Acadia Realty Trust (AKR) 10-Q 30 Apr 21 2021 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2021	Apr. 23, 2021
Cover [Abstract]
Entity Registrant Name	ACADIA REALTY TRUST
Entity Central Index Key	0000899629
Current Fiscal Year End Date	--12-31
Trading Symbol	AKR
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Document Type	10-Q
Document Period End Date	Mar. 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding		86,306,301
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity File Number	001-12002
Entity Tax Identification Number	23-2715194
Entity Address, Address Line One	411 THEODORE FREMD AVENUE
Entity Address, Address Line Two	SUITE 300
Entity Address, City or Town	RYE
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10580
City Area Code	914
Local Phone Number	288-8100
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common shares of beneficial interest, par value $0.001 per share
Security Exchange Name	NYSE
Document Quarterly Report	true
Document Transition Report	false
Entity Incorporation, State or Country Code	MD

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
ASSETS
Operating real estate, net	$ 3,238,031	$ 3,260,139
Real estate under development	234,338	247,349
Net investments in real estate	3,472,369	3,507,488
Notes receivable, net	101,410	101,450
Investments in and advances to unconsolidated affiliates	256,332	249,807
Other assets, net	162,596	173,809
Right-of-use assets - operating leases, net	74,803	76,268
Cash and cash equivalents	15,424	19,232
Restricted cash	15,723	14,692
Rents receivable, net	46,356	44,136
Assets of properties held for sale	8,669
Total assets	4,153,682	4,186,882
LIABILITIES
Mortgage and other notes payable, net	1,188,695	1,204,581
Unsecured notes payable, net	420,960	420,858
Unsecured line of credit	105,400	138,400
Accounts payable and other liabilities	237,058	269,911
Lease liability - operating leases, net	87,910	88,816
Dividends and distributions payable	14,018	147
Distributions in excess of income from, and investments in, unconsolidated affiliates	15,272	15,616
Total liabilities	2,069,313	2,138,329
Commitments and contingencies
Acadia Shareholders' Equity
Common shares, $0.001 par value, authorized 200,000,000 shares, issued and outstanding 86,302,352 and 86,268,303 shares, respectively	86	86
Additional paid-in capital	1,683,552	1,683,165
Accumulated other comprehensive loss	(41,962)	(74,891)
Distributions in excess of accumulated earnings	(174,829)	(167,046)
Total Acadia shareholders’ equity	1,466,847	1,441,314
Noncontrolling interests	617,522	607,239
Total equity	2,084,369	2,048,553
Total liabilities and equity	$ 4,153,682	$ 4,186,882

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 31, 2021	Dec. 31, 2020
Statement Of Financial Position [Abstract]
Common shares, par value (in dollars per share)	$ 0.001	$ 0.001
Common shares, authorized (in shares)	200,000,000	200,000,000
Common shares, issued (in shares)	86,302,352	86,268,303
Common shares, outstanding (in shares)	86,302,352	86,268,303

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Rental income	$ 67,205	$ 70,457
Revenues	69,394	71,420
Operating expenses
Depreciation and amortization	31,390	33,377
General and administrative	8,996	9,070
Real estate taxes	11,462	10,447
Property operating	13,477	13,320
Impairment charges		51,549
Total operating expenses	65,325	117,763
Gain on disposition of properties	4,612
Operating income (loss)	8,681	(46,343)
Equity in earnings of unconsolidated affiliates	2,263	1,255
Interest and other income	1,700	2,929
Realized and unrealized holding gains on investments and other	6,507	(530)
Interest expense	(17,141)	(18,302)
Income (loss) from continuing operations before income taxes	2,010	(60,991)
Income tax (provision) benefit	(150)	952
Net income (loss)	1,860	(60,039)
Net loss attributable to noncontrolling interests	3,302	51,625
Net income (loss) attributable to Acadia	$ 5,162	$ (8,414)
Basic and diluted earnings (loss) per share	$ 0.06	$ (0.10)
Other
Revenues	$ 2,189	$ 963

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ 1,860	$ (60,039)
Other comprehensive income (loss):
Unrealized gain (loss) on valuation of swap agreements	33,556	(74,774)
Reclassification of realized interest on swap agreements	5,317	977
Other comprehensive income (loss)	38,873	(73,797)
Comprehensive income (loss)	40,733	(133,836)
Comprehensive (income) loss attributable to noncontrolling interests	(2,642)	70,882
Comprehensive income (loss) attributable to Acadia	$ 38,091	$ (62,954)

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Cumulative Effect of Change in Accounting Principle	Common Shares	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Distributions in Excess of Accumulated Earnings	Distributions in Excess of Accumulated EarningsCumulative Effect of Change in Accounting Principle	Total Common Shareholders' Equity	Total Common Shareholders' EquityCumulative Effect of Change in Accounting Principle	Noncontrolling Interests	Noncontrolling InterestsCumulative Effect of Change in Accounting Principle
Balance at Dec. 31, 2019	$ 2,186,965	$ (400)	$ 87	$ 1,706,357	$ (31,175)	$ (132,961)	$ (389)	$ 1,542,308	$ (389)	$ 644,657	$ (11)
Balance (in Shares) at Dec. 31, 2019			87,050,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership	0			2,472				2,472		(2,472)
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership (in Shares)			148,000
Repurchase of Common Shares	$ (22,352)		$ (1)	(22,351)				(22,352)
Repurchase of Common Shares (in shares)	(1,219,065)		(1,219,000)
Dividends/distributions declared ($0.15 and $0.29 per Common Share/OP Unit for Three Months Ended March 31, 2021 and 2020)	$ (26,786)					(24,937)		(24,937)		(1,849)
Employee and trustee stock compensation, net	3,819			171				171		3,648
Employee and trustee stock compensation, net (in Shares)			11,000
Noncontrolling interest distributions	(3,118)									(3,118)
Noncontrolling interest contributions	7,268									7,268
Comprehensive income (loss)	(133,836)				(54,540)	(8,414)		(62,954)		(70,882)
Reallocation of noncontrolling interests	0			145				145		(145)
Balance at Mar. 31, 2020	2,011,560		$ 86	1,686,794	(85,715)	(166,701)		1,434,464		577,096
Balance (in Shares) at Mar. 31, 2020			85,990,000
Balance at Dec. 31, 2020	$ 2,048,553		$ 86	1,683,165	(74,891)	(167,046)		1,441,314		607,239
Balance (in Shares) at Dec. 31, 2020	86,268,303		86,269,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership	$ 0			294				294		(294)
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership (in Shares)			19,000
Repurchase of Common Shares (in shares)	0
Dividends/distributions declared ($0.15 and $0.29 per Common Share/OP Unit for Three Months Ended March 31, 2021 and 2020)	$ (13,993)					(12,945)		(12,945)		(1,048)
Employee and trustee stock compensation, net	4,511			462				462		4,049
Employee and trustee stock compensation, net (in Shares)			14,000
Noncontrolling interest distributions	(6,676)									(6,676)
Noncontrolling interest contributions	11,241									11,241
Comprehensive income (loss)	40,733				32,929	5,162		38,091		2,642
Reallocation of noncontrolling interests	0			(369)				(369)		369
Balance at Mar. 31, 2021	$ 2,084,369		$ 86	$ 1,683,552	$ (41,962)	$ (174,829)		$ 1,466,847		$ 617,522
Balance (in Shares) at Mar. 31, 2021	86,302,352		86,302,000

CONSOLIDATED STATEMENTS OF CH_2

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement Of Stockholders Equity [Abstract]
Cash dividends declared per common share (in dollars per share)	$ 0.15	$ 0.29

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (loss)	$ 1,860	$ (60,039)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	31,390	33,377
Straight-line rents	(1,128)	(1,128)
Non-cash lease expense	1,041	619
Net unrealized holding gains on investments	(6,135)
Distributions of operating income from unconsolidated affiliates	390	1,898
Equity in earnings of unconsolidated affiliates	(2,263)	(1,255)
Stock compensation expense	4,511	3,819
Amortization of financing costs	1,269	1,763
Impairment charges		51,549
Gain on disposition of properties	(4,612)
Allowance for credit loss	3,065	1,273
Adjustments to straight-line rent reserves	817	2,967
Other, net	(2,312)	(1,107)
Changes in assets and liabilities:
Other liabilities	3,847	(6,844)
Lease liability - operating leases	(494)	(376)
Prepaid expenses and other assets	1,859	2,107
Rents receivable	(2,408)	1,682
Accounts payable and accrued expenses	237	(2,327)
Net cash provided by operating activities	30,934	27,978
CASH FLOWS FROM INVESTING ACTIVITIES
Acquisition of real estate	0	(19,088)
Development, construction and property improvement costs	(5,425)	(13,576)
Proceeds from the disposition of properties, net	15,703
Investments in and advances to unconsolidated affiliates and other	(1,725)	(1,525)
Return of capital from unconsolidated affiliates and other	4,377	5,024
(Issuance) redemption of notes receivable		(59,000)
Return (payment) of deposits for properties under contract		200
Payment of deferred leasing costs	(1,438)	(2,763)
Net cash provided by (used in) investing activities	11,492	(90,728)
CASH FLOWS FROM FINANCING ACTIVITIES
Principal payments on mortgage and other notes	(20,406)	(1,488)
Principal payments on unsecured debt	(33,250)	(5,000)
Proceeds received on mortgage and other notes	3,809	689
Proceeds from unsecured debt	536	122,245
Payments of finance lease obligations		(625)
(Repurchase) proceeds from the sale of Common Shares		(22,352)
Capital contributions from noncontrolling interests	11,241	7,268
Distributions to noncontrolling interests	(6,800)	(4,914)
Dividends paid to Common Shareholders		(25,245)
Deferred financing and other costs	(333)	(222)
Net cash (used in) provided by financing activities	(45,203)	70,356
(Decrease) increase in cash and restricted cash	(2,777)	7,606
Cash of $19,232 and $15,845 and restricted cash of $14,692 and $14,165, respectively, beginning of period	33,924	30,010	$ 30,010
Cash of $15,424 and $23,404 and restricted cash of $15,723 and $14,212, respectively, end of period	31,147	37,616	$ 33,924
Supplemental disclosure of cash flow information
Cash paid during the period for interest, net of capitalized interest of $902 and $2,938 respectively	11,824	14,156
Cash paid for income taxes, net of refunds	100	219
Supplemental disclosure of non-cash investing and financing activities
Right-of-use assets, operating leases modified in exchange for operating lease liabilities	412
Assumption of accounts payable and accrued expenses through acquisition of real estate		116
Distribution declared and payable on April 15, 2021 and 2020, respectively	$ 13,993	$ 26,816

CONSOLIDATED STATEMENTS OF CA_2

CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement Of Cash Flows [Abstract]
Cash and cash equivalents, beginning balance	$ 19,232	$ 15,845
Cash and cash equivalents, ending balance	15,424	23,404
Restricted cash, beginning balance	14,692	14,165
Restricted cash, ending balance	15,723	14,212
Cash paid for capitalized interest	$ 902	$ 2,938

Organization, Basis of Presenta

Organization, Basis of Presentation and Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization, Basis of Presentation and Summary of Significant Accounting Policies	1. Organization, Basis of Presentation and Summary of Significant Accounting Policies Organization The Company is a fully-integrated equity real estate investment trust (“REIT”) focused on the ownership, acquisition, development, and management of retail properties located primarily in high-barrier-to-entry, supply-constrained, densely-populated metropolitan areas in the United States. All of the Company’s assets are held by, and all of its operations are conducted through, Acadia Realty Limited Partnership (the “Operating Partnership”) and entities in which the Operating Partnership owns an interest. As of March 31, 2021 and December 31, 2020, the Company controlled approximately 94% and 95%, respectively of the Operating Partnership as the sole general partner and is entitled to share, in proportion to its percentage interest, in the cash distributions and profits and losses of the Operating Partnership. The limited partners primarily represent entities or individuals that contributed their interests in certain properties or entities to the Operating Partnership in exchange for common or preferred units of limited partnership interest (“Common OP Units” or “Preferred OP Units”) and employees who have been awarded restricted Common OP Units (“LTIP Units”) as long-term incentive compensation ( Note 13 ). Limited partners holding Common OP and LTIP Units are generally entitled to exchange their units on a one-for-one basis for common shares of beneficial interest, par value $0.001 per share, of the Company (“Common Shares”). This structure is referred to as an umbrella partnership REIT or “UPREIT.” As of March 31, 2021, the Company has ownership interests in 130 properties within its core portfolio, which consist of those properties either 100% owned, or partially owned through joint venture interests, by the Operating Partnership, or subsidiaries thereof, not including those properties owned through its funds (“Core Portfolio”). The Company also has ownership interests in 56 properties within its opportunity funds, Acadia Strategic Opportunity Fund II, LLC (“Fund II”), Acadia Strategic Opportunity Fund III LLC (“Fund III”), Acadia Strategic Opportunity Fund IV LLC (“Fund IV”), and Acadia Strategic Opportunity Fund V LLC (“Fund V” The Operating Partnership is the sole general partner or managing member of the Funds and Mervyns II and earns fees or priority distributions for asset management, property management, construction, development, leasing, and legal services. Cash flows from the Funds and Mervyns II are distributed pro-rata to their respective partners and members (including the Operating Partnership) until each receives a certain cumulative return (“Preferred Return”) and the return of all capital contributions. Thereafter, remaining cash flow is distributed 20% to the Operating Partnership (“Promote”) and 80% to the partners or members (including the Operating Partnership). All transactions between the Funds and the Operating Partnership have been eliminated in consolidation. The following table summarizes the general terms and Operating Partnership’s equity interests in the Funds and Mervyns II (dollars in millions): Entity Formation Date Operating Partnership Share of Capital Capital Called as of March 31, 2021 (b) Unfunded Commitment (b, c) Equity Interest Held By Operating Partnership (a) Preferred Return Total Distributions as of March 31, 2021 (b, c) Fund II and Mervyns II (c) 6/2004 28.33 % $ 372.6 $ 12.7 28.33 % 8 % $ 169.8 Fund III 5/2007 24.54 % 448.1 1.9 24.54 % 6 % 568.8 Fund IV 5/2012 23.12 % 481.3 48.7 23.12 % 6 % 193.1 Fund V 8/2016 20.10 % 217.1 302.9 20.10 % 6 % 31.5 (a) Amount represents the current economic ownership at March 31, 2021, which could differ from the stated legal ownership based upon the cumulative preferred returns of the respective Fund. (b) Represents the total for the Funds, including the Operating Partnership and noncontrolling interests’ shares. (c) During August 2020, a recallable distribution of $ 15.7 million was made by Mervyn’s II to its investors, of which $ 4.5 million was the Company’s share. During the first quarter of 2021, Mervyn’s II re called $ 3.0 million of the $ 15.7 million. Basis of Presentation Segments At March 31, 2021, the Company had three reportable operating segments: Core Portfolio, Funds and Structured Financing. The Company’s chief operating decision maker may review operational and financial data on a property-level basis and does not differentiate properties on a geographical basis for purposes of allocating resources or capital. Principles of Consolidation The interim consolidated financial statements include the consolidated accounts of the Company and its investments in partnerships and limited liability companies in which the Company has control in accordance with Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 810 “Consolidation” (“ASC Topic 810”). The ownership interests of other investors in these entities are recorded as noncontrolling interests. All significant intercompany balances and transactions have been eliminated in consolidation. Investments in entities for which the Company has the ability to exercise significant influence over, but does not have financial or operating control, are accounted for using the equity method of accounting. Accordingly, the Company’s share of the earnings (or losses) of these entities are included in consolidated net income or loss. The interim consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) for interim financial information and the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”). Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. Operating results for the interim periods presented are not necessarily indicative of the results that may be expected for the full fiscal year. The information furnished in the accompanying consolidated financial statements reflects all adjustments that, in the opinion of management, are necessary for a fair presentation of the aforementioned consolidated financial statements for the interim periods. Such adjustments consisted of normal recurring items, with the exception of adjustments due to the adoption of the new credit loss standard and impairment. These interim consolidated financial statements should be read in conjunction with the Company’s 2020 Annual Report on Form 10-K, as filed with the SEC on February 22, 2021. Reclassifications Certain prior year amounts on the Company’s consolidated balance sheet at December 31, 2020 with regard to Mortgage and other notes payable, net and Unsecured notes payable, net have been reclassified to conform to the current period presentation. In addition, certain prior year amounts in the Company’s statement of cash flows for the three months ended March 31, 2020 with regard to Right-of-use assets – operating leases, lease liabilities – operating leases and credit losses have been reclassified to conform to the current period presentation. These reclassifications had no material effect on the reported results of operations, financial condition or cash flows. Use of Estimates GAAP requires the Company’s management to make estimates and assumptions that affect the amounts reported in the interim consolidated financial statements and accompanying notes. The most significant assumptions and estimates relate to the valuation of real estate, depreciable lives, revenue recognition and the collectability of notes receivable and rents receivable. Application of these estimates and assumptions requires the exercise of judgment as to future uncertainties and, as a result, actual results could differ from these estimates. Recently Adopted Accounting and Reporting Guidance In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740) Simplifying the Accounting for Income Taxes. During October 2020, the SEC issued new rules modernizing certain Regulation S-K disclosure requirements. The final rule is intended to improve the readability of disclosures, reduce repetition, and eliminate immaterial information, thereby simplifying compliance for registrants and making disclosures more meaningful for investors. These changes will be effective for all filings on or after November 7, 2020. The Company has made minor disclosure changes in this Report and to the "Business" and "Risk Factors" sections of the annual report on Form 10-K for 2020. On April 8, 2020, the FASB issued a Q&A allowing for reporting entities to make an accounting policy election to account for lease concessions related to the effects of COVID-19 consistent with how those concessions would be accounted for under Topic 842, which is as though the enforceable rights and obligations for those concessions existed regardless of whether those enforceable rights and obligations for the concessions explicitly exist in the contract. This election is available for concessions that result in the total cash flows required by the modified contract being substantially the same or less than total cash flows required by the original contract. Effective April 1, 2020, the Company has made the accounting policy election noted above. The Company entered into concession agreements both as lessor and lessee during the three months ended March 31, 2021 ( Note 11 ). The Company may grant further concessions during subsequent periods. In January 2020, the FASB issued ASU 2020-01 Investments—Equity securities (Topic 321), Investments—Equity Method and Joint Ventures (Topic 323), and Derivatives and Hedging (Topic 815)—Clarifying the Interactions Between Topic 321, Topic 323, and Topic 815. In October 2020, the FASB issued ASU 2020-08 Codification Improvements to Subtopic 310-20, Receivables—Nonrefundable Fees and Other Costs Recently Issued Accounting Pronouncements In August 2020, the FASB issued ASU 2020-06— 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 In January 2021, the FASB issued ASU 2021-01 Reference Rate Reform (Topic 848)

Real Estate

Real Estate	3 Months Ended
	Mar. 31, 2021
Acquisition And Disposition Of Properties And Discontinued Operations [Abstract]
Real Estate	2. Real Estate The Company’s consolidated real estate is comprised of the following for the periods presented (in thousands): March 31, 2021 December 31, 2020 Land $ 767,631 $ 776,275 Buildings and improvements 2,847,797 2,848,781 Tenant improvements 196,748 191,046 Construction in progress 6,453 5,751 Right-of-use assets - finance leases (Note 11) 25,086 25,086 Total 3,843,715 3,846,939 Less: Accumulated depreciation and amortization (605,684 ) (586,800 ) Operating real estate, net 3,238,031 3,260,139 Real estate under development 234,338 247,349 Net investments in real estate $ 3,472,369 $ 3,507,488 Acquisitions and Conversions During the three months ended March 31, 2021 and the year ended December 31, 2020, the Company acquired the following consolidated retail properties and other real estate investments (dollars in thousands): Property and Location Percent Acquired Date of Acquisition Purchase Price 2021 Acquisitions None 2020 Acquisitions and Conversions Core Soho Acquisitions - 37 Greene Street - New York, NY 100% Jan 9, 2020 $ 15,689 917 W. Armitage - Chicago, IL 100% Feb 13, 2020 3,515 Town Center - Wilmington, DE (Conversion) (Note 4) 100% Apr 1, 2020 138,939 Subtotal Core 158,143 Fund IV 230-240 W. Broughton Street - Savannah, GA 100% May 26, 2020 13,219 102 E. Broughton Street - Savannah, GA 100% May 26, 2020 790 Subtotal Fund IV 14,009 Total 2020 Acquisitions and Conversions $ 172,152 For the year ended December 31, 2020, the Company capitalized $1.3 million of acquisition costs. No debt was assumed in any of the 2020 Acquisitions. Conversions represent notes receivable that were converted to an interest in the underlying collateral in a non-cash transaction. Purchase Price Allocations The purchase prices for the 2020 Acquisitions were allocated to the acquired assets and assumed liabilities based on their estimated fair values at the dates of acquisition. The following table summarizes the allocation of the purchase price of properties acquired during the periods presented (in thousands): Three Months Ended March 31, 2021 Year Ended December 31, 2020 Net Assets Acquired Land $ — $ 25,440 Buildings and improvements — 123,459 Accounts receivable, prepaids and other assets — 5,770 Acquisition-related intangible assets ( Note 6 ) — 23,061 Right-of-use asset - Operating lease (Note 11) — 234 Acquisition-related intangible liabilities ( Note 6 ) — (4,569 ) Lease liability - Operating lease (Note 11) — (234 ) Accounts payable and other liabilities — (1,009 ) Net assets acquired $ — $ 172,152 Consideration Cash $ — $ 21,208 Conversion of note receivable — 38,674 Conversion of accrued interest — 1,995 Liabilities assumed — 116 Existing interest in previously unconsolidated investment — 109,571 Acquisition of noncontrolling interests — 588 Total consideration $ — $ 172,152 Dispositions During the three months ended March 31, 2021 and the year ended December 31, 2020, the Company disposed of the following consolidated properties and other real estate investments (in thousands): Property and Location Owner Date Sold Sale Price Gain on Sale 2021 Dispositions 60 Orange St - Bloomfield, NJ Core Jan 29, 2021 $ 16,400 $ 4,612 Total 2021 Dispositions $ 16,400 $ 4,612 2020 Dispositions 163 Highland Ave. (Easement) - Needham, MA Core Mar 19, 2020 $ 238 $ 88 Colonie Plaza - Albany, NY Fund IV Apr 13, 2020 15,250 485 Airport Mall (Parcel) - Bangor, ME Fund IV Sep 10, 2020 400 24 Cortlandt Crossing (Sewer Project and Retention Pond) - Cortlandt, NY Fund III Nov 30, 2020 6,325 — Union Township (Parcel) - New Castle, PA Core Dec 11, 2020 200 86 Total 2020 Dispositions $ 22,413 $ 683 During the three months ended March 31, 2021, Fund III entered into an agreement to sell its 654 Broadway property, which is reflected as assets of properties held for sale at March 31, 2021 on the consolidated balance sheet. The aggregate rental revenue, expenses and pre-tax income reported within continuing operations for the aforementioned consolidated properties that were sold during the three months ended March 31, 2021 and year ended December 31, 2020 were as follows (in thousands): Three Months Ended March 31, 2021 2020 Revenues $ 82 $ 870 Expenses (90 ) (864 ) Gain on disposition of properties 4,612 — Net income attributable to noncontrolling interests 1 48 Net income attributable to Acadia $ 4,605 $ 54 Real Estate Under Development and Construction in Progress Real estate under development represents the Company’s consolidated properties that have not yet been placed into service while undergoing substantial development or construction. Development activity for the Company’s consolidated properties comprised the following during the periods presented (dollars in thousands): January 1, 2021 Three Months Ended March 31, 2021 March 31, 2021 Number of Properties Carrying Value Transfers In Capitalized Costs Transfers Out Number of Properties Carrying Value Core — $ 63,875 $ — $ 933 $ 14,557 — $ 50,251 Fund II — 74,657 — 535 — — 75,192 Fund III 1 23,139 — 277 — 1 23,416 Fund IV 2 85,678 — 21 220 2 85,479 Total 3 $ 247,349 $ — $ 1,766 $ 14,777 3 $ 234,338 January 1, 2020 Year Ended December 31, 2020 December 31, 2020 Number of Properties Carrying Value Transfers In Capitalized Costs Transfers Out Number of Properties Carrying Value Core — $ 60,863 $ — $ 3,012 $ — — $ 63,875 Fund II (a) — 10,703 66,812 3,612 6,470 — 74,657 Fund III 1 36,240 — 70 13,171 1 23,139 Fund IV (b) 2 145,596 — 1,368 61,286 2 85,678 Total 3 $ 253,402 $ 66,812 $ 8,062 $ 80,927 3 $ 247,349 (a) Transfers in include $33.8 million of non-cash Fund II additions obtained through the conversion of a note receivable ( Note 3 ). (b) Transfers out include impairment charges totaling $16.5 million on two Fund IV development properties ( Note 8 ). The number of properties in the tables above refers to projects comprising the entire property under development; however, certain projects represent a portion of a property. Core amounts relate to City Center and Fund II amounts relate to the City Point Phase III project. During the three months ended March 31, 2021, the Company: • placed a portion of one Core project, City Center, into service • placed the remainder of one Fund project, Paramus, into service During the year ended December 31, 2020, the Company: • placed a portion of one Fund III property, Cortlandt Crossing, into service • converted, in a non-cash transaction, a note receivable in exchange for construction improvements in the amount of $33.8 million ( Note 3 ) • recognized impairment charges totaling $16.5 million on two Fund IV properties ( Note 8 ) including 717 N. Michigan Avenue and 110 University Place • placed a portion of one Fund IV property, 146 Geary Street, into service, which was also impaired ( Note 8 ) • placed a portion of Fund II’s City Point Phase II into development • suspended certain development projects due to aforementioned disruptions related to the COVID-19 Pandemic. Substantially all remaining development and redevelopment costs are discretionary and dependent upon the resumption of tenant interest. Construction in progress pertains to construction activity at the Company’s operating properties that are in service and continue to operate during the construction period.

Notes Receivable, Net

Notes Receivable, Net	3 Months Ended
	Mar. 31, 2021
Accounts And Notes Receivable Net [Abstract]
Notes Receivable, Net	3. Notes Receivable, Net The Company’s notes receivable, net are generally collateralized either by the underlying properties or the borrowers’ ownership interests in the entities that own the properties, and were as follows (dollars in thousands): March 31, December 31, March 31, 2021 Description 2021 2020 Number Maturity Date Interest Rate Core Portfolio (a) $ 96,794 $ 96,794 6 Apr 2020 - Dec 2027 2.65% - 9.00% Fund III 5,306 5,306 1 Jul 2020 18.00% Total notes receivable 102,100 102,100 Allowance for credit loss (690 ) (650 ) Notes receivable, net $ 101,410 $ 101,450 7 (a) Includes two notes receivable from OP Unit holders, with balances totaling $6.5 million at March 31, 2021 and December 31, 2020. During the three months ended March 31, 2021, the Company: • recorded an increase in its allowance for credit loss of approximately $0.1 million During the year ended December 31, 2020, the Company: • exchanged its Brandywine Note Receivable of $38.7 million plus accrued interest of $2.0 million for the remaining 24.78% undivided interest in Town Center on April 1, 2020 • recorded credit loss reserves of $0.4 million upon the adoption of ASC 326 • converted $33.8 million balance of a Fund II note receivable for interest in real estate on November 2, 2020. Prior to the exchange, the note had been increased by the interest accrued during 2020 of $0.6 million • made a Core loan for $54.0 million with an interest rate of 9% structured as a redeemable preferred equity investment in a property at 850 Third Avenue in Brooklyn, New York on January 14, 2020 • issued a new Core Portfolio note for $5.0 million with an interest rate of 8% collateralized by our partner’s 50% share of the LUF (Georgetown) Portfolio ( Note 4 ) in Washington, D.C. effective February 1, 2020; and • recorded additional credit loss reserves of $0.3 million related to new transactions and recent market volatility. One Core Portfolio note aggregating $21.6 million including accrued interest (exclusive of default interest and other amounts due on the loan . The Company monitors the credit quality of its notes receivable on an ongoing basis and considers indicators of credit quality such as loan payment activity, the estimated fair value of the underlying collateral, the seniority of the Company’s loan in relation to other debt secured by the collateral and the prospects of the borrower. Earnings from these notes and mortgages receivable are reported within the Company’s Structured Financing segment ( Note 12 ). The Company’s estimated allowance for credit losses related to its Structured Financing segment has been computed for its amortized cost basis in the portfolio, including accrued interest ( Note 5 ), factoring historical loss experience in the United Sates for similar loans, as adjusted for current conditions, as well as the Company’s expectations related to future economic conditions. Due to the lack of comparability across the Structured Financing portfolio, each loan was evaluated separately. As a result, for non-collateral dependent loans with a total amortized cost of $79.2 million, inclusive of accrued interest of $6.7 million, an allowance for credit losses has been recorded aggregating $0.7 million at March 31, 2021. For four loans in this portfolio, aggregating $38.4. million, inclusive of accrued interest of $8.8 million at March 31, 2021, the Company has elected to apply a practical expedient in accordance with ASC 326 and did not establish an allowance for credit losses because (i) these loans are collateral-dependent loans, which due to their settlement terms are not expected to be settled in cash but rather by the Company’s possession of the real estate collateral; and (ii) at March 31, 2021, the Company determined that the estimated fair value of the collateral at the expected realization date for these loans was sufficient to cover the carrying value of its investments in these notes receivable. Impairment charges may be required if and when such amounts are estimated to be nonrecoverable upon a realization event, which is generally at the time a loan is repaid, or in the case of foreclosure, when the underlying asset is sold; however, non-recoverability may also be concluded if it is reasonably certain that all amounts due will not be collected.

Investments in and Advances to

Investments in and Advances to Unconsolidated Affiliates	3 Months Ended
	Mar. 31, 2021
Equity Method Investments And Joint Ventures [Abstract]
Investments in and Advances to Unconsolidated Affiliates	4. Investments in and Advances to Unconsolidated Affiliates The Company accounts for its investments in and advances to unconsolidated affiliates primarily under the equity method of accounting as it has the ability to exercise significant influence, but does not have financial or operating control over the investment, which is maintained by each of the unaffiliated partners who co-invest with the Company. The Company’s investments in and advances to unconsolidated affiliates consist of the following (dollars in thousands): Ownership Interest March 31, December 31, Portfolio Property March 31, 2021 2021 2020 Core: 840 N. Michigan (a) 88.43% $ 54,924 $ 55,863 Renaissance Portfolio 20% 28,742 29,270 Gotham Plaza 49% 28,589 28,683 Georgetown Portfolio 50% 3,870 4,624 1238 Wisconsin Avenue 80% 3,008 2,571 119,133 121,011 Mervyns I & II: KLA/ABS (b) 36.7% 78,526 72,391 Fund III: Self Storage Management (c) 95% 207 207 Fund IV: Fund IV Other Portfolio 98.57% 12,394 11,719 650 Bald Hill Road 90% 12,532 12,550 24,926 24,269 Fund V: Family Center at Riverdale (a) 89.42% 12,679 11,824 Tri-City Plaza 90% 7,309 7,024 Frederick County Acquisitions 90% 10,647 10,837 30,635 29,685 Various: Due from (to) Related Parties 290 363 Other (d) 2,615 1,881 Investments in and advances to unconsolidated affiliates $ 256,332 $ 249,807 Core: Crossroads (e) 49% $ 15,272 $ 15,616 Distributions in excess of income from, and investments in, unconsolidated affiliates $ 15,272 $ 15,616 (a) Represents a tenancy-in-common interest. (b) Includes an interest in Albertsons (at fair value, as described below) ( Note 8 ). (c) Represents a variable interest entity for which the Company was determined not to be the primary beneficiary. (d) Includes cost-method investments in Storage Post, Fifth Wall and other investments. (e) Distributions have exceeded the Company’s investment; however, the Company recognizes a liability balance as it may be required to return distributions to fund future obligations of the entity. Core Portfolio Acquisition of Unconsolidated Investments On August 8, 2019, the Company invested $1.8 million in Fifth Wall Ventures Retail Fund, L.P. (“Fifth Wall”) Subsequent to its initial investment, the Company invested a total of $1.1 million through March 31, 2021. The Company accounts for its interest at cost less impairment given its ownership is less than five percent and the Company has no influence over the partnership’s operating and financial policies. During the fourth quarter of 2020, the Company impaired $ 0.4 million of this investment ( Note 8 ) reflecting management’s estimate of fair value at that date. At March 31, 2021 , the Company’s investment was $ 2.5 million. Town Center On April 1, 2020, the Company exchanged the remaining $38.7 million of Brandywine Notes Receivable ( Note 3 ), plus accrued interest of $2.0 million for the remaining 24.78% interest in Town Center, thereby obtaining a 100% controlling interest in the property. The property was then consolidated ( Note 2 ) and the Company recorded the remaining interest in the property investment at the carrying value of the notes. Fund Investments Albertsons During 2006, as part of a series of investments with a consortium of other investors known as the “RCP Venture”, Mervyns II acquired an indirect interest in Albertsons Companies, Inc. a private chain of grocery stores (“Albertsons”) through two 36.67% owned entities (KLA A Investments, LLC and ABS Opportunities, LLC, “KLA/ABS”). Its investment (the “Investment in Albertsons”) has been accounted for under the cost method as Mervyns II has no influence over operating and financial policies of KLA/ABS. Subsequent to the initial investment in 2006, Mervyns II received distributions from its Investment in Albertsons in excess of its initial contribution, which has been recognized in earnings. During the second and fourth quarters of 2020, Mervyns II realized gains of approximately $22.8 million and $0.4 million, respectively, from its Investment in Albertsons. The realized gains during the second quarter of 2020 resulted from the issuance and distribution of proceeds from a preferred equity investment and a sale of a portion of its investment in an initial public offering of Albertsons, both of which occurred in June 2020. Following these transactions, Mervyns II has retained an effective indirect ownership of approximately 4.1 million shares (approximately 1% interest) through its Investment in Albertsons, which it has accounted for at fair value following the initial public offering given the readily determinable fair value, resulting in an unrealized gain of approximately $64.9 million during the second quarter of 2020. During the year ended December 31, 2020, the Company recorded an additional net unrealized holding gain of $7.5 million reflecting the change in fair value of its Investment in Albertsons. During the three months ended March 31, 2021, Mervyns II realized gains of $0.4 million related to distributions from its Investment in Albertsons and recorded an additional net unrealized holding gain of $6.1 million reflecting the change in fair value of its Investment in Albertsons. The Company has reflected both the realized and net unrealized gain as Realized and unrealized holding gains on investments and other within its consolidated statements of operations. The Company has an effective ownership interest of 28.33% in Mervyns II. Broughton Street Portfolio On May 26, 2020, pursuant to the buy-sell provisions of the operating agreement of the Broughton Street Portfolio, Fund IV acquired all of the third-party equity of BSP II, which underlies two properties within Broughton Street Portfolio, for $1.3 million. These two BSP II properties were consolidated during the second quarter of 2020. Fees from Unconsolidated Affiliates The Company earned property management, construction, development, legal and leasing fees from its investments in unconsolidated partnerships totaling $0.1 million for each of the three months ended March 31, 2021 and 2020, which are included in other revenues in the consolidated statements of operations. In addition, the Company paid to certain unaffiliated partners of its joint ventures, $0.4 million and $1.0 million for the three months ended March 31, 2021 and 2020, respectively for leasing commissions, development, management, construction and overhead fees. Summarized Financial Information of Unconsolidated Affiliates The following combined and condensed Balance Sheets and Statements of operations, in each period, summarize the financial information of the Company’s investments in unconsolidated affiliates that were held as of December 31, 2020, and accordingly exclude the results of any investments disposed of or consolidated prior to that date (in thousands): March 31, 2021 December 31, 2020 Combined and Condensed Balance Sheets Assets: Rental property, net $ 552,262 $ 563,997 Real estate under development 15,907 14,517 Other assets 64,358 61,969 Total assets $ 632,527 $ 640,483 Liabilities and partners’ equity: Mortgage notes payable $ 505,245 $ 512,490 Other liabilities 75,268 74,872 Partners’ equity 52,014 53,121 Total liabilities and partners’ equity $ 632,527 $ 640,483 Company's share of accumulated equity $ 100,729 $ 100,767 Basis differential 54,582 55,017 Deferred fees, net of portion related to the Company's interest 4,111 3,565 Amounts receivable/payable by the Company 290 363 Investments in and advances to unconsolidated affiliates, net of Company's share of distributions in excess of income from and investments in unconsolidated affiliates 159,712 159,712 Investments carried at fair value or cost 81,348 74,479 Company's share of distributions in excess of income from and investments in unconsolidated affiliates 15,272 15,616 Investments in and advances to unconsolidated affiliates $ 256,332 $ 249,807 Three Months Ended March 31, 2021 2020 Combined and Condensed Statements of Operations Total revenues $ 17,281 $ 19,496 Operating and other expenses (6,219 ) (6,579 ) Interest expense (4,822 ) (5,256 ) Depreciation and amortization (8,801 ) (6,360 ) Gain on disposition of properties (a) 3,206 — Net income attributable to unconsolidated affiliates $ 645 $ 1,301 Company’s share of equity in net income of unconsolidated affiliates $ 2,699 $ 334 Basis differential amortization (436 ) (324 ) Company’s equity in earnings of unconsolidated affiliates $ 2,263 $ 10 (a) Represents the gain on the sale of two land parcels by the Family Center at Riverdale on January 4, 2021.

Other Assets, Net and Accounts

Other Assets, Net and Accounts Payable and Other Liabilities	3 Months Ended
	Mar. 31, 2021
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Other Assets, Net and Accounts Payable and Other Liabilities	5. Other Assets, Net and Accounts Payable and Other Liabilities Other assets, net and accounts payable and other liabilities are comprised of the following for the periods presented: (in thousands) March 31, 2021 December 31, 2020 Other Assets, Net: Lease intangibles, net ( Note 6 ) $ 91,371 $ 100,732 Deferred charges, net (a) 30,524 30,488 Accrued interest receivable 15,481 13,917 Prepaid expenses 14,121 17,468 Due from seller 3,364 3,682 Income taxes receivable 2,613 2,433 Other receivables 2,068 2,058 Deposits 1,744 1,728 Corporate assets, net 1,308 1,302 Derivative financial instruments ( Note 8 ) 2 1 $ 162,596 $ 173,809 (a) Deferred Charges, Net: Deferred leasing and other costs $ 61,107 $ 57,533 Deferred financing costs related to line of credit 11,380 11,341 72,487 68,874 Accumulated amortization (41,963 ) (38,386 ) Deferred charges, net $ 30,524 $ 30,488 Accounts Payable and Other Liabilities: Lease intangibles, net ( Note 6 ) $ 71,023 $ 76,434 Accounts payable and accrued expenses 56,149 53,031 Derivative financial instruments ( Note 8 ) 56,083 90,139 Deferred income 35,396 31,842 Tenant security deposits, escrow and other 12,025 12,178 Lease liability - finance leases, net ( Note 11 6,382 6,287 $ 237,058 $ 269,911

Lease Intangibles

Lease Intangibles	3 Months Ended
	Mar. 31, 2021
Goodwill And Intangible Assets Disclosure [Abstract]
Lease Intangibles	6. Lease Intangibles Upon acquisitions of real estate ( Note 2 ), the Company assesses the fair value of acquired assets (including land, buildings and improvements, and identified intangibles such as above- and below-market leases, including below-market options and acquired in-place leases) and assumed liabilities. The lease intangibles are amortized over the remaining terms of the respective leases, including option periods where applicable. Intangible assets and liabilities are included in Other assets and Accounts payable and other liabilities ( Note 5 ) on the consolidated balance sheet and summarized as follows (in thousands): March 31, 2021 December 31, 2020 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Amortizable Intangible Assets In-place lease intangible assets $ 265,722 $ (178,279 ) $ 87,443 $ 268,335 $ (171,856 ) $ 96,479 Above-market rent 19,188 (15,260 ) 3,928 19,188 (14,935 ) 4,253 $ 284,910 $ (193,539 ) $ 91,371 $ 287,523 $ (186,791 ) $ 100,732 Amortizable Intangible Liabilities Below-market rent $ (160,388 ) $ 89,812 $ (70,576 ) $ (164,923 ) $ 88,951 $ (75,972 ) Above-market ground lease (671 ) 224 (447 ) (671 ) 209 (462 ) $ (161,059 ) $ 90,036 $ (71,023 ) $ (165,594 ) $ 89,160 $ (76,434 ) During the three months ended March 31, 2021, the Company did not acquire or assume any intangible assets or liabilities. During the year ended December 31, 2020, the Company acquired in-place lease intangible assets of $21.0 million, above-market rents of $2.0 million, and below-market rents of $4.6 million with weighted-average useful lives of 4.9, 5.8, and 20.2 years, respectively. Amortization of in-place lease intangible assets is recorded in depreciation and amortization expense and amortization of above-market rent and below-market rent is recorded as a reduction to and increase to rental income, respectively, in the consolidated statements of operations. Amortization of above-market ground leases are recorded as a reduction to rent expense in the consolidated statements of operations. The scheduled amortization of acquired lease intangible assets and assumed liabilities as of March 31, 2021 is as follows (in thousands): Years Ending December 31, Net Increase in Lease Revenues Increase to Amortization Reduction of Rent Expense Net (Expense) Income 2021 (Remainder) $ 4,923 $ (17,375 ) $ 44 $ (12,408 ) 2022 5,944 (17,869 ) 58 (11,867 ) 2023 5,476 (13,239 ) 58 (7,705 ) 2024 5,126 (9,297 ) 58 (4,113 ) 2025 4,459 (6,939 ) 58 (2,422 ) Thereafter 40,720 (22,724 ) 171 18,167 Total $ 66,648 $ (87,443 ) $ 447 $ (20,348 )

Debt

Debt	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
Debt	7. Debt A summary of the Company’s consolidated indebtedness is as follows (dollars in thousands): Interest Rate at Carrying Value at March 31, December 31, Maturity Date at March 31, December 31, 2021 2020 March 31, 2021 2021 2020 Mortgages Payable Core Fixed Rate 3.88%-5.89% 3.88%-5.89% Feb 2024 - Apr 2035 $ 147,233 $ 147,810 Core Variable Rate - Swapped ( a) 3.41%-4.54% 3.41%-4.54% Jan 2023 - Nov 2028 73,569 80,500 Total Core Mortgages Payable 220,802 228,310 Fund II Variable Rate LIBOR+3.00% - PRIME+2.00% LIBOR+3.00% - PRIME+2.00% Mar 2022 - August 2022 229,101 228,282 Fund II Variable Rate - Swapped ( a) 2.88% 2.88% Nov 2021 18,733 18,803 Total Fund II Mortgages Payable 247,834 247,085 Fund III Variable Rate LIBOR+2.75%-LIBOR+3.10% LIBOR+2.75%-LIBOR+3.10% Jun 2021 - Jul 2022 71,613 71,918 Fund IV Fixed Rate 3.40%-4.50% 3.40%-4.50% Oct 2025 - Jun 2026 6,726 6,726 Fund IV Variable Rate LIBOR+1.60%-LIBOR+3.40% LIBOR+1.60%-LIBOR+3.40% Apr 2021 - Oct 2025 245,302 254,234 Fund IV Variable Rate - Swapped ( a) 3.48%-4.61% 3.48%-4.61% Apr 2022 - Dec 2022 66,250 66,590 Total Fund IV Mortgages and Other Notes Payable 318,278 327,550 Fund V Variable Rate LIBOR+1.50%-LIBOR+2.20% LIBOR+1.50%-LIBOR+2.20% Jun 2021 - Dec 2024 1,077 1,354 Fund V Variable Rate - Swapped (a) 2.95%-4.78% 2.95%-4.78% Jun 2021 - Dec 2024 334,339 334,323 Total Fund V Mortgages Payable 335,416 335,677 Net unamortized debt issuance costs (5,770 ) (6,507 ) Unamortized premium 522 548 Total Mortgages Payable $ 1,188,695 $ 1,204,581 Unsecured Notes Payable Core Variable Rate Credit Facility LIBOR+2.55% LIBOR+2.55% Jun 2021 $ 30,000 $ 30,000 Core Variable Rate Unsecured Term Loans - Swapped (a) 2.49%-5.02% 2.49%-5.02% Mar 2023 350,000 350,000 Total Core Unsecured Notes Payable 380,000 380,000 Fund II Unsecured Notes Payable LIBOR+1.65% LIBOR+1.65% Sep 2021 40,000 40,000 Fund IV Term Loan/Subscription Facility LIBOR+1.90% LIBOR+1.90% Dec 2021 1,400 864 Fund V Subscription Facility LIBOR+1.60% LIBOR+1.60% May 2021 — 250 Net unamortized debt issuance costs (440 ) (256 ) Total Unsecured Notes Payable $ 420,960 $ 420,858 Unsecured Line of Credit Core Unsecured Line of Credit -Swapped (a) 2.49%-5.02% 2.49%-5.02% Mar 2022 $ 105,400 $ 138,400 Total Debt - Fixed Rate (b, c ) $ 1,102,250 $ 1,143,152 Total Debt - Variable Rate (d) 618,493 626,902 Total Debt 1,720,743 1,770,054 Net unamortized debt issuance costs (6,210 ) (6,763 ) Unamortized premium 522 548 Total Indebtedness $ 1,715,055 $ 1,763,839 (a) At March 31, 2021, the stated rates ranged from LIBOR + 1.50% to LIBOR +1.90% LIBOR + 1.39% LIBOR + 2.75% to LIBOR + 3.10% LIBOR + 1.75% to LIBOR +2.00% LIBOR + 1.50% to LIBOR + 2.20% LIBOR + 1.25% (b) Includes $948.3 million and $988.6 million, respectively, of variable-rate debt that has been fixed with interest rate swap agreements as of the periods presented (c) Fixed-rate debt at March 31, 2021 and December 31, 2020 includes $36.2 million and $3.2 million, respectively of Core swaps that may be used to hedge debt instruments of the Funds. (d) Includes $140.0 million and $139.2 million, respectively, of variable-rate debt that is subject to interest cap agreements. Credit Facility The Company has a $600.0 million senior unsecured credit facility (the “Credit Facility”), comprised of a $250.0 million senior unsecured revolving credit facility (the “Revolver”) which bears interest at LIBOR + 1.40%, and a $350.0 million senior unsecured term loan (the “Term Loan”) which bears interest at LIBOR + 1.30%. The revolving credit facility matures on March 31, 2022, subject to two six-month extension options, and the $350.0 million Term Loan expires on March 31, 2023. Mortgages and Other Notes Payable During the three months ended March 31, 2021, the Company: • extended three Fund mortgages, two of which were extended for one year with aggregate outstanding balances of $37.7 million at March 31, 2021 and one of which was extended for one month with an outstanding balance of $23.1 million at March 31, 2021; • modified the terms of the Fund IV Bridge facility which had an outstanding balance of $79.2 million. Fund IV repaid $10.0 million of principal, the maturity date was extended from June 30, 2021 to December 31, 2021, and the interest rate was changed from LIBOR plus 2.0% to LIBOR plus 2.5% with a floor of 0.25%; • entered into a swap agreement in January 2021 with a notional value of $16.7 million, for its New Towne Plaza mortgage replacing the existing swap which expired. In addition, the Company terminated two forward starting interest rate swaps resulting in cash proceeds of approximately $3.4 million ( Note 8 ); • repaid one Core mortgage of $6.7 million in connection with the sale of 60 Orange Street in January 2021 ( Note 2 ); and • made scheduled principal payments of $2.0 million. During the year ended December 31, 2020, the Company: • extended the maturity date of a $200.0 million Fund II loan from May 2020 to May 2022. In addition, the Company extended seven Fund mortgages, two of which were extended for one year during the first quarter with aggregate outstanding balances of $46.0 million at December 31, 2020, two of which were extended for one year during the second quarter with an aggregate outstanding balance of $51.3 million at December 31, 2020, one of which was extended for one year during the third quarter with aggregate outstanding balances of $40.0 million at December 31, 2020, and two of which were extended for a minimum of one year during the fourth quarter with aggregate outstanding balances of $88.0 million at December 31, 2020; • modified the terms of one Fund IV $23.8 million mortgage, which had $18.9 million outstanding, in June 2020 to adjust the allowable timing of draws. At closing, an additional $1.0 million was drawn and in July 2020 an additional $0.9 million was drawn. The Company also modified one Fund III and two Fund IV loans aggregating $103.4 million requiring the repayment of $11.5 million; • entered into two swap agreements in February 2020 each with notional values of $50.0 million, which are not effective until April 2022 and April 2023 and were later terminated in the first quarter of 2021. In July 2020, two previously-executed forward swap agreements took effect with current notional values as of December 31, 2020 of $30.4 million each ( Note 8 ); • repaid one Core mortgage of $26.3 million in connection with the litigation settlement discussed below and one Fund IV mortgage of $11.6 million in connection with the sale of Colonie Plaza in April 2020 ( Note 2 ); and • made scheduled principal payments of $6.1 million. At March 31, 2021, a Fund III mortgage in the amount of $35.6 million, or $8.7 million at the Company’s share, had not met its liquidity requirement; however, this condition is expected to be remedied by the sale of 654 Broadway, which is reflected as held for sale at March 31, 2021 ( Note 2 ). At March 31, 2021 and December 31, 2020, the Company’s mortgages were collateralized by 41 and 42 properties, respectively, and the related tenant leases. Certain loans are cross-collateralized and contain cross-default provisions. The loan agreements contain customary representations, covenants and events of default. Certain loan agreements require the Company to comply with affirmative and negative covenants, including the maintenance of debt service coverage and leverage ratios. The Company is not in default on any of its loan agreements. A portion of the Company’s variable-rate mortgage debt has been effectively fixed through certain cash flow hedge transactions ( Note 8 ). A mortgage loan collateralized by the property held by Brandywine Holdings in the Core Portfolio, was in default and subject to litigation at December 31, 2019. The loan was originated in June 2006 and had an original principal amount of $26.3 million and a scheduled maturity of July 1, 2016. By maturity, the loan was in default. On October 30, 2020, the Company settled the litigation for approximately $30.0 million resulting in a gain on debt extinguishment of $18.3 million reflected in Realized and unrealized holding gains on investments and other in the consolidated statement of operations during the fourth quarter of 2020, of which the Company’s proportionate share was $4.1 million. Upon settlement of this litigation, the Company obtained its partner’s 77.78% noncontrolling interest for nominal consideration, resulting in a negative adjustment of $15.9 million to equity. Unsecured Notes Payable Unsecured notes payable for which total availability was $127.8 million and $128.7 million at March 31, 2021 and December 31, 2020, respectively, are comprised of the following: • The outstanding balance of the Core term loan was $350.0 • On July 1, 2020, the Company obtained an additional $30.0 million Core term loan, with an accordion option to increase up to $90.0 million. This term loan matures on June 30, 2021 and bears interest at LIBOR plus 2.55% with a LIBOR floor of 0.75%. The outstanding balance at each of March 31, 2021 and December 31, 2020 was $30.0 million. There was no availability at each of March 31, 2021 and December 31, 2020. • Fund II has a $40.0 million term loan secured by the real estate assets of City Point Phase II and guaranteed by the Operating Partnership. The outstanding balance of the Fund II term loan was $40.0 • Fund IV has a $5.0 million subscription line with an outstanding balance and total available credit of $1.4 million and $0, respectively at March 31, 2021, reflecting letters of credit of $3.6 million. The outstanding balance and total availability at December 31, 2020 were $0.9 million and $0.5 million, respectively, reflecting letters of credit of $3.6 million • Fund V has a $150.0 million subscription line collateralized by Fund V’s unfunded capital commitments, and, to the extent of Acadia’s capital commitments, is guaranteed by the Operating Partnership. During the year ended December 31, 2020, the Company modified the $150.0 million Fund V Subscription line and extended the due date from May 2020 to May 2021. The outstanding balance and total available credit of the Fund V subscription line was $0 and $127.8 million, respectively at March 31, 2021 reflecting outstanding letters of credit of $22.2 million. The outstanding balance were $0.3 million and $128.2 million at December 31, 2020 reflecting outstanding letters of credit of $21.5 million. Unsecured Revolving Line of Credit The Company had a total of $136.6 million and $101.1 million, respectively, available under its $250.0 million Core Revolver, reflecting borrowings of $105.4 million and $138.4 million and letters of credit of $8.0 million and $10.5 million at March 31, 2021 and December 31, 2020, respectively. At each of March 31, 2021 and December 31, 2020, all of the Core unsecured revolving line of credit was swapped to a fixed rate. Scheduled Debt Principal Payments The scheduled principal repayments, without regard to available extension options (described further below), of the Company’s consolidated indebtedness, as of March 31, 2021 are as follows (in thousands): Year Ending December 31, 2021 $ 365,838 2022 535,612 2023 409,359 2024 212,020 2025 65,326 Thereafter 132,588 1,720,743 Unamortized premium 522 Net unamortized debt issuance costs (6,210 ) Total indebtedness $ 1,715,055 The table above does not reflect available extension options (subject to customary conditions) on consolidated debt of $260.5 million contractually due in 2021, $250.6 million contractually due in 2022, and $41.5 million contractually due in 2023; most for which the Company has available options to extend by up to 12 months and for some an additional 12 months thereafter. However, there can be no assurance that the Company will be able to successfully execute any or all of its available extension options. See Note 4 for information about liabilities of the Company’s unconsolidated affiliates.

Financial Instruments and Fair

Financial Instruments and Fair Value Measurements	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Financial Instruments and Fair Value Measurements	8. Financial Instruments and Fair Value Measurements The fair value of an asset is defined as the exit price, which is the amount that would either be received when an asset is sold or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The guidance establishes a three-tier fair value hierarchy based on the inputs used in measuring fair value. These tiers are: Level 1, for which quoted market prices for identical instruments are available in active markets, such as money market funds, equity securities, and U.S. Treasury securities; Level 2, for which there are inputs other than quoted prices included within Level 1 that are observable for the instrument, such as certain derivative instruments including interest rate caps and interest rate swaps; and Level 3, for financial instruments or other assets/liabilities that do not fall into Level 1 or Level 2 and for which little or no market data exists, therefore requiring the Company to develop its own assumptions. Items Measured at Fair Value on a Recurring Basis The methods and assumptions described below were used to estimate the fair value of each class of financial instrument. For significant Level 3 items, the Company has also provided the unobservable inputs along with their weighted-average ranges. Money Market Funds — The Company has money market funds, which at times have zero balances and are included in Cash and cash equivalents in the consolidated balance sheets, and are comprised of government securities and/or U.S. Treasury bills. These funds were classified as Level 1 as we used quoted prices from active markets to determine their fair values. Equity Investments –Albertsons became publicly traded during 2020 ( Note 4 ). Upon Albertsons’ IPO, the Company’s Investment in Albertsons has a readily determinable market value (traded on an exchange) and is being accounted for as a Level 1 investment. Derivative Assets — The Company has derivative assets, which are included in Other assets, net on the consolidated balance sheets, and are comprised of interest rate swaps and caps. The derivative instruments were measured at fair value using readily observable market inputs, such as quotations on interest rates, and were classified as Level 2 as these instruments are custom, over-the-counter contracts with various bank counterparties that are not traded in an active market. See “Derivative Financial Instruments,” below. Derivative Liabilities — The Company has derivative liabilities, which are included in Accounts payable and other liabilities on the consolidated balance sheets, and are comprised of interest rate swaps. These derivative instruments were measured at fair value using readily observable market inputs, such as quotations on interest rates, and were classified as Level 2 because they are custom, over-the-counter contracts with various bank counterparties that are not traded in an active market. See “Derivative Financial Instruments,” below. Other than the Investment in Albertsons described above, the Company did not have any transfers into or out of Level 1, Level 2, and Level 3 measurements during the three months ended March 31, 2021 or 2020. The following table presents the Company’s fair value hierarchy for those assets and liabilities measured at fair value on a recurring basis (in thousands): March 31, 2021 December 31, 2020 Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Assets Money market funds $ — $ — $ — $ — $ — $ — Derivative financial instruments — 2 — — 1 — Investment in Albertsons ( Note 4 ) 78,526 — — 72,391 — — Liabilities Derivative financial instruments — 56,083 — — 90,139 — In instances where the determination of the fair value measurement is based on inputs from different levels of the fair value hierarchy, the level in the fair value hierarchy within which the entire fair value measurement falls is based on the lowest level input that is significant to the fair value measurement in its entirety. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment, and considers factors specific to the asset or liability. Items Measured at Fair Value on a Nonrecurring Basis (Including Impairment Charges) During 2020, the Company was impacted by the COVID-19 Pandemic ( Note 11 ), which caused the Company to reduce its holding periods and forecasted operating income at certain properties. As a result, several impairments were recorded. Impairment charges for the periods presented are as follows (in thousands): Impairment Charge Property and Location Owner Triggering Event Level 3 Inputs Effective Date Total Acadia's Share 2021 Impairment Charges None 2020 Impairment Charges Cortlandt Crossing, Mohegan Lake, NY Fund III Reduced holding period, reduced projected operating income Projections of: holding period, net operating income, cap rate, incremental costs Mar 31, 2020 $ 27,402 $ 6,726 654 Broadway, New York, NY Fund III Reduced holding period Projections of: holding period, net operating income, cap rate, incremental costs Mar 31, 2020 6,398 1,570 146 Geary Street, San Francisco, CA Fund IV Reduced holding period, reduced projected operating income Projections of: holding period, net operating income, cap rate, incremental costs Mar 31, 2020 6,718 1,553 801 Madison Avenue, New York, NY Fund IV Reduced holding period, reduced projected operating income Projections of: holding period, net operating income, cap rate, incremental costs Mar 31, 2020 11,031 2,551 717 N. Michigan Avenue, Chicago, IL Fund IV Reduced holding period, reduced projected operating income Projections of: holding period, net operating income, cap rate, incremental costs Dec 31, 2020 17,392 4,021 110 University, New York, NY Fund IV Reduced holding period, reduced projected operating income Projections of: holding period, net operating income, cap rate, incremental costs Dec 31, 2020 16,238 3,754 Fifth Wall Investment Core Decline in fair value Projections of: reported fair value of net assets Dec 31, 2020 419 419 Total 2020 Impairment Charges $ 85,598 $ 20,594 Derivative Financial Instruments The Company had the following interest rate swaps and caps for the periods presented (dollars in thousands): Strike Rate Fair Value Derivative Instrument Aggregate Notional Amount Effective Date Maturity Date Low High Balance Sheet Location March 31, 2021 December 31, 2020 Core Interest Rate Swaps $ 565,158 Dec 2012-Jul 2020 Jun 2021-Jul 2030 1.24 % — 3.77 % Other Liabilities $ (44,451 ) $ (74,990 ) $ 565,158 $ (44,451 ) $ (74,990 ) Fund II Interest Rate Swap $ 18,733 Oct 2014 Nov 2021 2.88 % — 2.88 % Other Liabilities $ (154 ) $ (219 ) Interest Rate Cap 45,000 Mar 2019 Mar 2022 3.50 % — 3.50 % Other Assets — — $ 63,733 $ (154 ) $ (219 ) Fund III Interest Rate Caps $ 35,970 Jan 2021 Jul 2022 3.00 % — 3.00 % Other Assets $ — $ — Fund IV Interest Rate Swaps $ 66,250 Mar 2017 - Dec 2019 Apr 2022 - Dec 2022 1.48 % — 4.00 % Other Liabilities $ (1,399 ) $ (1,713 ) Interest Rate Caps 77,400 July 2019 - Dec 2020 Jul 2021 - Dec 2022 3.00 % — 3.50 % Other Assets 2 1 $ 143,650 $ (1,397 ) $ (1,712 ) Fund V Interest Rate Swaps $ 334,339 Jun 2018-Feb 2021 Jun 2021-Oct 2024 0.23 % — 2.88 % Other Liabilities $ (10,079 ) $ (13,217 ) $ 334,339 $ (10,079 ) $ (13,217 ) Total asset derivatives $ 2 $ 1 Total liability derivatives $ (56,083 ) $ (90,139 ) All of the Company’s derivative instruments have been designated as cash flow hedges and hedge the future cash outflows on variable-rate debt ( Note 7 ). It is estimated that approximately $19.7 million included in Accumulated other comprehensive loss related to derivatives will be reclassified to interest expense within the next twelve months. As of March 31, 2021 and December 31, 2020, no derivatives were designated as fair value hedges or hedges of net investments in foreign operations. Additionally, the Company does not use derivatives for trading or speculative purposes and currently does not have any derivatives that are not designated hedges. During the first quarter of 2021, the Company terminated two forward swaps with an aggregate notional value of $100.0 million ( Note 7 ) for cash proceeds of $3.4 million. As the hedged forecasted transaction is still expected, amounts deferred in Accumulated other comprehensive loss will be amortized into earnings as a reduction of interest expense over the original term of the swaps, beginning in 2022. Risk Management Objective of Using Derivatives The Company is exposed to certain risks arising from both its business operations and economic conditions. The Company manages economic risks, including interest rate, liquidity and credit risk, primarily by managing the amount, sources and duration of its debt funding and, from time to time, through the use of derivative financial instruments. The Company enters into derivative financial instruments to manage exposures that result in the receipt or payment of future known and uncertain cash amounts, the The Company is exposed to credit risk in the event of non-performance by the counterparties to the swaps if the derivative position has a positive balance. The Company believes it mitigates its credit risk by entering into swaps with major financial institutions. The Company continually monitors and actively manages interest costs on its variable-rate debt portfolio and may enter into additional interest rate swap positions or other derivative interest rate instruments based on market conditions. Credit Risk-Related Contingent Features The Company has agreements with each of its swap counterparties that contain a provision whereby if the Company defaults on certain of its unsecured indebtedness, the Company could also be declared in default on its swaps, resulting in an acceleration of payment under the swaps. Other Financial Instruments The Company’s other financial instruments had the following carrying values and fair values as of the dates shown (dollars in thousands, inclusive of amounts attributable to noncontrolling interests where applicable): March 31, 2021 December 31, 2020 Level Carrying Amount Estimated Fair Value Carrying Amount Estimated Fair Value Notes Receivable (a) 3 $ 101,410 $ 101,917 $ 101,450 $ 102,135 Mortgage and Other Notes Payable (a) 3 1,193,943 1,171,180 1,210,540 1,190,214 Investment in non-traded equity securities (b) 3 2,460 2,386 1,726 1,456 Unsecured notes payable and Unsecured line of credit (c) 2 526,800 514,982 559,514 544,532 (a) The Company determined the estimated fair value of these financial instruments using a discounted cash flow model with rates that take into account the credit of the borrower or tenant, where applicable, and interest rate risk. The Company also considered the value of the underlying collateral, taking into account the quality of the collateral, the credit quality of the borrower, the time until maturity and the current market interest rate environment. (b) Represents the Operating Partnership’s cost-method investment in Fifth Wall ( Note 4 ). (c) The Company determined the estimated fair value of the unsecured notes payable and unsecured line of credit using quoted market prices in an open market with limited trading volume where available. In cases where there was no trading volume, the Company determined the estimated fair value using a discounted cash flow model using a rate that reflects the average yield of similar market participants. The Company’s cash and cash equivalents, restricted cash, rents receivable, accounts payable and certain financial instruments included in other assets and other liabilities had fair values that approximated their carrying values due to their short maturity profiles at March 31, 2021.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2021
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	9. Commitments and Contingencies The Company is involved in various matters of litigation arising out of, or incident to, its business. While the Company is unable to predict with certainty the outcome of any particular matter, management does not expect, when such litigation is resolved, that the Company’s resulting exposure to loss contingencies, if any, will have a material adverse effect on its consolidated financial position. Commitments and Guaranties In conjunction with the development and expansion of various properties, the Company has entered into agreements with general contractors for the construction or development of properties aggregating approximately $32.4 million and $32.7 million as of March 31, 2021 and December 31, 2020, respectively. At March 31, 2021 and December 31, 2020, the Company had Core and Fund letters of credit outstanding of $33.8 million and $35.6 million, respectively ( Note 7 ). The Company has not recorded any obligation associated with these letters of credit. The majority of the letters of credit are collateral for existing indebtedness and other obligations of the Company.

Shareholders' Equity, Noncontro

Shareholders' Equity, Noncontrolling Interests and Other Comprehensive Loss	3 Months Ended
	Mar. 31, 2021
Stockholders Equity Including Portion Attributable To Noncontrolling Interest [Abstract]
Shareholders' Equity, Noncontrolling Interests and Other Comprehensive Loss	10. Shareholders’ Equity, Noncontrolling Interests and Other Comprehensive Loss Common Shares and Units In addition to the share repurchase activity discussed below, the Company completed the following transactions in its Common Shares during the three months ended March 31, 2021: • The Company withheld 3,050 restricted shares of its Common Shares (“Restricted Shares”) to pay the employees’ statutory minimum income taxes due on the value of the portion of their Restricted Shares that vested. • The Company recognized Common Share and Common OP Unit-based compensation expense totaling $2.7 million and $2.4 million in connection with Restricted Shares and Units ( Note 13 ) for the three months ended March 31, 2021 and 2020, respectively. In addition to the ATM Program activity discussed below, the Company completed the following transactions in its Common Shares during the year ended December 31, 2020: • The Company withheld 2,075 Restricted Shares to pay the employees’ statutory minimum income taxes due on the value of the portion of their Restricted Shares that vested. • The Company recognized Common Share and Common OP Unit-based compensation expense totaling $8.4 million in connection with Restricted Shares and Units ( Note 13 ). ATM Program The Company has an at-the-market equity issuance program (“ATM Program”) that provides the Company an efficient and low-cost vehicle for raising public equity capital to fund its needs. The Company entered into its current $250.0 million ATM Program, which includes an optional “forward purchase” component, in the second quarter of 2019. The Company has not sold any Common Shares under its ATM Program nor issued any shares on a forward basis during the three months ended March 31, 2021 or the year ended December 31, 2020 and currently has approximately $170.0 million of availability under the ATM program. Share Repurchase Program During 2018, the Company’s board of trustees (the “Board”) approved a new share repurchase program, which authorizes management, at its discretion, to repurchase up to $200.0 million of its outstanding Common Shares. The program does not obligate the Company to repurchase any specific number of Common Shares and may be discontinued or extended at any time. The Company did not repurchase any shares during the three months ended March 31, 2021. During the first quarter of 2020, the Company repurchased 1,219,065 Common Shares for $22.4 million, inclusive of $0.1 million of fees at a weighted average price per share of $18.29, under the share repurchase program, under which $122.6 million remains available as of March 31, 2021. Dividends and Distributions The following table sets forth the distributions declared and/or paid during the periods presented: Date Declared Amount Per Share Record Date Payment Date November 5, 2019 $ 0.29 December 31, 2019 January 15, 2020 February 26, 2020 $ 0.29 March 31, 2020 April 15, 2020 March 15, 2021 $ 0.15 March 31, 2021 April 15, 2021 Beginning with the second quarter of 2020, the Board temporarily suspended distributions on its Common Shares and Common Units, which suspension continued through the fourth quarter of 2020; however, distributions of $0.1 million were payable to preferred unit holders at each of June 30, 2020, September 30, 2020 and December 31, 2020. The Company reinstated quarterly distributions beginning in the first quarter of 2021. Accumulated Other Comprehensive Loss The following tables set forth the activity in accumulated other comprehensive loss for three months ended March 31, 2021 and 2020 (in thousands): Gains or Losses on Derivative Instruments Balance at January 1, 2021 $ (74,891 ) Other comprehensive income before reclassifications - swap agreements 33,556 Reclassification of realized interest on swap agreements 5,317 Net current period other comprehensive income 38,873 Net current period other comprehensive income attributable to noncontrolling interests (5,944 ) Balance at March 31, 2021 $ (41,962 ) Balance at January 1, 2020 $ (31,175 ) Other comprehensive loss before reclassifications - swap agreements (74,774 ) Reclassification of realized interest on swap agreements 977 Net current period other comprehensive loss (73,797 ) Net current period other comprehensive loss attributable to noncontrolling interests 19,257 Balance at March 31, 2020 $ (85,715 ) Noncontrolling Interests The following tables summarize the change in the noncontrolling interests for the three months ended March 31, 2021 and 2020 (dollars in thousands): Noncontrolling Interests in Operating Partnership (a) Noncontrolling Interests in Partially-Owned Affiliates (b) Total Balance at January 1, 2021 $ 89,431 $ 517,808 $ 607,239 Distributions declared of $0.15 per Common OP Unit (1,048 ) — (1,048 ) Net income (loss) for the three months ended March 31, 2021 470 (3,772 ) (3,302 ) Conversion of 18,800 Common OP Units to Common Shares by limited partners of the Operating Partnership (294 ) — (294 ) Other comprehensive income - unrealized gain on valuation of swap agreements 1,900 2,143 4,043 Reclassification of realized interest expense on swap agreements 53 1,848 1,901 Noncontrolling interest contributions — 11,241 11,241 Noncontrolling interest distributions — (6,676 ) (6,676 ) Employee Long-term Incentive Plan Unit Awards 4,049 — 4,049 Reallocation of noncontrolling interests (c) 369 — 369 Balance at March 31, 2021 $ 94,930 $ 522,592 $ 617,522 Balance at January 1, 2020 $ 97,670 $ 546,987 $ 644,657 Distributions declared of $0.29 per Common OP Unit (1,849 ) — (1,849 ) Net loss for the three months ended March 31, 2020 (336 ) (51,289 ) (51,625 ) Conversion of 147,882 Common OP Units to Common Shares by limited partners of the Operating Partnership (2,472 ) — (2,472 ) Other comprehensive loss - unrealized loss on valuation of swap agreements (3,141 ) (16,388 ) (19,529 ) Reclassification of realized interest expense on swap agreements 7 265 272 Noncontrolling interest contributions — 7,268 7,268 Noncontrolling interest distributions — (3,118 ) (3,118 ) Employee Long-term Incentive Plan Unit Awards 3,648 — 3,648 Reallocation of noncontrolling interests (c) (145 ) — (145 ) Cumulative effect of change in accounting principle — (11 ) (11 ) Balance at March 31, 2020 $ 93,382 $ 483,714 $ 577,096 (a) Noncontrolling interests in the Operating Partnership are comprised of (i) the limited partners’ 3,101,958 and 3,205,931 Common OP Units at March 31, 2021 and March 31, 2020; (ii) 188 Series A Preferred OP Units at March 31, 2021 and March 31, 2020; (iii) 126,593 Series C Preferred OP Units at March 31, 2021 and March 31, 2020; and (iv) 3,409,232 and 3,003,027 LTIP units at March 31, 2021 and March 31, 2020, respectively, as discussed in Share Incentive Plan ( Note 13 (b) Noncontrolling interests in partially-owned affiliates comprise third-party interests in Funds II, III, IV and V, and Mervyns II, and six other subsidiaries. (c) Adjustment reflects the difference between the fair value of the consideration received or paid and the book value of the Common Shares, Common OP Units, Preferred OP Units, and LTIP Units involving changes in ownership. Preferred OP Units There were no issuances of Preferred OP Units during the three months ended March 31, 2021 or the year ended December 31, 2020. In 1999, the Operating Partnership issued 1,580 Series A Preferred OP Units in connection with the acquisition of a property, which have a stated value of $1,000 per unit, and are entitled to a preferred quarterly distribution of the greater of (i) $22.50 (9% annually) per Series A Preferred OP Unit or (ii) the quarterly distribution attributable to a Series A Preferred OP Unit if such unit was converted into a Common OP Unit. Through March 31, 2021, 1,392 Series A Preferred OP Units were converted into 185,600 Common OP Units and then into Common Shares. The 188 remaining Series A Preferred OP Units are currently convertible into Common OP Units based on the stated value divided by $7.50. Either the Company or the holders can currently call for the conversion of the Series A Preferred OP Units at the lesser of $7.50 or the market price of the Common Shares as of the conversion date. During 2016, the Operating Partnership issued 442,478 Common OP Units and 141,593 Series C Preferred OP Units to a third party to acquire Gotham Plaza ( Note 4 ). The Series C Preferred OP Units have a value of $100.00 per unit and are entitled to a preferred quarterly distribution of $0.9375 per unit and are convertible into Common OP Units at a rate based on the share price at the time of conversion. If the share price is below $28.80 on the conversion date, each Series C Preferred OP Unit will be convertible into 3.4722 Common OP Units. If the share price is between $28.80 and $35.20 on the conversion date, each Series C Preferred OP Unit will be convertible into a number of Common OP Units equal to $100.00 divided by the closing share price. If the share price is above $35.20 on the conversion date, each Series C Preferred OP Unit will be convertible into 2.8409 Common OP Units. The Series C Preferred OP Units have a mandatory conversion date of December 31, 2025, at which time all units that have not been converted will automatically be converted into Common OP Units based on the same calculations. Through March 31, 2021, 15,000 Series C Preferred OP Units were converted into 51,887 Common OP Units and then into Common Shares.

Leases

Leases	3 Months Ended
	Mar. 31, 2021
Leases [Abstract]
Leases	11. Leases As Lessor The Company is engaged in the operation of shopping centers and other retail properties that are either owned or, with respect to certain shopping centers, operated under long-term ground leases (see below) that expire at various dates through June 20, 2066, with renewal options (see below). Space in the shopping centers is leased to tenants pursuant to agreements that provide for terms ranging generally from one month to sixty years and generally provide for additional rents based on certain operating expenses as well as tenants’ sales volumes. During the three months ended March 31, 2021 and 2020, the Company earned $14.8 million and $14.6 million, respectively in variable lease revenues, primarily for real estate taxes and common area maintenance charges, which are included in rental income in the consolidated statements of operations. The activity for the reserves related to billed rents and straight-line rents is as follows: Three Months Ended March 31, 2021 Balance at Beginning of Period Charged to Expenses Adjustments to Valuation Accounts Deductions Balance at End of Period Allowance for credit loss - billed rents $ 30,366 $ 3,065 $ — $ (1,162 ) $ 32,269 Straight-line rent reserves 15,042 817 — (175 ) 15,684 Total - rents receivable $ 45,408 $ 3,882 $ — $ (1,337 ) $ 47,953 As Lessee During the three months ended March 31, 2021, the Company: • modified its Rye corporate office lease. As a result, of the modification, the lease was remeasured and the lease liability and right-of-use asset were each reduced by $0.4 million During the year ended December 31, 2020, the Company: • entered into one new office lease as lessee for which the lease commenced in the third quarter of 2020. The Company recorded a right-of-use asset and corresponding lease liability of $1.7 million; • modified its 991 Madison master lease by converting the 49-year fixed term to a 15-year term. As a result of the modification, the lease was reclassified from a finance lease to an operating lease during the second quarter of 2020; • consolidated one property within the BSP II portfolio, 102 E. Broughton, ( Note 2 ), which was subject to a ground lease classified as an operating lease, during the second quarter of 2020; • recorded an impairment charge of $12.3 million on a right-of-use asset for a Fund IV property, 110 University Place ( Note 8 ) • renewed one ground lease for Branch Plaza, an operating lease, for 22 years; and • modified its 1238 Wisconsin lease agreement for a reduced purchase price from $14.5 million to $11.5 million. As a result, remeasured and reduced its right-of-use asset and lease liability by $1.9 million in the fourth quarter of 2020. Additional disclosures regarding the Company’s leases as lessee are as follows: Three Months Ended March 31, 2021 2020 Lease Cost Finance lease cost: Amortization of right-of-use assets $ 226 $ 657 Interest on lease liabilities 95 850 Subtotal 321 1,507 Operating lease cost 2,286 1,394 Variable lease cost 101 16 Total lease cost $ 2,708 $ 2,917 Other Information Weighted-average remaining lease term - finance leases (years) 33.2 42.3 Weighted-average remaining lease term - operating leases (years) 24.5 34.1 Weighted-average discount rate - finance leases 6.3 % 4.4 % Weighted-average discount rate - operating leases 5.6 % 5.8 % Right-of-use assets – finance leases are included in Operating real estate ( Note 2 ) in the consolidated balance sheets. Lease liabilities – finance leases are included in Accounts payable and other liabilities in the consolidated balance sheets ( Note 5 ). Operating lease cost comprises amortization of right-of-use assets for operating properties (related to ground rents) or amortization of right-of-use assets for office and corporate assets and is included in Property operating expense or General and administrative expense, respectively, Lease Obligations The scheduled future minimum (i) rental revenues from rental properties under the terms of non-cancelable tenant leases greater than one year (assuming no new or renegotiated leases or option extensions for such premises) and (ii) rental payments under the terms of all non-cancelable operating and finance leases in which the Company is the lessee, principally for office space, land and equipment, as of March 31, 2021, are summarized as follows (in thousands): Minimum Rental Payments Year Ending December 31, Minimum Rental Revenues (a) Operating Leases (b) Finance Leases (b) 2021 (Remainder) $ 149,226 $ 6,465 $ 69 2022 198,269 7,768 28 2023 177,885 7,789 — 2024 152,363 7,974 — 2025 122,715 7,969 — Thereafter 503,880 150,446 12,289 1,304,338 188,411 12,386 Interest — (100,587 ) (6,230 ) Total $ 1,304,338 $ 87,824 $ 6,156 (a) Amount represents contractual lease maturities at March 31, 2021 including any extension options that management determined were reasonably certain of exercise. During 2020, numerous tenants were forced to suspend operations by government mandate as a result of the COVID-19 Pandemic. The Company has negotiated payment agreements with selected tenants which resulted in rent concessions or deferral of rents as discussed further below. (b) Minimum rental payments exclude options or renewals not reasonably certain of exercise. During the three months ended March 31, 2021 and 2020, no single tenant or property collectively comprised more than 10% of the Company’s consolidated total revenues. COVID-19 Pandemic Impacts Beginning in March 2020, the COVID-19 Pandemic has had a material adverse impact on economic and market conditions, and consumer activity, and triggered a period of global and domestic economic slowdown. The COVID-19 Pandemic and government responses created disruption in global supply chains and adversely impacting many industries, including the domestic retail sectors in which the Company’s tenants operate. Under governmental restrictions and guidance, certain retailers were considered “essential businesses” and were permitted to remain fully operating during the COVID-19 Pandemic, while other “non-essential businesses” were ordered to decrease or close operations for an indeterminate period of time to protect their employees and customers from the spread of the virus. These disruptions, which have been significantly reduced as of the date of this Report, have impacted the collectability of rent from the Company’s affected tenants. The Company cannot estimate with reasonable certainty which currently operating tenants will remain open or if and when non-operating retailers will re-open for business as the COVID-19 Pandemic progresses. While the Company considers disruptions related to the COVID-19 Pandemic to be temporary, if such government mandated closures are reinstated, they may have a material, adverse effect on the Company’s revenues, results of operations, financial condition, and liquidity in future periods. Tenant Operating Status – At March 31, 2021 92.4% and 94.8% of the Core Portfolio and Fund, respectively, consolidated and unconsolidated annualized base rents (“ABR”) were derived from stores that were open or partially open for business at that date. Rent Collections – The Company collected or negotiated payment agreements through March 31, 2021 for approximately 91.8% and 84.3% of its first quarter pre-COVID billings (original contract rents without regard to deferral or abatement agreements) for its Core Portfolio and the Funds, respectively. Earnings Impact – The Company was impacted as follows by the COVID-19 Pandemic during the periods presented: Three Months Ended March 31, 2021 Three Months Ended March 31, 2020 Consolidated Non-Controlling Interests Unconsolidated Attributable to Acadia Consolidated Non-Controlling Interests Unconsolidated Attributable to Acadia Credit Loss - Billed Rents Core $ 1,883 $ 17 $ 386 $ 2,286 $ 832 $ — $ 268 $ 1,100 Funds 1,182 (979 ) 37 240 526 (498 ) 110 138 Total 3,065 (962 ) 423 2,526 1,358 (498 ) 378 1,238 Straight - Line Rent Reserves Core (8 ) (1 ) (29 ) (38 ) 2,744 — 220 2,964 Funds 825 (645 ) 10 190 223 (220 ) 62 65 Total 817 (646 ) (19 ) 152 2,967 (220 ) 282 3,029 Rent Abatements Core 756 — 87 843 — — — — Funds 783 (611 ) 7 179 — — — — Total 1,539 (611 ) 94 1,022 — — — — Impairment charges Core — — — — — — — — Funds — — — — 51,549 (39,149 ) — 12,400 Total — — — — 51,549 (39,149 ) — 12,400 COVID Earnings Impact Core 2,631 16 444 3,091 3,576 — 488 4,064 Funds 2,790 (2,235 ) 54 609 52,298 (39,867 ) 172 12,603 Total $ 5,421 $ (2,219 ) $ 498 $ 3,700 $ 55,874 $ (39,867 ) $ 660 $ 16,667 Other Impacts • Rent Concession Agreements – During the three months ended March 31, 2021, the Company executed 47 rent concession arrangements with tenants comprised of 12 agreements for rent deferral and 35 agreements for rent abatements. Of these deferral agreements, 11 were accounted for as if no changes to the contract were made and therefore there were no changes to the current or future recognition of revenue and $8.9 million of deferred receivables are included in Rents receivable in the consolidated balance sheet at March 31, 2021. Consolidated rent abatements in the table above represent $1.5 million for the three months ended March 31, 2021, of which $1.2 million had been negotiated and reserved in prior periods. • Occupancy – At March 31, 2021, the Company’s pro rata Core and Fund leased occupancy rates were 91.0% and 89.0%, respectively, compared to 93.9% and 93.2%, respectively, at March 31, 2020 reflecting primarily leases terminated as a result of the COVID-19 Pandemic. • Bankruptcy Risk – Through March 31, 2021 there have been continued bankruptcies of national retailers, some of which are tenants of the Company. Of these bankruptcies, the Core Portfolio has three operating stores, with ABR attributable to Acadia totaling $0.7 million, or 0.6% of Core ABR, and the Fund Portfolio has five operating stores, with ABR attributable to Acadia totaling $0.6 million, or 2.7% of Fund ABR, for which it is possible that these leases may be rejected in the future. During the three months ended March 31, 2021, one operating store in the Core Portfolio rejected its lease with ABR attributable to Acadia of $0.1 million or 0.1% of Core ABR, and two operating stores in the Fund Portfolio assumed their locations with ABR attributable to Acadia of $0.1 million or 0.1% of Fund ABR.

Segment Reporting

Segment Reporting	3 Months Ended
	Mar. 31, 2021
Segment Reporting [Abstract]
Segment Reporting	12. Segment Reporting The Company has three reportable segments: Core Portfolio, Funds and Structured Financing. The Company’s Core Portfolio consists primarily of high-quality retail properties located primarily in high-barrier-to-entry, densely-populated metropolitan areas with a long-term investment horizon. The Company’s Funds hold primarily retail real estate in which the Company co-invests with high-quality institutional investors. The Company’s Structured Financing segment consists of earnings and expenses related to notes and mortgages receivable which are held within the Core Portfolio or the Funds ( Note 3 ). Fees earned by the Company as the general partner or managing member of the Funds are eliminated in the Company’s consolidated financial statements and are not presented in the Company’s segments. The following tables set forth certain segment information for the Company (in thousands): As of or for the Three Months Ended March 31, 2021 Core Portfolio Funds Structured Financing Unallocated Total Revenues $ 42,349 $ 27,045 $ — $ — $ 69,394 Depreciation and amortization (16,887 ) (14,503 ) — — (31,390 ) Property operating expenses, other operating and real estate taxes (13,657 ) (11,282 ) — — (24,939 ) General and administrative expenses — — — (8,996 ) (8,996 ) Gain on disposition of properties 4,612 — — — 4,612 Operating income 16,417 1,260 — (8,996 ) 8,681 Interest income — — 1,700 — 1,700 Realized and unrealized holding gains on investments and other — 6,547 (40 ) — 6,507 Equity in (losses) earnings of unconsolidated affiliates (1,129 ) 3,392 — — 2,263 Interest expense (7,214 ) (9,927 ) — — (17,141 ) Income tax provision — — — (150 ) (150 ) Net income 8,074 1,272 1,660 (9,146 ) 1,860 Net (income) loss attributable to noncontrolling interests (607 ) 3,909 — — 3,302 Net income attributable to Acadia (a) $ 7,467 $ 5,181 $ 1,660 $ (9,146 ) $ 5,162 Real estate at cost (b) $ 2,319,584 $ 1,758,469 $ — $ — $ 4,078,053 Total assets (b) $ 2,222,886 $ 1,829,386 $ 101,410 $ — $ 4,153,682 Cash paid for acquisition of real estate $ — $ — $ — $ — $ — Cash paid for development and property improvement costs $ 2,843 $ 2,582 $ — $ — $ 5,425 As of or for the Three Months Ended March 31, 2020 Core Portfolio Funds Structured Financing Unallocated Total Revenues $ 39,933 $ 31,487 $ — $ — $ 71,420 Depreciation and amortization (17,056 ) (16,321 ) — — (33,377 ) Property operating expenses, other operating and real estate taxes (11,814 ) (11,953 ) — — (23,767 ) General and administrative expenses — — — (9,070 ) (9,070 ) Impairment charges — (51,549 ) — — (51,549 ) Operating income (loss) 11,063 (48,336 ) — (9,070 ) (46,343 ) Interest and other income — — 2,929 — 2,929 Realized and unrealized holding gains on investments and other — — (530 ) — (530 ) Equity in earnings (losses) of unconsolidated affiliates 1,642 (387 ) — — 1,255 Interest expense (8,250 ) (10,052 ) — — (18,302 ) Income tax benefit — — — 952 952 Net income (loss) 4,455 (58,775 ) 2,399 (8,118 ) (60,039 ) Net loss attributable to noncontrolling interests 1,216 50,409 — — 51,625 Net income (loss) attributable to Acadia $ 5,671 $ (8,366 ) $ 2,399 $ (8,118 ) $ (8,414 ) Real estate at cost (a) $ 2,289,449 $ 1,792,667 $ — $ — $ 4,082,116 Total assets (a) $ 2,330,971 $ 1,801,008 $ 173,159 $ — $ 4,305,138 Cash paid for acquisition of real estate $ 19,088 $ — $ — $ — $ 19,088 Cash paid for development and property improvement costs $ 2,638 $ 10,695 $ — $ — $ 13,576 (a) Real estate at cost and total assets for the Funds segment include $643.0 million and $641.7 million, or $186.9 million and $186.5 million net of non-controlling interests, related to Fund II’s City Point property at March 31, 2021 and March 31, 2020, respectively.

Share Incentive and Other Compe

Share Incentive and Other Compensation	3 Months Ended
	Mar. 31, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Share Incentive and Other Compensation	13. Share Incentive and Other Compensation Share Incentive Plan The 2020 Share Incentive Plan (the “Share Incentive Plan”) authorizes the Company to issue options, Restricted Shares, LTIP Units and other securities (collectively “Awards”) to, among others, the Company’s officers, trustees and employees. At March 31, 2021 a total of 1,975,780 shares remained available to be issued under the Share Incentive Plan. Restricted Shares and LTIP Units During the three months ended March 31, 2021, and the year ended December 31, 2020, the Company issued 633,462 and 396,149 LTIP Units and 11,119 and 13,766 restricted share units (“Restricted Share Units”), respectively, to employees of the Company pursuant to the Share Incentive Plan. These awards were measured at their fair value on the grant date, incorporating the following factors: • A portion of these annual equity awards is granted in performance-based Restricted Share Units or LTIP Units that may be earned based on the Company’s attainment of specified relative total shareholder returns (“Relative TSR”) hurdles. • In the event the Relative TSR percentile falls between the 25th percentile and the 50th percentile, the Relative TSR vesting percentage is determined using a straight-line linear interpolation between 50% and 100% and in the event that the Relative TSR percentile falls between the 50th percentile and 75th percentile, the Relative TSR vesting percentage is determined using a straight-line linear interpolation between 100% and 200%. • Two-thirds ( 2/3 three-year 1/3 three-year • If the Company’s performance fails to achieve the aforementioned hurdles at the culmination of the three-year For valuation of the 2021 and 2020 Performance Shares, a Monte Carlo simulation was used to estimate the fair values based on probability of satisfying the market conditions and the projected share prices at the time of payments, discounted to the valuation dates over the three-year The total value of the above Restricted Share Units and LTIP Units as of the grant date was $12.5 million during the three months ended March 31, 2021 and $10.4 million during the year ended December 31, 2020. Total long-term incentive compensation expense, including the expense related to the Share Incentive Plan, was $2.7 million and $2.4 million for the three months ended March 31, 2021 and 2020, respectively and is recorded in General and Administrative on the Consolidated Statements of Operations. In addition, members of the Board have been issued shares and units under the Share Incentive Plan. During the three months ended March 31, 2021, the Company issued 1,242 Restricted Shares to Trustees of the Company in connection with Trustee fees. These Restricted Shares vest over three years with 33% vesting May 9, 2021 and the remaining amount vesting ratably on May 9, 2022 and May 9, 2023. The Restricted Shares do not carry voting rights or other rights of Common Shares until vesting and may not be transferred, assigned or pledged until the recipients have a vested non-forfeitable right to such shares. Dividends are not paid currently on unvested Restricted Shares, but are paid cumulatively from the issuance date through the applicable vesting date of such Restricted Shares. Total trustee fee expense, including the expense related to the Share Incentive Plan, was $0.4 million and $0.3 million for the three months ended March 31, 2021 and 2020, respectively. In 2009, the Company adopted the Long-Term Investment Alignment Program (the “Program”) pursuant to which the Company may grant awards to employees, entitling them to receive up to 25% of any potential future payments of Promote to the Operating Partnership from Funds III, IV and V. The Company has granted such awards to employees representing 25% of the potential Promote payments from Fund III to the Operating Partnership, 23.1% of the potential Promote payments from Fund IV to the Operating Partnership and 8.4% of the potential Promote payments from Fund V to the Operating Partnership. Payments to senior executives under the Program require further Board approval at the time any potential payments are due pursuant to these grants. Compensation relating to these awards will be recognized in each reporting period in which Board approval is granted. As payments to other employees are not subject to further Board approval, compensation relating to these awards will be recorded based on the estimated fair value at each reporting period in accordance with ASC Topic 718, Compensation– Stock Compensation. The Company did not recognize any compensation expense for the three months ended March 31, 2021 or the year ended December 31, 2020 related to the Program in connection with Fund III, Fund IV or Fund V. A summary of the status of the Company’s unvested Restricted Shares and LTIP Units is presented below: Unvested Restricted Shares and LTIP Units Common Restricted Shares Weighted Grant-Date Fair Value LTIP Units Weighted Grant-Date Fair Value Unvested at January 1, 2020 42,390 $ 23.73 936,180 $ 28.24 Granted 66,824 13.70 440,829 19.64 Vested (19,264 ) 27.72 (250,241 ) 30.44 Forfeited (39 ) 24.77 (3,879 ) 24.67 Unvested at December 31, 2020 89,911 15.42 1,122,889 24.38 Granted 12,361 18.50 633,462 19.42 Vested (7,847 ) 26.13 (250,748 ) 28.20 Forfeited (159 ) 36.22 (91,637 ) 36.22 Unvested at March 31, 2021 94,266 $ 14.90 1,413,966 $ 20.72 The weighted-average grant date fair value for Restricted Shares and LTIP Units granted for the three months ended March 31, 2021 and the year ended December 31, 2020 were $19.40 and $18.86, respectively. As of March 31, 2021, there was $23.5 million of total unrecognized compensation cost related to unvested share-based compensation arrangements granted under the Share Incentive Plan. That cost is expected to be recognized over a weighted-average period of 1.7 years. The total fair value of Restricted Shares that vested for the three months ended March 31, 2021 and the year ended December 31, 2020, was $0.2 million and $0.5 million, respectively. The total fair value of LTIP Units that vested (LTIP units vest primarily during the first quarter) during the three months ended March 31, 2021 and the year ended December 31, 2020, was $7.1 million and $7.6 million, respectively. Other Plans On a combined basis, the Company incurred a total of $0.1 million of compensation expense related to the following employee benefit plans for each of the three months ended March 31, 2021 and 2020. Employee Share Purchase Plan The Acadia Realty Trust Employee Share Purchase Plan (the “Purchase Plan”), allows eligible employees of the Company to purchase Common Shares through payroll deductions. The Purchase Plan provides for employees to purchase Common Shares on a quarterly basis at a 15% discount to the closing price of the Company’s Common Shares on either the first day or the last day of the quarter, whichever is lower. A participant may not purchase more than $25,000 in Common Shares per year. Compensation expense will be recognized by the Company to the extent of the above discount to the closing price of the Common Shares with respect to the applicable quarter. A total of 2,428 and 395 Common Shares were purchased by employees under the Purchase Plan for the three months ended March 31, 2021 and 2020, respectively. Deferred Share Plan During 2006, the Company adopted a Trustee Deferral and Distribution Election, under which the participating Trustees earn deferred compensation. Employee 401(k) Plan The Company maintains a 401(k) plan for employees under which the Company currently matches 50% of a plan participant’s contribution up to 6% of the employee’s annual salary. A plan participant may contribute up to a maximum of 15% of their compensation, up to $19,500, for the year ending December 31, 2021.

Earnings (Loss) Per Common Shar

Earnings (Loss) Per Common Share	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Earnings (Loss) Per Common Share	14. Earnings (Loss) Per Common Share Basic earnings per Common Share is computed by dividing net income (loss) attributable to Common Shareholders by the weighted-average Common Shares outstanding ( Note 10 ). During the periods presented, the Company had unvested LTIP Units which provide for non-forfeitable rights to dividend equivalent payments. Accordingly, these unvested LTIP Units are considered participating securities and are included in the computation of basic earnings per Common Share pursuant to the two-class method. Diluted earnings per Common Share reflects the potential dilution of the conversion of obligations and the assumed exercises of securities including the effects of Restricted Share Units issued under the Company’s Share Incentive Plans ( Note 13 ). The effect of such shares is excluded from the calculation of earnings per share when anti-dilutive as indicated in the table below. The effect of the conversion of Common OP Units is not reflected in the computation of basic and diluted earnings per share, as they are exchangeable for Common Shares on a one-for-one basis. The income allocable to such units is allocated on this same basis and reflected as noncontrolling interests in the accompanying consolidated financial statements. As such, the assumed conversion of these units would have no net impact on the determination of diluted earnings per share. Three Months Ended March 31, (dollars in thousands) 2021 2020 Numerator: Net income (loss) attributable to Acadia $ 5,162 $ (8,414 ) Less: net income attributable to participating securities (156 ) — Income (loss) from continuing operations net of income attributable to participating securities $ 5,006 $ (8,414 ) Denominator: Weighted average shares for basic earnings per share 86,323,267 86,971,552 Effect of dilutive securities: Employee unvested restricted shares 23,093 — Denominator for diluted earnings per share 86,346,360 86,971,552 Basic and diluted earnings and basic loss per Common Share from continuing operations attributable to Acadia $ 0.06 $ (0.10 ) Anti-Dilutive Shares Excluded from Denominator: Series A Preferred OP Units 188 188 Series A Preferred OP Units - Common share equivalent 25,067 25,067 Series C Preferred OP Units 126,593 126,593 Series C Preferred OP Units - Common share equivalent 439,556 439,556 Restricted shares — 49,182

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2021
Subsequent Events [Abstract]
Subsequent Events	15. Subsequent Events Dispositions On April 2, 2021, Fund IV entered into an agreement to sell its Airport Mall, Shaw’s North Windham, Shaw’s Waterville and Wells Plaza properties for a total of $40.4 million. Debt Extensions On April 6, 2021 Fund IV extended the maturity of the $23.1 million mortgage on its Lincoln Place property to March 13, 2022. On April 27, 2021, Fund IV extended the maturity of the $18.5 million mortgage on an unconsolidated property, 650 Bald Hill Road, to June 27, 2021. Fund V Extension As of April 8, 2021, Fund V’s investment period was extended by one year to August 25, 2022. Note Receivable On April 20, 2021, the Company issued a note for $16.0 million to the partner of its MCB venture, collateralized by real estate.

Organization, Basis of Presen_2

Organization, Basis of Presentation and Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Segments	Segments At March 31, 2021, the Company had three reportable operating segments: Core Portfolio, Funds and Structured Financing. The Company’s chief operating decision maker may review operational and financial data on a property-level basis and does not differentiate properties on a geographical basis for purposes of allocating resources or capital.
Principles of Consolidation	Principles of Consolidation The interim consolidated financial statements include the consolidated accounts of the Company and its investments in partnerships and limited liability companies in which the Company has control in accordance with Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 810 “Consolidation” (“ASC Topic 810”). The ownership interests of other investors in these entities are recorded as noncontrolling interests. All significant intercompany balances and transactions have been eliminated in consolidation. Investments in entities for which the Company has the ability to exercise significant influence over, but does not have financial or operating control, are accounted for using the equity method of accounting. Accordingly, the Company’s share of the earnings (or losses) of these entities are included in consolidated net income or loss. The interim consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) for interim financial information and the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”). Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. Operating results for the interim periods presented are not necessarily indicative of the results that may be expected for the full fiscal year. The information furnished in the accompanying consolidated financial statements reflects all adjustments that, in the opinion of management, are necessary for a fair presentation of the aforementioned consolidated financial statements for the interim periods. Such adjustments consisted of normal recurring items, with the exception of adjustments due to the adoption of the new credit loss standard and impairment. These interim consolidated financial statements should be read in conjunction with the Company’s 2020 Annual Report on Form 10-K, as filed with the SEC on February 22, 2021.
Reclassifications	Reclassifications Certain prior year amounts on the Company’s consolidated balance sheet at December 31, 2020 with regard to Mortgage and other notes payable, net and Unsecured notes payable, net have been reclassified to conform to the current period presentation. In addition, certain prior year amounts in the Company’s statement of cash flows for the three months ended March 31, 2020 with regard to Right-of-use assets – operating leases, lease liabilities – operating leases and credit losses have been reclassified to conform to the current period presentation. These reclassifications had no material effect on the reported results of operations, financial condition or cash flows.
Use of Estimates	Use of Estimates GAAP requires the Company’s management to make estimates and assumptions that affect the amounts reported in the interim consolidated financial statements and accompanying notes. The most significant assumptions and estimates relate to the valuation of real estate, depreciable lives, revenue recognition and the collectability of notes receivable and rents receivable. Application of these estimates and assumptions requires the exercise of judgment as to future uncertainties and, as a result, actual results could differ from these estimates.
Recently Adopted Accounting and Reporting Guidance	Recently Adopted Accounting and Reporting Guidance In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740) Simplifying the Accounting for Income Taxes. During October 2020, the SEC issued new rules modernizing certain Regulation S-K disclosure requirements. The final rule is intended to improve the readability of disclosures, reduce repetition, and eliminate immaterial information, thereby simplifying compliance for registrants and making disclosures more meaningful for investors. These changes will be effective for all filings on or after November 7, 2020. The Company has made minor disclosure changes in this Report and to the "Business" and "Risk Factors" sections of the annual report on Form 10-K for 2020. On April 8, 2020, the FASB issued a Q&A allowing for reporting entities to make an accounting policy election to account for lease concessions related to the effects of COVID-19 consistent with how those concessions would be accounted for under Topic 842, which is as though the enforceable rights and obligations for those concessions existed regardless of whether those enforceable rights and obligations for the concessions explicitly exist in the contract. This election is available for concessions that result in the total cash flows required by the modified contract being substantially the same or less than total cash flows required by the original contract. Effective April 1, 2020, the Company has made the accounting policy election noted above. The Company entered into concession agreements both as lessor and lessee during the three months ended March 31, 2021 ( Note 11 ). The Company may grant further concessions during subsequent periods. In January 2020, the FASB issued ASU 2020-01 Investments—Equity securities (Topic 321), Investments—Equity Method and Joint Ventures (Topic 323), and Derivatives and Hedging (Topic 815)—Clarifying the Interactions Between Topic 321, Topic 323, and Topic 815. In October 2020, the FASB issued ASU 2020-08 Codification Improvements to Subtopic 310-20, Receivables—Nonrefundable Fees and Other Costs Recently Issued Accounting Pronouncements In August 2020, the FASB issued ASU 2020-06— 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 In January 2021, the FASB issued ASU 2021-01 Reference Rate Reform (Topic 848)
Lease Intangibles	Upon acquisitions of real estate ( Note 2 ), the Company assesses the fair value of acquired assets (including land, buildings and improvements, and identified intangibles such as above- and below-market leases, including below-market options and acquired in-place leases) and assumed liabilities. The lease intangibles are amortized over the remaining terms of the respective leases, including option periods where applicable.
Earnings (Loss) Per Common Share	Basic earnings per Common Share is computed by dividing net income (loss) attributable to Common Shareholders by the weighted-average Common Shares outstanding ( Note 10 ). During the periods presented, the Company had unvested LTIP Units which provide for non-forfeitable rights to dividend equivalent payments. Accordingly, these unvested LTIP Units are considered participating securities and are included in the computation of basic earnings per Common Share pursuant to the two-class method. Diluted earnings per Common Share reflects the potential dilution of the conversion of obligations and the assumed exercises of securities including the effects of Restricted Share Units issued under the Company’s Share Incentive Plans ( Note 13 ). The effect of such shares is excluded from the calculation of earnings per share when anti-dilutive as indicated in the table below. The effect of the conversion of Common OP Units is not reflected in the computation of basic and diluted earnings per share, as they are exchangeable for Common Shares on a one-for-one basis. The income allocable to such units is allocated on this same basis and reflected as noncontrolling interests in the accompanying consolidated financial statements. As such, the assumed conversion of these units would have no net impact on the determination of diluted earnings per share.

Organization, Basis of Presen_3

Organization, Basis of Presentation and Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Schedule of Operating Partnership's Equity Interest	The following table summarizes the general terms and Operating Partnership’s equity interests in the Funds and Mervyns II (dollars in millions): Entity Formation Date Operating Partnership Share of Capital Capital Called as of March 31, 2021 (b) Unfunded Commitment (b, c) Equity Interest Held By Operating Partnership (a) Preferred Return Total Distributions as of March 31, 2021 (b, c) Fund II and Mervyns II (c) 6/2004 28.33 % $ 372.6 $ 12.7 28.33 % 8 % $ 169.8 Fund III 5/2007 24.54 % 448.1 1.9 24.54 % 6 % 568.8 Fund IV 5/2012 23.12 % 481.3 48.7 23.12 % 6 % 193.1 Fund V 8/2016 20.10 % 217.1 302.9 20.10 % 6 % 31.5 (a) Amount represents the current economic ownership at March 31, 2021, which could differ from the stated legal ownership based upon the cumulative preferred returns of the respective Fund. (b) Represents the total for the Funds, including the Operating Partnership and noncontrolling interests’ shares. (c) During August 2020, a recallable distribution of $ 15.7 million was made by Mervyn’s II to its investors, of which $ 4.5 million was the Company’s share. During the first quarter of 2021, Mervyn’s II re called $ 3.0 million of the $ 15.7 million.

Real Estate (Tables)

Real Estate (Tables)	3 Months Ended
	Mar. 31, 2021
Acquisition And Disposition Of Properties And Discontinued Operations [Abstract]
Schedule of Consolidated Real Estate	The Company’s consolidated real estate is comprised of the following for the periods presented (in thousands): March 31, 2021 December 31, 2020 Land $ 767,631 $ 776,275 Buildings and improvements 2,847,797 2,848,781 Tenant improvements 196,748 191,046 Construction in progress 6,453 5,751 Right-of-use assets - finance leases (Note 11) 25,086 25,086 Total 3,843,715 3,846,939 Less: Accumulated depreciation and amortization (605,684 ) (586,800 ) Operating real estate, net 3,238,031 3,260,139 Real estate under development 234,338 247,349 Net investments in real estate $ 3,472,369 $ 3,507,488
Schedule of Business Acquisitions, by Acquisition	During the three months ended March 31, 2021 and the year ended December 31, 2020, the Company acquired the following consolidated retail properties and other real estate investments (dollars in thousands): Property and Location Percent Acquired Date of Acquisition Purchase Price 2021 Acquisitions None 2020 Acquisitions and Conversions Core Soho Acquisitions - 37 Greene Street - New York, NY 100% Jan 9, 2020 $ 15,689 917 W. Armitage - Chicago, IL 100% Feb 13, 2020 3,515 Town Center - Wilmington, DE (Conversion) (Note 4) 100% Apr 1, 2020 138,939 Subtotal Core 158,143 Fund IV 230-240 W. Broughton Street - Savannah, GA 100% May 26, 2020 13,219 102 E. Broughton Street - Savannah, GA 100% May 26, 2020 790 Subtotal Fund IV 14,009 Total 2020 Acquisitions and Conversions $ 172,152
Schedule of Purchase Price Allocations	The following table summarizes the allocation of the purchase price of properties acquired during the periods presented (in thousands): Three Months Ended March 31, 2021 Year Ended December 31, 2020 Net Assets Acquired Land $ — $ 25,440 Buildings and improvements — 123,459 Accounts receivable, prepaids and other assets — 5,770 Acquisition-related intangible assets ( Note 6 ) — 23,061 Right-of-use asset - Operating lease (Note 11) — 234 Acquisition-related intangible liabilities ( Note 6 ) — (4,569 ) Lease liability - Operating lease (Note 11) — (234 ) Accounts payable and other liabilities — (1,009 ) Net assets acquired $ — $ 172,152 Consideration Cash $ — $ 21,208 Conversion of note receivable — 38,674 Conversion of accrued interest — 1,995 Liabilities assumed — 116 Existing interest in previously unconsolidated investment — 109,571 Acquisition of noncontrolling interests — 588 Total consideration $ — $ 172,152
Schedule of Property Dispositions	During the three months ended March 31, 2021 and the year ended December 31, 2020, the Company disposed of the following consolidated properties and other real estate investments (in thousands): Property and Location Owner Date Sold Sale Price Gain on Sale 2021 Dispositions 60 Orange St - Bloomfield, NJ Core Jan 29, 2021 $ 16,400 $ 4,612 Total 2021 Dispositions $ 16,400 $ 4,612 2020 Dispositions 163 Highland Ave. (Easement) - Needham, MA Core Mar 19, 2020 $ 238 $ 88 Colonie Plaza - Albany, NY Fund IV Apr 13, 2020 15,250 485 Airport Mall (Parcel) - Bangor, ME Fund IV Sep 10, 2020 400 24 Cortlandt Crossing (Sewer Project and Retention Pond) - Cortlandt, NY Fund III Nov 30, 2020 6,325 — Union Township (Parcel) - New Castle, PA Core Dec 11, 2020 200 86 Total 2020 Dispositions $ 22,413 $ 683
Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures	The aggregate rental revenue, expenses and pre-tax income reported within continuing operations for the aforementioned consolidated properties that were sold during the three months ended March 31, 2021 and year ended December 31, 2020 were as follows (in thousands): Three Months Ended March 31, 2021 2020 Revenues $ 82 $ 870 Expenses (90 ) (864 ) Gain on disposition of properties 4,612 — Net income attributable to noncontrolling interests 1 48 Net income attributable to Acadia $ 4,605 $ 54
Schedule Of Development In Process Activities	Development activity for the Company’s consolidated properties comprised the following during the periods presented (dollars in thousands): January 1, 2021 Three Months Ended March 31, 2021 March 31, 2021 Number of Properties Carrying Value Transfers In Capitalized Costs Transfers Out Number of Properties Carrying Value Core — $ 63,875 $ — $ 933 $ 14,557 — $ 50,251 Fund II — 74,657 — 535 — — 75,192 Fund III 1 23,139 — 277 — 1 23,416 Fund IV 2 85,678 — 21 220 2 85,479 Total 3 $ 247,349 $ — $ 1,766 $ 14,777 3 $ 234,338 January 1, 2020 Year Ended December 31, 2020 December 31, 2020 Number of Properties Carrying Value Transfers In Capitalized Costs Transfers Out Number of Properties Carrying Value Core — $ 60,863 $ — $ 3,012 $ — — $ 63,875 Fund II (a) — 10,703 66,812 3,612 6,470 — 74,657 Fund III 1 36,240 — 70 13,171 1 23,139 Fund IV (b) 2 145,596 — 1,368 61,286 2 85,678 Total 3 $ 253,402 $ 66,812 $ 8,062 $ 80,927 3 $ 247,349 (a) Transfers in include $33.8 million of non-cash Fund II additions obtained through the conversion of a note receivable ( Note 3 ). (b) Transfers out include impairment charges totaling $16.5 million on two Fund IV development properties ( Note 8 ).

Notes Receivable, Net (Tables)

Notes Receivable, Net (Tables)	3 Months Ended
	Mar. 31, 2021
Accounts And Notes Receivable Net [Abstract]
Schedule of Notes Receivable	The Company’s notes receivable, net are generally collateralized either by the underlying properties or the borrowers’ ownership interests in the entities that own the properties, and were as follows (dollars in thousands): March 31, December 31, March 31, 2021 Description 2021 2020 Number Maturity Date Interest Rate Core Portfolio (a) $ 96,794 $ 96,794 6 Apr 2020 - Dec 2027 2.65% - 9.00% Fund III 5,306 5,306 1 Jul 2020 18.00% Total notes receivable 102,100 102,100 Allowance for credit loss (690 ) (650 ) Notes receivable, net $ 101,410 $ 101,450 7 (a) Includes two notes receivable from OP Unit holders, with balances totaling $6.5 million at March 31, 2021 and December 31, 2020.

Investments in and Advances t_2

Investments in and Advances to Unconsolidated Affiliates (Tables)	3 Months Ended
	Mar. 31, 2021
Equity Method Investments And Joint Ventures [Abstract]
Schedule of Equity Method Investments	The Company’s investments in and advances to unconsolidated affiliates consist of the following (dollars in thousands): Ownership Interest March 31, December 31, Portfolio Property March 31, 2021 2021 2020 Core: 840 N. Michigan (a) 88.43% $ 54,924 $ 55,863 Renaissance Portfolio 20% 28,742 29,270 Gotham Plaza 49% 28,589 28,683 Georgetown Portfolio 50% 3,870 4,624 1238 Wisconsin Avenue 80% 3,008 2,571 119,133 121,011 Mervyns I & II: KLA/ABS (b) 36.7% 78,526 72,391 Fund III: Self Storage Management (c) 95% 207 207 Fund IV: Fund IV Other Portfolio 98.57% 12,394 11,719 650 Bald Hill Road 90% 12,532 12,550 24,926 24,269 Fund V: Family Center at Riverdale (a) 89.42% 12,679 11,824 Tri-City Plaza 90% 7,309 7,024 Frederick County Acquisitions 90% 10,647 10,837 30,635 29,685 Various: Due from (to) Related Parties 290 363 Other (d) 2,615 1,881 Investments in and advances to unconsolidated affiliates $ 256,332 $ 249,807 Core: Crossroads (e) 49% $ 15,272 $ 15,616 Distributions in excess of income from, and investments in, unconsolidated affiliates $ 15,272 $ 15,616 (a) Represents a tenancy-in-common interest. (b) Includes an interest in Albertsons (at fair value, as described below) ( Note 8 ). (c) Represents a variable interest entity for which the Company was determined not to be the primary beneficiary. (d) Includes cost-method investments in Storage Post, Fifth Wall and other investments. (e) Distributions have exceeded the Company’s investment; however, the Company recognizes a liability balance as it may be required to return distributions to fund future obligations of the entity.
Schedule of Condensed Balance Sheet	The following combined and condensed Balance Sheets and Statements of operations, in each period, summarize the financial information of the Company’s investments in unconsolidated affiliates that were held as of December 31, 2020, and accordingly exclude the results of any investments disposed of or consolidated prior to that date (in thousands): March 31, 2021 December 31, 2020 Combined and Condensed Balance Sheets Assets: Rental property, net $ 552,262 $ 563,997 Real estate under development 15,907 14,517 Other assets 64,358 61,969 Total assets $ 632,527 $ 640,483 Liabilities and partners’ equity: Mortgage notes payable $ 505,245 $ 512,490 Other liabilities 75,268 74,872 Partners’ equity 52,014 53,121 Total liabilities and partners’ equity $ 632,527 $ 640,483 Company's share of accumulated equity $ 100,729 $ 100,767 Basis differential 54,582 55,017 Deferred fees, net of portion related to the Company's interest 4,111 3,565 Amounts receivable/payable by the Company 290 363 Investments in and advances to unconsolidated affiliates, net of Company's share of distributions in excess of income from and investments in unconsolidated affiliates 159,712 159,712 Investments carried at fair value or cost 81,348 74,479 Company's share of distributions in excess of income from and investments in unconsolidated affiliates 15,272 15,616 Investments in and advances to unconsolidated affiliates $ 256,332 $ 249,807
Schedule of Condensed Income Statement	Three Months Ended March 31, 2021 2020 Combined and Condensed Statements of Operations Total revenues $ 17,281 $ 19,496 Operating and other expenses (6,219 ) (6,579 ) Interest expense (4,822 ) (5,256 ) Depreciation and amortization (8,801 ) (6,360 ) Gain on disposition of properties (a) 3,206 — Net income attributable to unconsolidated affiliates $ 645 $ 1,301 Company’s share of equity in net income of unconsolidated affiliates $ 2,699 $ 334 Basis differential amortization (436 ) (324 ) Company’s equity in earnings of unconsolidated affiliates $ 2,263 $ 10 (a) Represents the gain on the sale of two land parcels by the Family Center at Riverdale on January 4, 2021.

Other Assets, Net and Account_2

Other Assets, Net and Accounts Payable and Other Liabilities (Tables)	3 Months Ended
	Mar. 31, 2021
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Schedule of Other Assets and Other Liabilities	Other assets, net and accounts payable and other liabilities are comprised of the following for the periods presented: (in thousands) March 31, 2021 December 31, 2020 Other Assets, Net: Lease intangibles, net ( Note 6 ) $ 91,371 $ 100,732 Deferred charges, net (a) 30,524 30,488 Accrued interest receivable 15,481 13,917 Prepaid expenses 14,121 17,468 Due from seller 3,364 3,682 Income taxes receivable 2,613 2,433 Other receivables 2,068 2,058 Deposits 1,744 1,728 Corporate assets, net 1,308 1,302 Derivative financial instruments ( Note 8 ) 2 1 $ 162,596 $ 173,809 (a) Deferred Charges, Net: Deferred leasing and other costs $ 61,107 $ 57,533 Deferred financing costs related to line of credit 11,380 11,341 72,487 68,874 Accumulated amortization (41,963 ) (38,386 ) Deferred charges, net $ 30,524 $ 30,488 Accounts Payable and Other Liabilities: Lease intangibles, net ( Note 6 ) $ 71,023 $ 76,434 Accounts payable and accrued expenses 56,149 53,031 Derivative financial instruments ( Note 8 ) 56,083 90,139 Deferred income 35,396 31,842 Tenant security deposits, escrow and other 12,025 12,178 Lease liability - finance leases, net ( Note 11 6,382 6,287 $ 237,058 $ 269,911

Lease Intangibles (Tables)

Lease Intangibles (Tables)	3 Months Ended
	Mar. 31, 2021
Goodwill And Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets and Liabilities Included in Other Assets and Accounts Payable and Other Liabilities	Intangible assets and liabilities are included in Other assets and Accounts payable and other liabilities ( Note 5 ) on the consolidated balance sheet and summarized as follows (in thousands): March 31, 2021 December 31, 2020 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Amortizable Intangible Assets In-place lease intangible assets $ 265,722 $ (178,279 ) $ 87,443 $ 268,335 $ (171,856 ) $ 96,479 Above-market rent 19,188 (15,260 ) 3,928 19,188 (14,935 ) 4,253 $ 284,910 $ (193,539 ) $ 91,371 $ 287,523 $ (186,791 ) $ 100,732 Amortizable Intangible Liabilities Below-market rent $ (160,388 ) $ 89,812 $ (70,576 ) $ (164,923 ) $ 88,951 $ (75,972 ) Above-market ground lease (671 ) 224 (447 ) (671 ) 209 (462 ) $ (161,059 ) $ 90,036 $ (71,023 ) $ (165,594 ) $ 89,160 $ (76,434 )
Scheduled Amortization of Acquired Lease Intangible Assets and Assumed Liabilities	The scheduled amortization of acquired lease intangible assets and assumed liabilities as of March 31, 2021 is as follows (in thousands): Years Ending December 31, Net Increase in Lease Revenues Increase to Amortization Reduction of Rent Expense Net (Expense) Income 2021 (Remainder) $ 4,923 $ (17,375 ) $ 44 $ (12,408 ) 2022 5,944 (17,869 ) 58 (11,867 ) 2023 5,476 (13,239 ) 58 (7,705 ) 2024 5,126 (9,297 ) 58 (4,113 ) 2025 4,459 (6,939 ) 58 (2,422 ) Thereafter 40,720 (22,724 ) 171 18,167 Total $ 66,648 $ (87,443 ) $ 447 $ (20,348 )

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
Summary of Consolidated Indebtedness	A summary of the Company’s consolidated indebtedness is as follows (dollars in thousands): Interest Rate at Carrying Value at March 31, December 31, Maturity Date at March 31, December 31, 2021 2020 March 31, 2021 2021 2020 Mortgages Payable Core Fixed Rate 3.88%-5.89% 3.88%-5.89% Feb 2024 - Apr 2035 $ 147,233 $ 147,810 Core Variable Rate - Swapped ( a) 3.41%-4.54% 3.41%-4.54% Jan 2023 - Nov 2028 73,569 80,500 Total Core Mortgages Payable 220,802 228,310 Fund II Variable Rate LIBOR+3.00% - PRIME+2.00% LIBOR+3.00% - PRIME+2.00% Mar 2022 - August 2022 229,101 228,282 Fund II Variable Rate - Swapped ( a) 2.88% 2.88% Nov 2021 18,733 18,803 Total Fund II Mortgages Payable 247,834 247,085 Fund III Variable Rate LIBOR+2.75%-LIBOR+3.10% LIBOR+2.75%-LIBOR+3.10% Jun 2021 - Jul 2022 71,613 71,918 Fund IV Fixed Rate 3.40%-4.50% 3.40%-4.50% Oct 2025 - Jun 2026 6,726 6,726 Fund IV Variable Rate LIBOR+1.60%-LIBOR+3.40% LIBOR+1.60%-LIBOR+3.40% Apr 2021 - Oct 2025 245,302 254,234 Fund IV Variable Rate - Swapped ( a) 3.48%-4.61% 3.48%-4.61% Apr 2022 - Dec 2022 66,250 66,590 Total Fund IV Mortgages and Other Notes Payable 318,278 327,550 Fund V Variable Rate LIBOR+1.50%-LIBOR+2.20% LIBOR+1.50%-LIBOR+2.20% Jun 2021 - Dec 2024 1,077 1,354 Fund V Variable Rate - Swapped (a) 2.95%-4.78% 2.95%-4.78% Jun 2021 - Dec 2024 334,339 334,323 Total Fund V Mortgages Payable 335,416 335,677 Net unamortized debt issuance costs (5,770 ) (6,507 ) Unamortized premium 522 548 Total Mortgages Payable $ 1,188,695 $ 1,204,581 Unsecured Notes Payable Core Variable Rate Credit Facility LIBOR+2.55% LIBOR+2.55% Jun 2021 $ 30,000 $ 30,000 Core Variable Rate Unsecured Term Loans - Swapped (a) 2.49%-5.02% 2.49%-5.02% Mar 2023 350,000 350,000 Total Core Unsecured Notes Payable 380,000 380,000 Fund II Unsecured Notes Payable LIBOR+1.65% LIBOR+1.65% Sep 2021 40,000 40,000 Fund IV Term Loan/Subscription Facility LIBOR+1.90% LIBOR+1.90% Dec 2021 1,400 864 Fund V Subscription Facility LIBOR+1.60% LIBOR+1.60% May 2021 — 250 Net unamortized debt issuance costs (440 ) (256 ) Total Unsecured Notes Payable $ 420,960 $ 420,858 Unsecured Line of Credit Core Unsecured Line of Credit -Swapped (a) 2.49%-5.02% 2.49%-5.02% Mar 2022 $ 105,400 $ 138,400 Total Debt - Fixed Rate (b, c ) $ 1,102,250 $ 1,143,152 Total Debt - Variable Rate (d) 618,493 626,902 Total Debt 1,720,743 1,770,054 Net unamortized debt issuance costs (6,210 ) (6,763 ) Unamortized premium 522 548 Total Indebtedness $ 1,715,055 $ 1,763,839 (a) At March 31, 2021, the stated rates ranged from LIBOR + 1.50% to LIBOR +1.90% LIBOR + 1.39% LIBOR + 2.75% to LIBOR + 3.10% LIBOR + 1.75% to LIBOR +2.00% LIBOR + 1.50% to LIBOR + 2.20% LIBOR + 1.25% (b) Includes $948.3 million and $988.6 million, respectively, of variable-rate debt that has been fixed with interest rate swap agreements as of the periods presented (c) Fixed-rate debt at March 31, 2021 and December 31, 2020 includes $36.2 million and $3.2 million, respectively of Core swaps that may be used to hedge debt instruments of the Funds. (d) Includes $140.0 million and $139.2 million, respectively, of variable-rate debt that is subject to interest cap agreements.
Scheduled Principal Repayments	The scheduled principal repayments, without regard to available extension options (described further below), of the Company’s consolidated indebtedness, as of March 31, 2021 are as follows (in thousands): Year Ending December 31, 2021 $ 365,838 2022 535,612 2023 409,359 2024 212,020 2025 65,326 Thereafter 132,588 1,720,743 Unamortized premium 522 Net unamortized debt issuance costs (6,210 ) Total indebtedness $ 1,715,055

Financial Instruments and Fai_2

Financial Instruments and Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis	The following table presents the Company’s fair value hierarchy for those assets and liabilities measured at fair value on a recurring basis (in thousands): March 31, 2021 December 31, 2020 Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Assets Money market funds $ — $ — $ — $ — $ — $ — Derivative financial instruments — 2 — — 1 — Investment in Albertsons ( Note 4 ) 78,526 — — 72,391 — — Liabilities Derivative financial instruments — 56,083 — — 90,139 —
Schedule of Items Measured at Fair Value on Nonrecurring Basis	During 2020, the Company was impacted by the COVID-19 Pandemic ( Note 11 ), which caused the Company to reduce its holding periods and forecasted operating income at certain properties. As a result, several impairments were recorded. Impairment charges for the periods presented are as follows (in thousands): Impairment Charge Property and Location Owner Triggering Event Level 3 Inputs Effective Date Total Acadia's Share 2021 Impairment Charges None 2020 Impairment Charges Cortlandt Crossing, Mohegan Lake, NY Fund III Reduced holding period, reduced projected operating income Projections of: holding period, net operating income, cap rate, incremental costs Mar 31, 2020 $ 27,402 $ 6,726 654 Broadway, New York, NY Fund III Reduced holding period Projections of: holding period, net operating income, cap rate, incremental costs Mar 31, 2020 6,398 1,570 146 Geary Street, San Francisco, CA Fund IV Reduced holding period, reduced projected operating income Projections of: holding period, net operating income, cap rate, incremental costs Mar 31, 2020 6,718 1,553 801 Madison Avenue, New York, NY Fund IV Reduced holding period, reduced projected operating income Projections of: holding period, net operating income, cap rate, incremental costs Mar 31, 2020 11,031 2,551 717 N. Michigan Avenue, Chicago, IL Fund IV Reduced holding period, reduced projected operating income Projections of: holding period, net operating income, cap rate, incremental costs Dec 31, 2020 17,392 4,021 110 University, New York, NY Fund IV Reduced holding period, reduced projected operating income Projections of: holding period, net operating income, cap rate, incremental costs Dec 31, 2020 16,238 3,754 Fifth Wall Investment Core Decline in fair value Projections of: reported fair value of net assets Dec 31, 2020 419 419 Total 2020 Impairment Charges $ 85,598 $ 20,594
Schedule of Derivative Financial Instruments	The Company had the following interest rate swaps and caps for the periods presented (dollars in thousands): Strike Rate Fair Value Derivative Instrument Aggregate Notional Amount Effective Date Maturity Date Low High Balance Sheet Location March 31, 2021 December 31, 2020 Core Interest Rate Swaps $ 565,158 Dec 2012-Jul 2020 Jun 2021-Jul 2030 1.24 % — 3.77 % Other Liabilities $ (44,451 ) $ (74,990 ) $ 565,158 $ (44,451 ) $ (74,990 ) Fund II Interest Rate Swap $ 18,733 Oct 2014 Nov 2021 2.88 % — 2.88 % Other Liabilities $ (154 ) $ (219 ) Interest Rate Cap 45,000 Mar 2019 Mar 2022 3.50 % — 3.50 % Other Assets — — $ 63,733 $ (154 ) $ (219 ) Fund III Interest Rate Caps $ 35,970 Jan 2021 Jul 2022 3.00 % — 3.00 % Other Assets $ — $ — Fund IV Interest Rate Swaps $ 66,250 Mar 2017 - Dec 2019 Apr 2022 - Dec 2022 1.48 % — 4.00 % Other Liabilities $ (1,399 ) $ (1,713 ) Interest Rate Caps 77,400 July 2019 - Dec 2020 Jul 2021 - Dec 2022 3.00 % — 3.50 % Other Assets 2 1 $ 143,650 $ (1,397 ) $ (1,712 ) Fund V Interest Rate Swaps $ 334,339 Jun 2018-Feb 2021 Jun 2021-Oct 2024 0.23 % — 2.88 % Other Liabilities $ (10,079 ) $ (13,217 ) $ 334,339 $ (10,079 ) $ (13,217 ) Total asset derivatives $ 2 $ 1 Total liability derivatives $ (56,083 ) $ (90,139 )
Schedule of Other Financial Instruments Carrying Values and Fair values	The Company’s other financial instruments had the following carrying values and fair values as of the dates shown (dollars in thousands, inclusive of amounts attributable to noncontrolling interests where applicable): March 31, 2021 December 31, 2020 Level Carrying Amount Estimated Fair Value Carrying Amount Estimated Fair Value Notes Receivable (a) 3 $ 101,410 $ 101,917 $ 101,450 $ 102,135 Mortgage and Other Notes Payable (a) 3 1,193,943 1,171,180 1,210,540 1,190,214 Investment in non-traded equity securities (b) 3 2,460 2,386 1,726 1,456 Unsecured notes payable and Unsecured line of credit (c) 2 526,800 514,982 559,514 544,532 (a) The Company determined the estimated fair value of these financial instruments using a discounted cash flow model with rates that take into account the credit of the borrower or tenant, where applicable, and interest rate risk. The Company also considered the value of the underlying collateral, taking into account the quality of the collateral, the credit quality of the borrower, the time until maturity and the current market interest rate environment. (b) Represents the Operating Partnership’s cost-method investment in Fifth Wall ( Note 4 ). (c) The Company determined the estimated fair value of the unsecured notes payable and unsecured line of credit using quoted market prices in an open market with limited trading volume where available. In cases where there was no trading volume, the Company determined the estimated fair value using a discounted cash flow model using a rate that reflects the average yield of similar market participants.

Shareholders' Equity, Noncont_2

Shareholders' Equity, Noncontrolling Interests and Other Comprehensive Loss (Tables)	3 Months Ended
	Mar. 31, 2021
Stockholders Equity Including Portion Attributable To Noncontrolling Interest [Abstract]
Schedule of Dividends Declared and Paid	The following table sets forth the distributions declared and/or paid during the periods presented: Date Declared Amount Per Share Record Date Payment Date November 5, 2019 $ 0.29 December 31, 2019 January 15, 2020 February 26, 2020 $ 0.29 March 31, 2020 April 15, 2020 March 15, 2021 $ 0.15 March 31, 2021 April 15, 2021
Summary of Activity in Accumulated Other Comprehensive Loss	The following tables set forth the activity in accumulated other comprehensive loss for three months ended March 31, 2021 and 2020 (in thousands): Gains or Losses on Derivative Instruments Balance at January 1, 2021 $ (74,891 ) Other comprehensive income before reclassifications - swap agreements 33,556 Reclassification of realized interest on swap agreements 5,317 Net current period other comprehensive income 38,873 Net current period other comprehensive income attributable to noncontrolling interests (5,944 ) Balance at March 31, 2021 $ (41,962 ) Balance at January 1, 2020 $ (31,175 ) Other comprehensive loss before reclassifications - swap agreements (74,774 ) Reclassification of realized interest on swap agreements 977 Net current period other comprehensive loss (73,797 ) Net current period other comprehensive loss attributable to noncontrolling interests 19,257 Balance at March 31, 2020 $ (85,715 )
Summary of Change in Noncontrolling Interest	The following tables summarize the change in the noncontrolling interests for the three months ended March 31, 2021 and 2020 (dollars in thousands): Noncontrolling Interests in Operating Partnership (a) Noncontrolling Interests in Partially-Owned Affiliates (b) Total Balance at January 1, 2021 $ 89,431 $ 517,808 $ 607,239 Distributions declared of $0.15 per Common OP Unit (1,048 ) — (1,048 ) Net income (loss) for the three months ended March 31, 2021 470 (3,772 ) (3,302 ) Conversion of 18,800 Common OP Units to Common Shares by limited partners of the Operating Partnership (294 ) — (294 ) Other comprehensive income - unrealized gain on valuation of swap agreements 1,900 2,143 4,043 Reclassification of realized interest expense on swap agreements 53 1,848 1,901 Noncontrolling interest contributions — 11,241 11,241 Noncontrolling interest distributions — (6,676 ) (6,676 ) Employee Long-term Incentive Plan Unit Awards 4,049 — 4,049 Reallocation of noncontrolling interests (c) 369 — 369 Balance at March 31, 2021 $ 94,930 $ 522,592 $ 617,522 Balance at January 1, 2020 $ 97,670 $ 546,987 $ 644,657 Distributions declared of $0.29 per Common OP Unit (1,849 ) — (1,849 ) Net loss for the three months ended March 31, 2020 (336 ) (51,289 ) (51,625 ) Conversion of 147,882 Common OP Units to Common Shares by limited partners of the Operating Partnership (2,472 ) — (2,472 ) Other comprehensive loss - unrealized loss on valuation of swap agreements (3,141 ) (16,388 ) (19,529 ) Reclassification of realized interest expense on swap agreements 7 265 272 Noncontrolling interest contributions — 7,268 7,268 Noncontrolling interest distributions — (3,118 ) (3,118 ) Employee Long-term Incentive Plan Unit Awards 3,648 — 3,648 Reallocation of noncontrolling interests (c) (145 ) — (145 ) Cumulative effect of change in accounting principle — (11 ) (11 ) Balance at March 31, 2020 $ 93,382 $ 483,714 $ 577,096 (a) Noncontrolling interests in the Operating Partnership are comprised of (i) the limited partners’ 3,101,958 and 3,205,931 Common OP Units at March 31, 2021 and March 31, 2020; (ii) 188 Series A Preferred OP Units at March 31, 2021 and March 31, 2020; (iii) 126,593 Series C Preferred OP Units at March 31, 2021 and March 31, 2020; and (iv) 3,409,232 and 3,003,027 LTIP units at March 31, 2021 and March 31, 2020, respectively, as discussed in Share Incentive Plan ( Note 13 (b) Noncontrolling interests in partially-owned affiliates comprise third-party interests in Funds II, III, IV and V, and Mervyns II, and six other subsidiaries. (c) Adjustment reflects the difference between the fair value of the consideration received or paid and the book value of the Common Shares, Common OP Units, Preferred OP Units, and LTIP Units involving changes in ownership.

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2021
Leases [Abstract]
Activity for Reserves Related to Billed Rents and Straight-line Rents	The activity for the reserves related to billed rents and straight-line rents is as follows: Three Months Ended March 31, 2021 Balance at Beginning of Period Charged to Expenses Adjustments to Valuation Accounts Deductions Balance at End of Period Allowance for credit loss - billed rents $ 30,366 $ 3,065 $ — $ (1,162 ) $ 32,269 Straight-line rent reserves 15,042 817 — (175 ) 15,684 Total - rents receivable $ 45,408 $ 3,882 $ — $ (1,337 ) $ 47,953
Schedule of Lease Cost	Three Months Ended March 31, 2021 2020 Lease Cost Finance lease cost: Amortization of right-of-use assets $ 226 $ 657 Interest on lease liabilities 95 850 Subtotal 321 1,507 Operating lease cost 2,286 1,394 Variable lease cost 101 16 Total lease cost $ 2,708 $ 2,917 Other Information Weighted-average remaining lease term - finance leases (years) 33.2 42.3 Weighted-average remaining lease term - operating leases (years) 24.5 34.1 Weighted-average discount rate - finance leases 6.3 % 4.4 % Weighted-average discount rate - operating leases 5.6 % 5.8 %
Schedule of Future Minimum Rental Revenues and Payments for Operating and Capital Leases	The scheduled future minimum (i) rental revenues from rental properties under the terms of non-cancelable tenant leases greater than one year (assuming no new or renegotiated leases or option extensions for such premises) and (ii) rental payments under the terms of all non-cancelable operating and finance leases in which the Company is the lessee, principally for office space, land and equipment, as of March 31, 2021, are summarized as follows (in thousands): Minimum Rental Payments Year Ending December 31, Minimum Rental Revenues (a) Operating Leases (b) Finance Leases (b) 2021 (Remainder) $ 149,226 $ 6,465 $ 69 2022 198,269 7,768 28 2023 177,885 7,789 — 2024 152,363 7,974 — 2025 122,715 7,969 — Thereafter 503,880 150,446 12,289 1,304,338 188,411 12,386 Interest — (100,587 ) (6,230 ) Total $ 1,304,338 $ 87,824 $ 6,156 (a) Amount represents contractual lease maturities at March 31, 2021 including any extension options that management determined were reasonably certain of exercise. During 2020, numerous tenants were forced to suspend operations by government mandate as a result of the COVID-19 Pandemic. The Company has negotiated payment agreements with selected tenants which resulted in rent concessions or deferral of rents as discussed further below. (b) Minimum rental payments exclude options or renewals not reasonably certain of exercise.
Schedule of Earnings Impact	The Company was impacted as follows by the COVID-19 Pandemic during the periods presented: Three Months Ended March 31, 2021 Three Months Ended March 31, 2020 Consolidated Non-Controlling Interests Unconsolidated Attributable to Acadia Consolidated Non-Controlling Interests Unconsolidated Attributable to Acadia Credit Loss - Billed Rents Core $ 1,883 $ 17 $ 386 $ 2,286 $ 832 $ — $ 268 $ 1,100 Funds 1,182 (979 ) 37 240 526 (498 ) 110 138 Total 3,065 (962 ) 423 2,526 1,358 (498 ) 378 1,238 Straight - Line Rent Reserves Core (8 ) (1 ) (29 ) (38 ) 2,744 — 220 2,964 Funds 825 (645 ) 10 190 223 (220 ) 62 65 Total 817 (646 ) (19 ) 152 2,967 (220 ) 282 3,029 Rent Abatements Core 756 — 87 843 — — — — Funds 783 (611 ) 7 179 — — — — Total 1,539 (611 ) 94 1,022 — — — — Impairment charges Core — — — — — — — — Funds — — — — 51,549 (39,149 ) — 12,400 Total — — — — 51,549 (39,149 ) — 12,400 COVID Earnings Impact Core 2,631 16 444 3,091 3,576 — 488 4,064 Funds 2,790 (2,235 ) 54 609 52,298 (39,867 ) 172 12,603 Total $ 5,421 $ (2,219 ) $ 498 $ 3,700 $ 55,874 $ (39,867 ) $ 660 $ 16,667

Segment Reporting (Tables)

Segment Reporting (Tables)	3 Months Ended
	Mar. 31, 2021
Segment Reporting [Abstract]
Summary of Segment Information	The following tables set forth certain segment information for the Company (in thousands): As of or for the Three Months Ended March 31, 2021 Core Portfolio Funds Structured Financing Unallocated Total Revenues $ 42,349 $ 27,045 $ — $ — $ 69,394 Depreciation and amortization (16,887 ) (14,503 ) — — (31,390 ) Property operating expenses, other operating and real estate taxes (13,657 ) (11,282 ) — — (24,939 ) General and administrative expenses — — — (8,996 ) (8,996 ) Gain on disposition of properties 4,612 — — — 4,612 Operating income 16,417 1,260 — (8,996 ) 8,681 Interest income — — 1,700 — 1,700 Realized and unrealized holding gains on investments and other — 6,547 (40 ) — 6,507 Equity in (losses) earnings of unconsolidated affiliates (1,129 ) 3,392 — — 2,263 Interest expense (7,214 ) (9,927 ) — — (17,141 ) Income tax provision — — — (150 ) (150 ) Net income 8,074 1,272 1,660 (9,146 ) 1,860 Net (income) loss attributable to noncontrolling interests (607 ) 3,909 — — 3,302 Net income attributable to Acadia (a) $ 7,467 $ 5,181 $ 1,660 $ (9,146 ) $ 5,162 Real estate at cost (b) $ 2,319,584 $ 1,758,469 $ — $ — $ 4,078,053 Total assets (b) $ 2,222,886 $ 1,829,386 $ 101,410 $ — $ 4,153,682 Cash paid for acquisition of real estate $ — $ — $ — $ — $ — Cash paid for development and property improvement costs $ 2,843 $ 2,582 $ — $ — $ 5,425 As of or for the Three Months Ended March 31, 2020 Core Portfolio Funds Structured Financing Unallocated Total Revenues $ 39,933 $ 31,487 $ — $ — $ 71,420 Depreciation and amortization (17,056 ) (16,321 ) — — (33,377 ) Property operating expenses, other operating and real estate taxes (11,814 ) (11,953 ) — — (23,767 ) General and administrative expenses — — — (9,070 ) (9,070 ) Impairment charges — (51,549 ) — — (51,549 ) Operating income (loss) 11,063 (48,336 ) — (9,070 ) (46,343 ) Interest and other income — — 2,929 — 2,929 Realized and unrealized holding gains on investments and other — — (530 ) — (530 ) Equity in earnings (losses) of unconsolidated affiliates 1,642 (387 ) — — 1,255 Interest expense (8,250 ) (10,052 ) — — (18,302 ) Income tax benefit — — — 952 952 Net income (loss) 4,455 (58,775 ) 2,399 (8,118 ) (60,039 ) Net loss attributable to noncontrolling interests 1,216 50,409 — — 51,625 Net income (loss) attributable to Acadia $ 5,671 $ (8,366 ) $ 2,399 $ (8,118 ) $ (8,414 ) Real estate at cost (a) $ 2,289,449 $ 1,792,667 $ — $ — $ 4,082,116 Total assets (a) $ 2,330,971 $ 1,801,008 $ 173,159 $ — $ 4,305,138 Cash paid for acquisition of real estate $ 19,088 $ — $ — $ — $ 19,088 Cash paid for development and property improvement costs $ 2,638 $ 10,695 $ — $ — $ 13,576 (a) Real estate at cost and total assets for the Funds segment include $643.0 million and $641.7 million, or $186.9 million and $186.5 million net of non-controlling interests, related to Fund II’s City Point property at March 31, 2021 and March 31, 2020, respectively.

Share Incentive and Other Com_2

Share Incentive and Other Compensation (Tables)	3 Months Ended
	Mar. 31, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Schedule of Unvested Restricted Shares and LTIP Units	A summary of the status of the Company’s unvested Restricted Shares and LTIP Units is presented below: Unvested Restricted Shares and LTIP Units Common Restricted Shares Weighted Grant-Date Fair Value LTIP Units Weighted Grant-Date Fair Value Unvested at January 1, 2020 42,390 $ 23.73 936,180 $ 28.24 Granted 66,824 13.70 440,829 19.64 Vested (19,264 ) 27.72 (250,241 ) 30.44 Forfeited (39 ) 24.77 (3,879 ) 24.67 Unvested at December 31, 2020 89,911 15.42 1,122,889 24.38 Granted 12,361 18.50 633,462 19.42 Vested (7,847 ) 26.13 (250,748 ) 28.20 Forfeited (159 ) 36.22 (91,637 ) 36.22 Unvested at March 31, 2021 94,266 $ 14.90 1,413,966 $ 20.72

Earnings (Loss) Per Common Sh_2

Earnings (Loss) Per Common Share (Tables)	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Schedule of Earnings (Loss) Per Share, Basic and Diluted	Three Months Ended March 31, (dollars in thousands) 2021 2020 Numerator: Net income (loss) attributable to Acadia $ 5,162 $ (8,414 ) Less: net income attributable to participating securities (156 ) — Income (loss) from continuing operations net of income attributable to participating securities $ 5,006 $ (8,414 ) Denominator: Weighted average shares for basic earnings per share 86,323,267 86,971,552 Effect of dilutive securities: Employee unvested restricted shares 23,093 — Denominator for diluted earnings per share 86,346,360 86,971,552 Basic and diluted earnings and basic loss per Common Share from continuing operations attributable to Acadia $ 0.06 $ (0.10 ) Anti-Dilutive Shares Excluded from Denominator: Series A Preferred OP Units 188 188 Series A Preferred OP Units - Common share equivalent 25,067 25,067 Series C Preferred OP Units 126,593 126,593 Series C Preferred OP Units - Common share equivalent 439,556 439,556 Restricted shares — 49,182

Organization, Basis of Presen_4

Organization, Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Details)	3 Months Ended	12 Months Ended
	Mar. 31, 2021propertysegment$ / shares	Dec. 31, 2020$ / shares
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Limited partnership to common stock conversion ratio	100.00%
Common shares of beneficial interest, par value | $ / shares	$ 0.001	$ 0.001
Number of retail properties	186
Number of reportable segments | segment	3
Core Portfolio
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Number of retail properties	130
Properties owned percentage	100.00%
Opportunity Funds
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Number of retail properties	56
Operating Partnership, as General Partner or Managing Member
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Remaining funds rate of distribution to operating partnership (in percent)	20.00%
Operating Partnership, as General Partner or Managing Member | Acadia's OP Ownership
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Equity interest held by Operating Partnership	94.00%	95.00%
Institutional Investors
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Remaining funds rate of distribution to all partners (in percent)	80.00%

Organization, Basis of Presen_5

Organization, Basis of Presentation and Summary of Significant Accounting Policies - Schedule of Operating Partnership's Equity Interest (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Aug. 31, 2020	Mar. 31, 2021
Mervyns II
Variable Interest Entity [Line Items]
Recallable distributions	$ 15.7	$ 3
Mervyns II | Acadia
Variable Interest Entity [Line Items]
Recallable distributions	$ 4.5	$ 15.7
Fund II and Mervyns II
Variable Interest Entity [Line Items]
Operating Partnership Share of Capital		28.33%
Capital Called		$ 372.6
Unfunded Commitment		$ 12.7
Equity interest held by Operating Partnership		28.33%
Preferred Return		8.00%
Total Distributions		$ 169.8
Fund III
Variable Interest Entity [Line Items]
Operating Partnership Share of Capital		24.54%
Capital Called		$ 448.1
Unfunded Commitment		$ 1.9
Equity interest held by Operating Partnership		24.54%
Preferred Return		6.00%
Total Distributions		$ 568.8
Fund IV
Variable Interest Entity [Line Items]
Operating Partnership Share of Capital		23.12%
Capital Called		$ 481.3
Unfunded Commitment		$ 48.7
Equity interest held by Operating Partnership		23.12%
Preferred Return		6.00%
Total Distributions		$ 193.1
Fund V
Variable Interest Entity [Line Items]
Operating Partnership Share of Capital		20.10%
Capital Called		$ 217.1
Unfunded Commitment		$ 302.9
Equity interest held by Operating Partnership		20.10%
Preferred Return		6.00%
Total Distributions		$ 31.5

Real Estate - Schedule of Real

Real Estate - Schedule of Real Estate (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Acquisition And Disposition Of Properties And Discontinued Operations [Abstract]
Land	$ 767,631	$ 776,275
Buildings and improvements	2,847,797	2,848,781
Tenant improvements	196,748	191,046
Construction in progress	6,453	5,751
Right-of-use assets - finance leases	25,086	25,086
Total	3,843,715	3,846,939
Less: Accumulated depreciation and amortization	(605,684)	(586,800)
Operating real estate, net	3,238,031	3,260,139
Real estate under development	234,338	247,349	$ 253,402
Net investments in real estate	$ 3,472,369	$ 3,507,488

Real Estate - Schedule of Acqui

Real Estate - Schedule of Acquisitions and Conversions (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Business Acquisition [Line Items]
Purchase Price	$ 0	$ 172,152
Core Portfolio
Business Acquisition [Line Items]
Purchase Price		$ 158,143
Core Portfolio | 917 W. Armitage - Chicago, IL
Business Acquisition [Line Items]
Percent Acquired		100.00%
Purchase Price		$ 3,515
Core Portfolio | Soho Acquisitions | 37 Greene Street - New York, NY
Business Acquisition [Line Items]
Percent Acquired		100.00%
Purchase Price		$ 15,689
Core Portfolio | Town Center | Wilmington, DE
Business Acquisition [Line Items]
Percent Acquired		100.00%
Purchase Price		$ 138,939
Fund IV
Business Acquisition [Line Items]
Purchase Price		$ 14,009
Fund IV | 230-240 W. Broughton Street | GEORGIA
Business Acquisition [Line Items]
Percent Acquired		100.00%
Purchase Price		$ 13,219
Fund IV | 102 E. Broughton Street | GEORGIA
Business Acquisition [Line Items]
Percent Acquired		100.00%
Purchase Price		$ 790

Real Estate - Acquisitions and

Real Estate - Acquisitions and Conversions - Additional Information (Details)	12 Months Ended
	Dec. 31, 2020USD ($)
Acquisition And Disposition Of Properties And Discontinued Operations [Abstract]
Capitalized acquisition costs	$ 1,300,000
Debt assumed	$ 0

Real Estate - Schedule of Purch

Real Estate - Schedule of Purchase Price Allocations (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Purchase Price Allocation
Land	$ 0	$ 25,440
Buildings and improvements	0	123,459
Accounts receivable, prepaids and other assets	0	5,770
Acquisition-related intangible assets	0	23,061
Right-of-use asset - Operating lease	0	234
Acquisition-related intangible liabilities	0	(4,569)
Lease liability - Operating lease	0	(234)
Accounts payable and other liabilities	0	(1,009)
Net assets acquired	0	172,152
Consideration
Cash	0	21,208
Conversion of note receivable	0	38,674
Conversion of accrued interest	0	1,995
Liabilities assumed	0	116
Existing interest in previously unconsolidated investment	0	109,571
Acquisition of noncontrolling interests	0	588
Total consideration	$ 0	$ 172,152

Real Estate - Schedule of Prope

Real Estate - Schedule of Property Dispositions (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on Sale	$ 4,612
Disposed of by sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sale Price	16,400	$ 22,413
Gain on Sale	$ 4,612	$ 683
Core Portfolio | Disposed of by sale | 60 Orange St - Bloomfield, NJ.
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Date Sold	Jan. 29, 2021
Sale Price	$ 16,400
Gain on Sale	$ 4,612
Core Portfolio | Disposed of by sale | 163 Highland Ave. (Easement) - Needham, MA
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Date Sold		Mar. 19, 2020
Sale Price		$ 238
Gain on Sale		$ 88
Core Portfolio | Disposed of by sale | Union Township (Parcel) - New Castle, PA
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Date Sold		Dec. 11, 2020
Sale Price		$ 200
Gain on Sale		$ 86
Fund IV | Disposed of by sale | Colonie Plaza - Albany, NY
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Date Sold		Apr. 13, 2020
Sale Price		$ 15,250
Gain on Sale		$ 485
Fund IV | Disposed of by sale | Airport Mall (Parcel) - Bangor, ME
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Date Sold		Sep. 10, 2020
Sale Price		$ 400
Gain on Sale		$ 24
Fund III | Disposed of by sale | Cortlandt Crossing (Sewer Project and Retention Pond) - Cortlandt, NY
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Date Sold		Nov. 30, 2020
Sale Price		$ 6,325

Real Estate - Schedule of Dispo

Real Estate - Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
STATEMENTS OF INCOME
Gain on disposition of properties	$ 4,612
Disposal Group, Not Discontinued Operations
STATEMENTS OF INCOME
Revenues	82	$ 870
Expenses	(90)	(864)
Gain on disposition of properties	4,612
Net income attributable to noncontrolling interests	1	48
Net income attributable to Acadia	$ 4,605	$ 54

Real Estate - Schedule of Devel

Real Estate - Schedule of Development in Process Activities (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021USD ($)property	Dec. 31, 2020USD ($)property	Dec. 31, 2019USD ($)property
Property, Plant and Equipment [Line Items]
Number of properties under development | property	3	3	3
Real estate under development, beginning balance	$ 234,338	$ 247,349	$ 253,402
Transfers In	0	66,812
Capitalized Costs	1,766	8,062
Transfers Out	$ 14,777	$ 80,927
Core Portfolio
Property, Plant and Equipment [Line Items]
Number of properties under development | property	0	0	0
Real estate under development, beginning balance	$ 50,251	$ 63,875	$ 60,863
Transfers In	0	0
Capitalized Costs	933	3,012
Transfers Out	$ 14,557	$ 0
Fund Portfolio | Fund II
Property, Plant and Equipment [Line Items]
Number of properties under development | property	0	0	0
Real estate under development, beginning balance	$ 75,192	$ 74,657	$ 10,703
Transfers In	0	66,812
Capitalized Costs	535	3,612
Transfers Out	$ 0	$ 6,470
Fund Portfolio | Fund III
Property, Plant and Equipment [Line Items]
Number of properties under development | property	1	1	1
Real estate under development, beginning balance	$ 23,416	$ 23,139	$ 36,240
Transfers In	0	0
Capitalized Costs	277	70
Transfers Out	$ 0	$ 13,171
Fund Portfolio | Fund IV
Property, Plant and Equipment [Line Items]
Number of properties under development | property	2	2	2
Real estate under development, beginning balance	$ 85,479	$ 85,678	$ 145,596
Transfers In	0	0
Capitalized Costs	21	1,368
Transfers Out	$ 220	$ 61,286

Real Estate - Schedule of Dev_2

Real Estate - Schedule of Development in Process Activities (Parenthetical) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Mar. 31, 2021
Property, Plant and Equipment [Line Items]
Notes receivable, net	$ 101,450	$ 101,410
Fund II
Property, Plant and Equipment [Line Items]
Notes receivable, net	33,800
Fund Portfolio | Fund IV
Property, Plant and Equipment [Line Items]
Impairment charge	$ 16,500

Real Estate - Real Estate Under

Real Estate - Real Estate Under Development and Construction in Progress - Additional Information (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021USD ($)property	Dec. 31, 2020USD ($)property
Property, Plant and Equipment [Line Items]
Notes receivable, net | $	$ 101,410	$ 101,450
Fund IV
Property, Plant and Equipment [Line Items]
Number of projects put into service during period		1
Fund II
Property, Plant and Equipment [Line Items]
Notes receivable, net | $		$ 33,800
Core Portfolio
Property, Plant and Equipment [Line Items]
Number of projects put into service during period	1
Fund Portfolio
Property, Plant and Equipment [Line Items]
Number of projects put into service during period	1
Fund Portfolio | Fund IV
Property, Plant and Equipment [Line Items]
Number of projects put into service during period		2
Impairment charge | $		$ 16,500
Cortlandt Crossing | Fund III
Property, Plant and Equipment [Line Items]
Number of projects put into service during period		1

Notes Receivable, Net - Schedul

Notes Receivable, Net - Schedule of Notes Receivable (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)NotesReceivable	Dec. 31, 2020USD ($)
Accounts Notes And Loans Receivable [Line Items]
Total notes receivable	$ 102,100	$ 102,100
Allowance for credit loss	(690)	(650)
Notes receivable, net	$ 101,410	101,450
Number | NotesReceivable	7
Core Portfolio
Accounts Notes And Loans Receivable [Line Items]
Total notes receivable	$ 96,794	96,794
Number | NotesReceivable	6
Core Portfolio | Minimum
Accounts Notes And Loans Receivable [Line Items]
Maturity Date	2020-04
Interest Rate	2.65%
Core Portfolio | Maximum
Accounts Notes And Loans Receivable [Line Items]
Maturity Date	2027-12
Interest Rate	9.00%
Fund III | Fund Portfolio
Accounts Notes And Loans Receivable [Line Items]
Total notes receivable	$ 5,306	$ 5,306
Number | NotesReceivable	1
Maturity Date	2020-07
Interest Rate	18.00%

Notes Receivable, Net - Sched_2

Notes Receivable, Net - Schedule of Notes Receivable (Parenthetical) (Details) $ in Thousands	Mar. 31, 2021USD ($)NotesReceivable	Dec. 31, 2020USD ($)
Accounts Notes And Loans Receivable [Line Items]
Number of notes receivable | NotesReceivable	7
Notes receivable | $	$ 102,100	$ 102,100
Core Portfolio
Accounts Notes And Loans Receivable [Line Items]
Number of notes receivable | NotesReceivable	6
Notes receivable | $	$ 96,794	96,794
OP Unit Holders | Core Portfolio
Accounts Notes And Loans Receivable [Line Items]
Number of notes receivable | NotesReceivable	2
Notes receivable | $	$ 6,500	$ 6,500

Notes Receivable, Net - Additio

Notes Receivable, Net - Additional Information (Details) - USD ($)	Feb. 01, 2020	Mar. 31, 2021	Dec. 31, 2020	Nov. 02, 2020	Nov. 01, 2020	Apr. 01, 2020	Jan. 14, 2020
Accounts Notes And Loans Receivable [Line Items]
Increase in allowance for credit loss		$ 100,000
Notes receivable		102,100,000	$ 102,100,000
Note receivable accrued interest		15,481,000	13,917,000
Credit loss reserve		690,000	650,000
Notes receivable, net		101,410,000	101,450,000
Additional credit loss reserve			300,000
Aggregate loans		101,410,000	101,450,000
LUF Portfolio
Accounts Notes And Loans Receivable [Line Items]
Note receivable accrued interest	$ 5,000,000
Interest Rate	8.00%
Percentage of mortgage loan collateralized	50.00%
Core Note
Accounts Notes And Loans Receivable [Line Items]
Notes receivable modified, subsequent payment default		21,600,000	21,600,000
850 Third Avenue Brooklyn, NY
Accounts Notes And Loans Receivable [Line Items]
Notes receivable, net							$ 54,000,000
Interest Rate							9.00%
Fund II
Accounts Notes And Loans Receivable [Line Items]
Notes receivable				$ 33,800,000
Note receivable accrued interest					$ 600,000
Notes receivable, net			33,800,000
Fund III
Accounts Notes And Loans Receivable [Line Items]
Notes receivable modified, subsequent payment default		10,000,000
ASU 2016-13
Accounts Notes And Loans Receivable [Line Items]
Credit loss reserve			400,000
Core Portfolio
Accounts Notes And Loans Receivable [Line Items]
Notes receivable		96,794,000	$ 96,794,000
Structured Financing
Accounts Notes And Loans Receivable [Line Items]
Note receivable accrued interest		8,800,000
Credit loss reserve		0
Aggregate loans		38,400,000
Structured Financing | Non-Collateral Dependent Loans
Accounts Notes And Loans Receivable [Line Items]
Note receivable accrued interest		6,700,000
Credit loss reserve		700,000
Loans amortized cost		$ 79,200,000
Brandywine Portfolio | Core Portfolio
Accounts Notes And Loans Receivable [Line Items]
Notes receivable						$ 38,700,000
Note receivable accrued interest						$ 2,000,000
Equity method investment, ownership percentage by third party						24.78%

Investments in and Advances t_3

Investments in and Advances to Unconsolidated Affiliates - Schedule of Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Schedule of Equity Method Investments [Line Items]
Due from (to) Related Parties	$ 290	$ 363
Other	2,615	1,881
Investments in and advances to unconsolidated affiliates	256,332	249,807
Distributions in excess of income from, and investments in, unconsolidated affiliates	$ 15,272	15,616
KLA/ABS
Schedule of Equity Method Investments [Line Items]
Cost method investment, ownership percentage	36.70%
Cost Method Investment	$ 78,526	72,391
Self Storage Management
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	95.00%
Equity method investments	$ 207	207
Fund IV Other Portfolio
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	98.57%
Equity method investments	$ 12,394	11,719
650 Bald Hill Road
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	90.00%
Equity method investments	$ 12,532	12,550
Fund IV
Schedule of Equity Method Investments [Line Items]
Equity method investments	$ 24,926	24,269
Fund V Family Center at Riverdale
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	89.42%
Equity method investments	$ 12,679	11,824
Tri City Plaza
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	90.00%
Equity method investments	$ 7,309	7,024
Frederick County Acquisitions
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	90.00%
Equity method investments	$ 10,647	10,837
Fund V
Schedule of Equity Method Investments [Line Items]
Equity method investments	30,635	29,685
Core Portfolio
Schedule of Equity Method Investments [Line Items]
Equity method investments	119,133	121,011
Other	$ 2,500
Core Portfolio | 840 N. Michigan
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	88.43%
Equity method investments	$ 54,924	55,863
Core Portfolio | Renaissance Portfolio
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	20.00%
Equity method investments	$ 28,742	29,270
Core Portfolio | Gotham Plaza
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	49.00%
Equity method investments	$ 28,589	28,683
Core Portfolio | Georgetown Portfolio
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	50.00%
Equity method investments	$ 3,870	4,624
Core Portfolio | 1238 Wisconsin Avenue
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	80.00%
Equity method investments	$ 3,008	2,571
Core Portfolio | Crossroads
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	49.00%
Distributions in excess of income from, and investments in, unconsolidated affiliates	$ 15,272	$ 15,616

Investments in and Advances t_4

Investments in and Advances to Unconsolidated Affiliates - Core Portfolio - Additional Information (Details) - USD ($) $ in Thousands	Apr. 01, 2020	Dec. 31, 2020	Mar. 31, 2021	Aug. 08, 2019
Schedule of Equity Method Investments [Line Items]
Cost method investments		$ 1,881	$ 2,615
Core Portfolio
Schedule of Equity Method Investments [Line Items]
Cost method investments			2,500
Impairment of investments		$ 400
Core Portfolio | Fifth Wall Ventures Retail Fund, L.P.
Schedule of Equity Method Investments [Line Items]
Cost method investments			$ 1,100	$ 1,800
Cost method investment ownership percentage				5.00%
Core Portfolio | Brandywine Portfolio
Schedule of Equity Method Investments [Line Items]
Note receivable exchanged	$ 38,700
Note receivable accrued interest	$ 2,000
Equity method investment, ownership percentage by third party	24.78%
Equity method investment, controlling interest percentage	100.00%

Investments in and Advances t_5

Investments in and Advances to Unconsolidated Affiliates - Mervyns I & II - Additional Information (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended			12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Jun. 30, 2020	Dec. 31, 2020
Mervyns II
Schedule of Equity Method Investments [Line Items]
Cost method investment, ownership percentage	28.33%
Realized gain on investment	$ 0.4	$ 0.4	$ 22.8
Cost method investments effective ownership, shares	4.1
Cost method investments effective ownership interest	1.00%
Unrealized gain on investment			$ 64.9
Albertson
Schedule of Equity Method Investments [Line Items]
Cost method investment, ownership percentage	36.67%
Albertson | Mervyns II
Schedule of Equity Method Investments [Line Items]
Unrealized gain on investment	$ 6.1			$ 7.5

Investments in and Advances t_6

Investments in and Advances to Unconsolidated Affiliates - Fund Investments - Additional Information (Details) $ in Millions	Mar. 31, 2021property	Jun. 30, 2020property	May 26, 2020USD ($)property
Schedule of Equity Method Investments [Line Items]
Number of retail properties	186
Broughton St. Portfolio Savannah, GA
Schedule of Equity Method Investments [Line Items]
Number of retail properties			2
Purchase Price | $			$ 1.3
Consolidated Affiliates | BSP II
Schedule of Equity Method Investments [Line Items]
Number of retail properties		2

Investments in and Advances t_7

Investments in and Advances to Unconsolidated Affiliates - Unconsolidated Affiliates - Additional Information (Details) - Equity Method Investee - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Schedule of Equity Method Investments [Line Items]
Related party revenue	$ 0.1	$ 0.1
Expenses, related party	$ 0.4	$ 1

Investments in and Advances t_8

Investments in and Advances to Unconsolidated Affiliates - Unconsolidated Affiliates - Schedule of Condensed Balance Sheet (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020
Combined and Condensed Balance Sheets
Real estate under development	$ 234,338	$ 247,349
Other assets	162,596	173,809
Total assets	4,153,682	4,186,882	$ 4,305,138
Total liabilities and equity	4,153,682	4,186,882
Company's share of distributions in excess of income from and investments in unconsolidated affiliates	15,272	15,616
Investments in and advances to unconsolidated affiliates	256,332	249,807
Unconsolidated Affiliates
Combined and Condensed Balance Sheets
Rental property, net	552,262	563,997
Real estate under development	15,907	14,517
Other assets	64,358	61,969
Total assets	632,527	640,483
Mortgage notes payable	505,245	512,490
Other liabilities	75,268	74,872
Partners’ equity	52,014	53,121
Total liabilities and equity	632,527	640,483
Company's share of accumulated equity	100,729	100,767
Basis differential	54,582	55,017
Deferred fees, net of portion related to the Company's interest	4,111	3,565
Amounts receivable/payable by the Company	290	363
Investments in and advances to unconsolidated affiliates, net of Company's share of distributions in excess of income from and investments in unconsolidated affiliates	159,712	159,712
Investments carried at fair value or cost	81,348	74,479
Company's share of distributions in excess of income from and investments in unconsolidated affiliates	15,272	15,616
Investments in and advances to unconsolidated affiliates	$ 256,332	$ 249,807

Investments in and Advances t_9

Investments in and Advances to Unconsolidated Affiliates - Unconsolidated Affiliates - Schedule of Condensed Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Combined and Condensed Statements of Operations
Total revenues	$ 69,394	$ 71,420
Depreciation and amortization	(31,390)	(33,377)
Company’s equity in earnings of unconsolidated affiliates	2,263	1,255
Unconsolidated Affiliates
Combined and Condensed Statements of Operations
Total revenues	17,281	19,496
Operating and other expenses	(6,219)	(6,579)
Interest expense	(4,822)	(5,256)
Depreciation and amortization	(8,801)	(6,360)
Gain on disposition of properties	3,206
Net income attributable to unconsolidated affiliates	645	1,301
Company’s share of equity in net income of unconsolidated affiliates	2,699	334
Company’s equity in earnings of unconsolidated affiliates	2,263	10
Operating Partnership, as General Partner or Managing Member
Combined and Condensed Statements of Operations
Basis differential amortization	$ (436)	$ (324)

Investments in and Advances _10

Investments in and Advances to Unconsolidated Affiliates - Unconsolidated Affiliates - Schedule of Condensed Income Statement (Parenthetical) (Details)	Jan. 04, 2021landparcel
Equity Method Investments And Joint Ventures [Abstract]
Number of land parcels sold by the Family Center at Riverdale	2

Other Assets, Net and Account_3

Other Assets, Net and Accounts Payable and Other Liabilities - Schedule of other assets and other liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Other Assets, Net:
Lease intangibles, net (Note 6)	$ 91,371	$ 100,732
Deferred charges, net	30,524	30,488
Note receivable accrued interest	15,481	13,917
Prepaid expenses	14,121	17,468
Due from seller	3,364	3,682
Income taxes receivable	2,613	2,433
Other receivables	2,068	2,058
Deposits	1,744	1,728
Corporate assets, net	1,308	1,302
Derivative financial instruments (Note 8)	2	1
Other assets, net	162,596	173,809
Deferred Charges, Net:
Deferred leasing and other costs	61,107	57,533
Deferred financing costs related to line of credit	11,380	11,341
Deferred costs, gross	72,487	68,874
Accumulated amortization	(41,963)	(38,386)
Deferred charges, net	30,524	30,488
Accounts Payable and Other Liabilities:
Lease intangibles, net (Note 6)	$ 71,023	$ 76,434
Operating Lease, Liability, Statement of Financial Position [Extensible List]	Accounts payable and other liabilities	Accounts payable and other liabilities
Accounts payable and accrued expenses	$ 56,149	$ 53,031
Derivative financial instruments (Note 8)	56,083	90,139
Deferred income	35,396	31,842
Tenant security deposits, escrow and other	12,025	12,178
Lease liability - finance leases, net (Note 11)	6,382	6,287
Accounts payable and other liabilities	$ 237,058	$ 269,911

Lease Intangibles - Schedule of

Lease Intangibles - Schedule of Intangible Assets and Liabilities Included in Other Assets and Accounts Payable and Other Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Amortizable Intangible Assets, Gross Carrying Amount	$ 284,910	$ 287,523
Amortizable Intangible Assets, Accumulated Amortization	(193,539)	(186,791)
Amortizable Intangible Assets, Net Carrying Amount	91,371	100,732
Amortizable Intangible Liabilities
Amortizable Intangible Liabilities, Gross Carrying Amount	(160,388)	(164,923)
Amortizable Intangible Liabilities, Accumulated Amortization	89,812	88,951
Amortizable Intangible Liabilities, Net Carrying Amount	(70,576)	(75,972)
Above-market Ground Lease, Gross	(671)	(671)
Above-market Ground Lease, Accumulated Amortization	224	209
Above-market Ground Lease, Net	(447)	(462)
Finite-Lived Intangible Liabilities, Gross	(161,059)	(165,594)
Finite-Lived Intangible Liabilities, Accumulated Amortization	90,036	89,160
Finite-Lived Intangible Liabilities, Net	(71,023)	(76,434)
In-place lease intangible assets
Finite-Lived Intangible Assets [Line Items]
Amortizable Intangible Assets, Gross Carrying Amount	265,722	268,335
Amortizable Intangible Assets, Accumulated Amortization	(178,279)	(171,856)
Amortizable Intangible Assets, Net Carrying Amount	87,443	96,479
Amortizable Intangible Liabilities
Amortizable Intangible Liabilities, Net Carrying Amount	(66,648)
Above-market rent
Finite-Lived Intangible Assets [Line Items]
Amortizable Intangible Assets, Gross Carrying Amount	19,188	19,188
Amortizable Intangible Assets, Accumulated Amortization	(15,260)	(14,935)
Amortizable Intangible Assets, Net Carrying Amount	$ 3,928	$ 4,253

Lease Intangibles - Additional

Lease Intangibles - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Below market rents, acquired		$ 4.6
Below market rents acquired, weighted average useful life		20 years 2 months 12 days
In-place lease intangible assets
Finite-Lived Intangible Assets [Line Items]
Intangible assets acquired	$ 0	$ 21
Acquired intangible assets, weighted average useful life		4 years 10 months 24 days
Above-market rent
Finite-Lived Intangible Assets [Line Items]
Intangible assets acquired	$ 0	$ 2
Acquired intangible assets, weighted average useful life		5 years 9 months 18 days

Lease Intangibles - Scheduled A

Lease Intangibles - Scheduled Amortization of Acquired Lease Intangible Assets and Assumed Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Acquired Lease Intangibles [Abstract]
Net Increase In Lease Revenues, Total	$ 70,576	$ 75,972
Amortizable Intangible Assets, Net Carrying Amount	(91,371)	(100,732)
In-place lease intangible assets
Acquired Lease Intangibles [Abstract]
2021, Net Increase In Lease Revenues	4,923
2022, Net Increase In Lease Revenues	5,944
2023, Net Increase In Lease Revenues	5,476
2024, Net Increase In Lease Revenues	5,126
2025, Net Increase In Lease Revenues	4,459
Thereafter, Net Increase In Lease Revenues	40,720
Net Increase In Lease Revenues, Total	66,648
2021, Increase to Amortization	(17,375)
2022, Increase to Amortization	(17,869)
2023, Increase to Amortization	(13,239)
2024, Increase to Amortization	(9,297)
2025, Increase to Amortization	(6,939)
Thereafter, Increase to Amortization	(22,724)
Amortizable Intangible Assets, Net Carrying Amount	(87,443)	$ (96,479)
2021, Reduction of Rent Expense	44
2022, Reduction of Rent Expense	58
2023, Reduction of Rent Expense	58
2024, Reduction of Rent Expense	58
2025, Reduction of Rent Expense	58
Thereafter, Reduction of Rent Expense	171
Reduction of Rent Expense, Total	447
2021, Net Income (Expense)	(12,408)
2022, Net Income (Expense)	(11,867)
2023, Net Income (Expense)	(7,705)
2024, Net Income (Expense)	(4,113)
2025, Net Income (Expense)	(2,422)
Thereafter, Net Income (Expense)	18,167
Total, Net Income (Expense)	$ (20,348)

Debt - Summary of Consolidated

Debt - Summary of Consolidated Indebtedness (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Long-term debt, gross	$ 1,720,743	$ 1,770,054
Net unamortized debt issuance costs	(6,210)	(6,763)
Unamortized fair market value of assumed debt	522	548
Mortgage and other notes payable, net	1,188,695	1,204,581
Unsecured notes payable, net	420,960	420,858
Total Indebtedness	1,715,055	1,763,839
Mortgages
Debt Instrument [Line Items]
Net unamortized debt issuance costs	(5,770)	(6,507)
Unamortized fair market value of assumed debt	522	548
Mortgage and other notes payable, net	1,188,695	1,204,581
Unsecured Debt
Debt Instrument [Line Items]
Net unamortized debt issuance costs	(440)	(256)
Unsecured notes payable, net	$ 420,960	420,858
Core Portfolio | Variable Rate Debt | LIBOR | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	1.50%
Core Portfolio | Variable Rate Debt | LIBOR | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	1.90%
Core Portfolio | Unsecured Notes Payable | LIBOR | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	1.25%
Core Portfolio | Mortgages
Debt Instrument [Line Items]
Long-term debt, gross	$ 220,802	228,310
Core Portfolio | Mortgages | Fixed Rate
Debt Instrument [Line Items]
Long-term debt, gross	$ 147,233	$ 147,810
Core Portfolio | Mortgages | Fixed Rate | Minimum
Debt Instrument [Line Items]
Interest rate, stated percentage	3.88%	3.88%
Maturity Date	2024-02
Core Portfolio | Mortgages | Fixed Rate | Maximum
Debt Instrument [Line Items]
Interest rate, stated percentage	5.89%	5.89%
Maturity Date	2035-04
Core Portfolio | Mortgages | Variable Rate - Swapped
Debt Instrument [Line Items]
Long-term debt, gross	$ 73,569	$ 80,500
Core Portfolio | Mortgages | Variable Rate - Swapped | Minimum
Debt Instrument [Line Items]
Interest rate, stated percentage	3.41%	3.41%
Maturity Date	2023-01
Core Portfolio | Mortgages | Variable Rate - Swapped | Maximum
Debt Instrument [Line Items]
Interest rate, stated percentage	4.54%	4.54%
Maturity Date	2028-11
Core Portfolio | Unsecured Debt
Debt Instrument [Line Items]
Long-term debt, gross	$ 380,000	$ 380,000
Core Portfolio | Unsecured Debt | Variable Rate Credit Facility
Debt Instrument [Line Items]
Long-term debt, gross	$ 30,000	$ 30,000
Core Portfolio | Unsecured Debt | Variable Rate Credit Facility | LIBOR
Debt Instrument [Line Items]
Interest rate, stated percentage	2.55%	2.55%
Maturity Date	2021-06
Core Portfolio | Unsecured Debt | Variable Rate Unsecured Term Loans - Swapped
Debt Instrument [Line Items]
Maturity Date	2023-03
Long-term debt, gross	$ 350,000	$ 350,000
Core Portfolio | Unsecured Debt | Variable Rate Unsecured Term Loans - Swapped | Minimum
Debt Instrument [Line Items]
Interest rate, stated percentage	2.49%	2.49%
Core Portfolio | Unsecured Debt | Variable Rate Unsecured Term Loans - Swapped | Maximum
Debt Instrument [Line Items]
Interest rate, stated percentage	5.02%	5.02%
Core Portfolio | Unsecured Debt | Unsecured Line of Credit - Swapped
Debt Instrument [Line Items]
Maturity Date	2022-03
Core Portfolio | Line of Credit | Unsecured Line of Credit - Swapped
Debt Instrument [Line Items]
Long-term debt, gross	$ 105,400	$ 138,400
Core Portfolio | Line of Credit | Unsecured Line of Credit - Swapped | Minimum
Debt Instrument [Line Items]
Interest rate, stated percentage	2.49%	2.49%
Core Portfolio | Line of Credit | Unsecured Line of Credit - Swapped | Maximum
Debt Instrument [Line Items]
Interest rate, stated percentage	5.02%	5.02%
Fixed Rate
Debt Instrument [Line Items]
Long-term debt, gross	$ 1,102,250	$ 1,143,152
Variable Rate
Debt Instrument [Line Items]
Long-term debt, gross	618,493	626,902
Fund II | Fund Portfolio
Debt Instrument [Line Items]
Long-term debt, gross	$ 229,101	228,282
Fund II | Fund Portfolio | Variable Rate Debt | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.39%
Fund II | Fund Portfolio | Mortgages
Debt Instrument [Line Items]
Long-term debt, gross	$ 247,834	$ 247,085
Fund II | Fund Portfolio | Mortgages | Variable Rate - Swapped
Debt Instrument [Line Items]
Interest rate, stated percentage	2.88%	2.88%
Maturity Date	2021-11
Long-term debt, gross	$ 18,733	$ 18,803
Fund II | Fund Portfolio | Mortgages | Variable Rate Debt | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	3.00%	3.00%
Maturity Date	2022-03
Fund II | Fund Portfolio | Mortgages | Variable Rate Debt | Prime Rate
Debt Instrument [Line Items]
Basis spread on variable rate	2.00%	2.00%
Maturity Date	2022-08
Fund II | Fund Portfolio | Unsecured Debt | Variable Rate Debt | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.65%	1.65%
Fund II | Fund Portfolio | Unsecured Debt | Unsecured Notes Payable
Debt Instrument [Line Items]
Long-term debt, gross	$ 40,000	$ 40,000
Fund II | Fund Portfolio | Unsecured Debt | Unsecured Notes Payable | LIBOR
Debt Instrument [Line Items]
Maturity Date	2021-09
Fund III | Fund Portfolio | Variable Rate Debt | LIBOR | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	2.75%
Fund III | Fund Portfolio | Variable Rate Debt | LIBOR | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	3.10%
Fund III | Fund Portfolio | Mortgages | Variable Rate Debt
Debt Instrument [Line Items]
Long-term debt, gross	$ 71,613	$ 71,918
Fund III | Fund Portfolio | Mortgages | Variable Rate Debt | LIBOR | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	2.75%	2.75%
Maturity Date	2021-06
Fund III | Fund Portfolio | Mortgages | Variable Rate Debt | LIBOR | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	3.10%	3.10%
Maturity Date	2022-07
Fund IV | Fund Portfolio | LIBOR | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	1.75%
Fund IV | Fund Portfolio | LIBOR | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	2.00%
Fund IV | Fund Portfolio | Mortgages
Debt Instrument [Line Items]
Long-term debt, gross	$ 318,278	$ 327,550
Fund IV | Fund Portfolio | Mortgages | Fixed Rate
Debt Instrument [Line Items]
Long-term debt, gross	$ 6,726	$ 6,726
Fund IV | Fund Portfolio | Mortgages | Fixed Rate | Minimum
Debt Instrument [Line Items]
Interest rate, stated percentage	3.40%	3.40%
Maturity Date	2025-10
Fund IV | Fund Portfolio | Mortgages | Fixed Rate | Maximum
Debt Instrument [Line Items]
Interest rate, stated percentage	4.50%	4.50%
Maturity Date	2026-06
Fund IV | Fund Portfolio | Mortgages | Variable Rate - Swapped
Debt Instrument [Line Items]
Long-term debt, gross	$ 66,250	$ 66,590
Fund IV | Fund Portfolio | Mortgages | Variable Rate - Swapped | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	3.48%	3.48%
Maturity Date	2022-04
Fund IV | Fund Portfolio | Mortgages | Variable Rate - Swapped | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	4.61%	4.61%
Maturity Date	2022-12
Fund IV | Fund Portfolio | Mortgages | Variable Rate Debt
Debt Instrument [Line Items]
Long-term debt, gross	$ 245,302	$ 254,234
Fund IV | Fund Portfolio | Mortgages | Variable Rate Debt | LIBOR | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	1.60%	1.60%
Maturity Date	2021-04
Fund IV | Fund Portfolio | Mortgages | Variable Rate Debt | LIBOR | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	3.40%	3.40%
Maturity Date	2025-10
Fund IV | Fund Portfolio | Unsecured Debt | Term Loan Subscription Facility
Debt Instrument [Line Items]
Long-term debt, gross	$ 1,400	$ 864
Fund IV | Fund Portfolio | Unsecured Debt | Term Loan Subscription Facility | LIBOR
Debt Instrument [Line Items]
Maturity Date	2021-12
Fund IV | Fund Portfolio | Unsecured Debt | Term Loan Subscription Facility | LIBOR | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	1.90%	1.90%
Fund V | Fund Portfolio | LIBOR | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	1.50%
Fund V | Fund Portfolio | LIBOR | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	2.20%
Fund V | Fund Portfolio | Mortgages
Debt Instrument [Line Items]
Long-term debt, gross	$ 335,416	$ 335,677
Fund V | Fund Portfolio | Mortgages | Variable Rate - Swapped
Debt Instrument [Line Items]
Long-term debt, gross	$ 334,339	$ 334,323
Fund V | Fund Portfolio | Mortgages | Variable Rate - Swapped | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	2.95%	2.95%
Maturity Date	2021-06
Fund V | Fund Portfolio | Mortgages | Variable Rate - Swapped | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	4.78%	4.78%
Maturity Date	2024-12
Fund V | Fund Portfolio | Mortgages | Variable Rate Debt
Debt Instrument [Line Items]
Long-term debt, gross	$ 1,077	$ 1,354
Fund V | Fund Portfolio | Mortgages | Variable Rate Debt | LIBOR | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	1.50%	1.50%
Maturity Date	2021-06
Fund V | Fund Portfolio | Mortgages | Variable Rate Debt | LIBOR | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	2.20%	2.20%
Maturity Date	2024-12
Fund V | Fund Portfolio | Unsecured Debt | Subscription Line
Debt Instrument [Line Items]
Long-term debt, gross	$ 0	$ 250
Fund V | Fund Portfolio | Unsecured Debt | Subscription Line | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.60%	1.60%
Maturity Date	2021-05

Debt - Summary of Consolidate_2

Debt - Summary of Consolidated Indebtedness (Parenthetical) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Long-term debt, gross	$ 1,720,743	$ 1,770,054
Variable-rate debt that subject to interest cap agreements
Debt Instrument [Line Items]
Long-term debt, gross	140,000	139,200
Total Debt - Variable Rate Debt Fixed with Interest Rate Swap Agreements
Debt Instrument [Line Items]
Long-term debt, gross	948,300	988,600
Core Portfolio | Interest Rate Swaps
Debt Instrument [Line Items]
Long-term debt, gross	$ 36,200	3,200
Minimum | Core Portfolio | Variable Rate Debt | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.50%
Minimum | Core Portfolio | Unsecured Notes Payable | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.25%
Minimum | Core Portfolio | Unsecured Line of Credit [Member] | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.35%
Maximum | Core Portfolio | Variable Rate Debt | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.90%
Fund II | Fund Portfolio
Debt Instrument [Line Items]
Long-term debt, gross	$ 229,101	$ 228,282
Fund II | Fund Portfolio | Variable Rate Debt | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.39%
Fund III | Minimum | Fund Portfolio | Variable Rate Debt | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	2.75%
Fund III | Maximum | Fund Portfolio | Variable Rate Debt | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	3.10%
Fund IV | Minimum | Fund Portfolio | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.75%
Fund IV | Maximum | Fund Portfolio | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	2.00%
Fund V | Minimum | Fund Portfolio | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.50%
Fund V | Maximum | Fund Portfolio | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	2.20%

Debt - Credit Facility - Additi

Debt - Credit Facility - Additional Information (Details) - Unsecured Debt	3 Months Ended
	Mar. 31, 2021USD ($)
Debt Instrument [Line Items]
Maturity date	Mar. 31, 2023
Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 250,000,000
Basis spread on variable rate	1.40%
Maturity date	Mar. 31, 2022
Senior Unsecured Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 600,000,000
$300 Million Term Loan
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 350,000,000
Basis spread on variable rate	1.30%

Debt - Mortgages and Other Note

Debt - Mortgages and Other Notes Payable - Additional Information (Details) $ in Thousands	Mar. 30, 2021	Oct. 30, 2020USD ($)	Jan. 31, 2021USD ($)	Mar. 31, 2021USD ($)propertyloan	Dec. 31, 2020USD ($)property	Dec. 31, 2020USD ($)propertyloan	Jul. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Debt Instrument [Line Items]
Notes receivable, net				$ 101,410	$ 101,450	$ 101,450
Scheduled principal payment						$ 6,100
Amount of share failed to meet liquidity requirements				$ 8,700
Mortgages
Debt Instrument [Line Items]
Number of mortgage loans | loan				3
Number of properties collateralized | property				41	42	42
Mortgages | Subscription Line
Debt Instrument [Line Items]
Number of mortgage loans | loan						7
Notes receivable, net				$ 37,700	$ 46,000	$ 46,000
Mortgages | Subscription Line 1
Debt Instrument [Line Items]
Notes receivable, net				23,100	51,300	51,300
Mortgages | Subscription Line 2
Debt Instrument [Line Items]
Notes receivable, net					40,000	40,000
Mortgages | Subscription Line 3
Debt Instrument [Line Items]
Notes receivable, net					88,000	88,000
Fund IV | Bridge Facility
Debt Instrument [Line Items]
Maximum borrowing capacity				79,200
Repayments of debt				$ 10,000
Maturity date	Jun. 30, 2021			Dec. 31, 2021
LIBOR plus	2.00%			2.50%
LIBOR floor				0.25%
Fund IV | Mortgages
Debt Instrument [Line Items]
Holdback mortgage loan					23,800	23,800
Holdback mortgage loan outstanding					18,900	18,900
Holdback mortgage loan drew an additional					1,000	1,000	$ 900
Fund IV | Mortgages One | Colonie Plaza - Albany, NY
Debt Instrument [Line Items]
Repayments of debt						11,600
Core Portfolio
Debt Instrument [Line Items]
Repayments of debt						26,300
Derivative, notional amount				$ 565,158
Core Portfolio | Sixty Orange Street | Disposed of by sale
Debt Instrument [Line Items]
Repayments of debt				6,700
Scheduled principal payment				$ 2,000
Core Portfolio | Mortgages | Brandywine Portfolio
Debt Instrument [Line Items]
Debt default, amount								$ 26,300
Debt instrument, maturity date				Jul. 1, 2016
Gain (loss) on litigation settlement		$ 30,000
Acquisition of noncontrolling interest		$ 15,900
Core Portfolio | Mortgages | Brandywine Portfolio | Acadia's OP Ownership
Debt Instrument [Line Items]
Equity interest held by Operating Partnership		77.78%
Core Portfolio | Mortgages | Realized and Unrealized Holding Gains on Investments and Other | Brandywine Portfolio
Debt Instrument [Line Items]
Gain on debt extinguishment					18,300
Proportionate share		$ 4,100
Fund II | Mortgages
Debt Instrument [Line Items]
Notes receivable, net					200,000	200,000
Fund III and Fund IV | Mortgages
Debt Instrument [Line Items]
Holdback mortgage loan					103,400	103,400
Fund Loans Repaid					11,500	11,500
Fund III | Mortgages
Debt Instrument [Line Items]
Term loans failed to meet liquidity requirements				$ 35,600
Interest Rate Swaps
Debt Instrument [Line Items]
Derivative, notional amount					$ 50,000	$ 50,000	$ 30,400
Interest Rate Swaps | New Towne Plaza
Debt Instrument [Line Items]
Derivative, notional amount			$ 16,700
Cash proceeds from swaps			$ 3,400

Debt - Unsecured Notes Payable

Debt - Unsecured Notes Payable - Additional Information (Details) - USD ($)	Jul. 31, 2020	Mar. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Long-term debt outstanding		$ 1,720,743,000	$ 1,770,054,000
Letters of credit, outstanding amount		33,800,000	35,600,000
Fund Portfolio | Fund II
Debt Instrument [Line Items]
Long-term debt outstanding		229,101,000	228,282,000
Unsecured Debt | Fund IV | Letter of Credit
Debt Instrument [Line Items]
Letters of credit, outstanding amount		3,600,000	3,600,000
Unsecured Debt | Core Portfolio
Debt Instrument [Line Items]
Long-term debt outstanding		380,000,000	380,000,000
Term Loan
Debt Instrument [Line Items]
Debt available balance		0	0
Term loan	$ 30,000,000	30,000,000	30,000,000
Debt instrument, maturity date	Jun. 30, 2021
LIBOR plus	2.55%
LIBOR floor	0.75%
Term Loan | Maximum
Debt Instrument [Line Items]
Debt available balance	$ 90,000,000
Unsecured Notes Payable | Unsecured Debt
Debt Instrument [Line Items]
Debt available balance		127,800,000	128,700,000
Unsecured Notes Payable | Unsecured Debt | Fund Portfolio | Fund II
Debt Instrument [Line Items]
Long-term debt outstanding		40,000,000	40,000,000
Three Hundred And Fifty Millions Term Loan | Unsecured Debt | Core Portfolio
Debt Instrument [Line Items]
Long-term debt outstanding		350,000,000	350,000,000
Term Loan Maturing In September 2020 | Secured Debt | Fund II
Debt Instrument [Line Items]
Maximum borrowing capacity		40,000,000
Long-term line of credit, noncurrent		40,000,000	40,000,000
Remaining borrowing capacity		0	0
Subscription Line | Unsecured Debt | Fund IV
Debt Instrument [Line Items]
Maximum borrowing capacity		5,000,000
Long-term line of credit, noncurrent		1,400,000	900,000
Remaining borrowing capacity		0	500,000
Subscription Line | Unsecured Debt | Fund V
Debt Instrument [Line Items]
Maximum borrowing capacity		150,000,000
Subscription Line | Unsecured Debt | Fund V | Letter of Credit
Debt Instrument [Line Items]
Letters of credit, outstanding amount		22,200,000	21,500,000
Subscription Line | Unsecured Debt | Fund Portfolio | Fund V
Debt Instrument [Line Items]
Long-term debt outstanding		0	250,000
Remaining borrowing capacity		$ 127,800,000	$ 128,200,000

Debt - Unsecured Revolving Line

Debt - Unsecured Revolving Lines of Credit - Additional Information (Details) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Letters of credit, outstanding amount	$ 33,800,000	$ 35,600,000
Revolving Credit Facility | Unsecured Debt
Debt Instrument [Line Items]
Maximum borrowing capacity	250,000,000
Core Portfolio | Revolving Credit Facility | Unsecured Debt
Debt Instrument [Line Items]
Debt available balance	136,600,000	101,100,000
Maximum borrowing capacity	250,000,000
Credit facility amount outstanding	105,400,000	138,400,000
Letters of credit, outstanding amount	$ 8,000,000	$ 10,500,000

Debt - Scheduled Principal Repa

Debt - Scheduled Principal Repayments (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
2021	$ 365,838
2022	535,612
2023	409,359
2024	212,020
2025	65,326
Thereafter	132,588
Long-term debt and convertible notes payable	1,720,743	$ 1,770,054
Unamortized premium	522	548
Net unamortized debt issuance costs	(6,210)	(6,763)
Total Indebtedness	$ 1,715,055	$ 1,763,839

Debt - Scheduled Principal Re_2

Debt - Scheduled Principal Repayments - Additional Information (Details) $ in Thousands	Mar. 31, 2021USD ($)
Debt Instrument [Line Items]
Contractual due 2021	$ 365,838
Contractual due 2022	535,612
Contractual due 2023	409,359
Debt With Extension Options
Debt Instrument [Line Items]
Contractual due 2021	260,500
Contractual due 2022	250,600
Contractual due 2023	$ 41,500

Financial Instruments and Fai_3

Financial Instruments and Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Assets
Derivative financial instruments	$ 2	$ 1
Liabilities
Derivative financial instruments	56,083	90,139
Recurring | Level 1
Assets
Money market funds	0	0
Derivative financial instruments	0	0
Investment in Albertsons (Note 4)	78,526	72,391
Liabilities
Derivative financial instruments	0	0
Recurring | Level 2
Assets
Money market funds	0	0
Derivative financial instruments	2	1
Investment in Albertsons (Note 4)	0	0
Liabilities
Derivative financial instruments	56,083	90,139
Recurring | Level 3
Assets
Money market funds	0	0
Derivative financial instruments	0	0
Investment in Albertsons (Note 4)	0	0
Liabilities
Derivative financial instruments	$ 0	$ 0

Financial Instruments and Fai_4

Financial Instruments and Fair Value Measurements - Schedule of Items Measured at Fair Value on Nonrecurring Basis (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2020
Derivatives, Fair Value [Line Items]
Impairment charges	$ 51,549
Fair Value, Measurements, Nonrecurring
Derivatives, Fair Value [Line Items]
Impairment charges		$ 85,598
Fair Value, Measurements, Nonrecurring | Acadia Realty Trust
Derivatives, Fair Value [Line Items]
Impairment charges		$ 20,594
Cortlandt Crossing, Mohegan Lake, NY | Fair Value, Measurements, Nonrecurring | Fund III | Level 3 Inputs Projections
Derivatives, Fair Value [Line Items]
Triggering Event	Reduced holding period, reduced projected operating income
Impairment charges	$ 27,402
Cortlandt Crossing, Mohegan Lake, NY | Fair Value, Measurements, Nonrecurring | Fund III | Acadia Realty Trust | Level 3 Inputs Projections
Derivatives, Fair Value [Line Items]
Impairment charges	$ 6,726
654 Broadway, New York, NY | Fair Value, Measurements, Nonrecurring | Fund III | Level 3 Inputs Projections
Derivatives, Fair Value [Line Items]
Triggering Event	Reduced holding period
Impairment charges	$ 6,398
654 Broadway, New York, NY | Fair Value, Measurements, Nonrecurring | Fund III | Acadia Realty Trust | Level 3 Inputs Projections
Derivatives, Fair Value [Line Items]
Impairment charges	$ 1,570
146 Geary Street, San Francisco, CA | Fair Value, Measurements, Nonrecurring | Fund IV | Level 3 Inputs Projections
Derivatives, Fair Value [Line Items]
Triggering Event	Reduced holding period, reduced projected operating income
Impairment charges	$ 6,718
146 Geary Street, San Francisco, CA | Fair Value, Measurements, Nonrecurring | Fund IV | Acadia Realty Trust | Level 3 Inputs Projections
Derivatives, Fair Value [Line Items]
Impairment charges	$ 1,553
801 Madison Avenue, New York, NY | Fair Value, Measurements, Nonrecurring | Fund IV | Level 3 Inputs Projections
Derivatives, Fair Value [Line Items]
Triggering Event	Reduced holding period, reduced projected operating income
Impairment charges	$ 11,031
801 Madison Avenue, New York, NY | Fair Value, Measurements, Nonrecurring | Fund IV | Acadia Realty Trust | Level 3 Inputs Projections
Derivatives, Fair Value [Line Items]
Impairment charges	$ 2,551
717 N. Michigan Avenue, Chicago, IL | Fair Value, Measurements, Nonrecurring | Fund IV | Level 3 Inputs Projections
Derivatives, Fair Value [Line Items]
Triggering Event		Reduced holding period, reduced projected operating income
Impairment charges		$ 17,392
717 N. Michigan Avenue, Chicago, IL | Fair Value, Measurements, Nonrecurring | Fund IV | Acadia Realty Trust | Level 3 Inputs Projections
Derivatives, Fair Value [Line Items]
Impairment charges		$ 4,021
110 University, New York, NY | Fair Value, Measurements, Nonrecurring | Fund IV | Level 3 Inputs Projections
Derivatives, Fair Value [Line Items]
Triggering Event		Reduced holding period, reduced projected operating income
Impairment charges		$ 16,238
110 University, New York, NY | Fair Value, Measurements, Nonrecurring | Fund IV | Acadia Realty Trust | Level 3 Inputs Projections
Derivatives, Fair Value [Line Items]
Impairment charges		$ 3,754
Fifth Wall Investment | Fair Value, Measurements, Nonrecurring | Core Portfolio | Level 3 Inputs Fair Value of Net Assets Projections
Derivatives, Fair Value [Line Items]
Triggering Event		Decline in fair value
Impairment charges		$ 419
Fifth Wall Investment | Fair Value, Measurements, Nonrecurring | Core Portfolio | Acadia Realty Trust | Level 3 Inputs Fair Value of Net Assets Projections
Derivatives, Fair Value [Line Items]
Impairment charges		$ 419

Financial Instruments and Fai_5

Financial Instruments and Fair Value Measurements - Schedule of Derivative Financial Instruments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Jul. 31, 2020
Derivatives, Fair Value [Line Items]
Fair value, liability derivatives	$ (56,083)	$ (90,139)
Fair value, asset derivatives	2	1
Interest Rate Swaps
Derivatives, Fair Value [Line Items]
Aggregate Notional Amount		50,000	$ 30,400
Core Portfolio
Derivatives, Fair Value [Line Items]
Aggregate Notional Amount	565,158
Fair value, derivatives, net	(44,451)	(74,990)
Core Portfolio | Interest Rate Swaps | Other Liabilities
Derivatives, Fair Value [Line Items]
Aggregate Notional Amount	565,158
Fair value, liability derivatives	$ (44,451)	(74,990)
Core Portfolio | Interest Rate Swaps | Minimum | Other Liabilities
Derivatives, Fair Value [Line Items]
Derivative Effective Date	2012-12
Derivative Maturity Date	2021-06
Strike Rate	1.24%
Core Portfolio | Interest Rate Swaps | Maximum | Other Liabilities
Derivatives, Fair Value [Line Items]
Derivative Effective Date	2020-07
Derivative Maturity Date	2030-07
Strike Rate	3.77%
Fund Portfolio | Fund II
Derivatives, Fair Value [Line Items]
Aggregate Notional Amount	$ 63,733
Fair value, derivatives, net	(154)	(219)
Fund Portfolio | Fund II | Interest Rate Swaps | Other Liabilities
Derivatives, Fair Value [Line Items]
Aggregate Notional Amount	$ 18,733
Derivative Effective Date	2014-10
Derivative Maturity Date	2021-11
Fair value, liability derivatives	$ (154)	(219)
Fund Portfolio | Fund II | Interest Rate Swaps | Minimum | Other Liabilities
Derivatives, Fair Value [Line Items]
Strike Rate	2.88%
Fund Portfolio | Fund II | Interest Rate Swaps | Maximum | Other Liabilities
Derivatives, Fair Value [Line Items]
Strike Rate	2.88%
Fund Portfolio | Fund II | Interest Rate Caps | Other Assets
Derivatives, Fair Value [Line Items]
Aggregate Notional Amount	$ 45,000
Derivative Effective Date	2019-03
Derivative Maturity Date	2022-03
Fair value, asset derivatives	$ 0	0
Fund Portfolio | Fund II | Interest Rate Caps | Minimum | Other Assets
Derivatives, Fair Value [Line Items]
Strike Rate	3.50%
Fund Portfolio | Fund II | Interest Rate Caps | Maximum | Other Assets
Derivatives, Fair Value [Line Items]
Strike Rate	3.50%
Fund Portfolio | Fund III | Interest Rate Caps | Other Assets
Derivatives, Fair Value [Line Items]
Aggregate Notional Amount	$ 35,970
Derivative Effective Date	2021-01
Derivative Maturity Date	2022-07
Fair value, asset derivatives	$ 0	0
Fund Portfolio | Fund III | Interest Rate Caps | Minimum | Other Assets
Derivatives, Fair Value [Line Items]
Strike Rate	3.00%
Fund Portfolio | Fund III | Interest Rate Caps | Maximum | Other Assets
Derivatives, Fair Value [Line Items]
Strike Rate	3.00%
Fund Portfolio | Fund IV
Derivatives, Fair Value [Line Items]
Aggregate Notional Amount	$ 143,650
Fair value, derivatives, net	(1,397)	(1,712)
Fund Portfolio | Fund IV | Interest Rate Swaps | Other Liabilities
Derivatives, Fair Value [Line Items]
Aggregate Notional Amount	66,250
Fair value, liability derivatives	$ (1,399)	(1,713)
Fund Portfolio | Fund IV | Interest Rate Swaps | Minimum | Other Liabilities
Derivatives, Fair Value [Line Items]
Derivative Effective Date	2017-03
Derivative Maturity Date	2022-04
Strike Rate	1.48%
Fund Portfolio | Fund IV | Interest Rate Swaps | Maximum | Other Liabilities
Derivatives, Fair Value [Line Items]
Derivative Effective Date	2019-12
Derivative Maturity Date	2022-12
Strike Rate	4.00%
Fund Portfolio | Fund IV | Interest Rate Caps | Other Assets
Derivatives, Fair Value [Line Items]
Aggregate Notional Amount	$ 77,400
Fair value, asset derivatives	$ 2	1
Fund Portfolio | Fund IV | Interest Rate Caps | Minimum | Other Assets
Derivatives, Fair Value [Line Items]
Derivative Effective Date	2019-07
Derivative Maturity Date	2021-07
Strike Rate	3.00%
Fund Portfolio | Fund IV | Interest Rate Caps | Maximum | Other Assets
Derivatives, Fair Value [Line Items]
Derivative Effective Date	2020-12
Derivative Maturity Date	2022-12
Strike Rate	3.50%
Fund Portfolio | Fund V
Derivatives, Fair Value [Line Items]
Aggregate Notional Amount	$ 334,339
Fair value, derivatives, net	(10,079)	(13,217)
Fund Portfolio | Fund V | Interest Rate Swaps | Other Liabilities
Derivatives, Fair Value [Line Items]
Aggregate Notional Amount	334,339
Fair value, liability derivatives	$ (10,079)	$ (13,217)
Fund Portfolio | Fund V | Interest Rate Swaps | Minimum | Other Liabilities
Derivatives, Fair Value [Line Items]
Derivative Effective Date	2018-06
Derivative Maturity Date	2021-06
Strike Rate	0.23%
Fund Portfolio | Fund V | Interest Rate Swaps | Maximum | Other Liabilities
Derivatives, Fair Value [Line Items]
Derivative Effective Date	2021-02
Derivative Maturity Date	2024-10
Strike Rate	2.88%

Financial Instruments and Fai_6

Financial Instruments and Fair Value Measurements - Additional Information (Details)	3 Months Ended
	Mar. 31, 2021USD ($)Swap	Dec. 31, 2020USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Reclassification adjustment related to derivatives from AOCI to interest expense	$ 19,700,000
Derivatives designated as fair value hedges	0	$ 0
Derivative designated to hedges of net investments in foreign operations	$ 0	$ 0
Number of forward swaps terminated | Swap	2
Forward Swaps
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative, notional amount	$ 100,000,000
Cash proceeds from swaps	$ 3,400,000

Financial Instruments and Fai_7

Financial Instruments and Fair Value Measurements - Schedule of Other Financial Instruments Carrying Values and Fair values (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes Receivable	$ 101,410	$ 101,450
Mortgage and Other Notes Payable	1,715,055	1,763,839
Unsecured notes payable and Unsecured line of credit	420,960	420,858
Level 3 | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes Receivable	101,410	101,450
Mortgage and Other Notes Payable	1,193,943	1,210,540
Investment in non-traded equity securities	2,460	1,726
Level 3 | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes Receivable	101,917	102,135
Mortgage and Other Notes Payable	1,171,180	1,190,214
Investment in non-traded equity securities	2,386	1,456
Level 2 | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Unsecured notes payable and Unsecured line of credit	526,800	559,514
Level 2 | Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Unsecured notes payable and Unsecured line of credit	$ 514,982	$ 544,532

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Commitments And Contingencies Disclosure [Abstract]
Contractual obligation	$ 32.4	$ 32.7
Letters of credit, outstanding amount	$ 33.8	$ 35.6

Shareholders' Equity, Noncont_3

Shareholders' Equity, Noncontrolling Interests and Other Comprehensive Loss - Common Shares and Units - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Restricted shares
Class of Stock [Line Items]
Restricted stock, shares canceled for tax withholding for share based compensation (in shares)	3,050		2,075
LTIP Units and Restricted Stock
Class of Stock [Line Items]
Unit based compensation expense	$ 2.7	$ 2.4	$ 8.4

Shareholders' Equity, Noncont_4

Shareholders' Equity, Noncontrolling Interests and Other Comprehensive Loss - ATM Program - Additional Information (Details) - ATM Program - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Jun. 30, 2019	Dec. 31, 2020
Class of Stock [Line Items]
Issuance of ordinary shares (in shares)	0		0
Purchase new program included an optional forward purchase component		$ 250
Value of shares available for issuance	$ 170

Shareholders' Equity, Noncont_5

Shareholders' Equity, Noncontrolling Interests and Other Comprehensive Loss - Share Repurchases - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2018
Stockholders Equity Including Portion Attributable To Noncontrolling Interest [Abstract]
Authorized amount			$ 200,000,000
Number of shares repurchased during period (in shares)	0	1,219,065
Shares repurchased during period		$ 22,352,000
Stock repurchase fees		$ 100,000
Weighted Average Share Price		$ 18.29
Remaining authorized repurchase amount	$ 122,600,000

Shareholders' Equity, Noncont_6

Shareholders' Equity, Noncontrolling Interests and Other Comprehensive Loss - Schedule of Distributions Declared and paid (Details) - $ / shares	Mar. 15, 2021	Feb. 26, 2020	Nov. 05, 2019	Mar. 31, 2021	Mar. 31, 2020
Class of Stock [Line Items]
Cash dividends declared per common share (in dollars per share)				$ 0.15	$ 0.29
Fourth Quarter Two Thousand Nineteen
Class of Stock [Line Items]
Cash dividends, declared date				Nov. 5, 2019
Cash dividends declared per common share (in dollars per share)			$ 0.29
Cash dividends, record date				Dec. 31, 2019
Cash dividends, paid date				Jan. 15, 2020
First Quarter Two Thousand Twenty
Class of Stock [Line Items]
Cash dividends, declared date				Feb. 26, 2020
Cash dividends declared per common share (in dollars per share)		$ 0.29
Cash dividends, record date				Mar. 31, 2020
Cash dividends, paid date				Apr. 15, 2020
First Quarter Two Thousand Twenty One
Class of Stock [Line Items]
Cash dividends, declared date				Mar. 15, 2021
Cash dividends declared per common share (in dollars per share)	$ 0.15
Cash dividends, record date				Mar. 31, 2021
Cash dividends, paid date				Apr. 15, 2021

Shareholders' Equity, Noncont_7

Shareholders' Equity, Noncontrolling Interests and Other Comprehensive Loss - Dividends and Distributions - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020
Preferred Stock
Class of Stock [Line Items]
Distributions payable	$ 0.1	$ 0.1	$ 0.1

Shareholders' Equity, Noncont_8

Shareholders' Equity, Noncontrolling Interests and Other Comprehensive Loss - Summary of Activity in Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance	$ 2,048,553	$ 2,186,965
Other comprehensive income (loss) before reclassifications - swap agreements	33,556	(74,774)
Reclassification of realized interest on swap agreements	5,317	977
Net current period other comprehensive income (loss)	38,873	(73,797)
Balance	2,084,369	2,011,560
AOCI Attributable to Parent
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance	(74,891)	(31,175)
Balance	(41,962)	(85,715)
AOCI Attributable to Noncontrolling Interest
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Net current period other comprehensive income (loss)	$ (5,944)	$ 19,257

Shareholders' Equity, Noncont_9

Shareholders' Equity, Noncontrolling Interests and Other Comprehensive Loss - Summary of Change in Noncontrolling Interest (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	$ 607,239
Net income (loss)	1,860	$ (60,039)
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership	0	0
Other comprehensive income (loss) - unrealized gain (loss) on valuation of swap agreements	33,556	(74,774)
Reclassification of realized interest on swap agreements	5,317	977
Noncontrolling interest contributions	11,241	7,268
Noncontrolling interest distributions	(6,676)	(3,118)
Employee Long-term Incentive Plan Unit Awards	4,511	3,819
Reallocation of noncontrolling interests	0	0
Ending Balance	617,522
Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	607,239	644,657
Distributions declared per Common OP Unit	(1,048)	(1,849)
Net income (loss)	(3,302)	(51,625)
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership	(294)	(2,472)
Other comprehensive income (loss) - unrealized gain (loss) on valuation of swap agreements	4,043	(19,529)
Reclassification of realized interest on swap agreements	1,901	272
Noncontrolling interest contributions	11,241	7,268
Noncontrolling interest distributions	(6,676)	(3,118)
Employee Long-term Incentive Plan Unit Awards	4,049	3,648
Reallocation of noncontrolling interests	369	(145)
Ending Balance	617,522	577,096
Noncontrolling Interests | Cumulative Effect of Change in Accounting Principle
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Ending Balance		(11)
Noncontrolling Interests | Noncontrolling Interests in Partially-Owned Affiliates
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	517,808	546,987
Distributions declared per Common OP Unit	0	0
Net income (loss)	(3,772)	(51,289)
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership	0	0
Other comprehensive income (loss) - unrealized gain (loss) on valuation of swap agreements	2,143	(16,388)
Reclassification of realized interest on swap agreements	1,848	265
Noncontrolling interest contributions	11,241	7,268
Noncontrolling interest distributions	(6,676)	(3,118)
Employee Long-term Incentive Plan Unit Awards	0	0
Reallocation of noncontrolling interests	0	0
Ending Balance	522,592	483,714
Noncontrolling Interests | Noncontrolling Interests in Partially-Owned Affiliates | Cumulative Effect of Change in Accounting Principle
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Ending Balance		(11)
Noncontrolling Interests | Operating Partnership, as General Partner or Managing Member
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	89,431	97,670
Distributions declared per Common OP Unit	(1,048)	(1,849)
Net income (loss)	470	(336)
Conversion of OP Units to Common Shares by limited partners of the Operating Partnership	(294)	(2,472)
Other comprehensive income (loss) - unrealized gain (loss) on valuation of swap agreements	1,900	(3,141)
Reclassification of realized interest on swap agreements	53	7
Noncontrolling interest contributions	0	0
Noncontrolling interest distributions	0	0
Employee Long-term Incentive Plan Unit Awards	4,049	3,648
Reallocation of noncontrolling interests	369	(145)
Ending Balance	$ 94,930	93,382
Noncontrolling Interests | Operating Partnership, as General Partner or Managing Member | Cumulative Effect of Change in Accounting Principle
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Ending Balance		$ 0

Shareholders' Equity, Noncon_10

Shareholders' Equity, Noncontrolling Interests and Other Comprehensive Loss - Summary of Change in Noncontrolling Interest (Parenthetical) (Details) - $ / shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Minority Interest [Line Items]
Distributions declared (in dollars per share)	$ 0.15	$ 0.29
Conversion of Common OP Units to Common Shares by limited partners of the Operating Partnership (in shares)	18,800	147,882
Operating Partnership, as General Partner or Managing Member
Minority Interest [Line Items]
Series A Preferred OP Units (in shares)	3,101,958	3,205,931
Operating Partnership, as General Partner or Managing Member | Series A Preferred Stock
Minority Interest [Line Items]
Series A Preferred OP Units (in shares)	188	188
Operating Partnership, as General Partner or Managing Member | Series C Preferred Stock
Minority Interest [Line Items]
Series A Preferred OP Units (in shares)	126,593	126,593
LTIP Units
Minority Interest [Line Items]
LTIP units outstanding (in shares)	3,409,232	3,003,027

Shareholders' Equity, Noncon_11

Shareholders' Equity, Noncontrolling Interests and Other Comprehensive Loss - Preferred OP Units - Additional Information (Details) - $ / shares	3 Months Ended	12 Months Ended			63 Months Ended	267 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2016	Dec. 31, 1999	Mar. 31, 2021	Mar. 31, 2021	Mar. 31, 2020
Class of Stock [Line Items]
Denominator for Series A Preferred OP Unit conversion	$ 7.50				$ 7.50	$ 7.50
Gotham Plaza | Common Shares
Class of Stock [Line Items]
Issuance of common shares, net of issuance costs (in Shares)			442,478
Preferred quarterly distribution per share price			$ 0.9375
Number of convertible units if share price below $28.80 (in shares)			3.4722
Number of convertible units if share price above $35.20 (in shares)			2.8409
Operating Partnership, as General Partner or Managing Member
Class of Stock [Line Items]
Series A Preferred OP Units (in shares)	3,101,958				3,101,958	3,101,958	3,205,931
Preferred OP Units
Class of Stock [Line Items]
Issuance of common shares, net of issuance costs (in Shares)	0	0
Preferred OP Units | Gotham Plaza
Class of Stock [Line Items]
Issuance of common shares, net of issuance costs (in Shares)			141,593
Share price (in dollars per share)			$ 100
Preferred OP Units | Gotham Plaza | Minimum
Class of Stock [Line Items]
Share price at conversion date			28.80
Preferred OP Units | Gotham Plaza | Maximum
Class of Stock [Line Items]
Share price at conversion date			$ 35.20
Series A Preferred Stock
Class of Stock [Line Items]
Issuance of common shares, net of issuance costs (in Shares)				1,580
Preferred stock, stated value per unit	$ 1,000				$ 1,000	$ 1,000
Per unit conversion amount, Series A Preferred OP Units (in dollars per unit)	$ 22.50				$ 22.50	$ 22.50
Per unit conversion annual rate, Preferred OP Units	9.00%				9.00%	9.00%
Number of preferred OP Units converted (in shares)						1,392
Units converted from Preferred OP Units (in shares)						185,600
Series A Preferred Stock | Operating Partnership, as General Partner or Managing Member
Class of Stock [Line Items]
Series A Preferred OP Units (in shares)	188				188	188	188
Series C Preferred Stock | Gotham Plaza
Class of Stock [Line Items]
Number of preferred OP Units converted (in shares)					15,000
Units converted from Preferred OP Units (in shares)					51,887
Series C Preferred Stock | Operating Partnership, as General Partner or Managing Member
Class of Stock [Line Items]
Series A Preferred OP Units (in shares)	126,593				126,593	126,593	126,593

Leases - Additional Information

Leases - Additional Information (Details) $ in Thousands	3 Months Ended				12 Months Ended
	Mar. 31, 2021USD ($)AqreementStore	Sep. 30, 2020USD ($)item	Jun. 30, 2020item	Mar. 31, 2020USD ($)	Dec. 31, 2020USD ($)item
Operating Leased Assets [Line Items]
Variable lease revenues	$ 14,800			$ 14,600
Operating lease right-of-use asset	74,803				$ 76,268
Lease liability - operating lease	$ 87,910				88,816
Lease agreement purchase price					14,500
Number of sores having bankruptcies, in core portfolio | Store	3
Core portfolio annualized base rents for stores of bankruptcies	$ 700
Core portfolio annualized base rents for stores of bankruptcies percentage	0.60%
Number of sores having bankruptcies, in fund portfolio | Store	5
Fund portfolio annualized base rents for stores of bankruptcies	$ 600
Fund portfolio annualized base rents for stores of bankruptcies percentage	2.70%
Number of stores in core portfolio rejected lease with annualized base rents | Store	1
Core portfolio annualized base rents for stores rejected lease	$ 100
Core portfolio annualized base rents for stores rejected lease percentage	0.10%
Number of stores assumed their locations in fund portfolio | Store	2
Fund portfolio annualized base rents for stores assumed their locations	$ 100
Fund portfolio annualized base rents for stores assumed their locations percentage	0.10%
COVID-19
Operating Leased Assets [Line Items]
Number of rent concession agreements | Aqreement	47
Number of rent concession agreements for rent deferral | Aqreement	12
Number of rent concession agreements for rent abatements | Aqreement	35
Number of rent concession agreements accounted as no change in contract | Aqreement	11
Deferred receivables	$ 8,900
Rent abatements	1,539
Rent abatements negotiated and reserved in prior periods	$ 1,200
Pro rata core leased occupancy rate percentage	91.00%			93.90%
Pro rata fund leased occupancy rate percentage	89.00%			93.20%
Core Portfolio | COVID-19
Operating Leased Assets [Line Items]
Percentage of tenants open for business	92.40%
Percentage of rent collections	91.80%
Rent abatements	$ 756
Opportunity Funds | COVID-19
Operating Leased Assets [Line Items]
Percentage of tenants open for business	94.80%
Percentage of rent collections	84.30%
Rent abatements	$ 783
Fund IV Property
Operating Leased Assets [Line Items]
Impairment charge of right-of-use asset					$ 12,300
BSP II
Operating Leased Assets [Line Items]
Number of operating lease | item			1
Branch Plaza
Operating Leased Assets [Line Items]
Number of operating lease | item					1
Operating Lease term					22 years
1238 Wisconsin
Operating Leased Assets [Line Items]
Operating lease right-of-use asset					$ 1,900
Operating lease liability					1,900
Lease agreement purchase price					$ 11,500
Accounting Standards Update 2016-02 | 991 Madison Avenue Manhattan, NY
Operating Leased Assets [Line Items]
Capital lease term			49 years
Operating Lease term			15 years
Rye Corporate Office Lease
Operating Leased Assets [Line Items]
Operating lease right-of-use asset	400
Operating lease liability	$ 400
Office Lease
Operating Leased Assets [Line Items]
Operating lease right-of-use asset		$ 1,700
Number of operating lease | item		1
Lease liability - operating lease		$ 1,700
Minimum
Operating Leased Assets [Line Items]
Operating lease term	1 month
Maximum
Operating Leased Assets [Line Items]
Operating lease term	60 years

Leases - Activity for Reserves

Leases - Activity for Reserves Related to Billed Rents and Straight-line Rents (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)
Operating Leased Assets [Line Items]
Balance at Beginning of Period	$ 45,408
Charged to Expenses	3,882
Deductions	(1,337)
Balance at End of Period	47,953
Allowance for Credit Loss - Billed Rents
Operating Leased Assets [Line Items]
Balance at Beginning of Period	30,366
Charged to Expenses	3,065
Deductions	(1,162)
Balance at End of Period	32,269
Straight-line Rent Reserves
Operating Leased Assets [Line Items]
Balance at Beginning of Period	15,042
Charged to Expenses	817
Deductions	(175)
Balance at End of Period	$ 15,684

Leases - Schedule of Lease Cost

Leases - Schedule of Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Finance lease cost:
Amortization of right-of-use assets	$ 226	$ 657
Interest on lease liabilities	95	850
Subtotal	321	1,507
Operating lease cost	2,286	1,394
Variable lease cost	101	16
Total lease cost	$ 2,708	$ 2,917
Weighted-average remaining lease term - finance leases (years)	33 years 2 months 12 days	42 years 3 months 18 days
Weighted-average remaining lease term - operating leases (years)	24 years 6 months	34 years 1 month 6 days
Weighted-average discount rate - finance leases	6.30%	4.40%
Weighted-average discount rate - operating leases	5.60%	5.80%

Leases - Schedule of Future Min

Leases - Schedule of Future Minimum Rental Revenues and Payments for Operating and Capital Leases (Details) $ in Thousands	Mar. 31, 2021USD ($)
Minimum Rental Revenues
2021 (Remainder)	$ 149,226
2022	198,269
2023	177,885
2024	152,363
2025	122,715
Thereafter	503,880
Total	1,304,338
Total	1,304,338
Minimum Rental Payments, Operating Leases
2021 (Remainder)	6,465
2022	7,768
2023	7,789
2024	7,974
2025	7,969
Thereafter	150,446
Total before interest	188,411
Total before interest	188,411
Interest	(100,587)
Total	87,824
Minimum Rental Payments, Finance Leases
2021 (Remainder)	69
2022	28
Thereafter	12,289
Total before interest	12,386
Interest	(6,230)
Total	$ 6,156

Leases - Schedule of Earnings I

Leases - Schedule of Earnings Impact (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Straight - Line Rent Reserves	$ 1,128	$ 1,128
Impairment charges		51,549
COVID Earnings Impact	1,860	(60,039)
COVID-19
Finite-Lived Intangible Assets [Line Items]
Credit Loss - Billed Rents	3,065	1,358
Straight - Line Rent Reserves	817	2,967
Rent Abatements	1,539
Impairment charges		51,549
COVID Earnings Impact	5,421	55,874
Noncontrolling Interests | COVID-19
Finite-Lived Intangible Assets [Line Items]
Credit Loss - Billed Rents	(962)	(498)
Straight - Line Rent Reserves	(646)	(220)
Rent Abatements	(611)
Impairment charges		(39,149)
COVID Earnings Impact	(2,219)	(39,867)
Unconsolidated | COVID-19
Finite-Lived Intangible Assets [Line Items]
Credit Loss - Billed Rents	423	378
Straight - Line Rent Reserves	(19)	282
Rent Abatements	94
COVID Earnings Impact	498	660
Acadia | COVID-19
Finite-Lived Intangible Assets [Line Items]
Credit Loss - Billed Rents	2,526	1,238
Straight - Line Rent Reserves	152	3,029
Rent Abatements	1,022
Impairment charges		12,400
COVID Earnings Impact	3,700	16,667
Core Portfolio | COVID-19
Finite-Lived Intangible Assets [Line Items]
Credit Loss - Billed Rents	1,883	832
Straight - Line Rent Reserves	(8)	2,744
Rent Abatements	756
COVID Earnings Impact	2,631	3,576
Core Portfolio | Noncontrolling Interests | COVID-19
Finite-Lived Intangible Assets [Line Items]
Credit Loss - Billed Rents	17
Straight - Line Rent Reserves	(1)
COVID Earnings Impact	16
Core Portfolio | Unconsolidated | COVID-19
Finite-Lived Intangible Assets [Line Items]
Credit Loss - Billed Rents	386	268
Straight - Line Rent Reserves	(29)	220
Rent Abatements	87
COVID Earnings Impact	444	488
Core Portfolio | Acadia | COVID-19
Finite-Lived Intangible Assets [Line Items]
Credit Loss - Billed Rents	2,286	1,100
Straight - Line Rent Reserves	(38)	2,964
Rent Abatements	843
COVID Earnings Impact	3,091	4,064
Opportunity Funds | COVID-19
Finite-Lived Intangible Assets [Line Items]
Credit Loss - Billed Rents	1,182	526
Straight - Line Rent Reserves	825	223
Rent Abatements	783
Impairment charges		51,549
COVID Earnings Impact	2,790	52,298
Opportunity Funds | Noncontrolling Interests | COVID-19
Finite-Lived Intangible Assets [Line Items]
Credit Loss - Billed Rents	(979)	(498)
Straight - Line Rent Reserves	(645)	(220)
Rent Abatements	(611)
Impairment charges		(39,149)
COVID Earnings Impact	(2,235)	(39,867)
Opportunity Funds | Unconsolidated | COVID-19
Finite-Lived Intangible Assets [Line Items]
Credit Loss - Billed Rents	37	110
Straight - Line Rent Reserves	10	62
Rent Abatements	7
COVID Earnings Impact	54	172
Opportunity Funds | Acadia | COVID-19
Finite-Lived Intangible Assets [Line Items]
Credit Loss - Billed Rents	240	138
Straight - Line Rent Reserves	190	65
Rent Abatements	179
Impairment charges		12,400
COVID Earnings Impact	$ 609	$ 12,603

Segment Reporting - Additional

Segment Reporting - Additional Information (Details)	3 Months Ended
	Mar. 31, 2021segment
Segment Reporting [Abstract]
Number of reportable segments	3

Segment Reporting - Summary of

Segment Reporting - Summary of Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Segment Reporting Information [Line Items]
Total revenues	$ 69,394	$ 71,420
Depreciation and amortization	(31,390)	(33,377)
Property operating expenses, other operating and real estate taxes	(24,939)	(23,767)
General and administrative expenses	(8,996)	(9,070)
Gain on disposition of properties	4,612
Impairment charges		(51,549)
Operating income (loss)	8,681	(46,343)
Interest income	1,700
Interest and other income	1,700	2,929
Realized and unrealized holding gains on investments and other	6,507	(530)
Equity in earnings of unconsolidated affiliates	2,263	1,255
Interest expense	(17,141)	(18,302)
Income tax (provision) benefit	(150)	952
Net income (loss)	1,860	(60,039)
Net loss attributable to noncontrolling interests	3,302	51,625
Net income (loss) attributable to Acadia	5,162	(8,414)
Real estate at cost	4,078,053	4,082,116
Total assets	4,153,682	4,305,138	$ 4,186,882
Cash paid for acquisition of real estate	0	19,088
Cash paid for development and property improvement costs	5,425	13,576
Operating Segments | Core Portfolio
Segment Reporting Information [Line Items]
Total revenues	42,349	39,933
Depreciation and amortization	(16,887)	(17,056)
Property operating expenses, other operating and real estate taxes	(13,657)	(11,814)
General and administrative expenses	0	0
Gain on disposition of properties	4,612
Impairment charges		0
Operating income (loss)	16,417	11,063
Interest income	0
Interest and other income		0
Realized and unrealized holding gains on investments and other	0	0
Equity in earnings of unconsolidated affiliates	(1,129)	1,642
Interest expense	(7,214)	(8,250)
Income tax (provision) benefit	0	0
Net income (loss)	8,074	4,455
Net loss attributable to noncontrolling interests	(607)	1,216
Net income (loss) attributable to Acadia	7,467	5,671
Real estate at cost	2,319,584	2,289,449
Total assets	2,222,886	2,330,971
Cash paid for acquisition of real estate	0	19,088
Cash paid for development and property improvement costs	2,843	2,638
Operating Segments | Opportunity Funds
Segment Reporting Information [Line Items]
Total revenues	27,045	31,487
Depreciation and amortization	(14,503)	(16,321)
Property operating expenses, other operating and real estate taxes	(11,282)	(11,953)
General and administrative expenses	0	0
Gain on disposition of properties	0
Impairment charges		(51,549)
Operating income (loss)	1,260	(48,336)
Interest income	0
Interest and other income		0
Realized and unrealized holding gains on investments and other	6,547	0
Equity in earnings of unconsolidated affiliates	3,392	(387)
Interest expense	(9,927)	(10,052)
Income tax (provision) benefit	0	0
Net income (loss)	1,272	(58,775)
Net loss attributable to noncontrolling interests	3,909	50,409
Net income (loss) attributable to Acadia	5,181	(8,366)
Real estate at cost	1,758,469	1,792,667
Total assets	1,829,386	1,801,008
Cash paid for acquisition of real estate	0	0
Cash paid for development and property improvement costs	2,582	10,695
Operating Segments | Structured Financing
Segment Reporting Information [Line Items]
Total revenues	0	0
Depreciation and amortization	0	0
Property operating expenses, other operating and real estate taxes	0	0
General and administrative expenses	0	0
Gain on disposition of properties	0
Impairment charges		0
Operating income (loss)	0	0
Interest income	1,700
Interest and other income		2,929
Realized and unrealized holding gains on investments and other	(40)	(530)
Equity in earnings of unconsolidated affiliates	0	0
Interest expense	0	0
Income tax (provision) benefit	0	0
Net income (loss)	1,660	2,399
Net loss attributable to noncontrolling interests	0	0
Net income (loss) attributable to Acadia	1,660	2,399
Real estate at cost	0	0
Total assets	101,410	173,159
Cash paid for acquisition of real estate	0	0
Cash paid for development and property improvement costs	0	0
Unallocated
Segment Reporting Information [Line Items]
Total revenues	0	0
Depreciation and amortization	0	0
Property operating expenses, other operating and real estate taxes	0	0
General and administrative expenses	(8,996)	(9,070)
Gain on disposition of properties	0
Impairment charges		0
Operating income (loss)	(8,996)	(9,070)
Interest income	0
Interest and other income		0
Realized and unrealized holding gains on investments and other	0	0
Equity in earnings of unconsolidated affiliates	0	0
Interest expense	0	0
Income tax (provision) benefit	(150)	952
Net income (loss)	(9,146)	(8,118)
Net loss attributable to noncontrolling interests	0	0
Net income (loss) attributable to Acadia	(9,146)	(8,118)
Real estate at cost	0	0
Total assets	0	0
Cash paid for acquisition of real estate	0	0
Cash paid for development and property improvement costs	$ 0	$ 0

Segment Reporting - Summary o_2

Segment Reporting - Summary of Segment Information (Parenthetical) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Segment Reporting Information [Line Items]
Real estate at cost	$ 4,078,053	$ 4,082,116
Total assets	4,153,682	4,305,138	$ 4,186,882
Net (income) loss attributable to noncontrolling interests	(3,302)	(51,625)
Opportunity Funds | Fund II's City Point Property
Segment Reporting Information [Line Items]
Real estate at cost	643,000
Total assets	641,700
Net (income) loss attributable to noncontrolling interests	$ 186,900	$ 186,500

Share Incentive and Other Com_3

Share Incentive and Other Compensation - Additional Information (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2009
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unit based compensation	$ 4,511,000	$ 3,819,000
Trustee fees	400,000	300,000
Total unrecognized compensation cost related to nonvested awards	$ 23,500,000
Weighted-average period over which cost is expected to be recognized	1 year 8 months 12 days
Performance Period Ending December 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage	33.30%
Award vesting period	3 years
LTIP Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total fair value of shares that vested	$ 7,100,000		$ 7,600,000
LTIP Units | Performance Period Ending December 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage	66.70%
Award vesting period	3 years
Restricted shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total fair value of shares that vested	$ 200,000		500,000
Restricted shares | Trustee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued during period, share-based compensation, net of forfeitures	1,242
LTIP Units and Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total value of restricted shares and LTIP units as of the grant date	$ 12,500,000		$ 10,400,000
Weighted average grant date fair value, grants (in dollars per share)	$ 19.40		$ 18.86
LTIP Units and Restricted Stock | Trustee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years
Vesting rate of shares granted to trustees	33.00%
LTIP Units and Restricted Stock | General and Administrative Expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unit based compensation	$ 2,700,000	2,400,000
LTIP Units and Restricted Stock | Performance Period Ending December 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years
LTIP Units and Restricted Stock | Performance Fails To Achieve, Earned Performance-Based Shares Vest At End Of Performance Period
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage	60.00%
LTIP Units and Restricted Stock | Performance Fails To Achieve
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage	40.00%
Award vesting period	2 years
LTIP Units and Restricted Stock | Minimum | TSR percentile falls between the 25th percentile and the 50th percentile
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage	50.00%
LTIP Units and Restricted Stock | Minimum | TSR percentile falls between the 50th percentile and 75th percentile
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage	100.00%
LTIP Units and Restricted Stock | Maximum | TSR percentile falls between the 25th percentile and the 50th percentile
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage	100.00%
LTIP Units and Restricted Stock | Maximum | TSR percentile falls between the 50th percentile and 75th percentile
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage	200.00%
Employee Benefit Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 100,000	$ 100,000
Share Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized	1,975,780
Share Incentive Plan | LTIP Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued during period, share-based compensation, net of forfeitures	633,462		396,149
Share Incentive Plan | Restricted shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued during period, share-based compensation, net of forfeitures	11,119		13,766
Performance Shares 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period	3 years		3 years
Volatility rate	48.00%		21.00%
Risk-free interest rates	0.20%		1.40%
Long Term Investment Alignment Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Max percentage of future fund III promote that may be awarded to senior executives				25.00%
Long Term Investment Alignment Program | Fund III
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of promote awarded as share based compensation award	25.00%
Compensation expense	$ 0		$ 0
Long Term Investment Alignment Program | Fund IV
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of promote awarded as share based compensation award	23.10%
Awards in connection with fund to have intrinsic value	$ 0		0
Compensation expense	$ 0		0
Long Term Investment Alignment Program | Fund V
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of promote awarded as share based compensation award	8.40%
Awards in connection with fund to have intrinsic value	$ 0		0
Compensation expense	$ 0		$ 0

Share Incentive and Other Com_4

Share Incentive and Other Compensation - Schedule of Unvested Shares and LTIP Units (Details) - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Restricted shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Shares unvested, Beginning of period (in shares)	89,911	42,390
Shares granted (in shares)	12,361	66,824
Shares vested (in shares)	(7,847)	(19,264)
Shares forfeited (in shares)	(159)	(39)
Shares unvested, End of period (in shares)	94,266	89,911
Weighted Grant-Date Fair Value
Shares unvested, Weighted average grant date fair value, Beginning of period (in dollars per share)	$ 15.42	$ 23.73
Shares granted, Weighted average grant date fair value (in dollars per share)	18.50	13.70
Shares vested, Weighted average grant date fair value (in dollars per share)	26.13	27.72
Shares forfeited, Weighted average grant date fair value (in dollars per share)	36.22	24.77
Shares unvested, Weighted average grant date fair value, End of period (in dollars per share)	$ 14.90	$ 15.42
LTIP Units
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Shares unvested, Beginning of period (in shares)	1,122,889	936,180
Shares granted (in shares)	633,462	440,829
Shares vested (in shares)	(250,748)	(250,241)
Shares forfeited (in shares)	(91,637)	(3,879)
Shares unvested, End of period (in shares)	1,413,966	1,122,889
Weighted Grant-Date Fair Value
Shares unvested, Weighted average grant date fair value, Beginning of period (in dollars per share)	$ 24.38	$ 28.24
Shares granted, Weighted average grant date fair value (in dollars per share)	19.42	19.64
Shares vested, Weighted average grant date fair value (in dollars per share)	28.20	30.44
Shares forfeited, Weighted average grant date fair value (in dollars per share)	36.22	24.67
Shares unvested, Weighted average grant date fair value, End of period (in dollars per share)	$ 20.72	$ 24.38

Share Incentive and Other Com_5

Share Incentive and Other Compensation - Employee Share Purchase Plan and Deferred Share Plan - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee share purchase discount rate	15.00%
Employee share purchase maximum purchase amount	$ 25,000
Employee Share Purchase Plan 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of common shares allow for issuance	200,000
Common Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee share purchase (in shares)	2,428	395

Share Incentive and Other Com_6

Share Incentive and Other Compensation - Employee 401 (k) Plan - Additional Information (Details) - Forecast	12 Months Ended
	Dec. 31, 2021USD ($)
Defined Contribution Plan Disclosure [Line Items]
Employer matching contribution	50.00%
Maximum annual contribution per employee	6.00%
Maximum employee annual salary contribution	15.00%
Maximum employee annual salary contribution amount	$ 19,500

Earnings (Loss) Per Common Sh_3

Earnings (Loss) Per Common Share - Additional Information (Details)	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Description of conversion of common OP units to common shares	The effect of the conversion of Common OP Units is not reflected in the computation of basic and diluted earnings per share, as they are exchangeable for Common Shares on a one-for-one basis.
Conversion of common OP units to common shares	100.00%

Earnings (Loss) Per Common Sh_4

Earnings (Loss) Per Common Share - Schedule of Earnings (Loss) Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Numerator:
Net income (loss) attributable to Acadia	$ 5,162	$ (8,414)
Less: net income attributable to participating securities	(156)	0
Income (loss) from continuing operations net of income attributable to participating securities	$ 5,006	$ (8,414)
Denominator:
Weighted average shares for basic earnings per share (in shares)	86,323,267	86,971,552
Effect of dilutive securities:
Employee unvested restricted shares (in shares)	23,093	0
Denominator for diluted earnings per share (in shares)	86,346,360	86,971,552
Basic and diluted earnings and basic loss per Common Share from continuing operations attributable to Acadia	$ 0.06	$ (0.10)
Series A Preferred OP Units
Anti-Dilutive Shares Excluded from Denominator:
Antidilutive securities excluded from computation of earnings per share (in shares)	188	188
Series A Preferred OP Units - Common Share Equivalent
Anti-Dilutive Shares Excluded from Denominator:
Antidilutive securities excluded from computation of earnings per share (in shares)	25,067	25,067
Series C Preferred OP Units
Anti-Dilutive Shares Excluded from Denominator:
Antidilutive securities excluded from computation of earnings per share (in shares)	126,593	126,593
Series C Preferred OP Units - Common Share Equivalent
Anti-Dilutive Shares Excluded from Denominator:
Antidilutive securities excluded from computation of earnings per share (in shares)	439,556	439,556
Restricted shares
Anti-Dilutive Shares Excluded from Denominator:
Antidilutive securities excluded from computation of earnings per share (in shares)	0	49,182

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) - USD ($) $ in Thousands	Apr. 27, 2021	Apr. 08, 2021	Apr. 06, 2021	Apr. 02, 2021	Mar. 31, 2021	Apr. 20, 2021	Dec. 31, 2020
Subsequent Event [Line Items]
Proceeds from the disposition of properties, net					$ 15,703
Mortgage loan					$ 101,410		$ 101,450
Subsequent Event | MCB Venture
Subsequent Event [Line Items]
Notes receivable issued						$ 16,000
Subsequent Event | Fund V
Subsequent Event [Line Items]
Investment maturity date		Aug. 25, 2022
Subsequent Event | Airport Mall, Shaws North Windham, Shaws Waterville and Wells Plaza Properties | Fund IV | Disposed of by sale
Subsequent Event [Line Items]
Proceeds from the disposition of properties, net				$ 40,400
Subsequent Event | Lincoln Place Property | Fund IV | Mortgages
Subsequent Event [Line Items]
Mortgage loan			$ 23,100
Debt instrument, maturity date			Mar. 13, 2022
Subsequent Event | Unconsolidated Property, 650 Bald Hill Road | Fund IV | Mortgages
Subsequent Event [Line Items]
Mortgage loan	$ 18,500
Debt instrument, maturity date	Jun. 27, 2021