess of earnings	1,301	2,765	275
Leasing costs	(15,080)	(25,459)	(25,430)
Increase in mortgage and other notes receivable, net	(10,268)	(357)	(67)
Net cash used in investing activities	(368,383)	(316,532)	(192,247)
FINANCING ACTIVITIES
Net repayments under revolving credit facility, including costs	(638)	(4,012)	(41,000)
Issuance of senior notes, net of costs	1,094,283	399,913	0
Redemption and retirement of senior notes	(510,360)	0	0
Issuance of notes payable, net of costs	398,722	0	0
Repayment of mortgages, finance leases, and notes payable	(70,237)	(301,029)	(16,620)
Issuance of common shares, net of costs	99,177	143,027	130,918
Dividends paid to common and preferred shareholders	(324,596)	(313,649)	(301,194)
Shares withheld for employee taxes	(4,052)	(4,626)	(958)
Proceeds from Noncontrolling Interests	0	404	2,838
Distributions to and redemptions of noncontrolling interests	(20,563)	(20,133)	(15,293)
Net cash provided by (used in) financing activities	661,736	(100,105)	(241,309)
Increase in cash, cash equivalents, and restricted cash	663,282	45,282	83,132
Cash, cash equivalents, and restricted cash at beginning of year	153,614	108,332	25,200
Cash, cash equivalents, and restricted cash at end of year	$ 816,896	$ 153,614	$ 108,332

Business And Organization

Business And Organization	12 Months Ended
	Dec. 31, 2020
Nature Of Operations [Abstract]
BUSINESS AND ORGANIZATION	BUSINESS AND ORGANIZATION Federal Realty Investment Trust (the “Trust”) is an equity real estate investment trust (“REIT”) specializing in the ownership, management, and redevelopment of retail and mixed-use properties. Our properties are located primarily in densely populated and affluent communities in strategically selected metropolitan markets in the Mid-Atlantic and Northeast regions of the United States, California, and South Florida. As of December 31, 2020, we owned or had a majority interest in community and neighborhood shopping centers and mixed-use properties which are operated as 101 predominantly retail real estate projects. We operate in a manner intended to enable us to qualify as a REIT for federal income tax purposes. A REIT that distributes at least 90% of its taxable income to its shareholders each year and meets certain other conditions is not taxed on that portion of its taxable income which is distributed to its shareholders. Impacts of COVID-19 Pandemic In March 2020, the World Health Organization declared the outbreak of novel coronavirus disease ("COVID-19") as a pandemic. While we currently expect the impact to our properties is temporary in nature, the extent of the future effects of COVID-19 on our business, results of operations, cash flows, and growth prospects is highly uncertain and will ultimately depend on future developments, none of which can be predicted with any certainty.

Summary Of Significant Accounti

Summary Of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Principles of Consolidation Our consolidated financial statements include the accounts of the Trust, its corporate subsidiaries, and all entities in which the Trust has a controlling interest or has been determined to be the primary beneficiary of a variable interest entity (“VIE”). The equity interests of other investors are reflected as noncontrolling interests or redeemable noncontrolling interests. All significant intercompany transactions and balances are eliminated in consolidation. We account for our interests in joint ventures, which we do not control, using the equity method of accounting. Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America, referred to as “GAAP,” requires management to make estimates and assumptions that in certain circumstances affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities, and revenues and expenses. These estimates are prepared using management’s best judgment, after considering past, current and expected events and economic conditions. Actual results could differ from these estimates. Revenue Recognition and Accounts Receivable Policy beginning January 1, 2019, with our adoption of Accounting Standards Codification (ASC) 842, "Leases" Our leases with our tenants are classified as operating leases. When collection of substantially all lease payments during the lease term is considered probable, the lease qualifies for accrual accounting. Lease payments are recognized on a straight-line basis from the point in time when the tenant controls the space through the term of the related lease. Variable lease payments relating to percentage rent are recognized at the end of the lease year or earlier if we have determined the required sales level is achieved. Real estate tax and other cost reimbursements are recognized on an accrual basis over the periods in which the related expenditures are incurred. Many of our leases contain tenant options that enable the tenant to extend the term of the lease at expiration at pre-established rental rates that often include fixed rent increases, consumer price index adjustments or other market rate adjustments from the prior base rent. For a tenant to terminate its lease agreement prior to the end of the agreed term, we may require that they pay a fee to cancel the lease agreement. Lease termination fees are generally recognized on the termination date if the tenant has relinquished control of the space. When a lease is terminated early but the tenant continues to control the space under a modified lease agreement, the lease termination fee is generally recognized evenly over the remaining term of the modified lease agreement. Lease concessions (unrelated to the COVID-19 pandemic) are evaluated to determine whether the concession represents a modification of the original lease contract. Modifications generally result in a reassessment of the lease term and lease classification, and remeasurement of lease payments received. Remeasured lease payments are recognized on a straight-line basis over the remaining term of the modified lease contract. In April 2020, the Financial Accounting Standards Board ("FASB") issued interpretive guidance relating to the accounting for lease concessions provided as a result of the COVID-19 pandemic that allows entities to treat the concession as if it was a part of the existing contract instead of applying lease modification accounting. This guidance is only applicable to the COVID-19 pandemic related lease concessions that do not result in a substantial increase in the rights of the lessor or the obligations of the lessee. We have elected this option relating to qualifying rent deferral and rent abatement agreements. For qualifying lease modifications with rent deferrals, this results in no change to our revenue recognition but an increase in the lease receivable balance until the deferred rent has been repaid. For qualifying lease modifications that include rent abatement concessions, this results in a direct reduction of rental income in the current period. As of December 31, 2020, we have entered into rent deferral agreements and rent abatement agreements related to the COVID-19 pandemic representing approximately $36 million and $35 million, respectively, of rent otherwise owed during the year ended December 31, 2020, and continue negotiations with other tenants. When collection of substantially all lease payments during the lease term is not considered probable, total lease revenue is limited to the lesser of revenue recognized under accrual accounting or cash received. Determining the probability of collection of substantially all lease payments during a lease term requires significant judgment. This determination is impacted by numerous factors including our assessment of the tenant’s credit worthiness, economic conditions, tenant sales productivity in that location, historical experience with the tenant and tenants operating in the same industry, future prospects for the tenant and the industry in which it operates, and the length of the lease term. If leases currently classified as probable are subsequently reclassified as not probable, any outstanding lease receivables (including straight-line rent receivables) would be written-off with a corresponding decrease in rental income. If leases currently classified as not probable are subsequently changed to probable, any lease receivables (including straight-line rent receivables) are re-instated with a corresponding increase to rental income. Since March 2020, federal, state, and local governments have taken various actions to mitigate the spread of COVID-19. This includes initially ordering closures of nonessential business and ordering residents to generally stay at home, subsequent phased re-openings, and during the fourth quarter of 2020, additional closures and capacity limitations as infection levels increased in certain areas. These actions, along with the general concern over the spread of COVID-19, have resulted in many of our tenants temporarily or even permanently closing their businesses, and for some, it has impacted their ability to pay rent. As a result, we revised our collectibility assumptions for many of our tenants most significantly impacted by COVID-19. Accordingly, during the year ended December 31, 2020, we recognized collectibility related adjustments of $106.6 million. This includes changes in our collectibility assessments from probable to not probable, disputed rents, and any rent abatements directly related to COVID-19, as well as the write-off of $12.7 million of straight-line rent receivables related to tenants changed to a cash basis of revenue recognition during the year ended December 31, 2020. As of December 31, 2020, the revenue from approximately 35% of our tenants (based on total commercial leases) is being recognized on a cash basis. As of December 31, 2020 and 2019, our straight-line rent receivables balance was $103.3 million and $100.3 million, respectively, and is included in "accounts and notes receivable, net" on our consolidated balance sheet. Policy prior to January 1, 2019 Prior to January 1, 2019, management estimates of collectability were considered when reserving for billed and accrued lease receivables and straight-line rent receivables. Full and partial reserves were recorded when determined to be appropriate with a corresponding charge to bad debt expense. The primary impact of the adoption of ASC 842, “Leases,” on our recognition of lease revenue relates to the upfront and ongoing assessment of the collectability of substantially all lease payments required by the new standard. Other revenue recognition policies Sales of real estate are recognized generally upon the transfer of control, which usually occurs when the real estate is legally sold. When we enter into a transaction to sell a property or a portion of a property, we evaluate the recognition of the sale under ASC 610-20, "Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets." In accordance with ASC 610-20, we apply the guidance in ASC 606, "Revenue from Contracts with Customers," to determine whether and when control transfers and how to measure the associated gain or loss. We determine the transaction price based on the consideration we expect to receive. Variable consideration is included in the transaction price to the extent it is probable that a significant reversal of a gain recognized will not occur. We analyze the risk of a significant gain reversal and if necessary limit the amount of variable consideration recognized in order to mitigate this risk. The estimation of variable consideration requires us to make assumptions and apply significant judgment. Real Estate Land, buildings and improvements are recorded at cost. Depreciation is computed using the straight-line method. Estimated useful lives range generally from 35 years to a maximum of 50 years on buildings and major improvements. Minor improvements, furniture and equipment are capitalized and depreciated over useful lives ranging from 2 to 20 years. Maintenance and repairs that do not improve or extend the useful lives of the related assets are charged to operations as incurred. Tenant improvements are capitalized and depreciated over the life of the related lease or their estimated useful life, whichever is shorter. If a tenant vacates its space prior to contractual termination of its lease, the undepreciated balance of any tenant improvements are written off if they are replaced or have no future value. In 2020, 2019 and 2018, real estate depreciation expense was $227.9 million, $215.4 million and $216.0 million, respectively, including amounts from real estate sold. Our methodology of allocating the cost of acquisitions to assets acquired and liabilities assumed is based on estimated fair values, replacement cost and/or appraised values. When we acquire operating real estate properties, the purchase price is allocated to land, building, improvements, leasing costs, intangibles such as in-place leases, assumed debt, if any, and to current assets and liabilities acquired, if any. The value allocated to in-place leases is amortized over the related lease term and reflected as rental income in the consolidated statements of comprehensive income. We consider qualitative and quantitative factors in evaluating the likelihood of a tenant exercising a below market renewal option and include such renewal options in the calculation of in-place lease value when we consider these to be bargain renewal options. If the value of below market lease intangibles includes renewal option periods, we include such renewal periods in the amortization period utilized. If a tenant vacates its space prior to contractual termination of its lease, the unamortized balance of any in-place lease value is written off to rental income. Transaction costs related to asset acquisitions, such as broker fees, transfer taxes, legal, accounting, valuation, and other professional and consulting fees, are capitalized as part of the acquisition cost. The acquisition of an operating shopping center typically qualifies as an asset acquisition. Prior to the adoption of ASU 2016-02, "Leases," when applicable, as lessee, we classified our leases of land and building as operating or capital leases. We were required to use judgment and make estimates in determining the lease term, the estimated economic life of the property and the interest rate to be used in determining whether or not the lease meets the qualification of a capital lease. Subsequently, capital leases are now considered "finance leases." We capitalize certain costs related to the development and redevelopment of real estate including pre-construction costs, real estate taxes, insurance, construction costs and salaries and related costs of personnel directly involved, are capitalized. Additionally, we capitalize interest costs related to development and redevelopment activities. Capitalization of these costs begin when the activities and related expenditures commence and cease when the project is substantially complete and ready for its intended use at which time the project is placed in service and depreciation commences. Additionally, we make estimates as to the probability of certain development and redevelopment projects being completed. If we determine the development or redevelopment is no longer probable of completion, we expense all capitalized costs which are not recoverable. Long-Lived Assets and Impairment There are estimates and assumptions made by management in preparing the consolidated financial statements for which the actual results will be determined over long periods of time. This includes the recoverability of long-lived assets, including our properties that have been acquired or redeveloped and our investment in certain joint ventures. Management’s evaluation of impairment includes review for possible indicators of impairment as well as, in certain circumstances, undiscounted and discounted cash flow analysis. Since most of our investments in real estate are wholly-owned or controlled assets which are held for use, a property with impairment indicators is first tested for impairment by comparing the undiscounted cash flows, including residual value, to the current net book value of the property. If the undiscounted cash flows are less than the net book value, the property is written down to expected fair value. The calculation of both discounted and undiscounted cash flows requires management to make estimates of future cash flows including revenues, operating expenses, required maintenance and development expenditures, market conditions, demand for space by tenants and rental rates over long periods. Because our properties typically have a long life, the assumptions used to estimate the future recoverability of book value requires significant management judgment. Actual results could be significantly different from the estimates. These estimates have a direct impact on net income, because recording an impairment charge results in a negative adjustment to net income. Cash and Cash Equivalents We define cash and cash equivalents as cash on hand, demand deposits with financial institutions and short term liquid investments with an initial maturity, when purchased, under three months. Cash balances in individual banks may exceed the federally insured limit by the Federal Deposit Insurance Corporation (the “FDIC”). At December 31, 2020, we had $803.6 million in excess of the FDIC insured limit. Prepaid Expenses and Other Assets Prepaid expenses and other assets consist primarily of lease costs, prepaid property taxes and acquired above market leases. Capitalized lease costs are incremental direct costs incurred which were essential to originate a successful leasing arrangement and would not have been incurred had the leasing transaction not taken place. These costs include third party commissions related to obtaining a lease. Capitalized lease costs are amortized over the initial life of the related lease which generally ranges from three ten Debt Issuance Costs Costs related to the issuance of debt instruments are deferred and are amortized as interest expense over the estimated life of the related issue using the straight-line method which approximates the effective interest method. If a debt instrument is paid off prior to its original maturity date, the unamortized balance of debt issuance costs are written off to interest expense or, if significant, included in “early extinguishment of debt.” Debt issuance costs related to our revolving credit facility are classified as an asset and are included in "prepaid expenses and other assets" in our consolidated balance sheets. All other debt issuance costs are presented as a direct deduction from the carrying amount of the debt liability. Derivative Instruments We may use derivative instruments to manage exposure to variable interest rate risk. We generally enter into interest rate swaps to manage our exposure to variable interest rate risk and treasury locks to manage the risk of interest rates rising prior to the issuance of debt. We enter into derivative instruments that qualify as cash flow hedges and do not enter into derivative instruments for speculative purposes. Interest rate swaps associated with cash flow hedges are recorded at fair value on a recurring basis. Effectiveness of cash flow hedges is assessed both at inception and on an ongoing basis. The effective portion of changes in fair value of the interest rate swaps associated with cash flow hedges is recorded in other comprehensive income (loss) which is included in accumulated other comprehensive income (loss) on the balance sheet and statement of shareholders' equity. Cash flow hedges become ineffective if critical terms of the hedging instrument and the debt instrument do not perfectly match such as notional amounts, settlement dates, reset dates, calculation period and LIBOR rate. In addition, the default risk of the counterparty is evaluated by monitoring the credit worthiness of the counterparty which includes reviewing debt ratings and financial performance. If a cash flow hedge is deemed ineffective, the ineffective portion of changes in fair value of the interest rate swaps associated with cash flow hedges is recognized in earnings in the period affected. At December 31, 2020, we have two interest rate swap agreements that effectively fix the interest rate on a mortgage payable associated with our Hoboken acquisition at 3.67%. Both swaps were designated and qualify for cash flow hedge accounting. As of December 31, 2020, our Assembly Row hotel joint venture is a party to two interest rate swap agreements that effectively fix the interest rate on the joint venture's mortgage debt at 5.206%. Both swaps were designated and qualify as cash flow hedges. Hedge ineffectiveness has not impacted earnings in 2020, 2019 and 2018. Mortgage Notes Receivable We have invested in certain mortgage loans that, because of their nature, qualify as loan receivables. At the time of investment, we did not intend for the arrangement to be anything other than a financing and did not contemplate a real estate investment. We evaluate each investment to determine whether the loan arrangement qualifies as a loan, joint venture or real estate investment and the appropriate accounting thereon. Such determination affects our balance sheet classification of these investments and the recognition of interest income derived therefrom. In one of our mortgage loan arrangements, we receive additional interest, however, we never receive in excess of 50% of the residual profit in the project, and because the borrower has either a substantial investment in the project or has guaranteed all or a portion of our loan (or a combination thereof), the loans qualify for loan accounting. The amounts under these arrangements are presented as mortgage notes receivable at December 31, 2020 and 2019. Mortgage notes receivable are recorded at cost, net of any valuation adjustments. Effective January 1, 2020, (upon the adoption of ASU 2016-13, "Financial Instruments - Credit Losses," as amended and interpreted), we account for mortgage notes receivable using the "expected credit loss" model, and accordingly impairment losses are estimated and recorded for the entire life of the loan. Prior to the implementation of ASC 326, we recognized impairment losses as incurred. Interest income is accrued as earned. Mortgage notes receivable are considered past due based on the contractual terms of the note agreement. On a quarterly basis, we evaluate the collectability of each mortgage note receivable and update our expected credit loss model based on various factors which may include payment history, expected fair value of the collateral securing the loan, internal and external credit information and/or economic trends. A loan is considered impaired when it is probable that we will be unable to collect all amounts due under the existing contractual terms. When a loan is considered impaired, the amount of the loss accrual is calculated by comparing the carrying amount of the mortgage note receivable to the present value of expected future cash flows. Since two loans are collateralized by a first mortgage, these loans have risk characteristics similar to the risks in owning commercial real estate. At December 31, 2020, we had four mortgage notes receivable with an aggregate carrying amount, net of valuation adjustments of $39.9 million, and a weighted average interest rate of 10.0%. Approximately $30.3 million of the loans are secured by first mortgages on retail buildings at December 31, 2020. Share Based Compensation We grant share based compensation awards to employees and trustees typically in the form of restricted common shares, common shares, and options. We measure share based compensation expense based on the grant date fair value of the award and recognize the expense ratably over the requisite service period, which is typically the vesting period. See Note 12 for further discussion regarding our share based compensation plans and policies. Variable Interest Entities Certain entities that do not have sufficient equity at risk for the entity to finance its activities without additional subordinated financial support from other parties or in which equity investors do not have the characteristics of a controlling financial interest qualify as VIEs. VIEs are required to be consolidated by their primary beneficiary. The primary beneficiary of a VIE has both the power to direct the activities that most significantly impact economic performance of the VIE and the obligation to absorb losses or the right to receive benefits that could potentially be significant to the VIE. Our equity method investments in the Pike & Rose hotel joint venture, the Assembly Row hotel joint venture, and the La Alameda shopping center are also considered variable interests in a VIE. As we do not control the activities that most significantly impact the economic performance of the joint ventures, we are not the primary beneficiary and do not consolidate. As of December 31, 2020 and 2019, our investment in these joint ventures and maximum exposure to loss was $18.7 million and $23.4 million, respectively. On January 4, 2021, we acquired our partner's interest in the Pike & Rose hotel joint venture. See footnote 15 to the consolidated financial statements for additional details of this transaction. In addition, we have 17 entities that meet the criteria of a VIE in which we hold a variable interest. For each of these entities, we control the significant operating decisions and consequently have the power to direct the activities that most significantly impact the economic performance of the entities. As we also have the obligation to absorb the majority of the losses and/or the right to receive a majority of the benefits for each of these entities, all are consolidated in our financial statements. Net real estate assets related to VIEs included in our consolidated balance sheets were approximately $1.4 billion and $1.5 billion as of December 31, 2020 and 2019, respectively, and mortgages related to VIEs included in our consolidated balance sheets were approximately $413.7 million and $469.2 million, as of December 31, 2020 and 2019, respectively. We have also evaluated our mortgage notes receivable investments and determined that the entities obligated under the mortgage notes are not VIEs. Our equity method investments and mortgage notes receivable balances are presented separately in our consolidated balance sheets. Redeemable Noncontrolling Interests We have certain noncontrolling interests that are redeemable for cash upon the occurrence of an event that is not solely in our control and therefore are classified outside of permanent equity. We adjust the carrying amounts of these noncontrolling interests that are currently redeemable to redemption value at the balance sheet date. Adjustments to the carrying amount to reflect changes in redemption value are recorded as adjustments to additional paid-in capital in shareholders' equity. These amounts are classified within the mezzanine section of the consolidated balance sheets. The following table provides a rollforward of the redeemable noncontrolling interests: Year Ended December 31, 2020 2019 (In thousands) Beginning balance $ 139,758 $ 136,208 Contributions 19,335 9,961 Net income 2,228 3,430 Distributions & redemptions (1,197) (15,366) Other comprehensive loss - change in value of interest rate swaps (471) — Change in redemption value (21,933) 5,525 Ending balance $ 137,720 $ 139,758 On August 2, 2019, we acquired the 10.1% redeemable noncontrolling interest in the partnership that owns our Montrose Crossing Shopping Center for $10.0 million, bringing our ownership interest to 100%. Leases We adopted ASC 842 effective January 1, 2019 under the modified retrospective approach and elected the optional transition method to apply the provisions of ASC 842 as of the adoption date, rather than the earliest period presented. We elected to apply certain adoption related practical expedients for all leases that commenced prior to the election date. These practical expedients included not reassessing whether any expired or existing contracts were or contained leases; not reassessing the lease classification for any expired or existing leases; and not reassessing initial direct costs for any existing leases. We also elected the practical expedient for lessors to combine our lease and non-lease components (primarily impacts common area maintenance recoveries). Lessor We recorded a charge to the opening accumulated dividends in excess of net income of $7.1 million in 2019 as a result of the adoption of ASC 842. This charge was attributable to the write off certain direct leasing costs recorded under the previous lease accounting rules for leases which had not commenced as well as the write off of unreserved receivables (including straight-line receivables) for leases where we had determined the collection of substantially all the lease payments required for the term is not probable. Also upon adoption of ASC 842 and reflected in our 2019 and 2020 financial statements, we do not record a gross up of revenue and expense for costs (such as real estate taxes) paid directly by lessees on our behalf. Lessee We have ground leases at 12 properties which are accounted for as operating leases. The operating lease right of use ("ROU") assets and related liabilities are shown separately on the face of our consolidated balance sheet and reflect the present value of the minimum lease payments. A key input in the calculation is the discount rate. As the rate implied in the lease agreements is not readily determinable, we utilize our incremental borrowing rate that correspond to the remaining term of the lease, our credit spread, and and adjustment to reflect the collateralized payment terms present in the lease. Our operating lease agreements may include options to extend the lease term or terminate it early. We include options to extend or terminate leases in the ROU operating lease asset and liability when it is reasonably certain we will exercise these options. Operating lease expense is recognized on a straight-line basis over the non-cancellable lease term and is included in rental expenses in our consolidated statements of operations. We elected to apply the short-term lease exemption within ASC 842, and as such we have not recorded an ROU asset or lease liability for leases with terms of less than 12 months. Income Taxes We operate in a manner intended to enable us to qualify as a REIT for federal income tax purposes. A REIT that distributes at least 90% of its taxable income to its shareholders each year and meets certain other conditions is not taxed on that portion of its taxable income which is distributed to its shareholders. Therefore, federal income taxes on our taxable income have been and are generally expected to be immaterial. We are obligated to pay state taxes, generally consisting of franchise or gross receipts taxes in certain states. Such state taxes also have not been material. We have elected to treat certain of our subsidiaries as taxable REIT subsidiaries, which we refer to as a TRS. In general, a TRS may engage in any real estate business and certain non-real estate businesses, subject to certain limitations under the Internal Revenue Code of 1986, as amended (the “Code”). A TRS is subject to federal and state income taxes. Our TRS activities have not been material. With few exceptions, we are no longer subject to U.S. federal, state, and local tax examinations by tax authorities for years before 2016. As of December 31, 2020 and 2019, we had no material unrecognized tax benefits. While we currently have no material unrecognized tax benefits, as a policy, we recognize penalties and interest accrued related to unrecognized tax benefits as income tax expense. Segment Information Our primary business is the ownership, management, and redevelopment of retail and mixed-use properties. We review operating and financial information for each property on an individual basis and therefore, each property represents an individual operating segment. We evaluate financial performance using property operating income, which consists of rental income, other property income and mortgage interest income, less rental expenses and real estate taxes. No individual commercial or residential property constitutes more than 10% of our revenues or property operating income and we have no operations outside of the United States of America. Therefore, we have aggregated our properties into one reportable segment as the properties share similar long-term economic characteristics and have other similarities including the fact that they are operated using consistent business strategies, are typically located in major metropolitan areas, and have similar tenant mixes. Recent Accounting Pronouncements Standard Description Effect on the financial statements or significant matters Adopted on January 1, 2020: Financial Instruments - Credit Losses (Topic 326) and related updates: 2016, Financial Instruments - Credit Losses (Topic 326) November 2018, Codification Topic 326, Financial Instruments - Credit Losses This ASU changes the impairment model for most financial assets and certain other instruments, requiring the use of an "expected credit loss" model and adding more disclosure requirements. Upon adoption of this standard, we recorded expected losses of $0.5 million in opening accumulated dividends in excess of net income. During the year ended December 31, 2020, we recorded additional expected losses of $0.4 million, which are included in rental expenses. ASU 2018-15, August 2018, Intangibles - Goodwill and Other Internal Use Software: Customers Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract This ASU requires a customer in a cloud computing arrangement (i.e. hosting arrangement) that is a service contract to follow the internal-use software guidance in ASC 350-40 to determine which implementation costs to capitalize as assets. Capitalized implementation costs related to a hosting arrangement that is a service contract will be amortized over the term of the hosting arrangement. Entities will expense costs during the preliminary project and post-implementation stages as they are incurred. The adoption of this standard did not have a significant impact to our consolidated financial statements. Issued in 2020: ASU 2020-04, March 2020, Reference Rate Reform (Topic 848) This ASU provides companies with optional practical expedients to ease the accounting burden for contract modifications associated with transitioning away from LIBOR and other interbank offered rates that are expected to be discontinued as part of reference rate reform. For hedges, the guidance generally allows changes to the reference rate and other critical terms without having to de-designate the hedging relationship, as well as allows the shortcut method to continue to be applied. For contract modifications, changes in the reference rate or other critical terms will be treated as a continuation of the prior contract. This guidance can be applied immediately, however, is generally only available through December 31, 2022. We are still evaluating the impact of reference rate refor

Real Estate

Real Estate	12 Months Ended
	Dec. 31, 2020
Real Estate [Abstract]
Real Estate Disclosure	REAL ESTATE 2020 Property Acquisitions Date Acquired Property City/State Gross Leasable Area (GLA) Purchase Price (in square feet) (in millions) January 10, 2020 Fairfax Junction Fairfax, Virginia 49,000 $ 22.3 (1) February 12, 2020 Hoboken (2 mixed-use buildings) Hoboken, New Jersey 12,000 $ 14.3 (2) (1) This property is adjacent to, and will be operated as part of the property acquired in 2019. The purchase price was paid with a combination of cash and the issuance of 163,322 downREIT operating partnership units. Approximately $0.5 million and $0.4 million of net assets acquired were allocated to other assets for "above market leases," and other liabilities for "below market leases," respectively. (2) The purchase price includes the assumption of $8.9 million of mortgage debt, and is in addition to the 37 buildings previously acquired in 2019, and was completed through the same joint venture. Less than $0.1 million and approximately $3.3 million of net assets acquired were allocated to other assets for "above market leases," and other liabilities for "below market leases," respectively. 2020 Impairment On September 1, 2020, the $60.6 million non-recourse mortgage loan on The Shops at Sunset Place matured. The mortgage was not repaid, and thus the lender declared the loan in default. We evaluated our long-term plans for the property, taking into account current market conditions and prospective development and redevelopment returns, as well as the impact of COVID-19 on the revenue prospects for the property, and concluded we did not expect to move forward with the planned redevelopment or repay the mortgage balance, and thus, did not expect to be long term holders of the asset. Given these expectations, we recorded an impairment charge of $57.2 million during the third quarter of 2020. The fair value estimate used to determine the impairment charge was determined by market comparable data and discounted cash flow analyses. The cash flows utilized in such analyses are comprised of unobservable inputs which include forecasted rental revenue and expenses based upon market conditions and future expectations. The capitalization rates and discount rates utilized in such analyses are based upon unobservable rates that we believe to be within a reasonable range of current market rates for the property. Based on these inputs, we have determined that the $57 million estimated valuation of the property is classified within Level 3 of the fair value hierarchy. On December 31, 2020, we sold The Shops at Sunset Place for $65.5 million and repaid the mortgage loan. The resulting gain of $9.2 million is included in the cumulative 2020 gain of $98.1 million noted in the 2020 Property Dispositions section below. 2020 Property Dispositions During the year ended December 31, 2020, we sold three properties (including The Shops at Sunset Place discussed above) and one building for a total sales price of $186.1 million, which resulted in a gain of $98.1 million. During the year ended December 31, 2020, we closed on the sale of the remaining two condominium units at our Pike & Rose property, receiving proceeds net of closing costs of $2.1 million. 2019 Property Acquisitions Date Acquired Property City/State Gross Leasable Area (GLA) Purchase Price (in square feet) (in millions) February 8, 2019 Fairfax Junction Fairfax, Virginia 75,000 $ 22.5 (1) September 13, 2019 San Antonio Center Mountain View, California 6,000 $ 6.5 November 15, 2019 Georgetowne Shopping Center Brooklyn, New York 147,000 $ 83.7 (2) Various 2019 Hoboken (37 mixed-use buildings) Hoboken, New Jersey 158,000 $ 189.2 (3) (1) Approximately $0.6 million and $0.4 million of net assets acquired were allocated to other assets for "above market leases," and other liabilities for "below market leases," respectively. (2) Approximately $2.0 million and $0.4 million of net assets acquired were allocated to other assets for "above market leases," and other liabilities for "below market leases," respectively. (3) These acquisitions were completed through a newly formed joint venture, for which we own a 90% interest. The purchase price includes new and assumptions of mortgage debt totaling approximately $98.0 million. This property includes 123 residential units in addition to the GLA in the table above. Approximately $3.6 million and $8.1 million of net assets acquired were allocated to other assets for "above market leases," and other liabilities for "below market leases," respectively. 2019 Property Dispositions On December 11, 2019, w e received $154.7 million in net proceeds related to the sale under the threat of condemnation of 11.7 acres of San Antonio Center to a local school district ("the condemning authority"). As part of the transaction, the condemning authority will commence condemnation proceedings in order to terminate all existing leases they assumed at closing. We have indemnified the condemning authority for all costs incurred related to the condemnation proceedings including any payments required to tenants at the property and expect the process will take several years to complete. The consideration in the transaction is considered variable because we have agreed to indemnify the condemning authority for these costs. Consequently, at December 31, 2019, we recorded a liability of $45.5 million to reflect our estimate of the final consideration, net of estimated condemnation proceeding costs and other transaction related costs. The resulting net gain on sale was approximately $85.1 million. During the year ended December 31, 2019, we sold three properties and one land parcel for a net sales price of $149.0 million, which resulted in a net gain of $28.3 million.

Acquired In-Place Leases

Acquired In-Place Leases	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
ACQUIRED IN-PLACE LEASES	ACQUIRED IN-PLACE LEASES Acquired lease assets comprise above market leases where we are the lessor and below market leases where we are the lessee. Acquired lease liabilities comprise below market leases where we are the lessor and above market leases where we are the lessee. As a lessor, acquired above market leases are included in prepaid expenses and other assets, and acquired below market leases are included in other liabilities and deferred credits. In accordance with our adoption of ASC Topic 842, acquired below market leases and acquired above market leases where we are the lessee are included in right of use assets. The following is a summary of our acquired lease assets and liabilities: December 31, 2020 December 31, 2019 Cost Accumulated Amortization Cost Accumulated Amortization (in thousands) Above market leases, lessor $ 43,560 $ (31,661) $ 48,530 $ (32,833) Below market leases, lessee 34,604 (4,190) 34,604 (3,362) Total $ 78,164 $ (35,851) $ 83,134 $ (36,195) Below market leases, lessor $ (174,582) $ 68,286 $ (177,512) $ 66,419 Above market leases, lessee (9,084) 2,116 (9,084) 1,590 Total $ (183,666) $ 70,402 $ (186,596) $ 68,009 The value allocated to in-place leases where we are the lessor is amortized over the related lease term and reflected as additional rental income for below market leases or a reduction of rental income for above market leases in the consolidated statements of comprehensive income. The related amortization of in-place leases where we are the lessee is reflected as additional rental expense for below market leases or a reduction of rental expenses for above market leases in the consolidated statements of comprehensive income. The following is a summary of acquired lease amortization: Year Ended December 31, 2020 2019 2018 (in thousands) Amortization of above market leases, lessor $ (4,060) $ (3,239) $ (5,608) Amortization of below market leases, lessor 8,406 9,623 12,445 Net increase in rental income $ 4,346 $ 6,384 $ 6,837 Amortization of below market leases, lessee $ 828 $ 828 $ 828 Amortization of above market leases, lessee (525) (525) (505) Net increase in rental expense $ 303 $ 303 $ 323 The following is a summary of the remaining weighted average amortization period for our acquired lease assets and acquired lease liabilities: December 31, 2020 Above market leases, lessor 3.5 years Below market leases, lessee 38.6 years Below market leases, lessor 17.8 years Above market leases, lessee 13.4 years The amortization for acquired in-place leases during the next five years and thereafter, assuming no early lease terminations, is as follows: Acquired Lease Assets Acquired Lease Liabilities (In thousands) Year ending December 31, 2021 $ 3,302 $ 7,738 2022 2,637 7,501 2023 2,439 7,253 2024 2,189 6,784 2025 1,911 6,300 Thereafter 29,835 77,688 $ 42,313 $ 113,264

Debt

Debt	12 Months Ended
	Dec. 31, 2020
Debt Instruments [Abstract]
Debt Disclosure [Text Block]	DEBT The following is a summary of our total debt outstanding as of December 31, 2020 and 2019: Principal Balance as of December 31, Stated Interest Rate as of Stated Maturity Date as of Description of Debt 2020 2019 December 31, 2020 December 31, 2020 Mortgages payable (Dollars in thousands) The Shops at Sunset Place $ — $ 61,987 5.62 % September 1, 2020 29th Place — 3,878 5.91 % January 31, 2021 Sylmar Towne Center 16,236 16,630 5.39 % June 6, 2021 Plaza Del Sol 8,041 8,230 5.23 % December 1, 2021 THE AVENUE at White Marsh 52,705 52,705 3.35 % January 1, 2022 Montrose Crossing 65,596 67,492 4.20 % January 10, 2022 Azalea 40,000 40,000 3.73 % November 1, 2025 Bell Gardens 12,408 12,677 4.06 % August 1, 2026 Plaza El Segundo 125,000 125,000 3.83 % June 5, 2027 The Grove at Shrewsbury (East) 43,600 43,600 3.77 % September 1, 2027 Brook 35 11,500 11,500 4.65 % July 1, 2029 Hoboken (24 Buildings) 56,450 56,450 LIBOR + 1.95% December 15, 2029 Various Hoboken (14 Buildings) 32,705 24,627 Various (1) Various through 2029 Chelsea 5,234 5,597 5.36 % January 15, 2031 Hoboken (1 Building) 16,560 16,874 3.75 % July 1, 2042 Subtotal 486,035 547,247 Net unamortized premium and debt issuance costs (1,924) (1,568) Total mortgages payable 484,111 545,679 Notes payable Term loan 400,000 — LIBOR + 1.35% May 6, 2021 Revolving credit facility — — LIBOR + 0.775% January 19, 2024 Various 3,270 3,843 11.31 % Various through 2028 Subtotal 403,270 3,843 Net unamortized debt issuance costs (494) (62) Total notes payable 402,776 3,781 Senior notes and debentures 2.55% notes — 250,000 2.55 % January 15, 2021 3.00% notes — 250,000 3.00 % August 1, 2022 2.75% notes 275,000 275,000 2.75 % June 1, 2023 3.95% notes 600,000 300,000 3.95 % January 15, 2024 1.25% notes 400,000 — 1.25 % February 15, 2026 7.48% debentures 29,200 29,200 7.48 % August 15, 2026 3.25% notes 475,000 475,000 3.25 % July 15, 2027 6.82% medium term notes 40,000 40,000 6.82 % August 1, 2027 3.20% notes 400,000 400,000 3.20 % June 15, 2029 3.50% notes 400,000 — 3.50 % June 1, 2030 4.50% notes 550,000 550,000 4.50 % December 1, 2044 3.625% notes 250,000 250,000 3.625 % August 1, 2046 Subtotal 3,419,200 2,819,200 Net unamortized discount and debt issuance costs (14,712) (12,066) Total senior notes and debentures 3,404,488 2,807,134 Total debt $ 4,291,375 $ 3,356,594 _____________________ 1) The interest rates on these mortgages range from 3.91% to 5.00%. In connection with the two buildings we acquired in Hoboken, New Jersey on February 12, 2020, we assumed two mortgage loans with a net face amount of $8.9 million and a fair value of $9.0 million. The mortgage loans bear interest at 4.00% and mature on July 27, 2027. In March 2020, in order to strengthen our financial position and balance sheet, to maximize our liquidity, and to provide maximum financial flexibility to continue our business initiatives as the effects of COVID-19 continue to evolve, we borrowed $990.0 million under our revolving credit facility, representing a draw-down of almost the entirety of our $1.0 billion revolving credit facility. This amount was subsequently repaid when we entered into a $400.0 million unsecured term loan on May 6, 2020 and issued $700.0 million of fixed rate unsecured senior notes on May 11, 2020. The unsecured term loan matures on May 6, 2021, plus one twelve month extension at our option, and bears interest at LIBOR plus 135 basis points based on our current credit rating. Our net proceeds from this transaction after underwriting fees and other costs were $398.7 million. The $700.0 million of unsecured senior notes issued in May 2020 comprise a $300.0 million reopening of our 3.95% senior notes maturing on January 15, 2024 and a $400.0 million issuance of 3.50% senior notes maturing on June 1, 2030. The 3.95% senior notes were offered at 103.257% of the principal amount with a yield to maturity of 2.944%, and have the same terms and are of the same series as the $300.0 million senior notes issued on December 9, 2013. The 3.50% senior notes were offered at 98.911% of the principal amount with a yield to maturity of 3.630%. Our net proceeds from these transactions after the net issuance premium, underwriting fees, and other costs were $700.1 million. On September 1, 2020, the $60.6 million non-recourse mortgage loan on The Shops at Sunset Place matured and was not repaid. The lender declared the loan in default until the non-recourse loan was repaid as part of the sale of the property on December 31, 2020. The default did not trigger a cross default with any other indebtedness. The repayment amount including accrued interest and fees, net of $4.5 million of escrows held by the lender was $58.5 million. On October 13, 2020, we issued $400.0 million of fixed rate senior unsecured notes that mature on February 15, 2026 and bear interest at 1.25%. The notes were offered at 99.339% of the principal amount with a yield to maturity of 1.379%. The net proceeds of the notes, or "green bonds," after issuance discount, underwriting fees, and other costs were approximately $394.2 million, and will be allocated to the financing and refinancing of recently completed and future eligible green projects, which includes (i) investments in acquisitions of buildings; (ii) building developments or redevelopments; (iii) renovations in existing buildings; and (iv) tenant improvement projects, in each case that have received, or are expected to receive, in the three years prior to the issuance of the notes or during the term of the notes, a LEED Silver, Gold, or Platinum certification (or environmentally equivalent successor standards). Net proceeds allocated to previously incurred costs associated with eligible green projects will be available for repayment of indebtedness. On December 15, 2020, we repaid our $250.0 million 2.55% notes prior to the original maturity date of January 15, 2021 at par. The redemption price of $252.7 million included accrued but unpaid interest of $2.7 million. On December 31, 2020, we repaid our $250.0 million 3.00% notes prior to the original maturity date of August 1, 2022. The redemption price of $263.5 million included a make-whole premium of $10.4 million and accrued but unpaid interest of $3.1 million. The "early extinguishment of debt" charge in 2020 of $11.2 million includes the make-whole premium and the write off of the unamortized discount and debt issuance fees. On December 31, 2020, we also repaid the $3.6 million mortgage loan on 29th Place, at par, prior to its original maturity date. During 2020, 2019 and 2018, the maximum amount of borrowings outstanding under our revolving credit facility was $990.0 million, $116.5 million and $177.0 million, respectively. The weighted average amount of borrowings outstanding was $138.5 million, $26.8 million and $83.1 million, respectively, and the weighted average interest rate, before amortization of debt fees, was 1.5%, 3.2% and 2.7%, respectively. The revolving credit facility requires an annual facility fee of $1.0 million. At December 31, 2020 and 2019, our revolving credit facility had no balance outstanding. Our revolving credit facility, term loan, and certain notes require us to comply with various financial covenants, including the maintenance of minimum shareholders’ equity and debt coverage ratios and a maximum ratio of debt to net worth. As of December 31, 2020, we were in compliance with all default related debt covenants. Scheduled principal payments on mortgages payable, notes payable, senior notes and debentures as of December 31, 2020 are as follows: Mortgages Notes Senior Notes and Total (In thousands) Year ending December 31, 2021 $ 28,101 $ 400,676 (1) $ — $ 428,777 2022 119,706 751 — 120,457 2023 3,549 765 275,000 279,314 2024 3,688 656 (2) 600,000 604,344 2025 48,033 333 — 48,366 Thereafter 282,958 89 2,544,200 2,827,247 $ 486,035 $ 403,270 $ 3,419,200 $ 4,308,505 (3) _____________________ (1) Our $400.0 million term loan matures on May 6, 2021 plus one twelve month extension, at our option. (2) Our $1.0 billion revolving credit facility matures on January 19, 2024, plus two six-month extensions at our option. As of December 31, 2020, there was no outstanding balance under this credit facility. (3) The total debt maturities differ from the total reported on the consolidated balance sheet due to the unamortized net premium/discount and debt issuance costs on mortgage loans, notes payable, and senior notes as of December 31, 2020.

Fair Value Of Financial Instrum

Fair Value Of Financial Instruments	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
FAIR VALUE OF FINANCIAL INSTRUMENTS	NOTE 6—FAIR VALUE OF FINANCIAL INSTRUMENTS A fair value measurement is based on the assumptions that market participants would use in pricing an asset or liability in an orderly transaction. The hierarchy for inputs used in measuring fair value are as follows: 1. Level 1 Inputs—quoted prices in active markets for identical assets or liabilities 2. Level 2 Inputs—observable inputs other than quoted prices in active markets for identical assets and liabilities 3. Level 3 Inputs—prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, for disclosure purposes, the level within which the fair value measurement is categorized is based on the lowest level input that is significant to the fair value measurement. Except as disclosed below, the carrying amount of our financial instruments approximates their fair value. The fair value of our mortgages payable, notes payable and senior notes and debentures is sensitive to fluctuations in interest rates. Quoted market prices (Level 1) were used to estimate the fair value of our marketable senior notes and debentures and discounted cash flow analysis (Level 2) is generally used to estimate the fair value of our mortgages and notes payable. Considerable judgment is necessary to estimate the fair value of financial instruments. The estimates of fair value presented herein are not necessarily indicative of the amounts that could be realized upon disposition of the financial instruments. A summary of the carrying amount and fair value of our mortgages payable, notes payable and senior notes and debentures is as follows: December 31, 2020 December 31, 2019 Carrying Fair Value Carrying Fair Value (In thousands) Mortgages and notes payable $ 886,887 $ 879,390 $ 549,460 $ 562,049 Senior notes and debentures $ 3,404,488 $ 3,761,465 $ 2,807,134 $ 3,001,216 As of December 31, 2020, we have two interest rate swap agreements with notional amounts of $56.5 million that are measured at fair value on a recurring basis. The interest rate swap agreements fix the interest rate on $56.5 million of mortgage payables at 3.67% through December 15, 2029. The fair values of the interest rate swap agreements are based on the estimated amounts we would receive or pay to terminate the contracts at the reporting date and are determined using interest rate pricing models and interest rate related observable inputs. The fair value of our swaps at December 31, 2020 was a liability of $4.7 million and is included in "prepaid expenses and other assets" on our consolidated balance sheet. During 2020, the value of our interest rate swaps decreased $4.8 million (including $0.7 million reclassified from other comprehensive loss to interest expense). A summary of our financial (liabilities) assets that are measured at fair value on a recurring basis, by level within the fair value hierarchy is as follows: December 31, 2020 December 31, 2019 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total (In thousands) Interest rate swaps $ — $ (4,711) $ — $ (4,711) $ — $ 130 $ — $ 130 One of our equity method investees has two interest rate swaps which qualify as cash flow hedges. At December 31, 2020 and December 31, 2019, our share of the decrease in fair value of the related swaps included in "accumulated other comprehensive loss" was $0.5 million and $0.9 million, respectively.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES We are sometimes involved in lawsuits, warranty claims, and environmental matters arising in the ordinary course of business. Management makes assumptions and estimates concerning the likelihood and amount of any potential loss relating to these matters. We are currently a party to various legal proceedings. We accrue a liability for litigation if an unfavorable outcome is probable and the amount of loss can be reasonably estimated. If an unfavorable outcome is probable and a reasonable estimate of the loss is a range, we accrue the best estimate within the range; however, if no amount within the range is a better estimate than any other amount, the minimum within the range is accrued. Legal fees related to litigation are expensed as incurred. Other than as described below, we do not believe that the ultimate outcome of these matters, either individually or in the aggregate, could have a material adverse effect on our financial position or overall trends in results of operations; however, litigation is subject to inherent uncertainties. Also under our leases, tenants are typically obligated to indemnify us from and against all liabilities, costs and expenses imposed upon or asserted against us (1) as owner of the properties due to certain matters relating to the operation of the properties by the tenant, and (2) where appropriate, due to certain matters relating to the ownership of the properties prior to their acquisition by us. We are self-insured for general liability costs up to predetermined retained amounts per claim, and we believe that we maintain adequate accruals to cover our retained liability. We currently do not maintain third party stop-loss insurance policies to cover liability costs in excess of predetermined retained amounts. Our accrual for self-insurance liability is determined by management and is based on claims filed and an estimate of claims incurred but not yet reported. Management considers a number of factors, including third-party actuarial analysis, previous experience in our portfolio, and future increases in costs of claims, when making these determinations. If our liability costs exceed these accruals, it will reduce our net income. We reserve for estimated losses, if any, associated with warranties given to a buyer at the time real estate is sold or other potential liabilities relating to that sale, taking any insurance policies into account. These warranties may extend up to ten years and require significant judgment. If changes in facts and circumstances indicate that warranty reserves are understated, we will accrue additional reserves at such time a liability has been incurred and the costs can be reasonably estimated. Warranty reserves are released once the legal liability period has expired or all related work has been substantially completed. On December 17, 2020, we acquired one of our partner's preferred and common interests in the partnership that owns our Plaza El Segundo property for $7.3 million, bringing our ownership to approximately 78.2%. On December 11, 2019, w e received proceeds related to the sale under the threat of condemnation at San Antonio Center as discussed in Note 3 to the consolidated financial statements. We have indemnified the condemning authority for all costs incurred related to the condemnation proceedings including any payments required to tenants at the property and expect the process will take several years to complete. During 2020, we incurred $12.9 million of net payments to tenants, and consequently , at December 31, 2020, we have a liability of $32.6 million to reflect our estimate of the remaining consideration. At December 31, 2020 and 2019, our reserves for general liability costs were $4.6 million and $3.0 million, respectively, and are included in “accounts payable and accrued expenses” in our consolidated balance sheets. Any potential losses which exceed our estimates would result in a decrease in our net income. During 2020 and 2019, we made payments from these reserves of $0.8 million and $1.3 million, respectively. Although we consider the reserve to be adequate, there can be no assurance that the reserve will prove to be adequate over-time to cover losses due to the difference between the assumptions used to estimate the reserve and actual losses. At December 31, 2020, we had letters of credit outstanding of approximately $4.7 million. As of December 31, 2020 in connection with capital improvement, development, and redevelopment projects, the Trust has contractual obligations of approximately $356.1 million. We are obligated under operating lease agreements on several shopping centers and one office lease requiring minimum annual payments as follows, as of December 31, 2020: (In thousands) Year ending December 31, 2021 $ 5,077 2022 5,197 2023 5,243 2024 5,213 2025 5,084 Thereafter 175,387 Total future minimum operating lease payments $ 201,201 Less amount representing interest (128,760) Operating lease liabilities $ 72,441 Future minimum lease payments and their present value for properties under finance leases as of December 31, 2020, are as follows: (In thousands) Year ending December 31, 2021 $ 5,800 2022 5,810 2023 60,013 2024 1,013 2025 1,013 Thereafter 80,837 Total future minimum finance lease payments 154,486 Less amount representing interest (82,437) Finance lease liabilities $ 72,049 A master lease for Mercer Mall includes a fixed purchase price option for $55 million in 2023. If we fail to exercise our purchase option, the owner of Mercer Mall has a put option which would require us to purchase Mercer Mall for $60 million in 2025. Under the terms of the Congressional Plaza partnership agreement, a minority partner has the right to require us and the other minority partner to purchase its 26.63% interest in Congressional Plaza at the interest’s then-current fair market value. If the okother minority partner defaults in their obligation, we must purchase the full interest. Based on management’s current estimate of fair market value as of December 31, 2020, our estimated maximum liability upon exercise of the put option would range from approximately $69 million to $72 million. A master lease for Melville Mall includes a fixed purchase price option in 2021 for $5 million. If we fail to exercise our purchase option, the owner of Melville Mall has a put option which would require us to purchase Melville Mall in 2023 for $5 million. Two of the members in Plaza El Segundo have the right to require us to purchase their 10.0% and 11.8% ownership interests at the interests' then-current fair market value. If the members fail to exercise their put options, we have the right to purchase each of their interests on or after December 30, 2026 at fair market value. Based on management’s current estimate of fair market value as of December 31, 2020, our estimated maximum liability upon exercise of the put option would range from approximately $28 million to $35 million. The other member in The Grove at Shrewsbury and Brook 35 has the right to require us to purchase all of its approximately 4.1% interest in The Grove at Shrewsbury and approximately 6.5% interest in Brook 35 at the interests' then-current fair market value. Based on management's current estimate of fair market value as of December 31, 2020, our estimated maximum liability upon exercise of the put option would range from $6 million to $7 million. Effective September 18, 2023, the other member in Hoboken has the right to require us to purchase all of its 10.0% ownership interest at the interest's then-current fair market value. Based on management's current estimate of fair market value as of December 31, 2020, our estimated maximum liability upon exercise of the put option would range from $5 million to $6 million. Under the terms of certain partnership agreements, the partners have the right to exchange their operating partnership units for cash or the same number of our common shares, at our option. A total of 744,617 downREIT operating partnership units are outstanding which have a total fair value of $63.4 million, based on our closing stock price on December 31, 2020.

Shareholders' Equity

Shareholders' Equity	12 Months Ended
	Dec. 31, 2020
Stockholders' Equity Note [Abstract]
SHAREHOLDERS’ EQUITY	SHAREHOLDERS’ EQUITY We have a Dividend Reinvestment Plan (the “Plan”), whereby shareholders may use their dividends and optional cash payments to purchase shares. In 2020, 2019 and 2018, 24,491 shares, 15,909 shares and 17,952 shares, respectively, were issued under the Plan. As of December 31, 2020, 2019, and 2018, we had 6,000,000 Depositary Shares outstanding, each representing 1/1000th interest of 5.0% Series C Cumulative Redeemable Preferred Share, par value $0.01 per share ("Series C Preferred Shares"), at the liquidation preference of $25.00 per depositary share (or $25,000 per Series C Preferred share). The Series C Preferred Shares accrue dividends at a rate of 5.0% of the $25,000 liquidation preference per year and are redeemable at our option on or after September 29, 2022. Additionally, they are not convertible and holders of these shares generally have no voting rights, unless we fail to pay dividends for six or more quarters. As of December 31, 2020, 2019, and 2018, we had 399,896 shares of 5.417% Series 1 Cumulative Convertible Preferred Shares (“Series 1 Preferred Shares”) outstanding that have a liquidation preference of $25 per share and par value $0.01 per share. The Series 1 Preferred Shares accrue dividends at a rate of 5.417% per year and are convertible at any time by the holders to our common shares at a conversion rate of $104.69 per share. The Series 1 Preferred Shares are also convertible under certain circumstances at our election. The holders of the Series 1 Preferred Shares have no voting rights. On May 7, 2018, we replaced our existing at-the-market (“ATM”) equity program with a new ATM equity program in which we may from time to time offer and sell common shares having an aggregate offering price of up to $400.0 million. We intend to use the net proceeds to fund potential acquisition opportunities, fund our development and redevelopment pipeline, repay amounts of outstanding under our revolving credit facility and/or for general corporate purposes. For the year ended December 31, 2020, we issued 1,080,804 common shares at a weighted average price per share of $92.51 for net cash proceeds of $98.8 million including paying $1.0 million in commissions and $0.1 million in additional offering expenses related to the sales of these common shares. For the year ended December 31, 2019, we issued 1,069,699 common shares at a weighted average price per share of $134.71 for net cash proceeds of $142.7 million and paid $1.2 million in commissions and $0.2 million in additional offering expenses related to the sales of these common shares. As of December 31, 2020, we had the capacity to issue up to $28.4 million in common shares under our ATM equity program.

Dividends

Dividends	12 Months Ended
	Dec. 31, 2020
Dividends [Abstract]
DIVIDENDS	DIVIDENDS The following table provides a summary of dividends declared and paid per share: Year Ended December 31, 2020 2019 2018 Declared Paid Declared Paid Declared Paid Common shares $ 4.220 $ 4.210 $ 4.140 $ 4.110 $ 4.040 $ 4.020 5.417% Series 1 Cumulative Convertible Preferred shares $ 1.354 $ 1.354 $ 1.354 $ 1.354 $ 1.354 $ 1.354 5.0% Series C Cumulative Redeemable Preferred shares (1) $ 1.250 $ 1.250 $ 1.250 $ 1.250 $ 1.250 $ 1.306 (1) Amount represents dividends per depositary share, each representing 1/1000th of a share. A summary of the income tax status of dividends per share paid is as follows: Year Ended December 31, 2020 2019 2018 Common shares Ordinary dividend $ 3.452 $ 4.110 $ 3.859 Return of capital 0.758 — — Ordinary dividend eligible for 15% rate — — 0.161 $ 4.210 $ 4.110 $ 4.020 5.417% Series 1 Cumulative Convertible Preferred shares Ordinary dividend $ 1.354 $ 1.354 $ 1.300 Ordinary dividend eligible for 15% rate — — 0.054 $ 1.354 $ 1.354 $ 1.354 5.0% Series C Cumulative Redeemable Preferred shares Ordinary dividend $ 1.250 $ 1.250 1.254 Ordinary dividend eligible for 15% rate — — 0.052 $ 1.250 $ 1.250 $ 1.306 On November 5, 2020, the Trustees declared a quarterly cash dividend of $1.06 per common share, payable January 15, 2021 to common shareholders of record on January 4, 2021.

Operating Leases

Operating Leases	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
OPERATING LEASES	LEASES At December 31, 2020, our 101 predominantly retail shopping center and mixed-use properties are located in 11 states and the District of Columbia. There are approximately 2,800 commercial leases and 2,700 residential leases. Our commercial tenants range from sole proprietorships to national retailers and corporations. At December 31, 2020, no one tenant or corporate group of tenants accounted for more than 3.6% of annualized base rent. Our leases with commercial property and residential tenants are classified as operating leases. Commercial property leases generally range from three to ten years (certain leases with anchor tenants may be longer), and in addition to minimum rents, may provide for percentage rents based on the tenant’s level of sales achieved and cost recoveries for the tenant’s share of certain operating costs. Leases on apartments are generally for a period of 1 year or less. As of December 31, 2020, future minimum rentals from noncancelable commercial operating leases (excluding both tenant reimbursements of operating expenses and percentage rent based on tenants' sales) are as follows: (In thousands) Year ending December 31, 2021 $ 586,082 2022 549,529 2023 486,269 2024 421,945 2025 349,671 Thereafter 1,493,377 $ 3,886,873 The following table provides additional information on our operating and finance leases where we are the lessee: Year Ended December 31, 2020 2019 (In thousands) LEASE COST: Finance lease cost: Amortization of right-of-use assets $ 1,284 $ 1,284 Interest on lease liabilities 5,826 5,824 Operating lease cost 5,946 6,063 Variable lease cost 353 487 Total lease cost $ 13,409 $ 13,658 OTHER INFORMATION: ROU assets obtained in exchange for operating lease liabilities 855 — ROU assets obtained in exchange for finance lease liabilities — — Cash paid for amounts included in the measurement of lease liabilities Operating cash flows for finance leases 5,736 5,759 Operating cash flows for operating leases 5,498 5,561 Financing cash flows for finance leases 46 47 Year Ended December 31, 2020 2019 Weighted-average remaining term - finance leases 17.3 years 18.2 years Weighted-average remaining term - operating leases 53.4 years 53.7 years Weighted-average discount rate - finance leases 8.0 % 8.0 % Weighted-average discount rate - operating leases 4.4 % 4.5 %

Components Of Rental Expense

Components Of Rental Expense	12 Months Ended
	Dec. 31, 2020
Components Of Rental Expense [Abstract]
COMPONENTS OF RENTAL EXPENSE	COMPONENTS OF RENTAL EXPENSE The principal components of rental expenses are as follows: Year Ended December 31, 2020 2019 2018 (In thousands) Repairs and maintenance $ 66,845 $ 73,179 $ 67,745 Utilities 25,065 27,729 27,635 Management fees and costs 23,752 24,930 24,024 Payroll 16,691 16,485 16,140 Insurance 12,439 9,036 7,547 Marketing 6,432 7,427 7,935 Ground rent 4,595 4,803 4,697 Bad debt (1) — — 4,708 Other operating (2) 15,101 24,242 12,663 Total rental expenses $ 170,920 $ 187,831 $ 173,094 _____________________ (1) Collectibility adjustments are now presented as a reduction of rental income rather than rental expense in accordance with our adoption of the new lease standard in 2019. (2) Other operating for the year ended December 31, 2019 includes an $11.9 million charge relating to the buyout of a lease at Assembly Square Marketplace.

Share-Based Compensation Plans

Share-Based Compensation Plans	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
SHARE-BASED COMPENSATION PLANS	SHARE-BASED COMPENSATION PLANS A summary of share-based compensation expense included in net income is as follows: Year Ended December 31, 2020 2019 2018 (In thousands) Grants of common shares and options $ 13,243 $ 13,330 $ 12,736 Capitalized share-based compensation (1,319) (1,054) (1,017) Share-based compensation expense $ 11,924 $ 12,276 $ 11,719 As of December 31, 2020, we have grants outstanding under two share-based compensation plans. In May 2020, our shareholders approved the 2020 Performance Incentive Plan ("the 2020 Plan"), which authorized the grant of share options, common shares, and other share-based awards for up to 1,750,000 common shares of beneficial interest. Our 2010 Long Term Incentive Plan, as amended (the "2010 Plan”), which expired in May 2020, authorized the grant of share options, common shares and other share-based awards for up to 2,450,000 common shares of beneficial interest. Option awards under the plans are required to have an exercise price at least equal to the closing trading price of our common shares on the date of grant. Options and restricted share awards under the plan generally vest over three to seven years and option awards typically have a ten-year contractual term. We pay dividends on unvested shares. Certain options and share awards provide for accelerated vesting if there is a change in control. Additionally, the vesting on certain option and share awards can accelerate in part or in full upon retirement based on the age of the retiree or upon termination without cause. The fair value of each option award is estimated on the date of grant using the Black-Scholes model. Expected volatilities, term, dividend yields, employee exercises and estimated forfeitures are primarily based on historical data. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant. The fair value of each share award is determined based on the closing trading price of our common shares on the grant date. No options were granted in 2020 and 2019. The following table provides a summary of the assumptions used to value options granted in 2018: Year Ended December 31, 2018 Volatility 18.0 % Expected dividend yield 3.6 % Expected term (in years) 7.5 Risk free interest rate 2.8 % The following table provides a summary of option activity for 2020: Shares Weighted- Weighted- Aggregate (In years) (In thousands) Outstanding at December 31, 2019 682 $ 152.34 Granted — — Exercised — — Forfeited or expired — — Outstanding at December 31, 2020 682 $ 152.34 5.1 $ — Exercisable at December 31, 2020 546 $ 152.34 5.1 $ — The weighted-average grant-date fair value of options granted in 2018 was $14.42 per share, which were later forfeited during 2018. The total cash received from options exercised during 2018 was $4.6 million. The total intrinsic value of options exercised during the year ended December 31, 2018 was $8.2 million. The following table provides a summary of restricted share activity for 2020: Shares Weighted-Average Unvested at December 31, 2019 220,578 $ 129.78 Granted 116,351 124.55 Vested (101,651) 129.39 Forfeited (2,100) 131.78 Unvested at December 31, 2020 233,178 $ 127.32 The weighted-average grant-date fair value of stock awarded in 2020, 2019 and 2018 was $124.55, $133.30 and $112.88, respectively. The total vesting-date fair value of shares vested during the year ended December 31, 2020, 2019 and 2018, was $12.4 million, $13.0 million and $9.7 million, respectively. As of December 31, 2020, there was $17.0 million of total unrecognized compensation cost related to unvested share-based compensation arrangements (i.e. options and unvested shares) granted under our plans. This cost is expected to be recognized over the next 5.3 years with a weighted-average period of 2.1 years. Subsequent to December 31, 2020, common shares were awarded under various compensation plans as follows: Date Award Vesting Term Beneficiary January 4, 2021 9,928 Shares Immediate Trustees February 10, 2021 137,210 Restricted Shares 3-5 years Officers and key employees February 10, 2021 3,658 Options 5 years Officers and key employees Additionally, on February 10, 2021, 10,441 restricted stock units were awarded to an officer that vest at the end of four years. The final awards earned are based on meeting certain market based performance criteria, and may vary from 0% to 200% of the original award.

Savings and Retirement Plans

Savings and Retirement Plans	12 Months Ended
	Dec. 31, 2020
Savings and Retirement Plans [Abstract]
SAVINGS AND RETIREMENT PLANS	SAVINGS AND RETIREMENT PLANS We have a savings and retirement plan in accordance with the provisions of Section 401(k) of the Code. Generally, employees can elect, at their discretion, to contribute a portion of their compensation up to a maximum of $19,500 for 2020, $19,000 for 2019, and 18,500 for 2018. Under the plan, we contribute 50% of each employee’s elective deferrals up to 5% of eligible earnings. In addition, we may make discretionary contributions within the limits of deductibility set forth by the Code. Our full-time employees are immediately eligible to become plan participants. Employees are eligible to receive matching contributions immediately on their participation; however, these matching payments will not vest until their third anniversary of employment. Our expense for the years ended December 31, 2020, 2019 and 2018 was approximately $813,000, $764,000 and $688,000, respectively. A non-qualified deferred compensation plan for our officers and certain other employees was established in 1994 that allows the participants to defer a portion of their income. As of December 31, 2020 and 2019, we are liable to participants for approximately $18.0 million and $14.7 million, respectively, under this plan. Although this is an unfunded plan, we have purchased certain investments to match this obligation. Our obligation under this plan and the related investments are both included in the accompanying consolidated financial statements.

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
EARNINGS PER SHARE	EARNINGS PER SHARE We have calculated earnings per share (“EPS”) under the two-class method. The two-class method is an earnings allocation methodology whereby EPS for each class of common stock and participating securities is calculated according to dividends declared and participation rights in undistributed earnings. For 2020, 2019, and 2018 we had 0.2 million weighted average unvested shares outstanding, which are considered participating securities. Therefore, we have allocated our earnings for basic and diluted EPS between common shares and unvested shares; the portion of earnings allocated to the unvested shares is reflected as “earnings allocated to unvested shares” in the reconciliation below. In the dilutive EPS calculation, dilutive stock options were calculated using the treasury stock method consistent with prior periods. There were 682 anti-dilutive stock options in 2020, 2019, and 2018, respectively. The conversions of downREIT operating partnership units and 5.417% Series 1 Cumulative Convertible Preferred Shares are anti-dilutive for all periods presented and accordingly, have been excluded from the weighted average common shares used to compute diluted EPS. Year Ended December 31, 2020 2019 2018 (In thousands, except per share data) NUMERATOR Net income $ 135,888 $ 360,542 $ 249,026 Less: Preferred share dividends (8,042) (8,042) (8,042) Less: Income from operations attributable to noncontrolling interests (4,182) (6,676) (7,119) Less: Earnings allocated to unvested shares (992) (1,007) (930) Net income available for common shareholders, basic and diluted $ 122,672 $ 344,817 $ 232,935 DENOMINATOR Weighted average common shares outstanding—basic 75,515 74,766 73,274 Stock options — — 28 Weighted average common shares outstanding—diluted 75,515 74,766 73,302 EARNINGS PER COMMON SHARE, BASIC AND DILUTED Net income available for common shareholders $ 1.62 $ 4.61 $ 3.18

Subsequent Event

Subsequent Event	12 Months Ended
	Dec. 31, 2020
Subsequent Event [Line Items]
Subsequent Event	SUBSEQUENT EVENTS On January 4, 2021, we acquired our partner's 20% interest in our joint venture arrangement related to the Pike & Rose hotel for $2.3 million, and repaid the $31.5 million mortgage loan. As a result of the transaction, we gained control of the hotel portion of this property, and effective January 4, 2021, we have consolidated this asset. On February 5, 2021, we repaid the $16.2 million mortgage loan on Sylmar Town Center, at par, prior to its original maturity date.

Schedule III - Summary of Real

Schedule III - Summary of Real Estate and Accumulated Depreciation	12 Months Ended
	Dec. 31, 2020
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation Disclosure [Abstract]
Schedule III - Summary of Real Estate and Accumulated Depreciation	FEDERAL REALTY INVESTMENT TRUST SCHEDULE III SUMMARY OF REAL ESTATE AND ACCUMULATED DEPRECIATION DECEMBER 31, 2020 (Dollars in thousands) COLUMN A COLUMN B COLUMN C COLUMN D COLUMN E COLUMN F COLUMN G COLUMN H COLUMN I Descriptions Encumbrance Initial cost to company Cost Gross amount at which carried at Accumulated Date Date Life on which Land Building and Land Building and Total 29TH PLACE (Virginia) $ 10,211 $ 18,863 $ 9,588 $ 10,195 $ 28,467 $ 38,662 $ 14,173 1975 - 2001 5/30/2007 (1) ANDORRA (Pennsylvania) 2,432 12,346 16,148 2,432 28,494 30,926 21,200 1953 1/12/1988 (1) ASSEMBLY ROW/ASSEMBLY SQUARE MARKETPLACE (Massachusetts) 93,252 34,196 832,881 69,421 890,908 960,329 88,384 2005, 2012-2020 2005-2013 (1) AZALEA (California) 39,750 40,219 67,117 (7) 40,219 67,110 107,329 8,550 2014 8/2/2017 (1) BALA CYNWYD (Pennsylvania) 3,565 14,466 46,447 2,683 61,795 64,478 24,619 1955/2020 9/22/1993 (1) BARCROFT PLAZA (Virginia) 12,617 29,603 7,235 12,617 36,838 49,455 5,904 1963, 1972, 1990, & 2000 1/13/16 & 11/7/16 (1) BARRACKS ROAD (Virginia) 4,363 16,459 48,774 4,363 65,233 69,596 48,945 1958 12/31/1985 (1) BELL GARDENS (California) 12,082 24,406 85,947 671 24,406 86,618 111,024 14,425 1990, 2003, 2006 8/2/17 & 11/29/18 (1) BETHESDA ROW (Maryland) 46,579 35,406 162,367 43,904 200,448 244,352 92,357 1945-2008 12/31/93, 6/2/97, 1/20/06, 9/25/08, 9/30/08, & 12/27/10 (1) BRICK PLAZA (New Jersey) — 24,715 78,133 4,094 98,754 102,848 56,240 1958 12/28/1989 (1) BRISTOL PLAZA (Connecticut) 3,856 15,959 12,230 3,856 28,189 32,045 19,549 1959 9/22/1995 (1) BROOK 35 (New Jersey) 11,325 7,128 38,355 3,103 7,128 41,458 48,586 9,853 1986/2004 1/1/2014 (1) CAMPUS PLAZA (Massachusetts) 16,710 13,412 326 16,710 13,738 30,448 2,952 1970 1/13/2016 (1) CHELSEA COMMONS (Massachusetts) 5,057 8,689 19,466 2,410 8,669 21,896 30,565 9,040 1962/1969/ 8/25/06, 1/30/07, & 7/16/08 (1) COCOWALK (Florida) 34,406 72,123 73,504 50,838 129,195 180,033 12,333 1990/1994, 1922-1973, 2018-2019 5/4/15, 7/1/15, 12/16/15, 7/26/16, 6/30/17, & 8/10/17 (1) COLORADO BLVD (California) 2,415 3,964 6,905 2,415 10,869 13,284 9,397 1905-1988 8/14/98 (1) FEDERAL REALTY INVESTMENT TRUST SCHEDULE III SUMMARY OF REAL ESTATE AND ACCUMULATED DEPRECIATION DECEMBER 31, 2020 (Dollars in thousands) COLUMN A COLUMN B COLUMN C COLUMN D COLUMN E COLUMN F COLUMN G COLUMN H COLUMN I Descriptions Encumbrance Initial cost to company Cost Gross amount at which carried at Accumulated Date Date Life on which Land Building and Land Building and Total CONGRESSIONAL PLAZA (Maryland) 2,793 7,424 95,605 2,793 103,029 105,822 59,967 1965/2003/ 2016 4/1/1965 (1) COURTHOUSE CENTER (Maryland) 1,750 1,869 3,445 1,750 5,314 7,064 2,768 1975 12/17/1997 (1) CROSSROADS (Illinois) 4,635 11,611 19,649 4,635 31,260 35,895 20,191 1959 7/19/1993 (1) CROW CANYON COMMONS (California) 27,245 54,575 8,911 27,245 63,486 90,731 28,124 Late 1970's/ 12/29/05 & 2/28/07 (1) DEDHAM PLAZA (Massachusetts) 16,658 13,964 16,521 16,658 30,485 47,143 18,282 1959 12/31/93, 12/14/16, 1/29/19, & 3/12/19 (1) DEL MAR VILLAGE (Florida) 15,624 41,712 16,427 15,587 58,176 73,763 26,043 1982/1994/ 2007 5/30/08, 7/11/08, & 10/14/14 (1) EAST BAY BRIDGE (California) 29,069 138,035 12,123 29,069 150,158 179,227 41,377 1994-2001, 2011/2012 12/21/2012 (1) ELLISBURG (New Jersey) 4,028 11,309 18,872 4,013 30,196 34,209 21,740 1959 10/16/1992 (1) ESCONDIDO PROMENADE (California) 19,117 15,829 18,627 19,117 34,456 53,573 20,066 1987 12/31/96 & 11/10/10 (1) FAIRFAX JUNCTION (Virgina) 16,768 23,825 575 16,768 24,400 41,168 1,647 1981/1986/ 2000 2/8/19 & 1/10/20 (1) FALLS PLAZA (Virginia) 1,798 1,270 13,044 1,819 14,293 16,112 9,477 1960/1962 9/30/67 & 10/05/72 (1) FEDERAL PLAZA (Maryland) 10,216 17,895 42,735 10,216 60,630 70,846 48,440 1970 6/29/1989 (1) FINLEY SQUARE (Illinois) 9,252 9,544 22,603 9,252 32,147 41,399 23,198 1974 4/27/1995 (1) FLOURTOWN (Pennsylvania) 1,345 3,943 11,645 1,507 15,426 16,933 7,369 1957 4/25/1980 (1) FOURTH STREET (California) 13,978 9,909 3,085 13,978 12,994 26,972 1,752 1948,1975 5/19/2017 (1) FREEDOM PLAZA (California) — 3,255 37,242 — 40,497 40,497 761 2018-2020 6/15/2018 (1) FRESH MEADOWS (New York) 24,625 25,255 43,873 24,633 69,120 93,753 46,378 1946-1949 12/5/1997 (1) FRIENDSHIP CENTER (District of Columbia) 12,696 20,803 4,719 12,696 25,522 38,218 14,998 1998 9/21/2001 (1) GAITHERSBURG SQUARE (Maryland) 7,701 5,271 16,697 5,973 23,696 29,669 19,442 1966 4/22/1993 (1) GARDEN MARKET (Illinois) 2,677 4,829 7,370 2,677 12,199 14,876 9,241 1958 7/28/1994 (1) FEDERAL REALTY INVESTMENT TRUST SCHEDULE III SUMMARY OF REAL ESTATE AND ACCUMULATED DEPRECIATION DECEMBER 31, 2020 (Dollars in thousands) COLUMN A COLUMN B COLUMN C COLUMN D COLUMN E COLUMN F COLUMN G COLUMN H COLUMN I Descriptions Encumbrance Initial cost to company Cost Gross amount at which carried at Accumulated Date Date Life on which Land Building and Land Building and Total GEORGETOWNE SHOPPING CENTER (New York) 32,202 49,586 1,469 32,202 51,055 83,257 2,047 1969/2006/ 2015 11/15/19 (1) GOVERNOR PLAZA (Maryland) 2,068 4,905 19,272 2,068 24,177 26,245 21,399 1963 10/1/1985 (1) GRAHAM PARK PLAZA (Virginia) 1,237 15,096 20,319 1,169 35,483 36,652 28,815 1971 7/21/1983 (1) GRATIOT PLAZA (Michigan) 525 1,601 17,963 525 19,564 20,089 17,985 1964 3/29/1973 (1) GREENLAWN PLAZA (New York) 10,590 20,869 813 10,590 21,682 32,272 4,326 1975/2004 1/13/2016 (1) GREENWICH AVENUE (Connecticut) 7,484 5,445 10,819 7,484 16,264 23,748 5,472 1968 4/12/1995 (1) HASTINGS RANCH PLAZA (California) 2,257 22,393 616 2,257 23,009 25,266 3,013 1958, 1984, 2006, 2007 2/1/2017 (1) HAUPPAUGE (New York) 8,791 15,262 5,829 8,419 21,463 29,882 13,729 1963 8/6/1998 (1) HOBOKEN (New Jersey) 105,939 47,460 167,835 546 47,460 168,381 215,841 6,006 1887-2006 9/18/19, 11/26/19, 12/19/19, & 2/12/20 (1) HOLLYWOOD BLVD (California) 8,300 16,920 36,159 8,370 53,009 61,379 18,599 1929/1991 3/22/99 & 6/18/99 (1) HUNTINGTON (New York) 12,194 16,008 19,604 12,194 35,612 47,806 18,564 1962 12/12/88, 10/26/07, & 11/24/15 (1) HUNTINGTON SQUARE (New York) — 10,075 3,537 506 13,106 13,612 4,751 1980/2004-2007 8/16/2010 (1) IDYLWOOD PLAZA (Virginia) 4,308 10,026 3,089 4,308 13,115 17,423 10,100 1991 4/15/1994 (1) KINGS COURT (California) — 10,714 894 — 11,608 11,608 9,979 1960 8/24/1998 (1) LANCASTER (Pennsylvania) — 2,103 5,951 432 7,622 8,054 6,009 1958 4/24/1980 (1) LANGHORNE SQUARE (Pennsylvania) 720 2,974 18,968 720 21,942 22,662 17,239 1966 1/31/1985 (1) LAUREL (Maryland) 7,458 22,525 30,662 7,503 53,142 60,645 42,119 1956 8/15/1986 (1) LAWRENCE PARK (Pennsylvania) 6,150 8,491 26,556 6,161 35,036 41,197 23,922 1972 7/23/1980 & 4/3/17 (1) LEESBURG PLAZA (Virginia) 8,184 10,722 18,416 8,184 29,138 37,322 16,976 1967 9/15/1998 (1) LINDEN SQUARE (Massachusetts) 79,382 19,247 51,727 79,346 71,010 150,356 29,105 1960-2008 8/24/2006 (1) MELVILLE MALL (New York) 35,622 32,882 35,161 35,622 68,043 103,665 19,630 1974 10/16/2006 (1) FEDERAL REALTY INVESTMENT TRUST SCHEDULE III SUMMARY OF REAL ESTATE AND ACCUMULATED DEPRECIATION DECEMBER 31, 2020 (Dollars in thousands) COLUMN A COLUMN B COLUMN C COLUMN D COLUMN E COLUMN F COLUMN G COLUMN H COLUMN I Descriptions Encumbrance Initial cost to company Cost Gross amount at which carried at Accumulated Date Date Life on which Land Building and Land Building and Total MERCER MALL (New Jersey) 5,917 18,358 47,690 5,869 66,096 71,965 34,954 1975 10/14/03 & 1/31/17 (1) MONTROSE CROSSING (Maryland) 65,596 48,624 91,819 24,539 48,624 116,358 164,982 35,861 1960s, 1970s, 1996 & 2011 12/27/11 & 12/19/13 (1) MOUNT VERNON/SOUTH VALLEY/7770 RICHMOND HWY. (Virginia) 10,068 33,501 43,397 10,150 76,816 86,966 41,890 1966/1972/ 1987/2001 3/31/03, 3/21/03, & 1/27/06 (1) NORTH DARTMOUTH (Massachusetts) 9,366 — 3 9,366 3 9,369 2 2004 8/24/2006 (1) NORTHEAST (Pennsylvania) 938 8,779 23,919 939 32,697 33,636 19,880 1959 8/30/1983 (1) OLD KEENE MILL (Virginia) 638 998 11,425 638 12,423 13,061 6,466 1968 6/15/1976 (1) OLD TOWN CENTER (California) 3,420 2,765 31,684 3,420 34,449 37,869 23,745 1962, 1997-1998 10/22/1997 (1) OLIVO AT MISSION HILLS (California) 15,048 46,732 19,503 15,048 66,235 81,283 4,706 2017-2018 8/2/2017 (1) PAN AM (Virginia) 8,694 12,929 8,424 8,695 21,352 30,047 16,906 1979 2/5/1993 (1) PENTAGON ROW (Virginia) — 2,955 104,222 — 107,177 107,177 54,974 1999 - 2002 1998 & 11/22/10 (1) PERRING PLAZA (Maryland) 2,800 6,461 22,637 2,800 29,098 31,898 24,646 1963 10/1/1985 (1) PIKE & ROSE (Maryland) 31,471 10,335 608,663 27,929 622,540 650,469 65,962 1963, 2012-2020 5/18/82, 10/26/07, & 7/31/12 (1) PIKE 7 PLAZA (Virginia) 14,970 22,799 11,775 14,914 34,630 49,544 19,814 1968 3/31/97 & 7/8/15 (1) PLAZA DEL MERCADO (Maryland) 10,305 21,553 15,037 10,305 36,590 46,895 7,234 1969 1/13/2016 (1) PLAZA DEL SOL (California) 8,072 5,605 12,331 (26) 5,605 12,305 17,910 1,546 2009 8/2/2017 (1) PLAZA EL SEGUNDO/THE POINT (California) 124,429 62,127 153,556 81,203 64,788 232,098 296,886 61,152 2006/2007/ 2016 12/30/11, 6/14/13, 7/26/13, & 12/27/13 (1) QUEEN ANNE PLAZA (Massachusetts) 3,319 8,457 6,654 3,319 15,111 18,430 10,991 1967 12/23/1994 (1) QUINCE ORCHARD (Maryland) 3,197 7,949 29,958 2,928 38,176 41,104 24,574 1975 4/22/1993 (1) RIVERPOINT CENTER (Illinois) 15,422 104,572 1,930 15,422 106,502 121,924 12,907 1989, 2012 3/31/2017 (1) FEDERAL REALTY INVESTMENT TRUST SCHEDULE III SUMMARY OF REAL ESTATE AND ACCUMULATED DEPRECIATION DECEMBER 31, 2020 (Dollars in thousands) COLUMN A COLUMN B COLUMN C COLUMN D COLUMN E COLUMN F COLUMN G COLUMN H COLUMN I Descriptions Encumbrance Initial cost to company Cost Gross amount at which carried at Accumulated Date Date Life on which Land Building and Land Building and Total ROCKVILLE TOWN SQUARE (Maryland) — 8,092 37,191 — 45,283 45,283 18,838 2005 - 2007 2006 - 2007 (1) ROLLINGWOOD APTS. (Maryland) 552 2,246 8,805 774 10,829 11,603 10,237 1960 1/15/1971 (1) SAN ANTONIO CENTER (California) 26,400 18,462 1,714 26,400 20,176 46,576 4,584 1958, 1964-1965, 1974-1975, 1995-1997 1/9/2015, 9/13/19 (1) SANTANA ROW (California) 66,682 7,502 1,076,914 57,592 1,093,506 1,151,098 243,734 1999-2006, 2009, 2011, 2014, 2016-2020 3/5/97, 7/13/12, 9/6/12, 4/30/13 & 9/23/13 (1) SAUGUS PLAZA (Massachusetts) 4,383 8,291 4,580 4,383 12,871 17,254 8,135 1976 10/1/1996 (1) SYLMAR TOWNE CENTER (California) 16,238 18,522 24,637 2,501 18,522 27,138 45,660 3,062 1973 8/2/2017 (1) THE AVENUE AT WHITE MARSH (Maryland) 52,651 20,682 72,432 29,339 20,685 101,768 122,453 42,152 1997 3/8/2007 (1) THE COMMONS AT DARIEN (Connecticut) 30,368 19,523 26,037 30,368 45,560 75,928 5,051 1920-2009 4/3/13 & 7/20/18 (1) THE GROVE AT SHREWSBURY (New Jersey) 42,972 18,016 103,115 6,002 18,021 109,112 127,133 24,453 1988/1993/ 2007 1/1/2014 & 10/6/14 (1) THE SHOPPES AT NOTTINGHAM SQUARE (Maryland) 4,441 12,849 1,054 4,441 13,903 18,344 6,416 2005 - 2006 3/8/2007 (1) THIRD STREET PROMENADE (California) 22,645 12,709 43,667 25,125 53,896 79,021 34,458 1888-2000 1996-2000 (1) TOWER SHOPPNG CENTER (Virginia) 7,170 10,518 5,038 7,280 15,446 22,726 10,514 1953-1960 8/24/1998 (1) TOWER SHOPS (Florida) 29,940 43,390 24,934 29,962 68,302 98,264 23,599 1989, 2017 1/19/11 & 6/13/14 (1) TOWN CENTER OF NEW BRITAIN (Pennsylvania) 1,282 12,285 3,015 1,693 14,889 16,582 6,487 1969 6/29/2006 (1) TOWSON RESIDENTIAL (FLATS 703) (Maryland) 2,328 — 20,063 2,328 20,063 22,391 2,075 2016-2017 3/8/2007 (1) TROY HILLS (New Jersey) 3,126 5,193 32,700 5,865 35,154 41,019 24,180 1966 7/23/1980 (1) TYSON'S STATION (Virginia) 388 453 4,891 493 5,239 5,732 4,046 1954 1/17/1978 (1) VILLAGE AT SHIRLINGTON (Virginia) 9,761 14,808 39,325 4,234 59,660 63,894 32,191 1940, 2006-2009 12/21/1995 (1) FEDERAL REALTY INVESTMENT TRUST SCHEDULE III SUMMARY OF REAL ESTATE AND ACCUMULATED DEPRECIATION DECEMBER 31, 2020 (Dollars in thousands) COLUMN A COLUMN B COLUMN C COLUMN D COLUMN E COLUMN F COLUMN G COLUMN H COLUMN I Descriptions Encumbrance Initial cost to company Cost Gross amount at which carried at Accumulated Date Date Life on which Land Building and Land Building and Total WESTGATE CENTER (California) 6,319 107,284 43,851 6,319 151,135 157,454 66,806 1960-1966 3/31/2004 (1) WHITE MARSH PLAZA (Maryland) 3,478 21,413 1,497 3,488 22,900 26,388 10,402 1987 3/8/2007 (1) WHITE MARSH OTHER (Maryland) 29,724 1,843 148 29,754 1,961 31,715 968 1985 3/8/2007 (1) WILDWOOD (Maryland) 9,111 1,061 17,271 9,111 18,332 27,443 9,723 1958 5/5/1969 (1) WILLOW GROVE (Pennsylvania) 1,499 6,643 21,131 1,499 27,774 29,273 26,734 1953 11/20/1984 (1) WILLOW LAWN (Virginia) 3,192 7,723 93,859 7,790 96,984 104,774 65,247 1957 12/5/1983 (1) WYNNEWOOD (Pennsylvania) 8,055 13,759 20,822 8,055 34,581 42,636 26,423 1948 10/29/1996 (1) TOTALS $ 484,111 $ 1,387,748 $ 2,493,283 $ 4,701,839 $ 1,374,797 $ 7,208,073 $ 8,582,870 $ 2,357,692 (1) Depreciation of building and improvements is calculated based on useful lives ranging from the life of the lease to 50 years. Balance, December 31, 2017 $ 7,635,061 Additions during period Acquisitions 14,940 Improvements 407,225 Deduction during period—dispositions and retirements of property (237,754) Balance, December 31, 2018 7,819,472 January 1, 2019 adoption of new accounting standard - See Note 2 (71,859) Additions during period Acquisitions 309,921 Improvements 441,703 Deduction during period—dispositions and retirements of property (201,105) Balance, December 31, 2019 8,298,132 Additions during period Acquisitions 39,440 Improvements 473,679 Deductions during period Impairment of property (68,484) Dispositions and retirement of property (159,897) Balance, December 31, 2020 (1) $ 8,582,870 _____________________ (1) For Federal tax purposes, the aggregate cost basis is approximately $7.7 billion as of December 31, 2020. FEDERAL REALTY INVESTMENT TRUST SCHEDULE III SUMMARY OF REAL ESTATE AND ACCUMULATED DEPRECIATION - CONTINUED Three Years Ended December 31, 2020 Reconciliation of Accumulated Depreciation and Amortization (in thousands) Balance, December 31, 2017 $ 1,876,544 Additions during period—depreciation and amortization expense 215,969 Deductions during period—dispositions and retirements of property (33,370) Balance, December 31, 2018 2,059,143 January 1, 2019 adoption of new accounting standard - See Note 2 (18,173) Additions during period—depreciation and amortization expense 215,382 Deductions during period—dispositions and retirements of property (40,939) Balance, December 31, 2019 2,215,413 Additions during period—depreciation and amortization expense 229,199 Deductions during period Impairment of property (11,631) Dispositions and retirements of property (75,289) Balance, December 31, 2020 $ 2,357,692

Schedule III Part II - Summary

Schedule III Part II - Summary of Real Estate and Accumulated Depreciation	12 Months Ended
	Dec. 31, 2020
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation Disclosure [Abstract]
Schedule III - Summary of Real Estate and Accumulated Depreciation	FEDERAL REALTY INVESTMENT TRUST SCHEDULE III SUMMARY OF REAL ESTATE AND ACCUMULATED DEPRECIATION DECEMBER 31, 2020 (Dollars in thousands) COLUMN A COLUMN B COLUMN C COLUMN D COLUMN E COLUMN F COLUMN G COLUMN H COLUMN I Descriptions Encumbrance Initial cost to company Cost Gross amount at which carried at Accumulated Date Date Life on which Land Building and Land Building and Total 29TH PLACE (Virginia) $ 10,211 $ 18,863 $ 9,588 $ 10,195 $ 28,467 $ 38,662 $ 14,173 1975 - 2001 5/30/2007 (1) ANDORRA (Pennsylvania) 2,432 12,346 16,148 2,432 28,494 30,926 21,200 1953 1/12/1988 (1) ASSEMBLY ROW/ASSEMBLY SQUARE MARKETPLACE (Massachusetts) 93,252 34,196 832,881 69,421 890,908 960,329 88,384 2005, 2012-2020 2005-2013 (1) AZALEA (California) 39,750 40,219 67,117 (7) 40,219 67,110 107,329 8,550 2014 8/2/2017 (1) BALA CYNWYD (Pennsylvania) 3,565 14,466 46,447 2,683 61,795 64,478 24,619 1955/2020 9/22/1993 (1) BARCROFT PLAZA (Virginia) 12,617 29,603 7,235 12,617 36,838 49,455 5,904 1963, 1972, 1990, & 2000 1/13/16 & 11/7/16 (1) BARRACKS ROAD (Virginia) 4,363 16,459 48,774 4,363 65,233 69,596 48,945 1958 12/31/1985 (1) BELL GARDENS (California) 12,082 24,406 85,947 671 24,406 86,618 111,024 14,425 1990, 2003, 2006 8/2/17 & 11/29/18 (1) BETHESDA ROW (Maryland) 46,579 35,406 162,367 43,904 200,448 244,352 92,357 1945-2008 12/31/93, 6/2/97, 1/20/06, 9/25/08, 9/30/08, & 12/27/10 (1) BRICK PLAZA (New Jersey) — 24,715 78,133 4,094 98,754 102,848 56,240 1958 12/28/1989 (1) BRISTOL PLAZA (Connecticut) 3,856 15,959 12,230 3,856 28,189 32,045 19,549 1959 9/22/1995 (1) BROOK 35 (New Jersey) 11,325 7,128 38,355 3,103 7,128 41,458 48,586 9,853 1986/2004 1/1/2014 (1) CAMPUS PLAZA (Massachusetts) 16,710 13,412 326 16,710 13,738 30,448 2,952 1970 1/13/2016 (1) CHELSEA COMMONS (Massachusetts) 5,057 8,689 19,466 2,410 8,669 21,896 30,565 9,040 1962/1969/ 8/25/06, 1/30/07, & 7/16/08 (1) COCOWALK (Florida) 34,406 72,123 73,504 50,838 129,195 180,033 12,333 1990/1994, 1922-1973, 2018-2019 5/4/15, 7/1/15, 12/16/15, 7/26/16, 6/30/17, & 8/10/17 (1) COLORADO BLVD (California) 2,415 3,964 6,905 2,415 10,869 13,284 9,397 1905-1988 8/14/98 (1) FEDERAL REALTY INVESTMENT TRUST SCHEDULE III SUMMARY OF REAL ESTATE AND ACCUMULATED DEPRECIATION DECEMBER 31, 2020 (Dollars in thousands) COLUMN A COLUMN B COLUMN C COLUMN D COLUMN E COLUMN F COLUMN G COLUMN H COLUMN I Descriptions Encumbrance Initial cost to company Cost Gross amount at which carried at Accumulated Date Date Life on which Land Building and Land Building and Total CONGRESSIONAL PLAZA (Maryland) 2,793 7,424 95,605 2,793 103,029 105,822 59,967 1965/2003/ 2016 4/1/1965 (1) COURTHOUSE CENTER (Maryland) 1,750 1,869 3,445 1,750 5,314 7,064 2,768 1975 12/17/1997 (1) CROSSROADS (Illinois) 4,635 11,611 19,649 4,635 31,260 35,895 20,191 1959 7/19/1993 (1) CROW CANYON COMMONS (California) 27,245 54,575 8,911 27,245 63,486 90,731 28,124 Late 1970's/ 12/29/05 & 2/28/07 (1) DEDHAM PLAZA (Massachusetts) 16,658 13,964 16,521 16,658 30,485 47,143 18,282 1959 12/31/93, 12/14/16, 1/29/19, & 3/12/19 (1) DEL MAR VILLAGE (Florida) 15,624 41,712 16,427 15,587 58,176 73,763 26,043 1982/1994/ 2007 5/30/08, 7/11/08, & 10/14/14 (1) EAST BAY BRIDGE (California) 29,069 138,035 12,123 29,069 150,158 179,227 41,377 1994-2001, 2011/2012 12/21/2012 (1) ELLISBURG (New Jersey) 4,028 11,309 18,872 4,013 30,196 34,209 21,740 1959 10/16/1992 (1) ESCONDIDO PROMENADE (California) 19,117 15,829 18,627 19,117 34,456 53,573 20,066 1987 12/31/96 & 11/10/10 (1) FAIRFAX JUNCTION (Virgina) 16,768 23,825 575 16,768 24,400 41,168 1,647 1981/1986/ 2000 2/8/19 & 1/10/20 (1) FALLS PLAZA (Virginia) 1,798 1,270 13,044 1,819 14,293 16,112 9,477 1960/1962 9/30/67 & 10/05/72 (1) FEDERAL PLAZA (Maryland) 10,216 17,895 42,735 10,216 60,630 70,846 48,440 1970 6/29/1989 (1) FINLEY SQUARE (Illinois) 9,252 9,544 22,603 9,252 32,147 41,399 23,198 1974 4/27/1995 (1) FLOURTOWN (Pennsylvania) 1,345 3,943 11,645 1,507 15,426 16,933 7,369 1957 4/25/1980 (1) FOURTH STREET (California) 13,978 9,909 3,085 13,978 12,994 26,972 1,752 1948,1975 5/19/2017 (1) FREEDOM PLAZA (California) — 3,255 37,242 — 40,497 40,497 761 2018-2020 6/15/2018 (1) FRESH MEADOWS (New York) 24,625 25,255 43,873 24,633 69,120 93,753 46,378 1946-1949 12/5/1997 (1) FRIENDSHIP CENTER (District of Columbia) 12,696 20,803 4,719 12,696 25,522 38,218 14,998 1998 9/21/2001 (1) GAITHERSBURG SQUARE (Maryland) 7,701 5,271 16,697 5,973 23,696 29,669 19,442 1966 4/22/1993 (1) GARDEN MARKET (Illinois) 2,677 4,829 7,370 2,677 12,199 14,876 9,241 1958 7/28/1994 (1) FEDERAL REALTY INVESTMENT TRUST SCHEDULE III SUMMARY OF REAL ESTATE AND ACCUMULATED DEPRECIATION DECEMBER 31, 2020 (Dollars in thousands) COLUMN A COLUMN B COLUMN C COLUMN D COLUMN E COLUMN F COLUMN G COLUMN H COLUMN I Descriptions Encumbrance Initial cost to company Cost Gross amount at which carried at Accumulated Date Date Life on which Land Building and Land Building and Total GEORGETOWNE SHOPPING CENTER (New York) 32,202 49,586 1,469 32,202 51,055 83,257 2,047 1969/2006/ 2015 11/15/19 (1) GOVERNOR PLAZA (Maryland) 2,068 4,905 19,272 2,068 24,177 26,245 21,399 1963 10/1/1985 (1) GRAHAM PARK PLAZA (Virginia) 1,237 15,096 20,319 1,169 35,483 36,652 28,815 1971 7/21/1983 (1) GRATIOT PLAZA (Michigan) 525 1,601 17,963 525 19,564 20,089 17,985 1964 3/29/1973 (1) GREENLAWN PLAZA (New York) 10,590 20,869 813 10,590 21,682 32,272 4,326 1975/2004 1/13/2016 (1) GREENWICH AVENUE (Connecticut) 7,484 5,445 10,819 7,484 16,264 23,748 5,472 1968 4/12/1995 (1) HASTINGS RANCH PLAZA (California) 2,257 22,393 616 2,257 23,009 25,266 3,013 1958, 1984, 2006, 2007 2/1/2017 (1) HAUPPAUGE (New York) 8,791 15,262 5,829 8,419 21,463 29,882 13,729 1963 8/6/1998 (1) HOBOKEN (New Jersey) 105,939 47,460 167,835 546 47,460 168,381 215,841 6,006 1887-2006 9/18/19, 11/26/19, 12/19/19, & 2/12/20 (1) HOLLYWOOD BLVD (California) 8,300 16,920 36,159 8,370 53,009 61,379 18,599 1929/1991 3/22/99 & 6/18/99 (1) HUNTINGTON (New York) 12,194 16,008 19,604 12,194 35,612 47,806 18,564 1962 12/12/88, 10/26/07, & 11/24/15 (1) HUNTINGTON SQUARE (New York) — 10,075 3,537 506 13,106 13,612 4,751 1980/2004-2007 8/16/2010 (1) IDYLWOOD PLAZA (Virginia) 4,308 10,026 3,089 4,308 13,115 17,423 10,100 1991 4/15/1994 (1) KINGS COURT (California) — 10,714 894 — 11,608 11,608 9,979 1960 8/24/1998 (1) LANCASTER (Pennsylvania) — 2,103 5,951 432 7,622 8,054 6,009 1958 4/24/1980 (1) LANGHORNE SQUARE (Pennsylvania) 720 2,974 18,968 720 21,942 22,662 17,239 1966 1/31/1985 (1) LAUREL (Maryland) 7,458 22,525 30,662 7,503 53,142 60,645 42,119 1956 8/15/1986 (1) LAWRENCE PARK (Pennsylvania) 6,150 8,491 26,556 6,161 35,036 41,197 23,922 1972 7/23/1980 & 4/3/17 (1) LEESBURG PLAZA (Virginia) 8,184 10,722 18,416 8,184 29,138 37,322 16,976 1967 9/15/1998 (1) LINDEN SQUARE (Massachusetts) 79,382 19,247 51,727 79,346 71,010 150,356 29,105 1960-2008 8/24/2006 (1) MELVILLE MALL (New York) 35,622 32,882 35,161 35,622 68,043 103,665 19,630 1974 10/16/2006 (1) FEDERAL REALTY INVESTMENT TRUST SCHEDULE III SUMMARY OF REAL ESTATE AND ACCUMULATED DEPRECIATION DECEMBER 31, 2020 (Dollars in thousands) COLUMN A COLUMN B COLUMN C COLUMN D COLUMN E COLUMN F COLUMN G COLUMN H COLUMN I Descriptions Encumbrance Initial cost to company Cost Gross amount at which carried at Accumulated Date Date Life on which Land Building and Land Building and Total MERCER MALL (New Jersey) 5,917 18,358 47,690 5,869 66,096 71,965 34,954 1975 10/14/03 & 1/31/17 (1) MONTROSE CROSSING (Maryland) 65,596 48,624 91,819 24,539 48,624 116,358 164,982 35,861 1960s, 1970s, 1996 & 2011 12/27/11 & 12/19/13 (1) MOUNT VERNON/SOUTH VALLEY/7770 RICHMOND HWY. (Virginia) 10,068 33,501 43,397 10,150 76,816 86,966 41,890 1966/1972/ 1987/2001 3/31/03, 3/21/03, & 1/27/06 (1) NORTH DARTMOUTH (Massachusetts) 9,366 — 3 9,366 3 9,369 2 2004 8/24/2006 (1) NORTHEAST (Pennsylvania) 938 8,779 23,919 939 32,697 33,636 19,880 1959 8/30/1983 (1) OLD KEENE MILL (Virginia) 638 998 11,425 638 12,423 13,061 6,466 1968 6/15/1976 (1) OLD TOWN CENTER (California) 3,420 2,765 31,684 3,420 34,449 37,869 23,745 1962, 1997-1998 10/22/1997 (1) OLIVO AT MISSION HILLS (California) 15,048 46,732 19,503 15,048 66,235 81,283 4,706 2017-2018 8/2/2017 (1) PAN AM (Virginia) 8,694 12,929 8,424 8,695 21,352 30,047 16,906 1979 2/5/1993 (1) PENTAGON ROW (Virginia) — 2,955 104,222 — 107,177 107,177 54,974 1999 - 2002 1998 & 11/22/10 (1) PERRING PLAZA (Maryland) 2,800 6,461 22,637 2,800 29,098 31,898 24,646 1963 10/1/1985 (1) PIKE & ROSE (Maryland) 31,471 10,335 608,663 27,929 622,540 650,469 65,962 1963, 2012-2020 5/18/82, 10/26/07, & 7/31/12 (1) PIKE 7 PLAZA (Virginia) 14,970 22,799 11,775 14,914 34,630 49,544 19,814 1968 3/31/97 & 7/8/15 (1) PLAZA DEL MERCADO (Maryland) 10,305 21,553 15,037 10,305 36,590 46,895 7,234 1969 1/13/2016 (1) PLAZA DEL SOL (California) 8,072 5,605 12,331 (26) 5,605 12,305 17,910 1,546 2009 8/2/2017 (1) PLAZA EL SEGUNDO/THE POINT (California) 124,429 62,127 153,556 81,203 64,788 232,098 296,886 61,152 2006/2007/ 2016 12/30/11, 6/14/13, 7/26/13, & 12/27/13 (1) QUEEN ANNE PLAZA (Massachusetts) 3,319 8,457 6,654 3,319 15,111 18,430 10,991 1967 12/23/1994 (1) QUINCE ORCHARD (Maryland) 3,197 7,949 29,958 2,928 38,176 41,104 24,574 1975 4/22/1993 (1) RIVERPOINT CENTER (Illinois) 15,422 104,572 1,930 15,422 106,502 121,924 12,907 1989, 2012 3/31/2017 (1) FEDERAL REALTY INVESTMENT TRUST SCHEDULE III SUMMARY OF REAL ESTATE AND ACCUMULATED DEPRECIATION DECEMBER 31, 2020 (Dollars in thousands) COLUMN A COLUMN B COLUMN C COLUMN D COLUMN E COLUMN F COLUMN G COLUMN H COLUMN I Descriptions Encumbrance Initial cost to company Cost Gross amount at which carried at Accumulated Date Date Life on which Land Building and Land Building and Total ROCKVILLE TOWN SQUARE (Maryland) — 8,092 37,191 — 45,283 45,283 18,838 2005 - 2007 2006 - 2007 (1) ROLLINGWOOD APTS. (Maryland) 552 2,246 8,805 774 10,829 11,603 10,237 1960 1/15/1971 (1) SAN ANTONIO CENTER (California) 26,400 18,462 1,714 26,400 20,176 46,576 4,584 1958, 1964-1965, 1974-1975, 1995-1997 1/9/2015, 9/13/19 (1) SANTANA ROW (California) 66,682 7,502 1,076,914 57,592 1,093,506 1,151,098 243,734 1999-2006, 2009, 2011, 2014, 2016-2020 3/5/97, 7/13/12, 9/6/12, 4/30/13 & 9/23/13 (1) SAUGUS PLAZA (Massachusetts) 4,383 8,291 4,580 4,383 12,871 17,254 8,135 1976 10/1/1996 (1) SYLMAR TOWNE CENTER (California) 16,238 18,522 24,637 2,501 18,522 27,138 45,660 3,062 1973 8/2/2017 (1) THE AVENUE AT WHITE MARSH (Maryland) 52,651 20,682 72,432 29,339 20,685 101,768 122,453 42,152 1997 3/8/2007 (1) THE COMMONS AT DARIEN (Connecticut) 30,368 19,523 26,037 30,368 45,560 75,928 5,051 1920-2009 4/3/13 & 7/20/18 (1) THE GROVE AT SHREWSBURY (New Jersey) 42,972 18,016 103,115 6,002 18,021 109,112 127,133 24,453 1988/1993/ 2007 1/1/2014 & 10/6/14 (1) THE SHOPPES AT NOTTINGHAM SQUARE (Maryland) 4,441 12,849 1,054 4,441 13,903 18,344 6,416 2005 - 2006 3/8/2007 (1) THIRD STREET PROMENADE (California) 22,645 12,709 43,667 25,125 53,896 79,021 34,458 1888-2000 1996-2000 (1) TOWER SHOPPNG CENTER (Virginia) 7,170 10,518 5,038 7,280 15,446 22,726 10,514 1953-1960 8/24/1998 (1) TOWER SHOPS (Florida) 29,940 43,390 24,934 29,962 68,302 98,264 23,599 1989, 2017 1/19/11 & 6/13/14 (1) TOWN CENTER OF NEW BRITAIN (Pennsylvania) 1,282 12,285 3,015 1,693 14,889 16,582 6,487 1969 6/29/2006 (1) TOWSON RESIDENTIAL (FLATS 703) (Maryland) 2,328 — 20,063 2,328 20,063 22,391 2,075 2016-2017 3/8/2007 (1) TROY HILLS (New Jersey) 3,126 5,193 32,700 5,865 35,154 41,019 24,180 1966 7/23/1980 (1) TYSON'S STATION (Virginia) 388 453 4,891 493 5,239 5,732 4,046 1954 1/17/1978 (1) VILLAGE AT SHIRLINGTON (Virginia) 9,761 14,808 39,325 4,234 59,660 63,894 32,191 1940, 2006-2009 12/21/1995 (1) FEDERAL REALTY INVESTMENT TRUST SCHEDULE III SUMMARY OF REAL ESTATE AND ACCUMULATED DEPRECIATION DECEMBER 31, 2020 (Dollars in thousands) COLUMN A COLUMN B COLUMN C COLUMN D COLUMN E COLUMN F COLUMN G COLUMN H COLUMN I Descriptions Encumbrance Initial cost to company Cost Gross amount at which carried at Accumulated Date Date Life on which Land Building and Land Building and Total WESTGATE CENTER (California) 6,319 107,284 43,851 6,319 151,135 157,454 66,806 1960-1966 3/31/2004 (1) WHITE MARSH PLAZA (Maryland) 3,478 21,413 1,497 3,488 22,900 26,388 10,402 1987 3/8/2007 (1) WHITE MARSH OTHER (Maryland) 29,724 1,843 148 29,754 1,961 31,715 968 1985 3/8/2007 (1) WILDWOOD (Maryland) 9,111 1,061 17,271 9,111 18,332 27,443 9,723 1958 5/5/1969 (1) WILLOW GROVE (Pennsylvania) 1,499 6,643 21,131 1,499 27,774 29,273 26,734 1953 11/20/1984 (1) WILLOW LAWN (Virginia) 3,192 7,723 93,859 7,790 96,984 104,774 65,247 1957 12/5/1983 (1) WYNNEWOOD (Pennsylvania) 8,055 13,759 20,822 8,055 34,581 42,636 26,423 1948 10/29/1996 (1) TOTALS $ 484,111 $ 1,387,748 $ 2,493,283 $ 4,701,839 $ 1,374,797 $ 7,208,073 $ 8,582,870 $ 2,357,692 (1) Depreciation of building and improvements is calculated based on useful lives ranging from the life of the lease to 50 years. Balance, December 31, 2017 $ 7,635,061 Additions during period Acquisitions 14,940 Improvements 407,225 Deduction during period—dispositions and retirements of property (237,754) Balance, December 31, 2018 7,819,472 January 1, 2019 adoption of new accounting standard - See Note 2 (71,859) Additions during period Acquisitions 309,921 Improvements 441,703 Deduction during period—dispositions and retirements of property (201,105) Balance, December 31, 2019 8,298,132 Additions during period Acquisitions 39,440 Improvements 473,679 Deductions during period Impairment of property (68,484) Dispositions and retirement of property (159,897) Balance, December 31, 2020 (1) $ 8,582,870 _____________________ (1) For Federal tax purposes, the aggregate cost basis is approximately $7.7 billion as of December 31, 2020. FEDERAL REALTY INVESTMENT TRUST SCHEDULE III SUMMARY OF REAL ESTATE AND ACCUMULATED DEPRECIATION - CONTINUED Three Years Ended December 31, 2020 Reconciliation of Accumulated Depreciation and Amortization (in thousands) Balance, December 31, 2017 $ 1,876,544 Additions during period—depreciation and amortization expense 215,969 Deductions during period—dispositions and retirements of property (33,370) Balance, December 31, 2018 2,059,143 January 1, 2019 adoption of new accounting standard - See Note 2 (18,173) Additions during period—depreciation and amortization expense 215,382 Deductions during period—dispositions and retirements of property (40,939) Balance, December 31, 2019 2,215,413 Additions during period—depreciation and amortization expense 229,199 Deductions during period Impairment of property (11,631) Dispositions and retirements of property (75,289) Balance, December 31, 2020 $ 2,357,692

Schedule IV - Mortgage Loans on

Schedule IV - Mortgage Loans on Real Estate	12 Months Ended
	Dec. 31, 2020
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Abstract]
Schedule IV - Mortgage Loans on Real Estate	FEDERAL REALTY INVESTMENT TRUST SCHEDULE IV MORTGAGE LOANS ON REAL ESTATE Year Ended December 31, 2020 (Dollars in thousands) Column A Column B Column C Column D Column E Column F Column G Column H Description of Lien Interest Rate Maturity Date Periodic Payment Prior Face Amount Carrying Principal Mortgage on 8% or 10% May 2021 Interest only $ — $ 21,872 $ 21,082 (2) $ 21,082 (3) Mortgage on retail buildings in Philadelphia, PA 10% plus participation May 2021 Interest only monthly; — 9,250 9,250 9,250 (3) Second mortgage on a retail shopping center in Rockville, MD 11.5% February 2026 Interest only monthly; 58,750 (4) 5,075 5,075 — Second mortgage on a retail shopping center in Rockville, MD 10.75% February 2026 Interest only monthly; 58,750 (4) 4,500 4,485 — $ 58,750 $ 40,697 $ 39,892 $ 30,332 _____________________ (1) For Federal tax purposes, the aggregate tax basis is approximately $40.7 million as of December 31, 2020. Upon the adoption of ASU 2016-13, we recorded expected losses related to these loans, and are required to do so going forward. See note 2 to the consolidated financial statements. (2) This mortgage is available for up to $25.0 million. (3) The borrower was notified in October 2020 that these mortgages were in default. No interest payments were made from April through July, and partial payments from August through December 31, 2020. (4) These mortgages are both subordinate to a first mortgage of $58.8 million in total. We do not hold the first mortgage loan on this property. Accordingly, the amount of the prior lien at December 31, 2020 is estimated. FEDERAL REALTY INVESTMENT TRUST SCHEDULE IV MORTGAGE LOANS ON REAL ESTATE - CONTINUED Three Years Ended December 31, 2020 Reconciliation of Carrying Amount (in thousands) Balance, December 31, 2017, 2018, and 2019 $ 30,429 January 1, 2020 adoption of new accounting standard - See Note 2 (790) Additions during period: Acquisition of loans, net of valuation adjustments 9,560 Issuance of loans 693 Balance, December 31, 2020 $ 39,892

Summary Of Significant Accoun_2

Summary Of Significant Accounting Policies (Policy)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Principles of Consolidation	Principles of ConsolidationOur consolidated financial statements include the accounts of the Trust, its corporate subsidiaries, and all entities in which the Trust has a controlling interest or has been determined to be the primary beneficiary of a variable interest entity (“VIE”). The equity interests of other investors are reflected as noncontrolling interests or redeemable noncontrolling interests. All significant intercompany transactions and balances are eliminated in consolidation. We account for our interests in joint ventures, which we do not control, using the equity method of accounting.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America, referred to as “GAAP,” requires management to make estimates and assumptions that in certain circumstances affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities, and revenues and expenses. These estimates are prepared using management’s best judgment, after considering past, current and expected events and economic conditions. Actual results could differ from these estimates.
Revenue Recognition and Accounts Receivable	Revenue Recognition and Accounts Receivable Policy beginning January 1, 2019, with our adoption of Accounting Standards Codification (ASC) 842, "Leases" Our leases with our tenants are classified as operating leases. When collection of substantially all lease payments during the lease term is considered probable, the lease qualifies for accrual accounting. Lease payments are recognized on a straight-line basis from the point in time when the tenant controls the space through the term of the related lease. Variable lease payments relating to percentage rent are recognized at the end of the lease year or earlier if we have determined the required sales level is achieved. Real estate tax and other cost reimbursements are recognized on an accrual basis over the periods in which the related expenditures are incurred. Many of our leases contain tenant options that enable the tenant to extend the term of the lease at expiration at pre-established rental rates that often include fixed rent increases, consumer price index adjustments or other market rate adjustments from the prior base rent. For a tenant to terminate its lease agreement prior to the end of the agreed term, we may require that they pay a fee to cancel the lease agreement. Lease termination fees are generally recognized on the termination date if the tenant has relinquished control of the space. When a lease is terminated early but the tenant continues to control the space under a modified lease agreement, the lease termination fee is generally recognized evenly over the remaining term of the modified lease agreement. Lease concessions (unrelated to the COVID-19 pandemic) are evaluated to determine whether the concession represents a modification of the original lease contract. Modifications generally result in a reassessment of the lease term and lease classification, and remeasurement of lease payments received. Remeasured lease payments are recognized on a straight-line basis over the remaining term of the modified lease contract. In April 2020, the Financial Accounting Standards Board ("FASB") issued interpretive guidance relating to the accounting for lease concessions provided as a result of the COVID-19 pandemic that allows entities to treat the concession as if it was a part of the existing contract instead of applying lease modification accounting. This guidance is only applicable to the COVID-19 pandemic related lease concessions that do not result in a substantial increase in the rights of the lessor or the obligations of the lessee. We have elected this option relating to qualifying rent deferral and rent abatement agreements. For qualifying lease modifications with rent deferrals, this results in no change to our revenue recognition but an increase in the lease receivable balance until the deferred rent has been repaid. For qualifying lease modifications that include rent abatement concessions, this results in a direct reduction of rental income in the current period. As of December 31, 2020, we have entered into rent deferral agreements and rent abatement agreements related to the COVID-19 pandemic representing approximately $36 million and $35 million, respectively, of rent otherwise owed during the year ended December 31, 2020, and continue negotiations with other tenants. When collection of substantially all lease payments during the lease term is not considered probable, total lease revenue is limited to the lesser of revenue recognized under accrual accounting or cash received. Determining the probability of collection of substantially all lease payments during a lease term requires significant judgment. This determination is impacted by numerous factors including our assessment of the tenant’s credit worthiness, economic conditions, tenant sales productivity in that location, historical experience with the tenant and tenants operating in the same industry, future prospects for the tenant and the industry in which it operates, and the length of the lease term. If leases currently classified as probable are subsequently reclassified as not probable, any outstanding lease receivables (including straight-line rent receivables) would be written-off with a corresponding decrease in rental income. If leases currently classified as not probable are subsequently changed to probable, any lease receivables (including straight-line rent receivables) are re-instated with a corresponding increase to rental income. Since March 2020, federal, state, and local governments have taken various actions to mitigate the spread of COVID-19. This includes initially ordering closures of nonessential business and ordering residents to generally stay at home, subsequent phased re-openings, and during the fourth quarter of 2020, additional closures and capacity limitations as infection levels increased in certain areas. These actions, along with the general concern over the spread of COVID-19, have resulted in many of our tenants temporarily or even permanently closing their businesses, and for some, it has impacted their ability to pay rent. As a result, we revised our collectibility assumptions for many of our tenants most significantly impacted by COVID-19. Accordingly, during the year ended December 31, 2020, we recognized collectibility related adjustments of $106.6 million. This includes changes in our collectibility assessments from probable to not probable, disputed rents, and any rent abatements directly related to COVID-19, as well as the write-off of $12.7 million of straight-line rent receivables related to tenants changed to a cash basis of revenue recognition during the year ended December 31, 2020. As of December 31, 2020, the revenue from approximately 35% of our tenants (based on total commercial leases) is being recognized on a cash basis. As of December 31, 2020 and 2019, our straight-line rent receivables balance was $103.3 million and $100.3 million, respectively, and is included in "accounts and notes receivable, net" on our consolidated balance sheet. Policy prior to January 1, 2019 Prior to January 1, 2019, management estimates of collectability were considered when reserving for billed and accrued lease receivables and straight-line rent receivables. Full and partial reserves were recorded when determined to be appropriate with a corresponding charge to bad debt expense. The primary impact of the adoption of ASC 842, “Leases,” on our recognition of lease revenue relates to the upfront and ongoing assessment of the collectability of substantially all lease payments required by the new standard. Other revenue recognition policies
Real Estate	Real Estate Land, buildings and improvements are recorded at cost. Depreciation is computed using the straight-line method. Estimated useful lives range generally from 35 years to a maximum of 50 years on buildings and major improvements. Minor improvements, furniture and equipment are capitalized and depreciated over useful lives ranging from 2 to 20 years. Maintenance and repairs that do not improve or extend the useful lives of the related assets are charged to operations as incurred. Tenant improvements are capitalized and depreciated over the life of the related lease or their estimated useful life, whichever is shorter. If a tenant vacates its space prior to contractual termination of its lease, the undepreciated balance of any tenant improvements are written off if they are replaced or have no future value. In 2020, 2019 and 2018, real estate depreciation expense was $227.9 million, $215.4 million and $216.0 million, respectively, including amounts from real estate sold. Our methodology of allocating the cost of acquisitions to assets acquired and liabilities assumed is based on estimated fair values, replacement cost and/or appraised values. When we acquire operating real estate properties, the purchase price is allocated to land, building, improvements, leasing costs, intangibles such as in-place leases, assumed debt, if any, and to current assets and liabilities acquired, if any. The value allocated to in-place leases is amortized over the related lease term and reflected as rental income in the consolidated statements of comprehensive income. We consider qualitative and quantitative factors in evaluating the likelihood of a tenant exercising a below market renewal option and include such renewal options in the calculation of in-place lease value when we consider these to be bargain renewal options. If the value of below market lease intangibles includes renewal option periods, we include such renewal periods in the amortization period utilized. If a tenant vacates its space prior to contractual termination of its lease, the unamortized balance of any in-place lease value is written off to rental income. Transaction costs related to asset acquisitions, such as broker fees, transfer taxes, legal, accounting, valuation, and other professional and consulting fees, are capitalized as part of the acquisition cost. The acquisition of an operating shopping center typically qualifies as an asset acquisition. Prior to the adoption of ASU 2016-02, "Leases," when applicable, as lessee, we classified our leases of land and building as operating or capital leases. We were required to use judgment and make estimates in determining the lease term, the estimated economic life of the property and the interest rate to be used in determining whether or not the lease meets the qualification of a capital lease. Subsequently, capital leases are now considered "finance leases." We capitalize certain costs related to the development and redevelopment of real estate including pre-construction costs, real estate taxes, insurance, construction costs and salaries and related costs of personnel directly involved, are capitalized. Additionally, we capitalize interest costs related to development and redevelopment activities. Capitalization of these costs begin when the activities and related expenditures commence and cease when the project is substantially complete and ready for its intended use at which time the project is placed in service and depreciation commences. Additionally, we make estimates as to the probability of certain development and redevelopment projects being completed. If we determine the development or redevelopment is no longer probable of completion, we expense all capitalized costs which are not recoverable.
Long Lived Assets and Impairment	Long-Lived Assets and Impairment There are estimates and assumptions made by management in preparing the consolidated financial statements for which the actual results will be determined over long periods of time. This includes the recoverability of long-lived assets, including our properties that have been acquired or redeveloped and our investment in certain joint ventures. Management’s evaluation of impairment includes review for possible indicators of impairment as well as, in certain circumstances, undiscounted and discounted cash flow analysis. Since most of our investments in real estate are wholly-owned or controlled assets which are held for use, a property with impairment indicators is first tested for impairment by comparing the undiscounted cash flows, including residual value, to the current net book value of the property. If the undiscounted cash flows are less than the net book value, the property is written down to expected fair value. The calculation of both discounted and undiscounted cash flows requires management to make estimates of future cash flows including revenues, operating expenses, required maintenance and development expenditures, market conditions, demand for space by tenants and rental rates over long periods. Because our properties typically have a long life, the assumptions used to estimate the future recoverability of book value requires significant management judgment. Actual results could be significantly different from the estimates. These estimates have a direct impact on net income, because recording an impairment charge results in a negative adjustment to net income.
Cash and Cash Equivalents	Cash and Cash Equivalents We define cash and cash equivalents as cash on hand, demand deposits with financial institutions and short term liquid investments with an initial maturity, when purchased, under three months. Cash balances in individual banks may exceed the federally insured limit by the Federal Deposit Insurance Corporation (the “FDIC”). At December 31, 2020, we had $803.6 million in excess of the FDIC insured limit.
Prepaid Expenses and Other Assets	Prepaid Expenses and Other Assets Prepaid expenses and other assets consist primarily of lease costs, prepaid property taxes and acquired above market leases. Capitalized lease costs are incremental direct costs incurred which were essential to originate a successful leasing arrangement and would not have been incurred had the leasing transaction not taken place. These costs include third party commissions related to obtaining a lease. Capitalized lease costs are amortized over the initial life of the related lease which generally ranges from three ten
Debt Issuance Costs	Debt Issuance Costs Costs related to the issuance of debt instruments are deferred and are amortized as interest expense over the estimated life of the related issue using the straight-line method which approximates the effective interest method. If a debt instrument is paid off prior to its original maturity date, the unamortized balance of debt issuance costs are written off to interest expense or, if significant, included in “early extinguishment of debt.” Debt issuance costs related to our revolving credit facility are classified as an asset and are included in "prepaid expenses and other assets" in our consolidated balance sheets. All other debt issuance costs are presented as a direct deduction from the carrying amount of the debt liability.
Derivative Instruments	Derivative Instruments We may use derivative instruments to manage exposure to variable interest rate risk. We generally enter into interest rate swaps to manage our exposure to variable interest rate risk and treasury locks to manage the risk of interest rates rising prior to the issuance of debt. We enter into derivative instruments that qualify as cash flow hedges and do not enter into derivative instruments for speculative purposes. Interest rate swaps associated with cash flow hedges are recorded at fair value on a recurring basis. Effectiveness of cash flow hedges is assessed both at inception and on an ongoing basis. The effective portion of changes in fair value of the interest rate swaps associated with cash flow hedges is recorded in other comprehensive income (loss) which is included in accumulated other comprehensive income (loss) on the balance sheet and statement of shareholders' equity. Cash flow hedges become ineffective if critical terms of the hedging instrument and the debt instrument do not perfectly match such as notional amounts, settlement dates, reset dates, calculation period and LIBOR rate. In addition, the default risk of the counterparty is evaluated by monitoring the credit worthiness of the counterparty which includes reviewing debt ratings and financial performance. If a cash flow hedge is deemed ineffective, the ineffective portion of changes in fair value of the interest rate swaps associated with cash flow hedges is recognized in earnings in the period affected. At December 31, 2020, we have two interest rate swap agreements that effectively fix the interest rate on a mortgage payable associated with our Hoboken acquisition at 3.67%. Both swaps were designated and qualify for cash flow hedge accounting. As of December 31, 2020, our Assembly Row hotel joint venture is a party to two interest rate swap agreements that effectively fix the interest rate on the joint venture's mortgage debt at 5.206%. Both swaps were designated and qualify as cash flow hedges. Hedge ineffectiveness has not impacted earnings in 2020, 2019 and 2018.
Mortgage Notes Receivable	Mortgage Notes Receivable We have invested in certain mortgage loans that, because of their nature, qualify as loan receivables. At the time of investment, we did not intend for the arrangement to be anything other than a financing and did not contemplate a real estate investment. We evaluate each investment to determine whether the loan arrangement qualifies as a loan, joint venture or real estate investment and the appropriate accounting thereon. Such determination affects our balance sheet classification of these investments and the recognition of interest income derived therefrom. In one of our mortgage loan arrangements, we receive additional interest, however, we never receive in excess of 50% of the residual profit in the project, and because the borrower has either a substantial investment in the project or has guaranteed all or a portion of our loan (or a combination thereof), the loans qualify for loan accounting. The amounts under these arrangements are presented as mortgage notes receivable at December 31, 2020 and 2019. Mortgage notes receivable are recorded at cost, net of any valuation adjustments. Effective January 1, 2020, (upon the adoption of ASU 2016-13, "Financial Instruments - Credit Losses," as amended and interpreted), we account for mortgage notes receivable using the "expected credit loss" model, and accordingly impairment losses are estimated and recorded for the entire life of the loan. Prior to the implementation of ASC 326, we recognized impairment losses as incurred. Interest income is accrued as earned. Mortgage notes receivable are considered past due based on the contractual terms of the note agreement. On
Share Based Compensation	Share Based Compensation We grant share based compensation awards to employees and trustees typically in the form of restricted common shares, common shares, and options. We measure share based compensation expense based on the grant date fair value of the award and recognize the expense ratably over the requisite service period, which is typically the vesting period. See Note 12 for further discussion regarding our share based compensation plans and policies.
Variable Interest Entities	Variable Interest Entities Certain entities that do not have sufficient equity at risk for the entity to finance its activities without additional subordinated financial support from other parties or in which equity investors do not have the characteristics of a controlling financial interest qualify as VIEs. VIEs are required to be consolidated by their primary beneficiary. The primary beneficiary of a VIE has both the power to direct the activities that most significantly impact economic performance of the VIE and the obligation to absorb losses or the right to receive benefits that could potentially be significant to the VIE. Our equity method investments in the Pike & Rose hotel joint venture, the Assembly Row hotel joint venture, and the La Alameda shopping center are also considered variable interests in a VIE. As we do not control the activities that most significantly impact the economic performance of the joint ventures, we are not the primary beneficiary and do not consolidate. As of December 31, 2020 and 2019, our investment in these joint ventures and maximum exposure to loss was $18.7 million and $23.4 million, respectively. On January 4, 2021, we acquired our partner's interest in the Pike & Rose hotel joint venture. See footnote 15 to the consolidated financial statements for additional details of this transaction. In addition, we have 17 entities that meet the criteria of a VIE in which we hold a variable interest. For each of these entities, we control the significant operating decisions and consequently have the power to direct the activities that most significantly impact the economic performance of the entities. As we also have the obligation to absorb the majority of the losses and/or the right to receive a majority of the benefits for each of these entities, all are consolidated in our financial statements. Net real estate assets related to VIEs included in our consolidated balance sheets were approximately $1.4 billion and $1.5 billion as of December 31, 2020 and 2019, respectively, and mortgages related to VIEs included in our consolidated balance sheets were approximately $413.7 million and $469.2 million, as of December 31, 2020 and 2019, respectively. We have also evaluated our mortgage notes receivable investments and determined that the entities obligated under the mortgage notes are not VIEs. Our equity method investments and mortgage notes receivable balances are presented separately in our consolidated balance sheets.
Redeemable Noncontrolling Interests	Redeemable Noncontrolling Interests We have certain noncontrolling interests that are redeemable for cash upon the occurrence of an event that is not solely in our control and therefore are classified outside of permanent equity. We adjust the carrying amounts of these noncontrolling interests that are currently redeemable to redemption value at the balance sheet date. Adjustments to the carrying amount to reflect changes in redemption value are recorded as adjustments to additional paid-in capital in shareholders' equity. These amounts are classified within the mezzanine section of the consolidated balance sheets. The following table provides a rollforward of the redeemable noncontrolling interests: Year Ended December 31, 2020 2019 (In thousands) Beginning balance $ 139,758 $ 136,208 Contributions 19,335 9,961 Net income 2,228 3,430 Distributions & redemptions (1,197) (15,366) Other comprehensive loss - change in value of interest rate swaps (471) — Change in redemption value (21,933) 5,525 Ending balance $ 137,720 $ 139,758
Leases	Leases We adopted ASC 842 effective January 1, 2019 under the modified retrospective approach and elected the optional transition method to apply the provisions of ASC 842 as of the adoption date, rather than the earliest period presented. We elected to apply certain adoption related practical expedients for all leases that commenced prior to the election date. These practical expedients included not reassessing whether any expired or existing contracts were or contained leases; not reassessing the lease classification for any expired or existing leases; and not reassessing initial direct costs for any existing leases. We also elected the practical expedient for lessors to combine our lease and non-lease components (primarily impacts common area maintenance recoveries). Lessor We recorded a charge to the opening accumulated dividends in excess of net income of $7.1 million in 2019 as a result of the adoption of ASC 842. This charge was attributable to the write off certain direct leasing costs recorded under the previous lease accounting rules for leases which had not commenced as well as the write off of unreserved receivables (including straight-line receivables) for leases where we had determined the collection of substantially all the lease payments required for the term is not probable. Also upon adoption of ASC 842 and reflected in our 2019 and 2020 financial statements, we do not record a gross up of revenue and expense for costs (such as real estate taxes) paid directly by lessees on our behalf. Lessee
Income Taxes	Income Taxes We operate in a manner intended to enable us to qualify as a REIT for federal income tax purposes. A REIT that distributes at least 90% of its taxable income to its shareholders each year and meets certain other conditions is not taxed on that portion of its taxable income which is distributed to its shareholders. Therefore, federal income taxes on our taxable income have been and are generally expected to be immaterial. We are obligated to pay state taxes, generally consisting of franchise or gross receipts taxes in certain states. Such state taxes also have not been material. We have elected to treat certain of our subsidiaries as taxable REIT subsidiaries, which we refer to as a TRS. In general, a TRS may engage in any real estate business and certain non-real estate businesses, subject to certain limitations under the Internal Revenue Code of 1986, as amended (the “Code”). A TRS is subject to federal and state income taxes. Our TRS activities have not been material. With few exceptions, we are no longer subject to U.S. federal, state, and local tax examinations by tax authorities for years before 2016. As of December 31, 2020 and 2019, we had no material unrecognized tax benefits. While we currently have no material unrecognized tax benefits, as a policy, we recognize penalties and interest accrued related to unrecognized tax benefits as income tax expense.
Segment Information	Segment Information Our primary business is the ownership, management, and redevelopment of retail and mixed-use properties. We review operating and financial information for each property on an individual basis and therefore, each property represents an individual operating segment. We evaluate financial performance using property operating income, which consists of rental income, other property income and mortgage interest income, less rental expenses and real estate taxes. No individual commercial or residential property constitutes more than 10% of our revenues or property operating income and we have no operations outside of the United States of America. Therefore, we have aggregated our properties into one reportable segment as the properties share similar long-term economic characteristics and have other similarities including the fact that they are operated using consistent business strategies, are typically located in major metropolitan areas, and have similar tenant mixes.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Standard Description Effect on the financial statements or significant matters Adopted on January 1, 2020: Financial Instruments - Credit Losses (Topic 326) and related updates: 2016, Financial Instruments - Credit Losses (Topic 326) November 2018, Codification Topic 326, Financial Instruments - Credit Losses This ASU changes the impairment model for most financial assets and certain other instruments, requiring the use of an "expected credit loss" model and adding more disclosure requirements. Upon adoption of this standard, we recorded expected losses of $0.5 million in opening accumulated dividends in excess of net income. During the year ended December 31, 2020, we recorded additional expected losses of $0.4 million, which are included in rental expenses. ASU 2018-15, August 2018, Intangibles - Goodwill and Other Internal Use Software: Customers Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract This ASU requires a customer in a cloud computing arrangement (i.e. hosting arrangement) that is a service contract to follow the internal-use software guidance in ASC 350-40 to determine which implementation costs to capitalize as assets. Capitalized implementation costs related to a hosting arrangement that is a service contract will be amortized over the term of the hosting arrangement. Entities will expense costs during the preliminary project and post-implementation stages as they are incurred. The adoption of this standard did not have a significant impact to our consolidated financial statements. Issued in 2020: ASU 2020-04, March 2020, Reference Rate Reform (Topic 848) This ASU provides companies with optional practical expedients to ease the accounting burden for contract modifications associated with transitioning away from LIBOR and other interbank offered rates that are expected to be discontinued as part of reference rate reform. For hedges, the guidance generally allows changes to the reference rate and other critical terms without having to de-designate the hedging relationship, as well as allows the shortcut method to continue to be applied. For contract modifications, changes in the reference rate or other critical terms will be treated as a continuation of the prior contract. This guidance can be applied immediately, however, is generally only available through December 31, 2022. We are still evaluating the impact of reference rate reform and whether we will apply any of these practical expedients. ASU 2020-06, August 2020, Debt - Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging - Contracts in Entity's Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity's Own Equity This ASU simplifies the accounting for convertible instruments by removing the requirements to separately present certain conversion features in equity, simplifying the settlement assessment that entities are required to perform to determine whether a contract qualifies for equity classification, and generally requiring use of the if-converted method for all convertible instruments in the diluted EPS calculation and include the effect of potential share settlement (if the effect is more dilutive). The guidance is effective for annual periods beginning after December 15, 2021, and interim periods therein. The adoption of this standard is not expected to have a significant impact to our consolidated financial statements.

Summary Of Significant Accoun_3

Summary Of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Rollforward table of the redeemable noncontrolling interest	The following table provides a rollforward of the redeemable noncontrolling interests: Year Ended December 31, 2020 2019 (In thousands) Beginning balance $ 139,758 $ 136,208 Contributions 19,335 9,961 Net income 2,228 3,430 Distributions & redemptions (1,197) (15,366) Other comprehensive loss - change in value of interest rate swaps (471) — Change in redemption value (21,933) 5,525 Ending balance $ 137,720 $ 139,758
Schedule of supplemental disclosures related to the Consolidated Statements Of Cash Flows	The following table provides supplemental disclosures related to the Consolidated Statements of Cash Flows: Year Ended December 31, 2020 2019 2018 (In thousands) SUPPLEMENTAL DISCLOSURES: Total interest costs incurred $ 159,718 $ 130,110 $ 129,001 Interest capitalized (23,429) (20,487) (18,847) Interest expense $ 136,289 $ 109,623 $ 110,154 Cash paid for interest, net of amounts capitalized $ 130,248 $ 106,180 $ 107,494 Cash paid for income taxes $ 580 $ 483 $ 675 NON-CASH INVESTING AND FINANCING TRANSACTIONS (1): DownREIT operating partnership units issued with acquisition $ 18,920 $ — $ — Mortgage loans assumed with acquisition $ 8,903 $ 98,041 $ — DownREIT operating partnership units redeemed for common shares $ — $ 14,105 $ 101 Settlement of partner loan receivable via dilution of partner interests $ — $ 5,379 $ — Shares issued under dividend reinvestment plan $ 1,734 $ 1,784 $ 1,884 Contribution from noncontrolling interest $ — $ — $ 1,435
Reconcilition of cash, cash equivalents, and restricted cash	December 31, 2020 2019 (In thousands) RECONCILIATION OF CASH, CASH EQUIVALENTS, AND RESTRICTED CASH: Cash and cash equivalents $ 798,329 $ 127,432 Restricted cash (1) 18,567 26,182 Total cash, cash equivalents, and restricted cash $ 816,896 $ 153,614 (1) Restricted cash balances are included in "prepaid expenses and other assets" on our consolidated balance sheets.

Real Estate (Tables)

Real Estate (Tables)	12 Months Ended
	Dec. 31, 2020
Real Estate [Abstract]
Acquisitions and Dispositions	2020 Property Acquisitions Date Acquired Property City/State Gross Leasable Area (GLA) Purchase Price (in square feet) (in millions) January 10, 2020 Fairfax Junction Fairfax, Virginia 49,000 $ 22.3 (1) February 12, 2020 Hoboken (2 mixed-use buildings) Hoboken, New Jersey 12,000 $ 14.3 (2) (1) This property is adjacent to, and will be operated as part of the property acquired in 2019. The purchase price was paid with a combination of cash and the issuance of 163,322 downREIT operating partnership units. Approximately $0.5 million and $0.4 million of net assets acquired were allocated to other assets for "above market leases," and other liabilities for "below market leases," respectively. (2) The purchase price includes the assumption of $8.9 million of mortgage debt, and is in addition to the 37 buildings previously acquired in 2019, and was completed through the same joint venture. Less than $0.1 million and approximately $3.3 million of net assets acquired were allocated to other assets for "above market leases," and other liabilities for "below market leases," respectively. 2019 Property Acquisitions Date Acquired Property City/State Gross Leasable Area (GLA) Purchase Price (in square feet) (in millions) February 8, 2019 Fairfax Junction Fairfax, Virginia 75,000 $ 22.5 (1) September 13, 2019 San Antonio Center Mountain View, California 6,000 $ 6.5 November 15, 2019 Georgetowne Shopping Center Brooklyn, New York 147,000 $ 83.7 (2) Various 2019 Hoboken (37 mixed-use buildings) Hoboken, New Jersey 158,000 $ 189.2 (3) (1) Approximately $0.6 million and $0.4 million of net assets acquired were allocated to other assets for "above market leases," and other liabilities for "below market leases," respectively. (2) Approximately $2.0 million and $0.4 million of net assets acquired were allocated to other assets for "above market leases," and other liabilities for "below market leases," respectively. (3) These acquisitions were completed through a newly formed joint venture, for which we own a 90% interest. The purchase price includes new and assumptions of mortgage debt totaling approximately $98.0 million. This property includes 123 residential units in addition to the GLA in the table above. Approximately $3.6 million and $8.1 million of net assets acquired were allocated to other assets for "above market leases," and other liabilities for "below market leases," respectively.

Acquired In-Place Leases (Table

Acquired In-Place Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Finite-Lived Intangible Assets [Table Text Block]	The following is a summary of our acquired lease assets and liabilities: December 31, 2020 December 31, 2019 Cost Accumulated Amortization Cost Accumulated Amortization (in thousands) Above market leases, lessor $ 43,560 $ (31,661) $ 48,530 $ (32,833) Below market leases, lessee 34,604 (4,190) 34,604 (3,362) Total $ 78,164 $ (35,851) $ 83,134 $ (36,195) Below market leases, lessor $ (174,582) $ 68,286 $ (177,512) $ 66,419 Above market leases, lessee (9,084) 2,116 (9,084) 1,590 Total $ (183,666) $ 70,402 $ (186,596) $ 68,009
Finite-lived Intangible Assets Amortization Expense [Table Text Block]	The following is a summary of acquired lease amortization: Year Ended December 31, 2020 2019 2018 (in thousands) Amortization of above market leases, lessor $ (4,060) $ (3,239) $ (5,608) Amortization of below market leases, lessor 8,406 9,623 12,445 Net increase in rental income $ 4,346 $ 6,384 $ 6,837 Amortization of below market leases, lessee $ 828 $ 828 $ 828 Amortization of above market leases, lessee (525) (525) (505) Net increase in rental expense $ 303 $ 303 $ 323 The following is a summary of the remaining weighted average amortization period for our acquired lease assets and acquired lease liabilities: December 31, 2020 Above market leases, lessor 3.5 years Below market leases, lessee 38.6 years Below market leases, lessor 17.8 years Above market leases, lessee 13.4 years
Amortization for acquired in-place leases during the next five years and thereafter	The amortization for acquired in-place leases during the next five years and thereafter, assuming no early lease terminations, is as follows: Acquired Lease Assets Acquired Lease Liabilities (In thousands) Year ending December 31, 2021 $ 3,302 $ 7,738 2022 2,637 7,501 2023 2,439 7,253 2024 2,189 6,784 2025 1,911 6,300 Thereafter 29,835 77,688 $ 42,313 $ 113,264

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2020
Debt Instruments [Abstract]
Schedule of principal payments on mortgages payable, notes payable, senior notes and debentures	Scheduled principal payments on mortgages payable, notes payable, senior notes and debentures as of December 31, 2020 are as follows: Mortgages Notes Senior Notes and Total (In thousands) Year ending December 31, 2021 $ 28,101 $ 400,676 (1) $ — $ 428,777 2022 119,706 751 — 120,457 2023 3,549 765 275,000 279,314 2024 3,688 656 (2) 600,000 604,344 2025 48,033 333 — 48,366 Thereafter 282,958 89 2,544,200 2,827,247 $ 486,035 $ 403,270 $ 3,419,200 $ 4,308,505 (3) _____________________ (1) Our $400.0 million term loan matures on May 6, 2021 plus one twelve month extension, at our option. (2) Our $1.0 billion revolving credit facility matures on January 19, 2024, plus two six-month extensions at our option. As of December 31, 2020, there was no outstanding balance under this credit facility. (3) The total debt maturities differ from the total reported on the consolidated balance sheet due to the unamortized net premium/discount and debt issuance costs on mortgage loans, notes payable, and senior notes as of December 31, 2020.

Fair Value Of Financial Instr_2

Fair Value Of Financial Instruments Fair Value Of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Summary of carrying amount and fair value of financial instruments	A summary of the carrying amount and fair value of our mortgages payable, notes payable and senior notes and debentures is as follows: December 31, 2020 December 31, 2019 Carrying Fair Value Carrying Fair Value (In thousands) Mortgages and notes payable $ 886,887 $ 879,390 $ 549,460 $ 562,049 Senior notes and debentures $ 3,404,488 $ 3,761,465 $ 2,807,134 $ 3,001,216
Summary of financial assets/(liabilities) measured at fair value on a recurring basis	A summary of our financial (liabilities) assets that are measured at fair value on a recurring basis, by level within the fair value hierarchy is as follows: December 31, 2020 December 31, 2019 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total (In thousands) Interest rate swaps $ — $ (4,711) $ — $ (4,711) $ — $ 130 $ — $ 130

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Minimum annual payments	We are obligated under operating lease agreements on several shopping centers and one office lease requiring minimum annual payments as follows, as of December 31, 2020: (In thousands) Year ending December 31, 2021 $ 5,077 2022 5,197 2023 5,243 2024 5,213 2025 5,084 Thereafter 175,387 Total future minimum operating lease payments $ 201,201 Less amount representing interest (128,760) Operating lease liabilities $ 72,441
Finance Lease, Liability, Fiscal Year Maturity	Future minimum lease payments and their present value for properties under finance leases as of December 31, 2020, are as follows: (In thousands) Year ending December 31, 2021 $ 5,800 2022 5,810 2023 60,013 2024 1,013 2025 1,013 Thereafter 80,837 Total future minimum finance lease payments 154,486 Less amount representing interest (82,437) Finance lease liabilities $ 72,049

Equity (Tables)

Equity (Tables)	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Schedule of Stockholders Equity	We have a Dividend Reinvestment Plan (the “Plan”), whereby shareholders may use their dividends and optional cash payments to purchase shares. In 2020, 2019 and 2018, 24,491 shares, 15,909 shares and 17,952 shares, respectively, were issued under the Plan. As of December 31, 2020, 2019, and 2018, we had 6,000,000 Depositary Shares outstanding, each representing 1/1000th interest of 5.0% Series C Cumulative Redeemable Preferred Share, par value $0.01 per share ("Series C Preferred Shares"), at the liquidation preference of $25.00 per depositary share (or $25,000 per Series C Preferred share). The Series C Preferred Shares accrue dividends at a rate of 5.0% of the $25,000 liquidation preference per year and are redeemable at our option on or after September 29, 2022. Additionally, they are not convertible and holders of these shares generally have no voting rights, unless we fail to pay dividends for six or more quarters. As of December 31, 2020, 2019, and 2018, we had 399,896 shares of 5.417% Series 1 Cumulative Convertible Preferred Shares (“Series 1 Preferred Shares”) outstanding that have a liquidation preference of $25 per share and par value $0.01 per share. The Series 1 Preferred Shares accrue dividends at a rate of 5.417% per year and are convertible at any time by the holders to our common shares at a conversion rate of $104.69 per share. The Series 1 Preferred Shares are also convertible under certain circumstances at our election. The holders of the Series 1 Preferred Shares have no voting rights. On May 7, 2018, we replaced our existing at-the-market (“ATM”) equity program with a new ATM equity program in which we may from time to time offer and sell common shares having an aggregate offering price of up to $400.0 million. We intend to use the net proceeds to fund potential acquisition opportunities, fund our development and redevelopment pipeline, repay amounts of outstanding under our revolving credit facility and/or for general corporate purposes. For the year ended December 31, 2020, we issued 1,080,804 common shares at a weighted average price per share of $92.51 for net cash proceeds of $98.8 million including paying $1.0 million in commissions and $0.1 million in additional offering expenses related to the sales of these common shares. For the year ended December 31, 2019, we issued 1,069,699 common shares at a weighted average price per share of $134.71 for net cash proceeds of $142.7 million and paid $1.2 million in commissions and $0.2 million in additional offering expenses related to the sales of these common shares. As of December 31, 2020, we had the capacity to issue up to $28.4 million in common shares under our ATM equity program.

Dividends (Tables)

Dividends (Tables)	12 Months Ended
	Dec. 31, 2020
Dividends [Abstract]
Summary of dividends declared and paid per share	The following table provides a summary of dividends declared and paid per share: Year Ended December 31, 2020 2019 2018 Declared Paid Declared Paid Declared Paid Common shares $ 4.220 $ 4.210 $ 4.140 $ 4.110 $ 4.040 $ 4.020 5.417% Series 1 Cumulative Convertible Preferred shares $ 1.354 $ 1.354 $ 1.354 $ 1.354 $ 1.354 $ 1.354 5.0% Series C Cumulative Redeemable Preferred shares (1) $ 1.250 $ 1.250 $ 1.250 $ 1.250 $ 1.250 $ 1.306 (1) Amount represents dividends per depositary share, each representing 1/1000th of a share.
Summary of income tax status of dividends per share paid	A summary of the income tax status of dividends per share paid is as follows: Year Ended December 31, 2020 2019 2018 Common shares Ordinary dividend $ 3.452 $ 4.110 $ 3.859 Return of capital 0.758 — — Ordinary dividend eligible for 15% rate — — 0.161 $ 4.210 $ 4.110 $ 4.020 5.417% Series 1 Cumulative Convertible Preferred shares Ordinary dividend $ 1.354 $ 1.354 $ 1.300 Ordinary dividend eligible for 15% rate — — 0.054 $ 1.354 $ 1.354 $ 1.354 5.0% Series C Cumulative Redeemable Preferred shares Ordinary dividend $ 1.250 $ 1.250 1.254 Ordinary dividend eligible for 15% rate — — 0.052 $ 1.250 $ 1.250 $ 1.306

Operating Leases (Tables)

Operating Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Schedule of minimum future commercial property rentals from noncancelable operating leases	As of December 31, 2020, future minimum rentals from noncancelable commercial operating leases (excluding both tenant reimbursements of operating expenses and percentage rent based on tenants' sales) are as follows: (In thousands) Year ending December 31, 2021 $ 586,082 2022 549,529 2023 486,269 2024 421,945 2025 349,671 Thereafter 1,493,377 $ 3,886,873
LEASE COST	The following table provides additional information on our operating and finance leases where we are the lessee: Year Ended December 31, 2020 2019 (In thousands) LEASE COST: Finance lease cost: Amortization of right-of-use assets $ 1,284 $ 1,284 Interest on lease liabilities 5,826 5,824 Operating lease cost 5,946 6,063 Variable lease cost 353 487 Total lease cost $ 13,409 $ 13,658 OTHER INFORMATION: ROU assets obtained in exchange for operating lease liabilities 855 — ROU assets obtained in exchange for finance lease liabilities — — Cash paid for amounts included in the measurement of lease liabilities Operating cash flows for finance leases 5,736 5,759 Operating cash flows for operating leases 5,498 5,561 Financing cash flows for finance leases 46 47 Year Ended December 31, 2020 2019 Weighted-average remaining term - finance leases 17.3 years 18.2 years Weighted-average remaining term - operating leases 53.4 years 53.7 years Weighted-average discount rate - finance leases 8.0 % 8.0 % Weighted-average discount rate - operating leases 4.4 % 4.5 %

Components of Rental Expense (T

Components of Rental Expense (Tables)	12 Months Ended
	Dec. 31, 2020
Components Of Rental Expense [Abstract]
Schedule of principal components of rental expenses	The principal components of rental expenses are as follows: Year Ended December 31, 2020 2019 2018 (In thousands) Repairs and maintenance $ 66,845 $ 73,179 $ 67,745 Utilities 25,065 27,729 27,635 Management fees and costs 23,752 24,930 24,024 Payroll 16,691 16,485 16,140 Insurance 12,439 9,036 7,547 Marketing 6,432 7,427 7,935 Ground rent 4,595 4,803 4,697 Bad debt (1) — — 4,708 Other operating (2) 15,101 24,242 12,663 Total rental expenses $ 170,920 $ 187,831 $ 173,094 _____________________ (1) Collectibility adjustments are now presented as a reduction of rental income rather than rental expense in accordance with our adoption of the new lease standard in 2019. (2) Other operating for the year ended December 31, 2019 includes an $11.9 million charge relating to the buyout of a lease at Assembly Square Marketplace.

Share-Based Compensation Plans

Share-Based Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Summary of share-based compensation expense	A summary of share-based compensation expense included in net income is as follows: Year Ended December 31, 2020 2019 2018 (In thousands) Grants of common shares and options $ 13,243 $ 13,330 $ 12,736 Capitalized share-based compensation (1,319) (1,054) (1,017) Share-based compensation expense $ 11,924 $ 12,276 $ 11,719
Summary of weighted average assumptions used to value options granted	The following table provides a summary of the assumptions used to value options granted in 2018: Year Ended December 31, 2018 Volatility 18.0 % Expected dividend yield 3.6 % Expected term (in years) 7.5 Risk free interest rate 2.8 %
Summary of option activity	The following table provides a summary of option activity for 2020: Shares Weighted- Weighted- Aggregate (In years) (In thousands) Outstanding at December 31, 2019 682 $ 152.34 Granted — — Exercised — — Forfeited or expired — — Outstanding at December 31, 2020 682 $ 152.34 5.1 $ — Exercisable at December 31, 2020 546 $ 152.34 5.1 $ —
Summary of restricted share activity	The following table provides a summary of restricted share activity for 2020: Shares Weighted-Average Unvested at December 31, 2019 220,578 $ 129.78 Granted 116,351 124.55 Vested (101,651) 129.39 Forfeited (2,100) 131.78 Unvested at December 31, 2020 233,178 $ 127.32
Schedule of common shares awarded under various compensation plans	Subsequent to December 31, 2020, common shares were awarded under various compensation plans as follows: Date Award Vesting Term Beneficiary January 4, 2021 9,928 Shares Immediate Trustees February 10, 2021 137,210 Restricted Shares 3-5 years Officers and key employees February 10, 2021 3,658 Options 5 years Officers and key employees

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Schedule of earnings per share	In the dilutive EPS calculation, dilutive stock options were calculated using the treasury stock method consistent with prior periods. There were 682 anti-dilutive stock options in 2020, 2019, and 2018, respectively. The conversions of downREIT operating partnership units and 5.417% Series 1 Cumulative Convertible Preferred Shares are anti-dilutive for all periods presented and accordingly, have been excluded from the weighted average common shares used to compute diluted EPS. Year Ended December 31, 2020 2019 2018 (In thousands, except per share data) NUMERATOR Net income $ 135,888 $ 360,542 $ 249,026 Less: Preferred share dividends (8,042) (8,042) (8,042) Less: Income from operations attributable to noncontrolling interests (4,182) (6,676) (7,119) Less: Earnings allocated to unvested shares (992) (1,007) (930) Net income available for common shareholders, basic and diluted $ 122,672 $ 344,817 $ 232,935 DENOMINATOR Weighted average common shares outstanding—basic 75,515 74,766 73,274 Stock options — — 28 Weighted average common shares outstanding—diluted 75,515 74,766 73,302 EARNINGS PER COMMON SHARE, BASIC AND DILUTED Net income available for common shareholders $ 1.62 $ 4.61 $ 3.18

Business And Organization (Deta

Business And Organization (Details)	12 Months Ended
	Dec. 31, 2020project
Nature Of Operations [Abstract]
Number of real estate properties	101
Minimum percentage of taxable income distributed to shareholders	90.00%

Summary Of Significant Accoun_4

Summary Of Significant Accounting Policies (Revenue Recognition and Accounts Receivable) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Accounting Policies [Abstract]
Rent abatement agreements	$ 35,000
Rent deferral agreements	36,000
Collectibility Adjustment	106,600
Straight Line Rent Adjustments	$ 12,700
Percentage of tenants with revenue recognized on a cash basis	35.00%
Straight line rent receivable	$ 103,300	$ 100,300

Summary Of Significant Accoun_5

Summary Of Significant Accounting Policies (Real Estate) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Depreciation Expense Real Estate	$ 227.9	$ 215.4	$ 216
Building and Building Improvements | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	35 years
Building and Building Improvements | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	50 years
Minor Improvements, Furniture and Equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	2 years
Minor Improvements, Furniture and Equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	20 years

Summary Of Significant Accoun_6

Summary Of Significant Accounting Policies (Cash and Cash Equivalents) (Details) $ in Millions	Dec. 31, 2020USD ($)
Accounting Policies [Abstract]
Cash in excess of the FDIC insured limit	$ 803.6

Summary Of Significant Accoun_7

Summary Of Significant Accounting Policies (Prepaid Expenses and Other Assets) (Details)	12 Months Ended
	Dec. 31, 2020
Minimum
Prepaid expenses and other assets
Capitalized lease costs amortization range	3 years
Maximum
Prepaid expenses and other assets
Capitalized lease costs amortization range	10 years

Summary Of Significant Accoun_8

Summary Of Significant Accounting Policies (Derivative Instruments and Mortgage Notes Receivable) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Residual profit maximum	50.00%
Number of mortgage receivables	4
Mortgage receivable, net of valuation allowances	$ 39,900
Weighted average interest rate on mortgage note receivables	10.00%
Hoboken
Derivatives, Fair Value [Line Items]
Number of interest rate swap agreements	2
Assembly Row Hotel
Derivatives, Fair Value [Line Items]
Number of interest rate swap agreements	2
Equity Method Investee | Assembly Row Hotel
Derivatives, Fair Value [Line Items]
Fixed interest rate of derivative instrument	5.206%
First Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage receivable, net of valuation allowances	$ 30,300
Hoboken | Mortgages Payable
Derivatives, Fair Value [Line Items]
Number of interest rate swap agreements	2
Fixed interest rate of derivative instrument	3.67%

Summary Of Significant Accoun_9

Summary Of Significant Accounting Policies (Variable Interest Entities) (Details) $ in Thousands	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Variable Interest Entity [Line Items]
Number of consolidated variable interest entities	17
Net real estate assets of consolidated VIEs	$ 1,400,000	$ 1,500,000
Mortgage Payable From Consolidated Variable Interest Entities	413,681	469,184
Unconsolidated variable interest entities
Variable Interest Entity [Line Items]
Maximum exposure to loss in variable interest entity	$ 18,700	$ 23,400

Summary Of Significant Accou_10

Summary Of Significant Accounting Policies (Redeemable Noncontrolling Interests) (Details) - USD ($) $ in Thousands	Aug. 02, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Rollforward of Redeemable Noncontrolling Interests
Beginning balance		$ 139,758	$ 136,208
Contributions		19,335	9,961
Net income		2,228	3,430	$ 3,865
Distributions & redemptions		(1,197)	(15,366)
Other comprehensive loss - change in value of interest rate swaps		(471)	0	0
Change in redemption value		(21,933)	5,525
Ending balance		$ 137,720	$ 139,758	$ 136,208
Montrose Crossing
Redeemable Noncontrolling Interest [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	10.10%
Montrose Crossing
Redeemable Noncontrolling Interest [Line Items]
Purchase Price Under Option	$ 10,000
Ownership interest subsequent to redemption	100.00%

Summary Of Significant Accou_11

Summary Of Significant Accounting Policies Lease Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2020properties
Accounting Policies [Abstract]
Number of properties subject to operating leases | properties		12
Accounting Standards Update 2016-02
Lessor, Lease, Description [Line Items]
Cumulative Effect on Retained Earnings | $	$ 7,100

Summary Of Significant Accou_12

Summary Of Significant Accounting Policies (Income Taxes and Segments) (Details)	12 Months Ended
	Dec. 31, 2020USD ($)segmentproperty
Accounting Policies [Abstract]
Minimum percentage of taxable income distributed to shareholders	90.00%
Material unrecognized tax benefits | $	$ 0
Number of properties exceeding segment reporting threshold | property	0
Segment Reporting, Factors Used to Identify Entity's Reportable Segments	10% of our revenues or property operating income
Number of segments | segment	1

Summary Of Significant Accou_13

Summary Of Significant Accounting Policies (Recent Accounting Pronouncements) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Rental Expenses
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Additional credit losses recorded during the year	$ 400
Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect on Retained Earnings	$ 500

Summary Of Significant Accou_14

Summary Of Significant Accounting Policies (Supplemental Cash Flow Disclosures) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Supplemental Cash Flow Information [Abstract]
Total interest costs incurred	$ 159,718	$ 130,110	$ 129,001
Interest capitalized	23,429	20,487	18,847
Interest expense	136,289	109,623	110,154
Cash paid for interest, net of amounts capitalized	130,248	106,180	107,494
Cash paid for income taxes	580	483	675
NON-CASH INVESTING AND FINANCING TRANSACTIONS (1):
Mortgage loans assumed with acquisition	8,903	98,041	0
DownREIT operating partnership units issued with acquisition	18,920	0	0
DownREIT operating partnership units redeemed for common shares	0	14,105	101
Settlement of partner loan via dilution	0	5,379	0
Shares issued under dividend reinvestment plan	1,734	1,784	1,884
Contribution of noncontrolling interest	$ 0	$ 0	$ 1,435

Summary Of Significant Accou_15

Summary Of Significant Accounting Policies Consolidated Statement of Cash Flows - Reconciliation of Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Thousands		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents		$ 798,329	$ 127,432
Restricted cash	[1]	18,567	26,182
Total cash, cash equivalents, and restricted cash		$ 816,896	$ 153,614	$ 108,332	$ 25,200
[1]	Restricted cash balances are included in "prepaid expenses and other assets" on our consolidated balance sheets.

Real Estate (Significant Acquis

Real Estate (Significant Acquisitions and Dispositions) (Details)		Dec. 31, 2020USD ($)	Feb. 12, 2020USD ($)ft²		Jan. 10, 2020USD ($)ft²shares		Dec. 11, 2019USD ($)a	Nov. 15, 2019USD ($)ft²	Sep. 13, 2019USD ($)ft²	Feb. 08, 2019USD ($)ft²		Dec. 31, 2020USD ($)	Sep. 30, 2020USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)ft²condominiums		Dec. 31, 2018USD ($)	Sep. 01, 2020USD ($)
Business Acquisition and Disposition
Gain on sale of real estate, net of tax														$ 98,117,000	$ 116,393,000		$ 11,915,000
Assets held for sale		$ 0										$ 0		0	1,729,000
Mortgage loans assumed with acquisition														8,903,000	98,041,000		0
Units of Partnership Interest, Amount | shares					163,322
Impairment charge														57,218,000	$ 0		$ 0
Fair value of property		$ 57,000,000										$ 57,000,000		$ 57,000,000
Fairfax Junction
Business Acquisition and Disposition
Square footage of real estate property | ft²					49,000					75,000
Purchase price of real estate acquisition					$ 22,300,000	[1]				$ 22,500,000	[2]
Georgetowne Shopping Center
Business Acquisition and Disposition
Square footage of real estate property | ft²								147,000
Purchase price of real estate acquisition	[3]							$ 83,700,000
Hoboken
Business Acquisition and Disposition
Square footage of real estate property | ft²			12,000												158,000
Purchase price of real estate acquisition			$ 14,300,000	[4]											$ 189,200,000	[5]
Mortgage loans assumed with acquisition															$ 98,000,000
Number of Units in Real Estate Property															123
Ownership percentage in partnership		90.00%										90.00%		90.00%
San Antonio Center
Business Acquisition and Disposition
Square footage of real estate property							11.7		6,000
Estimated Litigation Liability		$ 32,600,000					$ 45,500,000					$ 32,600,000		$ 32,600,000
Proceeds from sale							$ 154,700,000
Gain on sale of real estate, net of tax												$ 85,100,000
Purchase price of real estate acquisition									$ 6,500,000
Three properties [Member]
Business Acquisition and Disposition
Proceeds from sale															$ 149,000,000
Gain on sale of real estate, net of tax															28,300,000
The Shops at Sunset Place
Business Acquisition and Disposition
Proceeds from sale		65,500,000
Gain on sale of real estate, net of tax		$ 9,200,000
Impairment charge													$ 57,200,000
Three properties 2020 [Member]
Business Acquisition and Disposition
Proceeds from sale														186,100,000
Gain on sale of real estate, net of tax														98,100,000
Other Assets | Above Market Leases | Fairfax Junction
Business Acquisition and Disposition
Net assets acquired allocated to intangible lease assets or liabilities					500,000					600,000
Other Assets | Above Market Leases | Georgetowne Shopping Center
Business Acquisition and Disposition
Net assets acquired allocated to intangible lease assets or liabilities								2,000,000
Other Assets | Above Market Leases | Hoboken
Business Acquisition and Disposition
Net assets acquired allocated to intangible lease assets or liabilities			100,000												3,600,000
Other Liabilities | Fairfax Junction
Business Acquisition and Disposition
Net assets acquired allocated to below market leases					$ 400,000					$ 400,000
Other Liabilities | Georgetowne Shopping Center
Business Acquisition and Disposition
Net assets acquired allocated to below market leases								$ 400,000
Other Liabilities | Hoboken
Business Acquisition and Disposition
Net assets acquired allocated to below market leases			3,300,000												8,100,000
Condominiums | Assembly Row and Pike & Rose
Business Acquisition and Disposition
Proceeds from sale														$ 2,100,000	$ 20,100,000
Number of condominium units sold														2	43
Assets held for sale															$ 1,700,000
Gain or loss on sale of properties, net of tax															$ 2,600,000
Mortgages [Member] | The Shops at Sunset Place | Nonrecourse [Member]
Business Acquisition and Disposition
Debt Instrument, Face Amount																		$ 60,600,000
Mortgages [Member] | Hoboken2Buildings [Member]
Business Acquisition and Disposition
Mortgage loans assumed with acquisition			$ 8,900,000
[1]	(2)
[2]	Approximately $0.6 million and $0.4 million of net assets acquired were allocated to other assets for "above market leases," and other liabilities for "below market leases," respectively.
[3]	Approximately $2.0 million and $0.4 million of net assets acquired were allocated to other assets for "above market leases," and other liabilities for "below market leases," respectively.
[4]	(2)
[5]	These acquisitions were completed through a newly formed joint venture, for which we own a 90% interest. The purchase price includes new and assumptions of mortgage debt totaling approximately $98.0 million. This property includes 123 residential units in addition to the GLA in the table above. Approximately $3.6 million and $8.1 million of net assets acquired were allocated to other assets for "above market leases," and other liabilities for "below market leases," respectively.

Acquired In-Place Leases Acqure

Acquired In-Place Leases Acqured Lease Assets and Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Total	$ 78,164	$ 83,134
Finite-Lived Intangible Assets, Accumulated Amortization	(35,851)	(36,195)
Finite-Lived Intangible Liabilities, Total	(183,666)	(186,596)
Finite-Lived Intangible Liabilities, Accumulated Amortization	70,402	68,009
Amortization of below market leases, lessor	8,406	9,623	$ 12,445
Net increase in rental income	4,346	6,384	6,837
Amortization of Below Market Lease, Lessee	828	828	828
Net increase in rental expense	303	303	323
Acquired Lease Liabilities
2021	7,738
2022	7,501
2023	7,253
2024	6,784
2025	6,300
Thereafter	77,688
Total future amortization expense from acquired below market leases	113,264
Above Market Leases
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of above market leases, lessor	(4,060)	(3,239)	(5,608)
Amortization of above market leases, lessee	$ (525)	(525)	$ (505)
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	3 years 6 months
Acquired Finite-Lived Intangible Liabilities, Weighted Average Useful Life	17 years 9 months 18 days
Acquired Lease Assets
2021	$ 3,302
2022	2,637
2023	2,439
2024	2,189
2025	1,911
Thereafter	29,835
Acquired Lease Liabilities
Finite-Lived Intangible Assets, Net	42,313
Above Market Leases, Lessor
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Total	43,560	48,530
Finite-Lived Intangible Assets, Accumulated Amortization	(31,661)	(32,833)
Below Market Leases, Lessee
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Total	34,604	34,604
Finite-Lived Intangible Assets, Accumulated Amortization	$ (4,190)	(3,362)
Below Market Lease
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	38 years 7 months 6 days
Acquired Finite-Lived Intangible Liabilities, Weighted Average Useful Life	13 years 4 months 24 days
Below Market Leases, Lessor
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Liabilities, Total	$ (174,582)	(177,512)
Finite-Lived Intangible Liabilities, Accumulated Amortization	68,286	66,419
Above Market Leases, Lessee
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Liabilities, Total	(9,084)	(9,084)
Finite-Lived Intangible Liabilities, Accumulated Amortization	$ 2,116	$ 1,590

Debt (Summary Of Debt Outstandi

Debt (Summary Of Debt Outstanding) (Details) - USD ($) $ in Thousands	Jul. 25, 2019	Dec. 31, 2020	Dec. 15, 2020	Oct. 13, 2020	May 11, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Mortgages payable		$ 484,111				$ 545,679
Revolving credit facility		0				0
Notes payable		402,776				3,781
Net unamortized discount and debt issuance costs		(494)				(62)
Senior notes and debentures, net		3,404,488				2,807,134
Total debt		4,291,375				3,356,594
Mortgages Payable
Debt Instrument [Line Items]
Principal balance		486,035				547,247
Net unamortized (discount) premium and debt issuance costs		(1,924)				(1,568)
Notes Payable
Debt Instrument [Line Items]
Notes payable		403,270				3,843
Senior Notes and Debentures
Debt Instrument [Line Items]
Principal balance		3,419,200				2,819,200
Net unamortized (discount) premium and debt issuance costs		(14,712)				(12,066)
The Shops at Sunset Place | Mortgages Payable
Debt Instrument [Line Items]
Principal balance		$ 0				61,987
Interest rate		5.62%
29th Place | Mortgages Payable
Debt Instrument [Line Items]
Principal balance		$ 0				3,878
Interest rate		5.91%
Sylmar Towne Center | Mortgages Payable
Debt Instrument [Line Items]
Principal balance		$ 16,236				16,630
Interest rate		5.39%
Plaza Del Sol | Mortgages Payable
Debt Instrument [Line Items]
Principal balance		$ 8,041				8,230
Interest rate		5.23%
THE AVENUE at White Marsh | Mortgages Payable
Debt Instrument [Line Items]
Principal balance		$ 52,705				52,705
Interest rate		3.35%
Montrose Crossing | Mortgages Payable
Debt Instrument [Line Items]
Principal balance		$ 65,596				67,492
Interest rate		4.20%
Azalea | Mortgages Payable
Debt Instrument [Line Items]
Principal balance		$ 40,000				40,000
Interest rate		3.73%
Bell Gardens | Mortgages Payable
Debt Instrument [Line Items]
Principal balance		$ 12,408				12,677
Interest rate		4.06%
Plaza El Segundo | Mortgages Payable
Debt Instrument [Line Items]
Principal balance		$ 125,000				125,000
Interest rate		3.83%
Brook 35 | Mortgages Payable
Debt Instrument [Line Items]
Principal balance		$ 11,500				11,500
Interest rate		4.65%
Hoboken (24 Buildings) | Mortgages Payable
Debt Instrument [Line Items]
Principal balance		$ 56,450				56,450
Debt Instrument, Basis Spread on Variable Rate		1.95%
Grove at Shrewsbury (East) | Mortgages Payable
Debt Instrument [Line Items]
Principal balance		$ 43,600				43,600
Interest rate		3.77%
Hoboken (14 Buildings) | Mortgages Payable
Debt Instrument [Line Items]
Principal balance		$ 32,705				24,627
Chelsea | Mortgages Payable
Debt Instrument [Line Items]
Principal balance		$ 5,234				5,597
Interest rate		5.36%
Hoboken (1 Building) | Mortgages Payable
Debt Instrument [Line Items]
Principal balance		$ 16,560				16,874
Interest rate		3.75%
Term Loan | Notes Payable
Debt Instrument [Line Items]
Other Notes Payable		$ 400,000				0
Debt Instrument, Basis Spread on Variable Rate		0.90%
Various | Notes Payable
Debt Instrument [Line Items]
Interest rate		11.31%
Other Notes Payable		$ 3,270				3,843
2.55% notes | Senior Notes and Debentures
Debt Instrument [Line Items]
Principal balance		$ 0				250,000
Interest rate		2.55%	2.55%
3.00% notes | Senior Notes and Debentures
Debt Instrument [Line Items]
Principal balance		$ 0				250,000
Interest rate		3.00%
2.75% notes | Senior Notes and Debentures
Debt Instrument [Line Items]
Principal balance		$ 275,000				275,000
Interest rate		2.75%
3.95% notes | Senior Notes and Debentures
Debt Instrument [Line Items]
Principal balance		$ 600,000				300,000
Interest rate		3.95%
7.48% debentures | Senior Notes and Debentures
Debt Instrument [Line Items]
Principal balance		$ 29,200				29,200
Interest rate		7.48%
3.25% Senior notes | Senior Notes and Debentures
Debt Instrument [Line Items]
Principal balance		$ 475,000				475,000
Interest rate		3.25%
6.82% medium term notes | Senior Notes and Debentures
Debt Instrument [Line Items]
Principal balance		$ 40,000				40,000
Interest rate		6.82%
3.2% Senior Note | Senior Notes and Debentures
Debt Instrument [Line Items]
Principal balance		$ 400,000				400,000
Interest rate		3.20%
4.50% notes | Senior Notes and Debentures
Debt Instrument [Line Items]
Principal balance		$ 550,000				550,000
Interest rate		4.50%
3.625% Senior notes | Senior Notes and Debentures
Debt Instrument [Line Items]
Principal balance		$ 250,000				250,000
Interest rate		3.625%
1.25% Senior Note [Member] | Senior Notes and Debentures
Debt Instrument [Line Items]
Principal balance		$ 400,000				0
Interest rate		1.25%		1.25%
3.5% Senior Note [Member] | Senior Notes and Debentures
Debt Instrument [Line Items]
Principal balance		$ 400,000				$ 0
Interest rate		3.50%			3.50%
Revolving credit facility
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.775%
Revolving credit facility | Notes Payable
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate		0.775%
Minimum | Hoboken (14 Buildings) | Mortgages Payable
Debt Instrument [Line Items]
Interest rate		3.91%
Maximum | Hoboken (14 Buildings) | Mortgages Payable
Debt Instrument [Line Items]
Interest rate		5.00%

Debt (Narrative) (Details)

Debt (Narrative) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 15, 2020	Oct. 13, 2020	May 11, 2020	May 06, 2020	Feb. 12, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Sep. 01, 2020	Dec. 09, 2013
Debt Instrument [Line Items]
Senior notes	$ 3,404,488						$ 3,404,488	$ 2,807,134
Issuance of senior notes, net of costs							1,094,283	399,913	$ 0
Revolving credit facility	0						0	0
Maximum borrowing capacity under revolving credit facility	1,000,000						1,000,000
Maximum amount of borrowings outstanding							990,000	116,500	177,000
Weighted average amount of borrowings outstanding							$ 138,500	$ 26,800	$ 83,100
Weighted average interest rate before amortization of debt fees							1.50%	3.20%	2.70%
Line of credit facility, annual facility fee	1,000						$ 1,000
Mortgage loans assumed with acquisition							8,903	$ 98,041	$ 0
Early extinguishment of debt							(11,179)	0	$ 0
The Shops at Sunset Place
Debt Instrument [Line Items]
Repayments of Debt	58,500
Escrow Deposit	4,500						4,500
29th Place
Debt Instrument [Line Items]
Repayments of Debt	3,600
Term Loan
Debt Instrument [Line Items]
Proceeds from Unsecured Notes Payable					$ 398,700
Other Notes Payable					400,000
Other Notes Payable					400,000
Proceeds from Unsecured Notes Payable					$ 398,700
Mortgages [Member] | Hoboken2Buildings [Member]
Debt Instrument [Line Items]
Stated Interest Rate						4.00%
Mortgage loans assumed with acquisition						$ 8,900
Fair value of long-term debt						9,000
Fair value of long-term debt						$ 9,000
Mortgages [Member] | The Shops at Sunset Place | Nonrecourse [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount										$ 60,600
Term Loan | Notes Payable
Debt Instrument [Line Items]
Other Notes Payable	400,000						400,000	0
Other Notes Payable	$ 400,000						$ 400,000	$ 0
3.5% Senior Note [Member] | Senior Notes and Debentures
Debt Instrument [Line Items]
Stated Interest Rate	3.50%			3.50%			3.50%
Note Offering Percent				98.911%
Debt yield to maturity percent				3.63%
3.95% Senior Note [Member] | Senior Notes and Debentures
Debt Instrument [Line Items]
Stated Interest Rate				3.95%
Note Offering Percent				103.257%
Debt yield to maturity percent				2.944%
Debt Instrument, Face Amount				$ 300,000							$ 300,000
3.95% and 3.50% Senior Notes [Member] | Senior Notes and Debentures
Debt Instrument [Line Items]
Issuance of senior notes, net of costs				700,100
Debt Instrument, Face Amount				700,000
3.50% Senior Note [Member] | Senior Notes and Debentures
Debt Instrument [Line Items]
Debt Instrument, Face Amount				$ 400,000
The Shops at Sunset Place | Mortgages Payable
Debt Instrument [Line Items]
Stated Interest Rate	5.62%						5.62%
1.25% Senior Note [Member] | Senior Notes and Debentures
Debt Instrument [Line Items]
Stated Interest Rate	1.25%		1.25%				1.25%
Note Offering Percent			99.339%
Debt yield to maturity percent			1.379%
Issuance of senior notes, net of costs			$ 394,200
Debt Instrument, Face Amount			$ 400,000
2.55% notes | Senior Notes and Debentures
Debt Instrument [Line Items]
Stated Interest Rate	2.55%	2.55%					2.55%
Debt Instrument, Face Amount		$ 250,000
Early Repayment of Senior Debt		252,700
Debt Instrument, Increase, Accrued Interest		$ 2,700
3.00% Senior Note [Member] | Senior Notes and Debentures
Debt Instrument [Line Items]
Stated Interest Rate	3.00%						3.00%
Debt Instrument, Face Amount	$ 250,000						$ 250,000
Early Repayment of Senior Debt	263,500
Debt Instrument, Increase, Accrued Interest	3,100
Payment for Debt Extinguishment or Debt Prepayment Cost	10,400
Early extinguishment of debt	$ 11,200

Debt (Principal Payments On Mor

Debt (Principal Payments On Mortgage Payable, Notes Payable, Senior Notes and Debentures) (Details) - USD ($) $ in Thousands		Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
2021		$ 428,777
2022		120,457
2023		279,314
2024		604,344
2025		48,366
Thereafter		2,827,247
Long-term Debt	[1]	4,308,505
Maximum borrowing capacity under revolving credit facility		1,000,000
Revolving credit facility		0	$ 0
Mortgages Payable
Debt Instrument [Line Items]
Principal balance		486,035	547,247
2021		28,101
2022		119,706
2023		3,549
2024		3,688
2025		48,033
Thereafter		282,958
Long-term Debt		486,035
Notes Payable
Debt Instrument [Line Items]
2021	[2]	400,676
2022		751
2023		765
2024	[3]	656
2025		333
Thereafter		89
Long-term Debt		403,270
Senior Notes and Debentures
Debt Instrument [Line Items]
Principal balance		3,419,200	$ 2,819,200
2021		0
2022		0
2023		275,000
2024		600,000
2025		0
Thereafter		2,544,200
Long-term Debt		$ 3,419,200
[1]	The total debt maturities differ from the total reported on the consolidated balance sheet due to the unamortized net premium/discount and debt issuance costs on mortgage loans, notes payable, and senior notes as of December 31, 2020
[2]	Our $400.0 million term loan matures on May 6, 2021 plus one twelve month extension, at our option.
[3]	Our $1.0 billion revolving credit facility matures on January 19, 2024, plus two six-month extensions at our option. As of December 31, 2020, there was no outstanding balance under this credit facility.

Fair Value Of Financial Instr_3

Fair Value Of Financial Instruments (Summary Of Carrying Amount And Fair Value Of Financial Instruments) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Mortgages payable and notes payable | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Fair value of long-term debt	$ 886,887	$ 549,460
Mortgages payable and notes payable | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Fair value of long-term debt	879,390	562,049
Senior notes and debentures | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Fair value of long-term debt	3,404,488	2,807,134
Senior notes and debentures | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Fair value of long-term debt	$ 3,761,465	$ 3,001,216

Fair Value Of Financial Instr_4

Fair Value Of Financial Instruments (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Interest expense reclassified from other comprehensive income (less than for 2019)	$ 700
Other comprehensive loss - change in value of interest rate swaps	(5,302)	$ (397)	$ (438)
Increase (Decrease) in Derivative Assets	4,800
Prepaid expenses and other assets
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Fair value of interest rate swaps	4,700
Fair Value, Measurements, Recurring | Interest Rate Swap
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Fair value of interest rate swaps	(4,711)	130
Accumulated Other Comprehensive Income (loss)
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Other comprehensive loss - change in value of interest rate swaps		(397)	$ (438)
Accumulated Other Comprehensive Income (loss) | Equity Method Investee
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Other comprehensive loss - change in value of interest rate swaps	500	900
Mortgage Payable
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Mortgage payable	$ 486,035	$ 547,247
Hoboken | Mortgage Payable
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Number of interest rate swap agreements	2
Notional amount of interest rate swap agreements	$ 56,500
Mortgage payable	$ 56,500
Fixed interest rate of derivative instrument	3.67%

Fair Value Of Financial Instr_5

Fair Value Of Financial Instruments (Summary of Financial Liabilities Measured At Fair Value On A Recurring Basis) (Details) - Interest Rate Swap - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Derivative financial asset	$ (4,711)	$ 130
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Derivative financial asset	0	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Derivative financial asset	(4,711)	130
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Derivative financial asset	$ 0	$ 0

Commitments and Contingencies_2

Commitments and Contingencies (Details) - USD ($) $ in Thousands	Dec. 17, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Sep. 30, 2025	Oct. 16, 2023	Sep. 30, 2023	Oct. 16, 2021	Dec. 11, 2019
Loss Contingencies [Line Items]
Reserves for warranties and general liability		$ 4,600	$ 3,000
Payments from reserves		800	1,300
Letters of credit outstanding, amount		$ 4,700
DownREIT operating partnership units, outstanding		744,617
Operating partnership units outstanding, fair value		$ 63,400
Costs associated with property sold under threat of condemnation, net		12,924	$ 0	$ 0
San Antonio Center
Loss Contingencies [Line Items]
Costs associated with property sold under threat of condemnation, net		12,900
Estimated Litigation Liability		$ 32,600							$ 45,500
Plaza El Segundo
Loss Contingencies [Line Items]
Payments to Acquire Limited Partnership Interests	$ 7,300
Controlling interest percentage	78.20%
Congressional Plaza | Put Option
Loss Contingencies [Line Items]
Indexed ownership interest percentage		26.63%
Maximum partnership percentage required to purchase		100.00%
Congressional Plaza | Put Option | Minimum
Loss Contingencies [Line Items]
Estimated maximum liability upon exercise of the put option		$ 69,000
Congressional Plaza | Put Option | Maximum
Loss Contingencies [Line Items]
Estimated maximum liability upon exercise of the put option		$ 72,000
Plaza El Segundo | Put Option
Loss Contingencies [Line Items]
Number of members with purchase options		2
Plaza El Segundo | Put Option | Minimum
Loss Contingencies [Line Items]
Estimated maximum liability upon exercise of the put option		$ 28,000
Plaza El Segundo | Put Option | Maximum
Loss Contingencies [Line Items]
Estimated maximum liability upon exercise of the put option		$ 35,000
The Grove at Shrewsbury | Put Option
Loss Contingencies [Line Items]
Indexed ownership interest percentage		4.10%
Brook 35 | Put Option
Loss Contingencies [Line Items]
Indexed ownership interest percentage		6.50%
Grove at Shrewsbury and Brook 35 | Put Option | Minimum
Loss Contingencies [Line Items]
Estimated maximum liability upon exercise of the put option		$ 6,000
Grove at Shrewsbury and Brook 35 | Put Option | Maximum
Loss Contingencies [Line Items]
Estimated maximum liability upon exercise of the put option		$ 7,000
Hoboken | Put Option
Loss Contingencies [Line Items]
Indexed ownership interest percentage		10.00%
Hoboken | Put Option | Minimum
Loss Contingencies [Line Items]
Estimated maximum liability upon exercise of the put option		$ 5,000
Hoboken | Put Option | Maximum
Loss Contingencies [Line Items]
Estimated maximum liability upon exercise of the put option		$ 6,000
Scenario, Forecast | Mercer Mall
Loss Contingencies [Line Items]
Purchase price under option							$ 55,000
Scenario, Forecast | Mercer Mall | Put Option
Loss Contingencies [Line Items]
Purchase price under option					$ 60,000
Scenario, Forecast | Melville Mall
Loss Contingencies [Line Items]
Purchase price under option								$ 5,000
Scenario, Forecast | Melville Mall | Put Option
Loss Contingencies [Line Items]
Purchase price under option						$ 5,000
Member One In Plaza El Segundo | Plaza El Segundo | Put Option
Loss Contingencies [Line Items]
Indexed ownership interest percentage		10.00%
Member Two In Plaza El Segundo | Plaza El Segundo | Put Option
Loss Contingencies [Line Items]
Indexed ownership interest percentage		11.80%
Capital Improvement, Development, and Redevelopment Projects
Loss Contingencies [Line Items]
Contractual obligations		$ 356,100

Commitments and Contingencies F

Commitments and Contingencies Future Minimum Lease Payments (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2021	$ 5,077
2022	5,197
2023	5,243
2024	5,213
2025	5,084
Thereafter	175,387
Total future minimum operating lease payments	201,201
Less amount representing interest	(128,760)
Operating lease liabilities	$ 72,441	$ 73,628

Commitments and Contingencies_3

Commitments and Contingencies Finance Lease Payments (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Finance Lease, Liability, Payment, Due [Abstract]
2021	$ 5,800
2022	5,810
2023	60,013
2024	1,013
2025	1,013
Thereafter	80,837
Total future minimum finance lease payments	154,486
Less amount representing interest	(82,437)
Finance lease liabilities	$ 72,049	$ 72,062

Shareholders' Equity (Details)

Shareholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands	Sep. 29, 2017	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	May 07, 2018
Class of Stock [Line Items]
Shares issued under dividend reinvestment plan (in shares)		24,491	15,909	17,952
Preferred shares, percentage		5.00%	5.00%	5.00%
Preferred shares, par value		$ 0.01	$ 0.01
Net cash proceeds of common stock		$ 99,177	$ 143,027	$ 130,918
At The Market Equity Program
Class of Stock [Line Items]
Shares issued		1,080,804	1,069,699
Aggregate offering price of common shares					$ 400,000
Net cash proceeds of common stock		$ 98,800	$ 142,700
Weighted average price per common share		$ 92.51	$ 134.71
Remaining capacity to issue		$ 28,400
At The Market Equity Program | Commissions
Class of Stock [Line Items]
Commissions related to sales of common shares		1,000	$ 1,200
At The Market Equity Program | Other Offering Costs
Class of Stock [Line Items]
Commissions related to sales of common shares		$ 100	$ 200
5.0% Series C Cumulative Redeemable Preferred Shares
Class of Stock [Line Items]
Preferred shares, percentage	5.00%	5.00%	5.00%	5.00%
Preferred shares, par value	$ 0.01	$ 0.01	$ 0.01	$ 0.01
Preferred shares, liquidation preference per share	25,000	$ 25,000	$ 25,000	$ 25,000
Preferred shares, shares outstanding		6,000	6,000
5.417% Series 1 Cumulative Convertible Preferred Shares
Class of Stock [Line Items]
Preferred shares, percentage		5.417%	5.417%	5.417%
Preferred shares, par value		$ 0.01	$ 0.01	$ 0.01
Preferred shares, liquidation preference per share		$ 25	$ 25	$ 25
Preferred shares, shares outstanding		399,896	399,896	399,896
Conversion price per share		$ 104.69
Depositary Shares | 5.0% Series C Cumulative Redeemable Preferred Shares
Class of Stock [Line Items]
Preferred shares, liquidation preference per share	$ 25	$ 25	$ 25	$ 25
Preferred Shares | Depositary Shares | 5.0% Series C Cumulative Redeemable Preferred Shares
Class of Stock [Line Items]
Shares issued	6,000,000
Preferred shares, shares outstanding		6,000,000	6,000,000	6,000,000

Dividends (Details)

Dividends (Details) - $ / shares	Nov. 05, 2020	Sep. 29, 2017	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Class of Stock [Line Items]
Preferred shares, percentage			5.00%	5.00%	5.00%
Dividends declared to common shareholders	$ 1.06		$ 4.220	$ 4.140	$ 4.040
Common shares, paid			4.210	4.110	4.020
Payments of ordinary dividends, common stock			3.452	4.110	3.859
Return of capital, common shares			0.758	0	0
Common shares, ordinary dividend eligible for 15% rate			$ 0	$ 0	$ 0.161
Common shares, qualified dividends, tax rate			15.00%	15.00%	15.00%
Preferred stock, qualified dividends, tax rate			15.00%	15.00%	15.00%
5.417% Series 1 Cumulative Convertible Preferred Shares
Class of Stock [Line Items]
Preferred shares, percentage			5.417%	5.417%	5.417%
Preferred shares, declared			$ 1.354	$ 1.354	$ 1.354
Preferred shares, paid			1.354	1.354	1.354
Payment of ordinary dividends, preferred stock			1.354	1.354	1.300
Preferred shares, ordinary dividend eligible for 15% rate			$ 0	$ 0	$ 0.054
5.0% Series C Cumulative Redeemable Preferred Shares
Class of Stock [Line Items]
Preferred shares, percentage		5.00%	5.00%	5.00%	5.00%
Preferred shares, declared			$ 1.250	$ 1.250	$ 1.250
Preferred shares, paid			1.250	1.250	1.306
Payment of ordinary dividends, preferred stock			1.250	1.250	1.254
Preferred shares, ordinary dividend eligible for 15% rate			$ 0	$ 0	$ 0.052

Operating Leases (Details)

Operating Leases (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)projectstatelease
Property Subject to or Available for Operating Lease [Line Items]
Number of real estate properties | project	101
Number of states in which entity has properties | state	11
Percent of annualized base rent	3.60%
Operating Leases, Future Minimum Payments Receivable [Abstract]
2021	$ 586,082
2022	549,529
2023	486,269
2024	421,945
2025	349,671
Thereafter	1,493,377
Total	$ 3,886,873
Retail and commercial
Property Subject to or Available for Operating Lease [Line Items]
Number of leases | lease	2,800
Retail and commercial | Minimum
Property Subject to or Available for Operating Lease [Line Items]
Operating lease, term	3 years
Retail and commercial | Maximum
Property Subject to or Available for Operating Lease [Line Items]
Operating lease, term	10 years
Residential
Property Subject to or Available for Operating Lease [Line Items]
Number of leases	2,700
Residential | Maximum
Property Subject to or Available for Operating Lease [Line Items]
Operating lease, term	1 year

Lease Costs (Detail)

Lease Costs (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Finance Lease, amortization of right-of-use assets	$ 1,284	$ 1,284
Finance Lease, interest on lease liabilities	5,826	5,824
Operating lease cost	5,946	6,063
Variable lease cost	353	487
Total Lease Cost	13,409	13,658
ROU assets obtained in exchange for operating lease liabilities	855	0
ROU assets obtained in exchange for operating lease liabilities	0	0
Operating cash flows for finance leases	5,736	5,759
Operating cash flows for operating leases	5,498	5,561
Financing cash flows for finance leases	$ 46	$ 47
Weighted-average remaining lease term - finance leases	17 years 3 months 18 days	18 years 2 months 12 days
Weighted-average remaining lease term - operating leases	53 years 4 months 24 days	53 years 8 months 12 days
Weighted-average discount rate - finance leases	8.00%	8.00%
Weighted-average discount rate - operating leases	4.40%	4.50%

Components of Rental Expense (C

Components of Rental Expense (Components Of Rental Expenses) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Repairs and maintenance		$ 66,845	$ 73,179	$ 67,745
Utilities		25,065	27,729	27,635
Management fees and costs		23,752	24,930	24,024
Payroll		16,691	16,485	16,140
Insurance		12,439	9,036	7,547
Marketing		6,432	7,427	7,935
Ground rent		4,595	4,803	4,697
Bad debt	[1]	0	0	4,708
Other operating		15,101	24,242	12,663
Total rental expenses		$ 170,920	187,831	$ 173,094
Assembly Square Marketplace
Charge related to the buyout of a lease			$ 11,900
[1]	Collectibility adjustments are now presented as a reduction of rental income rather than rental expense in accordance with our adoption of the new lease standard in 2019.(2)Other operating for the year ended December 31, 2019 includes an $11.9 million charge relating to the buyout of a lease at Assembly Square Marketplace

Share-Based Compensation Plan_2

Share-Based Compensation Plans (Allocated Share-Based Compensation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Abstract]
Grants of common shares and options	$ 13,243	$ 13,330	$ 12,736
Capitalized share-based compensation	(1,319)	(1,054)	(1,017)
Share-based compensation expense	$ 11,924	$ 12,276	$ 11,719

Share-Based Compensation Plan_3

Share-Based Compensation Plans (Weighted Average Assumptions Used to Value Option Granted) (Details)	12 Months Ended
	Dec. 31, 2018
Share-based Payment Arrangement [Abstract]
Volatility	18.00%
Expected dividend yield	3.60%
Expected term (in years)	7 years 6 months
Risk free interest rate	2.80%

Share-Based Compensation Plan_4

Share-Based Compensation Plans (Schedule of Option Activity) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at the beginning of year (in shares)	682
Granted (in shares)	0	0
Exercised (in shares)	0
Forfeited or expired (in shares)	0
Outstanding at the end of year (in shares)	682	682
Exercisable at the end of year (in shares)	546
Outstanding at the beginning of year, Weighted-Average Exercise Price (in dollars per share)	$ 152.34
Granted, Weighted-Average Exercise Price (in dollars per share)	0
Exercised, Weighted-Average Exercise Price (in dollars per share)	0
Forfeited or Expired, Weighted-Average Exercise Price (in dollars per share)	0
Outstanding at the end of year, Weighted-Average Exercise Price (in dollars per share)	152.34	$ 152.34
Exercisable at the end of the year, Weighted-Average Exercise Price (in dollars per share)	$ 152.34
Outstanding at the end of year, Weighted-Average Remaining Contractual Term (in years)	5 years 1 month 6 days
Exercisable at the end of year, Weighted-Average Remaining Contractual Term (in years)	5 years 1 month 6 days
Outstanding at the end of year, Aggregate Intrinsic Value	$ 0
Exercisable at the end of year, Aggregate Intrinsic Value	$ 0

Share-Based Compensation Plan_5

Share-Based Compensation Plans (Restricted Share Activity) (Details) - Restricted Stock - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Unvested at the beginning of year (in shares)	220,578
Granted (in shares)	116,351
Vested (in shares)	(101,651)
Forfeited (in shares)	(2,100)
Unvested at the end of year (in shares)	233,178	220,578
Unvested at the beginning of year, Weighted-Average Grant-Date Fair Value (in dollars per share)	$ 129.78
Granted, Weighted-Average Grant-Date Fair Value (in dollars per share)	124.55	$ 133.30	$ 112.88
Vested, Weighted-Average Grant-Date Fair Value (in dollars per share)	129.39
Forfeited, Weighted-Average Grant-Date Fair Value (in dollars per share)	131.78
Unvested at the end of year, Weighted-Average Grant-Date Fair Value (in dollars per share)	$ 127.32	$ 129.78

Share-Based Compensation Plan_6

Share-Based Compensation Plans (Common Shares Awarded Under Various Compensation Plans) (Details) - shares	Feb. 10, 2021	Jan. 04, 2021	Dec. 31, 2020
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)			116,351
Grants of common shares and options | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term			3 years
Grants of common shares and options | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term			7 years
Subsequent Event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	3,658
Subsequent Event | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	137,210	9,928
Subsequent Event | Restricted Stock | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term	3 years
Subsequent Event | Restricted Stock | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term	5 years
Subsequent Event | Restricted Stock Units (RSUs) | Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	10,441
Vesting Term	4 years
Subsequent Event | Restricted Stock Units (RSUs) | Minimum | Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Final award earned percentage of original award	0.00%
Subsequent Event | Restricted Stock Units (RSUs) | Maximum | Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Final award earned percentage of original award	200.00%
Subsequent Event | Grants of common shares and options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term	5 years

Share-Based Compensation Plan_7

Share-Based Compensation Plans (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options granted in period	0	0
Weighted average grant date fair value of options granted			$ 14.42
Total cash received from options exercised			$ 4.6
Total intrinsic value of options exercised			$ 8.2
Total unrecognized compensation cost related to unvested share-based compensation arrangements	$ 17
Period for recognition (in years)	5 years 3 months 18 days
Weighted-average period for recognition	2 years 1 month 6 days
Performance Incentive Plan 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized	2,450,000
Performance Incentive Plan 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized	1,750,000
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant-date fair value of stock awarded	$ 124.55	$ 133.30	$ 112.88
Total vesting-date fair value of shares vested during the year	$ 12.4	$ 13	$ 9.7
Granted (in shares)	116,351
Grants of common shares and options | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term	3 years
Grants of common shares and options | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term	7 years
Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual term (in years)	10 years

Savings and Retirement Plans (D

Savings and Retirement Plans (Details) - 401(K) and Deferred Compensation Plan - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
401(k) Maximum annual contribution per employee	$ 19,500	$ 19,000	$ 18,500
401(k) Employer match	50.00%	50.00%	50.00%
401(k) Employer contribution expense	$ 813,000	$ 764,000	$ 688,000
Deferred compensation liability to participants	$ 18,000,000	$ 14,700,000
Maximum
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
401(k) Maximum of employer match as a percentage of employee eligible earnings	5.00%	5.00%	5.00%

Earnings Per Share (Narrative)

Earnings Per Share (Narrative) (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings Per Share Narrative [Line Items]
Weighted average unvested shares outstanding	200,000	200,000	200,000
Anti-dilutive stock options excluded from dilutive earnings per share calculation	682	682	682
Cumulative convertible preferred share, dividend rate	5.00%	5.00%	5.00%
5.417% Series 1 Cumulative Convertible Preferred Shares
Earnings Per Share Narrative [Line Items]
Cumulative convertible preferred share, dividend rate	5.417%	5.417%	5.417%

Earnings Per Share (Schedule Of

Earnings Per Share (Schedule Of Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings Per Share [Abstract]
Net income	$ 135,888	$ 360,542	$ 249,026
Less: Preferred share dividends	(8,042)	(8,042)	(8,042)
Net income attributable to noncontrolling interests	(4,182)	(6,676)	(7,119)
Less: Earnings allocated to unvested shares	(992)	(1,007)	(930)
Net income available for common shareholders, basic and diluted	$ 122,672	$ 344,817	$ 232,935
Weighted average common shares outstanding—basic	75,515	74,766	73,274
Stock options	0	0	28
Weighted average common shares outstanding—diluted	75,515	74,766	73,302
Earnings per common share, basic and diluted	$ 1.62	$ 4.61	$ 3.18

Subsequent Event (Details)

Subsequent Event (Details) - Subsequent Event - USD ($) $ in Thousands	Feb. 05, 2021	Jan. 04, 2021
Sylmar Towne Center
Subsequent Event [Line Items]
Repayments of Secured Debt	$ 16,200
Pike&Rose Hotel JV
Subsequent Event [Line Items]
Ownership interest of partner in our joint venture		20.00%
Purchase price of partner's interest		$ 2,300
Repayments of Secured Debt		$ 31,500

Schedule III - Summary of Rea_2

Schedule III - Summary of Real Estate and Accumulated Depreciation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	$ 484,111
Initial cost to company, Land	1,387,748
Initial cost to company, Buildings and Improvements	2,493,283
Cost Capitalized Subsequent to Acquisition	4,701,839
Gross amount at which carried at close of period, Land	1,374,797
Gross amount at which carried at close of period, Buildings and Improvements	7,208,073
Gross amount at which carried at close of period, Total	8,582,870	$ 8,298,132	$ 7,819,472	$ 7,635,061
Accumulated Depreciation and Amortization	$ 2,357,692	$ 2,215,413	$ 2,059,143	$ 1,876,544
Maximum
Real Estate and Accumulated Depreciation [Line Items]
Life on  which depreciation in latest income statements is computed	50 years
29th Place
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances
Initial cost to company, Land	10,211
Initial cost to company, Buildings and Improvements	18,863
Cost Capitalized Subsequent to Acquisition	9,588
Gross amount at which carried at close of period, Land	10,195
Gross amount at which carried at close of period, Buildings and Improvements	28,467
Gross amount at which carried at close of period, Total	38,662
Accumulated Depreciation and Amortization	14,173
Andorra
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	2,432
Initial cost to company, Buildings and Improvements	12,346
Cost Capitalized Subsequent to Acquisition	16,148
Gross amount at which carried at close of period, Land	2,432
Gross amount at which carried at close of period, Buildings and Improvements	28,494
Gross amount at which carried at close of period, Total	30,926
Accumulated Depreciation and Amortization	21,200
Assembly Row/Assembly Square Market Place
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	93,252
Initial cost to company, Buildings and Improvements	34,196
Cost Capitalized Subsequent to Acquisition	832,881
Gross amount at which carried at close of period, Land	69,421
Gross amount at which carried at close of period, Buildings and Improvements	890,908
Gross amount at which carried at close of period, Total	960,329
Accumulated Depreciation and Amortization	88,384
Azalea
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	39,750
Initial cost to company, Land	40,219
Initial cost to company, Buildings and Improvements	67,117
Cost Capitalized Subsequent to Acquisition	(7)
Gross amount at which carried at close of period, Land	40,219
Gross amount at which carried at close of period, Buildings and Improvements	67,110
Gross amount at which carried at close of period, Total	107,329
Accumulated Depreciation and Amortization	8,550
Bala Cynwyd
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	3,565
Initial cost to company, Buildings and Improvements	14,466
Cost Capitalized Subsequent to Acquisition	46,447
Gross amount at which carried at close of period, Land	2,683
Gross amount at which carried at close of period, Buildings and Improvements	61,795
Gross amount at which carried at close of period, Total	64,478
Accumulated Depreciation and Amortization	24,619
Barcroft Plaza
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	12,617
Initial cost to company, Buildings and Improvements	29,603
Cost Capitalized Subsequent to Acquisition	7,235
Gross amount at which carried at close of period, Land	12,617
Gross amount at which carried at close of period, Buildings and Improvements	36,838
Gross amount at which carried at close of period, Total	49,455
Accumulated Depreciation and Amortization	5,904
Barracks Road
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	4,363
Initial cost to company, Buildings and Improvements	16,459
Cost Capitalized Subsequent to Acquisition	48,774
Gross amount at which carried at close of period, Land	4,363
Gross amount at which carried at close of period, Buildings and Improvements	65,233
Gross amount at which carried at close of period, Total	69,596
Accumulated Depreciation and Amortization	48,945
Bell Gardens
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	12,082
Initial cost to company, Land	24,406
Initial cost to company, Buildings and Improvements	85,947
Cost Capitalized Subsequent to Acquisition	671
Gross amount at which carried at close of period, Land	24,406
Gross amount at which carried at close of period, Buildings and Improvements	86,618
Gross amount at which carried at close of period, Total	111,024
Accumulated Depreciation and Amortization	14,425
Bethesda Row
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	46,579
Initial cost to company, Buildings and Improvements	35,406
Cost Capitalized Subsequent to Acquisition	162,367
Gross amount at which carried at close of period, Land	43,904
Gross amount at which carried at close of period, Buildings and Improvements	200,448
Gross amount at which carried at close of period, Total	244,352
Accumulated Depreciation and Amortization	92,357
Brick Plaza
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	0
Initial cost to company, Buildings and Improvements	24,715
Cost Capitalized Subsequent to Acquisition	78,133
Gross amount at which carried at close of period, Land	4,094
Gross amount at which carried at close of period, Buildings and Improvements	98,754
Gross amount at which carried at close of period, Total	102,848
Accumulated Depreciation and Amortization	56,240
Bristol Plaza
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	3,856
Initial cost to company, Buildings and Improvements	15,959
Cost Capitalized Subsequent to Acquisition	12,230
Gross amount at which carried at close of period, Land	3,856
Gross amount at which carried at close of period, Buildings and Improvements	28,189
Gross amount at which carried at close of period, Total	32,045
Accumulated Depreciation and Amortization	19,549
Brook 35
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	11,325
Initial cost to company, Land	7,128
Initial cost to company, Buildings and Improvements	38,355
Cost Capitalized Subsequent to Acquisition	3,103
Gross amount at which carried at close of period, Land	7,128
Gross amount at which carried at close of period, Buildings and Improvements	41,458
Gross amount at which carried at close of period, Total	48,586
Accumulated Depreciation and Amortization	9,853
Campus Plaza
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	16,710
Initial cost to company, Buildings and Improvements	13,412
Cost Capitalized Subsequent to Acquisition	326
Gross amount at which carried at close of period, Land	16,710
Gross amount at which carried at close of period, Buildings and Improvements	13,738
Gross amount at which carried at close of period, Total	30,448
Accumulated Depreciation and Amortization	2,952
Chelsea Commons
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	5,057
Initial cost to company, Land	8,689
Initial cost to company, Buildings and Improvements	19,466
Cost Capitalized Subsequent to Acquisition	2,410
Gross amount at which carried at close of period, Land	8,669
Gross amount at which carried at close of period, Buildings and Improvements	21,896
Gross amount at which carried at close of period, Total	30,565
Accumulated Depreciation and Amortization	9,040
CocoWalk
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	34,406
Initial cost to company, Buildings and Improvements	72,123
Cost Capitalized Subsequent to Acquisition	73,504
Gross amount at which carried at close of period, Land	50,838
Gross amount at which carried at close of period, Buildings and Improvements	129,195
Gross amount at which carried at close of period, Total	180,033
Accumulated Depreciation and Amortization	12,333
Colorado Blvd
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	2,415
Initial cost to company, Buildings and Improvements	3,964
Cost Capitalized Subsequent to Acquisition	6,905
Gross amount at which carried at close of period, Land	2,415
Gross amount at which carried at close of period, Buildings and Improvements	10,869
Gross amount at which carried at close of period, Total	13,284
Accumulated Depreciation and Amortization	9,397
Congressional Plaza
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	2,793
Initial cost to company, Buildings and Improvements	7,424
Cost Capitalized Subsequent to Acquisition	95,605
Gross amount at which carried at close of period, Land	2,793
Gross amount at which carried at close of period, Buildings and Improvements	103,029
Gross amount at which carried at close of period, Total	105,822
Accumulated Depreciation and Amortization	59,967
Courthouse Center
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	1,750
Initial cost to company, Buildings and Improvements	1,869
Cost Capitalized Subsequent to Acquisition	3,445
Gross amount at which carried at close of period, Land	1,750
Gross amount at which carried at close of period, Buildings and Improvements	5,314
Gross amount at which carried at close of period, Total	7,064
Accumulated Depreciation and Amortization	2,768
Crossroads
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	4,635
Initial cost to company, Buildings and Improvements	11,611
Cost Capitalized Subsequent to Acquisition	19,649
Gross amount at which carried at close of period, Land	4,635
Gross amount at which carried at close of period, Buildings and Improvements	31,260
Gross amount at which carried at close of period, Total	35,895
Accumulated Depreciation and Amortization	20,191
Crow Canyon Commons
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	27,245
Initial cost to company, Buildings and Improvements	54,575
Cost Capitalized Subsequent to Acquisition	8,911
Gross amount at which carried at close of period, Land	27,245
Gross amount at which carried at close of period, Buildings and Improvements	63,486
Gross amount at which carried at close of period, Total	90,731
Accumulated Depreciation and Amortization	28,124
Dedham Plaza
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	16,658
Initial cost to company, Buildings and Improvements	13,964
Cost Capitalized Subsequent to Acquisition	16,521
Gross amount at which carried at close of period, Land	16,658
Gross amount at which carried at close of period, Buildings and Improvements	30,485
Gross amount at which carried at close of period, Total	47,143
Accumulated Depreciation and Amortization	18,282
Del Mar Village
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	15,624
Initial cost to company, Buildings and Improvements	41,712
Cost Capitalized Subsequent to Acquisition	16,427
Gross amount at which carried at close of period, Land	15,587
Gross amount at which carried at close of period, Buildings and Improvements	58,176
Gross amount at which carried at close of period, Total	73,763
Accumulated Depreciation and Amortization	26,043
East Bay Bridge
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	29,069
Initial cost to company, Buildings and Improvements	138,035
Cost Capitalized Subsequent to Acquisition	12,123
Gross amount at which carried at close of period, Land	29,069
Gross amount at which carried at close of period, Buildings and Improvements	150,158
Gross amount at which carried at close of period, Total	179,227
Accumulated Depreciation and Amortization	41,377
Elllisburg
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	4,028
Initial cost to company, Buildings and Improvements	11,309
Cost Capitalized Subsequent to Acquisition	18,872
Gross amount at which carried at close of period, Land	4,013
Gross amount at which carried at close of period, Buildings and Improvements	30,196
Gross amount at which carried at close of period, Total	34,209
Accumulated Depreciation and Amortization	21,740
Escondido Promenade
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	19,117
Initial cost to company, Buildings and Improvements	15,829
Cost Capitalized Subsequent to Acquisition	18,627
Gross amount at which carried at close of period, Land	19,117
Gross amount at which carried at close of period, Buildings and Improvements	34,456
Gross amount at which carried at close of period, Total	53,573
Accumulated Depreciation and Amortization	20,066
Fairfax Junction
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	16,768
Initial cost to company, Buildings and Improvements	23,825
Cost Capitalized Subsequent to Acquisition	575
Gross amount at which carried at close of period, Land	16,768
Gross amount at which carried at close of period, Buildings and Improvements	24,400
Gross amount at which carried at close of period, Total	41,168
Accumulated Depreciation and Amortization	1,647
Falls Plaza
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	1,798
Initial cost to company, Buildings and Improvements	1,270
Cost Capitalized Subsequent to Acquisition	13,044
Gross amount at which carried at close of period, Land	1,819
Gross amount at which carried at close of period, Buildings and Improvements	14,293
Gross amount at which carried at close of period, Total	16,112
Accumulated Depreciation and Amortization	9,477
Federal Plaza
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	10,216
Initial cost to company, Buildings and Improvements	17,895
Cost Capitalized Subsequent to Acquisition	42,735
Gross amount at which carried at close of period, Land	10,216
Gross amount at which carried at close of period, Buildings and Improvements	60,630
Gross amount at which carried at close of period, Total	70,846
Accumulated Depreciation and Amortization	48,440
Finley Square
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	9,252
Initial cost to company, Buildings and Improvements	9,544
Cost Capitalized Subsequent to Acquisition	22,603
Gross amount at which carried at close of period, Land	9,252
Gross amount at which carried at close of period, Buildings and Improvements	32,147
Gross amount at which carried at close of period, Total	41,399
Accumulated Depreciation and Amortization	23,198
Flourtown
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	1,345
Initial cost to company, Buildings and Improvements	3,943
Cost Capitalized Subsequent to Acquisition	11,645
Gross amount at which carried at close of period, Land	1,507
Gross amount at which carried at close of period, Buildings and Improvements	15,426
Gross amount at which carried at close of period, Total	16,933
Accumulated Depreciation and Amortization	7,369
Fourth Street
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	13,978
Initial cost to company, Buildings and Improvements	9,909
Cost Capitalized Subsequent to Acquisition	3,085
Gross amount at which carried at close of period, Land	13,978
Gross amount at which carried at close of period, Buildings and Improvements	12,994
Gross amount at which carried at close of period, Total	26,972
Accumulated Depreciation and Amortization	1,752
Freedom Plaza
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	0
Initial cost to company, Buildings and Improvements	3,255
Cost Capitalized Subsequent to Acquisition	37,242
Gross amount at which carried at close of period, Land	0
Gross amount at which carried at close of period, Buildings and Improvements	40,497
Gross amount at which carried at close of period, Total	40,497
Accumulated Depreciation and Amortization	761
Fresh Meadows
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	24,625
Initial cost to company, Buildings and Improvements	25,255
Cost Capitalized Subsequent to Acquisition	43,873
Gross amount at which carried at close of period, Land	24,633
Gross amount at which carried at close of period, Buildings and Improvements	69,120
Gross amount at which carried at close of period, Total	93,753
Accumulated Depreciation and Amortization	46,378
Friendship Center
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	12,696
Initial cost to company, Buildings and Improvements	20,803
Cost Capitalized Subsequent to Acquisition	4,719
Gross amount at which carried at close of period, Land	12,696
Gross amount at which carried at close of period, Buildings and Improvements	25,522
Gross amount at which carried at close of period, Total	38,218
Accumulated Depreciation and Amortization	14,998
Gaithersburg Square
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	7,701
Initial cost to company, Buildings and Improvements	5,271
Cost Capitalized Subsequent to Acquisition	16,697
Gross amount at which carried at close of period, Land	5,973
Gross amount at which carried at close of period, Buildings and Improvements	23,696
Gross amount at which carried at close of period, Total	29,669
Accumulated Depreciation and Amortization	19,442
Garden Market
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	2,677
Initial cost to company, Buildings and Improvements	4,829
Cost Capitalized Subsequent to Acquisition	7,370
Gross amount at which carried at close of period, Land	2,677
Gross amount at which carried at close of period, Buildings and Improvements	12,199
Gross amount at which carried at close of period, Total	14,876
Accumulated Depreciation and Amortization	9,241
Georgetowne Shopping Center
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	32,202
Initial cost to company, Buildings and Improvements	49,586
Cost Capitalized Subsequent to Acquisition	1,469
Gross amount at which carried at close of period, Land	32,202
Gross amount at which carried at close of period, Buildings and Improvements	51,055
Gross amount at which carried at close of period, Total	83,257
Accumulated Depreciation and Amortization	2,047
Governor Plaza
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	2,068
Initial cost to company, Buildings and Improvements	4,905
Cost Capitalized Subsequent to Acquisition	19,272
Gross amount at which carried at close of period, Land	2,068
Gross amount at which carried at close of period, Buildings and Improvements	24,177
Gross amount at which carried at close of period, Total	26,245
Accumulated Depreciation and Amortization	21,399
Graham Park Plaza
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	1,237
Initial cost to company, Buildings and Improvements	15,096
Cost Capitalized Subsequent to Acquisition	20,319
Gross amount at which carried at close of period, Land	1,169
Gross amount at which carried at close of period, Buildings and Improvements	35,483
Gross amount at which carried at close of period, Total	36,652
Accumulated Depreciation and Amortization	28,815
Gratiot Plaza
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	525
Initial cost to company, Buildings and Improvements	1,601
Cost Capitalized Subsequent to Acquisition	17,963
Gross amount at which carried at close of period, Land	525
Gross amount at which carried at close of period, Buildings and Improvements	19,564
Gross amount at which carried at close of period, Total	20,089
Accumulated Depreciation and Amortization	17,985
Greenlawn Plaza
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	10,590
Initial cost to company, Buildings and Improvements	20,869
Cost Capitalized Subsequent to Acquisition	813
Gross amount at which carried at close of period, Land	10,590
Gross amount at which carried at close of period, Buildings and Improvements	21,682
Gross amount at which carried at close of period, Total	32,272
Accumulated Depreciation and Amortization	4,326
Greenwich Avenue
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	7,484
Initial cost to company, Buildings and Improvements	5,445
Cost Capitalized Subsequent to Acquisition	10,819
Gross amount at which carried at close of period, Land	7,484
Gross amount at which carried at close of period, Buildings and Improvements	16,264
Gross amount at which carried at close of period, Total	23,748
Accumulated Depreciation and Amortization	5,472
Hastings Ranch Plaza
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	2,257
Initial cost to company, Buildings and Improvements	22,393
Cost Capitalized Subsequent to Acquisition	616
Gross amount at which carried at close of period, Land	2,257
Gross amount at which carried at close of period, Buildings and Improvements	23,009
Gross amount at which carried at close of period, Total	25,266
Accumulated Depreciation and Amortization	3,013
Hauppauge
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	8,791
Initial cost to company, Buildings and Improvements	15,262
Cost Capitalized Subsequent to Acquisition	5,829
Gross amount at which carried at close of period, Land	8,419
Gross amount at which carried at close of period, Buildings and Improvements	21,463
Gross amount at which carried at close of period, Total	29,882
Accumulated Depreciation and Amortization	13,729
Hoboken
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	105,939
Initial cost to company, Land	47,460
Initial cost to company, Buildings and Improvements	167,835
Cost Capitalized Subsequent to Acquisition	546
Gross amount at which carried at close of period, Land	47,460
Gross amount at which carried at close of period, Buildings and Improvements	168,381
Gross amount at which carried at close of period, Total	215,841
Accumulated Depreciation and Amortization	6,006
Hollywood Blvd.
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	8,300
Initial cost to company, Buildings and Improvements	16,920
Cost Capitalized Subsequent to Acquisition	36,159
Gross amount at which carried at close of period, Land	8,370
Gross amount at which carried at close of period, Buildings and Improvements	53,009
Gross amount at which carried at close of period, Total	61,379
Accumulated Depreciation and Amortization	18,599
Huntington
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	12,194
Initial cost to company, Buildings and Improvements	16,008
Cost Capitalized Subsequent to Acquisition	19,604
Gross amount at which carried at close of period, Land	12,194
Gross amount at which carried at close of period, Buildings and Improvements	35,612
Gross amount at which carried at close of period, Total	47,806
Accumulated Depreciation and Amortization	18,564
Huntington Square
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	0
Initial cost to company, Buildings and Improvements	10,075
Cost Capitalized Subsequent to Acquisition	3,537
Gross amount at which carried at close of period, Land	506
Gross amount at which carried at close of period, Buildings and Improvements	13,106
Gross amount at which carried at close of period, Total	13,612
Accumulated Depreciation and Amortization	4,751
Idylwood Plaza
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	4,308
Initial cost to company, Buildings and Improvements	10,026
Cost Capitalized Subsequent to Acquisition	3,089
Gross amount at which carried at close of period, Land	4,308
Gross amount at which carried at close of period, Buildings and Improvements	13,115
Gross amount at which carried at close of period, Total	17,423
Accumulated Depreciation and Amortization	10,100
Kings Court
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	0
Initial cost to company, Buildings and Improvements	10,714
Cost Capitalized Subsequent to Acquisition	894
Gross amount at which carried at close of period, Land	0
Gross amount at which carried at close of period, Buildings and Improvements	11,608
Gross amount at which carried at close of period, Total	11,608
Accumulated Depreciation and Amortization	9,979
Lancaster
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances
Initial cost to company, Land	0
Initial cost to company, Buildings and Improvements	2,103
Cost Capitalized Subsequent to Acquisition	5,951
Gross amount at which carried at close of period, Land	432
Gross amount at which carried at close of period, Buildings and Improvements	7,622
Gross amount at which carried at close of period, Total	8,054
Accumulated Depreciation and Amortization	6,009
Langhorne Square
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	720
Initial cost to company, Buildings and Improvements	2,974
Cost Capitalized Subsequent to Acquisition	18,968
Gross amount at which carried at close of period, Land	720
Gross amount at which carried at close of period, Buildings and Improvements	21,942
Gross amount at which carried at close of period, Total	22,662
Accumulated Depreciation and Amortization	17,239
Laurel
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	7,458
Initial cost to company, Buildings and Improvements	22,525
Cost Capitalized Subsequent to Acquisition	30,662
Gross amount at which carried at close of period, Land	7,503
Gross amount at which carried at close of period, Buildings and Improvements	53,142
Gross amount at which carried at close of period, Total	60,645
Accumulated Depreciation and Amortization	42,119
Lawrence Park
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	6,150
Initial cost to company, Buildings and Improvements	8,491
Cost Capitalized Subsequent to Acquisition	26,556
Gross amount at which carried at close of period, Land	6,161
Gross amount at which carried at close of period, Buildings and Improvements	35,036
Gross amount at which carried at close of period, Total	41,197
Accumulated Depreciation and Amortization	23,922
Leesburg Plaza
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	8,184
Initial cost to company, Buildings and Improvements	10,722
Cost Capitalized Subsequent to Acquisition	18,416
Gross amount at which carried at close of period, Land	8,184
Gross amount at which carried at close of period, Buildings and Improvements	29,138
Gross amount at which carried at close of period, Total	37,322
Accumulated Depreciation and Amortization	16,976
Linden Square
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	79,382
Initial cost to company, Buildings and Improvements	19,247
Cost Capitalized Subsequent to Acquisition	51,727
Gross amount at which carried at close of period, Land	79,346
Gross amount at which carried at close of period, Buildings and Improvements	71,010
Gross amount at which carried at close of period, Total	150,356
Accumulated Depreciation and Amortization	29,105
Melville Mall
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	35,622
Initial cost to company, Buildings and Improvements	32,882
Cost Capitalized Subsequent to Acquisition	35,161
Gross amount at which carried at close of period, Land	35,622
Gross amount at which carried at close of period, Buildings and Improvements	68,043
Gross amount at which carried at close of period, Total	103,665
Accumulated Depreciation and Amortization	19,630
Mercer Mall
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances
Initial cost to company, Land	5,917
Initial cost to company, Buildings and Improvements	18,358
Cost Capitalized Subsequent to Acquisition	47,690
Gross amount at which carried at close of period, Land	5,869
Gross amount at which carried at close of period, Buildings and Improvements	66,096
Gross amount at which carried at close of period, Total	71,965
Accumulated Depreciation and Amortization	34,954
Montrose Crossing
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	65,596
Initial cost to company, Land	48,624
Initial cost to company, Buildings and Improvements	91,819
Cost Capitalized Subsequent to Acquisition	24,539
Gross amount at which carried at close of period, Land	48,624
Gross amount at which carried at close of period, Buildings and Improvements	116,358
Gross amount at which carried at close of period, Total	164,982
Accumulated Depreciation and Amortization	35,861
Mount Vernon/South Valley/7770 Richmond Hwy,
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	10,068
Initial cost to company, Buildings and Improvements	33,501
Cost Capitalized Subsequent to Acquisition	43,397
Gross amount at which carried at close of period, Land	10,150
Gross amount at which carried at close of period, Buildings and Improvements	76,816
Gross amount at which carried at close of period, Total	86,966
Accumulated Depreciation and Amortization	41,890
North Dartmouth
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	9,366
Initial cost to company, Buildings and Improvements	0
Cost Capitalized Subsequent to Acquisition	3
Gross amount at which carried at close of period, Land	9,366
Gross amount at which carried at close of period, Buildings and Improvements	3
Gross amount at which carried at close of period, Total	9,369
Accumulated Depreciation and Amortization	2
Northeast
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	938
Initial cost to company, Buildings and Improvements	8,779
Cost Capitalized Subsequent to Acquisition	23,919
Gross amount at which carried at close of period, Land	939
Gross amount at which carried at close of period, Buildings and Improvements	32,697
Gross amount at which carried at close of period, Total	33,636
Accumulated Depreciation and Amortization	19,880
Old Keene Mill
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	638
Initial cost to company, Buildings and Improvements	998
Cost Capitalized Subsequent to Acquisition	11,425
Gross amount at which carried at close of period, Land	638
Gross amount at which carried at close of period, Buildings and Improvements	12,423
Gross amount at which carried at close of period, Total	13,061
Accumulated Depreciation and Amortization	6,466
Old Town Center
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	3,420
Initial cost to company, Buildings and Improvements	2,765
Cost Capitalized Subsequent to Acquisition	31,684
Gross amount at which carried at close of period, Land	3,420
Gross amount at which carried at close of period, Buildings and Improvements	34,449
Gross amount at which carried at close of period, Total	37,869
Accumulated Depreciation and Amortization	23,745
Olivo at Mission Hills
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	15,048
Initial cost to company, Buildings and Improvements	46,732
Cost Capitalized Subsequent to Acquisition	19,503
Gross amount at which carried at close of period, Land	15,048
Gross amount at which carried at close of period, Buildings and Improvements	66,235
Gross amount at which carried at close of period, Total	81,283
Accumulated Depreciation and Amortization	4,706
Pan Am Shopping Center
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	8,694
Initial cost to company, Buildings and Improvements	12,929
Cost Capitalized Subsequent to Acquisition	8,424
Gross amount at which carried at close of period, Land	8,695
Gross amount at which carried at close of period, Buildings and Improvements	21,352
Gross amount at which carried at close of period, Total	30,047
Accumulated Depreciation and Amortization	16,906
Pentagon Row
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	0
Initial cost to company, Buildings and Improvements	2,955
Cost Capitalized Subsequent to Acquisition	104,222
Gross amount at which carried at close of period, Land	0
Gross amount at which carried at close of period, Buildings and Improvements	107,177
Gross amount at which carried at close of period, Total	107,177
Accumulated Depreciation and Amortization	54,974
Perring Plaza
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	2,800
Initial cost to company, Buildings and Improvements	6,461
Cost Capitalized Subsequent to Acquisition	22,637
Gross amount at which carried at close of period, Land	2,800
Gross amount at which carried at close of period, Buildings and Improvements	29,098
Gross amount at which carried at close of period, Total	31,898
Accumulated Depreciation and Amortization	24,646
Pike & Rose
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	31,471
Initial cost to company, Buildings and Improvements	10,335
Cost Capitalized Subsequent to Acquisition	608,663
Gross amount at which carried at close of period, Land	27,929
Gross amount at which carried at close of period, Buildings and Improvements	622,540
Gross amount at which carried at close of period, Total	650,469
Accumulated Depreciation and Amortization	65,962
Pike 7
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	14,970
Initial cost to company, Buildings and Improvements	22,799
Cost Capitalized Subsequent to Acquisition	11,775
Gross amount at which carried at close of period, Land	14,914
Gross amount at which carried at close of period, Buildings and Improvements	34,630
Gross amount at which carried at close of period, Total	49,544
Accumulated Depreciation and Amortization	19,814
Plaza Del Mercado
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	10,305
Initial cost to company, Buildings and Improvements	21,553
Cost Capitalized Subsequent to Acquisition	15,037
Gross amount at which carried at close of period, Land	10,305
Gross amount at which carried at close of period, Buildings and Improvements	36,590
Gross amount at which carried at close of period, Total	46,895
Accumulated Depreciation and Amortization	7,234
Plaza Del Sol
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	8,072
Initial cost to company, Land	5,605
Initial cost to company, Buildings and Improvements	12,331
Cost Capitalized Subsequent to Acquisition	(26)
Gross amount at which carried at close of period, Land	5,605
Gross amount at which carried at close of period, Buildings and Improvements	12,305
Gross amount at which carried at close of period, Total	17,910
Accumulated Depreciation and Amortization	1,546
Plaza El Segundo/The Point
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	124,429
Initial cost to company, Land	62,127
Initial cost to company, Buildings and Improvements	153,556
Cost Capitalized Subsequent to Acquisition	81,203
Gross amount at which carried at close of period, Land	64,788
Gross amount at which carried at close of period, Buildings and Improvements	232,098
Gross amount at which carried at close of period, Total	296,886
Accumulated Depreciation and Amortization	61,152
Queen Anne Plaza
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	3,319
Initial cost to company, Buildings and Improvements	8,457
Cost Capitalized Subsequent to Acquisition	6,654
Gross amount at which carried at close of period, Land	3,319
Gross amount at which carried at close of period, Buildings and Improvements	15,111
Gross amount at which carried at close of period, Total	18,430
Accumulated Depreciation and Amortization	10,991
Quince Orchard Plaza
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	3,197
Initial cost to company, Buildings and Improvements	7,949
Cost Capitalized Subsequent to Acquisition	29,958
Gross amount at which carried at close of period, Land	2,928
Gross amount at which carried at close of period, Buildings and Improvements	38,176
Gross amount at which carried at close of period, Total	41,104
Accumulated Depreciation and Amortization	24,574
Riverpoint Center
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	15,422
Initial cost to company, Buildings and Improvements	104,572
Cost Capitalized Subsequent to Acquisition	1,930
Gross amount at which carried at close of period, Land	15,422
Gross amount at which carried at close of period, Buildings and Improvements	106,502
Gross amount at which carried at close of period, Total	121,924
Accumulated Depreciation and Amortization	12,907
Rockville Town Square
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances
Initial cost to company, Land	0
Initial cost to company, Buildings and Improvements	8,092
Cost Capitalized Subsequent to Acquisition	37,191
Gross amount at which carried at close of period, Land	0
Gross amount at which carried at close of period, Buildings and Improvements	45,283
Gross amount at which carried at close of period, Total	45,283
Accumulated Depreciation and Amortization	18,838
Rollingwood Apts.
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances
Initial cost to company, Land	552
Initial cost to company, Buildings and Improvements	2,246
Cost Capitalized Subsequent to Acquisition	8,805
Gross amount at which carried at close of period, Land	774
Gross amount at which carried at close of period, Buildings and Improvements	10,829
Gross amount at which carried at close of period, Total	11,603
Accumulated Depreciation and Amortization	10,237
San Antonio Center
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	26,400
Initial cost to company, Buildings and Improvements	18,462
Cost Capitalized Subsequent to Acquisition	1,714
Gross amount at which carried at close of period, Land	26,400
Gross amount at which carried at close of period, Buildings and Improvements	20,176
Gross amount at which carried at close of period, Total	46,576
Accumulated Depreciation and Amortization	4,584
Santana Row
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	66,682
Initial cost to company, Buildings and Improvements	7,502
Cost Capitalized Subsequent to Acquisition	1,076,914
Gross amount at which carried at close of period, Land	57,592
Gross amount at which carried at close of period, Buildings and Improvements	1,093,506
Gross amount at which carried at close of period, Total	1,151,098
Accumulated Depreciation and Amortization	243,734
Saugus
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	4,383
Initial cost to company, Buildings and Improvements	8,291
Cost Capitalized Subsequent to Acquisition	4,580
Gross amount at which carried at close of period, Land	4,383
Gross amount at which carried at close of period, Buildings and Improvements	12,871
Gross amount at which carried at close of period, Total	17,254
Accumulated Depreciation and Amortization	8,135
Sylmar Towne Center
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	16,238
Initial cost to company, Land	18,522
Initial cost to company, Buildings and Improvements	24,637
Cost Capitalized Subsequent to Acquisition	2,501
Gross amount at which carried at close of period, Land	18,522
Gross amount at which carried at close of period, Buildings and Improvements	27,138
Gross amount at which carried at close of period, Total	45,660
Accumulated Depreciation and Amortization	3,062
The Avenue at White Marsh
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	52,651
Initial cost to company, Land	20,682
Initial cost to company, Buildings and Improvements	72,432
Cost Capitalized Subsequent to Acquisition	29,339
Gross amount at which carried at close of period, Land	20,685
Gross amount at which carried at close of period, Buildings and Improvements	101,768
Gross amount at which carried at close of period, Total	122,453
Accumulated Depreciation and Amortization	42,152
The Commons at Darien
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	30,368
Initial cost to company, Buildings and Improvements	19,523
Cost Capitalized Subsequent to Acquisition	26,037
Gross amount at which carried at close of period, Land	30,368
Gross amount at which carried at close of period, Buildings and Improvements	45,560
Gross amount at which carried at close of period, Total	75,928
Accumulated Depreciation and Amortization	5,051
The Grove at Shrewsbury
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances	42,972
Initial cost to company, Land	18,016
Initial cost to company, Buildings and Improvements	103,115
Cost Capitalized Subsequent to Acquisition	6,002
Gross amount at which carried at close of period, Land	18,021
Gross amount at which carried at close of period, Buildings and Improvements	109,112
Gross amount at which carried at close of period, Total	127,133
Accumulated Depreciation and Amortization	24,453
The Shoppes At Nottingham Square
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	4,441
Initial cost to company, Buildings and Improvements	12,849
Cost Capitalized Subsequent to Acquisition	1,054
Gross amount at which carried at close of period, Land	4,441
Gross amount at which carried at close of period, Buildings and Improvements	13,903
Gross amount at which carried at close of period, Total	18,344
Accumulated Depreciation and Amortization	6,416
Third Street Promenade
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	22,645
Initial cost to company, Buildings and Improvements	12,709
Cost Capitalized Subsequent to Acquisition	43,667
Gross amount at which carried at close of period, Land	25,125
Gross amount at which carried at close of period, Buildings and Improvements	53,896
Gross amount at which carried at close of period, Total	79,021
Accumulated Depreciation and Amortization	34,458
Tower
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	7,170
Initial cost to company, Buildings and Improvements	10,518
Cost Capitalized Subsequent to Acquisition	5,038
Gross amount at which carried at close of period, Land	7,280
Gross amount at which carried at close of period, Buildings and Improvements	15,446
Gross amount at which carried at close of period, Total	22,726
Accumulated Depreciation and Amortization	10,514
Tower Shops
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	29,940
Initial cost to company, Buildings and Improvements	43,390
Cost Capitalized Subsequent to Acquisition	24,934
Gross amount at which carried at close of period, Land	29,962
Gross amount at which carried at close of period, Buildings and Improvements	68,302
Gross amount at which carried at close of period, Total	98,264
Accumulated Depreciation and Amortization	23,599
Town Center of New Britain
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	1,282
Initial cost to company, Buildings and Improvements	12,285
Cost Capitalized Subsequent to Acquisition	3,015
Gross amount at which carried at close of period, Land	1,693
Gross amount at which carried at close of period, Buildings and Improvements	14,889
Gross amount at which carried at close of period, Total	16,582
Accumulated Depreciation and Amortization	6,487
Townson Residential
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	2,328
Initial cost to company, Buildings and Improvements	0
Cost Capitalized Subsequent to Acquisition	20,063
Gross amount at which carried at close of period, Land	2,328
Gross amount at which carried at close of period, Buildings and Improvements	20,063
Gross amount at which carried at close of period, Total	22,391
Accumulated Depreciation and Amortization	2,075
Troy
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	3,126
Initial cost to company, Buildings and Improvements	5,193
Cost Capitalized Subsequent to Acquisition	32,700
Gross amount at which carried at close of period, Land	5,865
Gross amount at which carried at close of period, Buildings and Improvements	35,154
Gross amount at which carried at close of period, Total	41,019
Accumulated Depreciation and Amortization	24,180
Tyson's Station
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	388
Initial cost to company, Buildings and Improvements	453
Cost Capitalized Subsequent to Acquisition	4,891
Gross amount at which carried at close of period, Land	493
Gross amount at which carried at close of period, Buildings and Improvements	5,239
Gross amount at which carried at close of period, Total	5,732
Accumulated Depreciation and Amortization	4,046
Village at Shirlington
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances
Initial cost to company, Land	9,761
Initial cost to company, Buildings and Improvements	14,808
Cost Capitalized Subsequent to Acquisition	39,325
Gross amount at which carried at close of period, Land	4,234
Gross amount at which carried at close of period, Buildings and Improvements	59,660
Gross amount at which carried at close of period, Total	63,894
Accumulated Depreciation and Amortization	32,191
Westgate Center
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	6,319
Initial cost to company, Buildings and Improvements	107,284
Cost Capitalized Subsequent to Acquisition	43,851
Gross amount at which carried at close of period, Land	6,319
Gross amount at which carried at close of period, Buildings and Improvements	151,135
Gross amount at which carried at close of period, Total	157,454
Accumulated Depreciation and Amortization	66,806
White Marsh Plaza
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	3,478
Initial cost to company, Buildings and Improvements	21,413
Cost Capitalized Subsequent to Acquisition	1,497
Gross amount at which carried at close of period, Land	3,488
Gross amount at which carried at close of period, Buildings and Improvements	22,900
Gross amount at which carried at close of period, Total	26,388
Accumulated Depreciation and Amortization	10,402
White Marsh Other
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	29,724
Initial cost to company, Buildings and Improvements	1,843
Cost Capitalized Subsequent to Acquisition	148
Gross amount at which carried at close of period, Land	29,754
Gross amount at which carried at close of period, Buildings and Improvements	1,961
Gross amount at which carried at close of period, Total	31,715
Accumulated Depreciation and Amortization	968
Wildwood
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	9,111
Initial cost to company, Buildings and Improvements	1,061
Cost Capitalized Subsequent to Acquisition	17,271
Gross amount at which carried at close of period, Land	9,111
Gross amount at which carried at close of period, Buildings and Improvements	18,332
Gross amount at which carried at close of period, Total	27,443
Accumulated Depreciation and Amortization	9,723
Willow Grove
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	1,499
Initial cost to company, Buildings and Improvements	6,643
Cost Capitalized Subsequent to Acquisition	21,131
Gross amount at which carried at close of period, Land	1,499
Gross amount at which carried at close of period, Buildings and Improvements	27,774
Gross amount at which carried at close of period, Total	29,273
Accumulated Depreciation and Amortization	26,734
Willow Lawn
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	3,192
Initial cost to company, Buildings and Improvements	7,723
Cost Capitalized Subsequent to Acquisition	93,859
Gross amount at which carried at close of period, Land	7,790
Gross amount at which carried at close of period, Buildings and Improvements	96,984
Gross amount at which carried at close of period, Total	104,774
Accumulated Depreciation and Amortization	65,247
Wynnewood
Real Estate and Accumulated Depreciation [Line Items]
Initial cost to company, Land	8,055
Initial cost to company, Buildings and Improvements	13,759
Cost Capitalized Subsequent to Acquisition	20,822
Gross amount at which carried at close of period, Land	8,055
Gross amount at which carried at close of period, Buildings and Improvements	34,581
Gross amount at which carried at close of period, Total	42,636
Accumulated Depreciation and Amortization	$ 26,423

Schedule III Part II - Summar_2

Schedule III Part II - Summary of Real Estate and Accumulated Depreciation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Real Estate and Accumulated Depreciation, Carrying Amount of Land and Buildings and Improvements [Abstract]
Balance at beginning of year	$ 8,298,132	$ 7,819,472	$ 7,635,061
Acquisitions	39,440	309,921	14,940
Improvements	473,679	441,703	407,225
Impairment of property	(68,484)
Deduction during period—dispositions and retirements of property	(159,897)	(201,105)	(237,754)
Balance at end of year	8,582,870	8,298,132	7,819,472
Aggregate cost basis for Federal tax purposes	7,700,000
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Balance at beginning of year	2,215,413	2,059,143	1,876,544
Additions during period—depreciation and amortization expense	229,199	215,382	215,969
Deductions during period—dispositions and retirements of property	(75,289)	(40,939)	(33,370)
Real estate accumulated depreciation impairment of property	(11,631)
Balance at end of year	$ 2,357,692	2,215,413	$ 2,059,143
Accounting Standards Update 2016-02
January 1, 2019 adoption of new accounting standard - See Note 2		(71,859)
January 1, 2019 adoption of new accounting standard - See Note 2		$ (18,173)

Schedule IV - Mortgage Loans _2

Schedule IV - Mortgage Loans on Real Estate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2018	Dec. 31, 2017
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Prior Liens		$ 58,750
Face Amount of Mortgages		40,697
Carrying Amount of Mortgages	$ 39,892	39,892	$ 30,429	$ 30,429
Principal Amount of Loans Subject to delinquent Principal or Interest		30,332
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Other Disclosure [Abstract]
Aggregate tax basis for Federal tax purposes		40,700
SEC Schedule, 12-29, Real Estate Companies, Investment in Movement in Mortgage Loans on Real Estate [Roll Forward]
Balance at beginning of year	30,429
January 1, 2020 adoption of new accounting standard	(790)
Acquisitions of loans, net of valuation adjustements	9,560
Issuance of loans	693
Balance at end of year	39,892
Mortgage On Retail Buildings in Philadelphia, PA, Loan One
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Prior Liens		0
Face Amount of Mortgages		21,872
Carrying Amount of Mortgages	21,082	21,082
Principal Amount of Loans Subject to delinquent Principal or Interest		21,082
SEC Schedule, 12-29, Real Estate Companies, Investment in Movement in Mortgage Loans on Real Estate [Roll Forward]
Balance at end of year	$ 21,082
Mortgage On Retail Buildings in Philadelphia, PA, Loan One | Maximum
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Face Amount of Mortgages		25,000
Mortgage On Retail Buildings in Philadelphia, PA, Loan Two
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	10.00%
Prior Liens		0
Face Amount of Mortgages		9,250
Carrying Amount of Mortgages	$ 9,250	9,250
Principal Amount of Loans Subject to delinquent Principal or Interest		9,250
SEC Schedule, 12-29, Real Estate Companies, Investment in Movement in Mortgage Loans on Real Estate [Roll Forward]
Balance at end of year	9,250
Second Mortgage on a retail shopping center in Rockville, MD One
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Prior Liens		58,750
Face Amount of Mortgages		5,075
Carrying Amount of Mortgages	5,075	5,075
Principal Amount of Loans Subject to delinquent Principal or Interest		0
SEC Schedule, 12-29, Real Estate Companies, Investment in Movement in Mortgage Loans on Real Estate [Roll Forward]
Balance at end of year	5,075
Second Mortgage on a retail shopping center in Rockville, MD Two
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Prior Liens		58,750
Face Amount of Mortgages		4,500
Carrying Amount of Mortgages	4,485	4,485
Principal Amount of Loans Subject to delinquent Principal or Interest		$ 0
SEC Schedule, 12-29, Real Estate Companies, Investment in Movement in Mortgage Loans on Real Estate [Roll Forward]
Balance at end of year	$ 4,485
Interest Rate One | Mortgage On Retail Buildings in Philadelphia, PA, Loan One
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	8.00%
Interest Rate One | Second Mortgage on a retail shopping center in Rockville, MD One
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	11.50%
Interest Rate Two | Mortgage On Retail Buildings in Philadelphia, PA, Loan One
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	10.00%
Interest Rate Two | Second Mortgage on a retail shopping center in Rockville, MD Two
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest Rate	10.75%