Alexander's (ALX) 10-Q 30 Oct 23 2023 Q3 Quarterly report Financial data

Cover

Cover	9 Months Ended
	Sep. 30, 2023 shares
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2023
Document Transition Report	false
Entity File Number	001-06064
Entity Registrant Name	ALEXANDERS INC
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	51-0100517
Entity Address, Address Line One	210 Route 4 East,
Entity Address, City or Town	Paramus,
Entity Address, State or Province	NJ
Entity Address, Postal Zip Code	07652
City Area Code	(201)
Local Phone Number	587-8541
Title of 12(b) Security	Common Stock, $1 par value per share
Trading Symbol	ALX
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding	5,107,290
Amendment Flag	false
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3
Entity Central Index Key	0000003499
Current Fiscal Year End Date	--12-31

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Real estate, at cost:
Land	$ 32,271	$ 33,050
Buildings and leasehold improvements	1,036,129	1,029,504
Development and construction in progress	0	22,044
Total	1,068,400	1,084,598
Accumulated depreciation and amortization	(412,015)	(396,268)
Real estate, net	656,385	688,330
Cash and cash equivalents	507,918	194,933
Restricted cash	21,163	19,545
Investments in U.S. Treasury bills	0	266,963
Tenant and other receivables	6,420	4,705
Receivable arising from the straight-lining of rents	121,548	127,497
Deferred leasing costs, net, including unamortized leasing fees to Vornado of $20,778 and $22,174, respectively	26,306	28,490
Other assets	71,156	67,313
Total assets	1,410,896	1,397,776
LIABILITIES AND EQUITY
Mortgages payable, net of deferred debt issuance costs	1,092,125	1,091,051
Amounts due to Vornado	1,500	801
Accounts payable and accrued expenses	44,534	48,785
Other liabilities	20,913	20,640
Total liabilities	1,159,072	1,161,277
Commitments and contingencies
Preferred stock: $1.00 par value per share; authorized, 3,000,000 shares; issued and outstanding, none	0	0
Common stock: $1.00 par value per share; authorized, 10,000,000 shares; issued, 5,173,450 shares; outstanding, 5,107,290 shares	5,173	5,173
Additional capital	34,315	33,865
Retained earnings	189,138	172,243
Accumulated other comprehensive income	23,566	25,586
Equity before treasury stock	252,192	236,867
Treasury stock: 66,160 shares, at cost	(368)	(368)
Total equity	251,824	236,499
Total liabilities and equity	$ 1,410,896	$ 1,397,776

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Unamortized leasing fees to Vornado	$ 20,778	$ 22,174
Preferred stock: par value per share (in usd per share)	$ 1	$ 1
Preferred stock: authorized shares (in shares)	3,000,000	3,000,000
Preferred stock: issued shares (in shares)	0	0
Preferred stock: outstanding shares (in shares)	0	0
Common stock: par value per share (in usd per share)	$ 1	$ 1
Common stock: authorized shares (in shares)	10,000,000	10,000,000
Common stock: issued shares (in shares)	5,173,450	5,173,450
Common stock: outstanding shares (in shares)	5,107,290	5,107,290
Treasury stock: shares (in shares)	66,160	66,160

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
REVENUES
Rental revenues	$ 55,413	$ 53,729	$ 162,027	$ 152,768
EXPENSES
Operating, including fees to Vornado of $1,557, $1,357, $4,780 and $4,271, respectively	(25,593)	(23,731)	(75,355)	(66,645)
Depreciation and amortization	(7,933)	(7,508)	(23,492)	(22,272)
General and administrative, including management fees to Vornado of $610, $610, $1,830 and $1,830, respectively	(1,580)	(1,370)	(4,845)	(4,755)
Total expenses	(35,106)	(32,609)	(103,692)	(93,672)
Interest and other income	6,622	2,017	15,464	3,284
Interest and debt expense	(16,175)	(8,028)	(41,624)	(17,925)
Net gain on sale of real estate	0	0	53,952	0
Net income	$ 10,754	$ 15,109	$ 86,127	$ 44,455
Net income per common share - basic (in usd per share)	$ 2.10	$ 2.95	$ 16.79	$ 8.67
Net income per common share - diluted (in usd per share)	$ 2.10	$ 2.95	$ 16.79	$ 8.67
Weighted average shares outstanding - basic (in shares)	5,130,678	5,127,086	5,128,875	5,125,768
Weighted average shares outstanding - diluted (in shares)	5,130,678	5,127,086	5,128,875	5,125,768

Consolidated Statements of In_2

Consolidated Statements of Income (Parenthetical) - Related Party - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Operating fees to Vornado	$ 1,557	$ 1,357	$ 4,780	$ 4,271
Management fees to Vornado	$ 610	$ 610	$ 1,830	$ 1,830

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 10,754	$ 15,109	$ 86,127	$ 44,455
Other comprehensive (loss) income:
Change in fair value of interest rate derivatives and other	(1,486)	6,393	(2,020)	20,044
Comprehensive income	$ 9,268	$ 21,502	$ 84,107	$ 64,499

Consolidated Statements of Chan

Consolidated Statements of Changes in Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Capital	Retained Earnings	Accumulated  Other Comprehensive Income	Treasury Stock
Beginning balance (in shares) at Dec. 31, 2021		5,173,000
Beginning balance at Dec. 31, 2021	$ 252,589	$ 5,173	$ 33,415	$ 206,875	$ 7,494	$ (368)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	44,455			44,455
Dividends paid	(69,192)			(69,192)
Change in fair value of interest rate derivatives and other	20,044				20,044
Deferred stock unit grants	450		450
Ending balance (in shares) at Sep. 30, 2022		5,173,000
Ending balance at Sep. 30, 2022	248,346	$ 5,173	33,865	182,138	27,538	(368)
Beginning balance (in shares) at Jun. 30, 2022		5,173,000
Beginning balance at Jun. 30, 2022	249,916	$ 5,173	33,865	190,101	21,145	(368)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	15,109			15,109
Dividends paid	(23,072)			(23,072)
Change in fair value of interest rate derivatives and other	6,393				6,393
Ending balance (in shares) at Sep. 30, 2022		5,173,000
Ending balance at Sep. 30, 2022	$ 248,346	$ 5,173	33,865	182,138	27,538	(368)
Beginning balance (in shares) at Dec. 31, 2022	5,173,450	5,173,000
Beginning balance at Dec. 31, 2022	$ 236,499	$ 5,173	33,865	172,243	25,586	(368)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	86,127			86,127
Dividends paid	(69,232)			(69,232)
Change in fair value of interest rate derivatives and other	(2,020)				(2,020)
Deferred stock unit grants	$ 450		450
Ending balance (in shares) at Sep. 30, 2023	5,173,450	5,173,000
Ending balance at Sep. 30, 2023	$ 251,824	$ 5,173	34,315	189,138	23,566	(368)
Beginning balance (in shares) at Jun. 30, 2023		5,173,000
Beginning balance at Jun. 30, 2023	265,644	$ 5,173	34,315	201,472	25,052	(368)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	10,754			10,754
Dividends paid	(23,088)			(23,088)
Change in fair value of interest rate derivatives and other	$ (1,486)				(1,486)
Ending balance (in shares) at Sep. 30, 2023	5,173,450	5,173,000
Ending balance at Sep. 30, 2023	$ 251,824	$ 5,173	$ 34,315	$ 189,138	$ 23,566	$ (368)

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Equity (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Statement of Stockholders' Equity [Abstract]
Dividends per common share (in usd per share)	$ 4.50	$ 4.50	$ 13.50	$ 13.50

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 86,127	$ 44,455
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization, including amortization of debt issuance costs	24,771	23,510
Net gain on sale of real estate	(53,952)	0
Straight-lining of rents	5,949	6,028
Stock-based compensation expense	450	450
Interest rate cap premium amortization	4,049	0
Other non-cash adjustments	1,295	(1,420)
Change in operating assets and liabilities:
Tenant and other receivables	(951)	1,031
Other assets	(1,377)	(9,412)
Amounts due to Vornado	725	(230)
Accounts payable and accrued expenses	(2,705)	11,540
Other liabilities	(14)	251
Net cash provided by operating activities	64,367	76,203
CASH FLOWS FROM INVESTING ACTIVITIES
Construction in progress and real estate additions	(3,796)	(8,710)
Proceeds from sale of real estate	67,821	0
Proceeds from maturities of U.S. Treasury bills	264,881	0
Purchase of interest rate cap	(11,258)	0
Proceeds from interest rate cap	1,889	0
Purchase of U.S. Treasury bills	0	(197,407)
Net cash provided by (used in) investing activities	319,537	(206,117)
CASH FLOWS FROM FINANCING ACTIVITIES
Dividends paid	(69,232)	(69,192)
Debt issuance costs	(69)	(8)
Net cash used in financing activities	(69,301)	(69,200)
Net increase (decrease) in cash and cash equivalents and restricted cash	314,603	(199,114)
Cash and cash equivalents and restricted cash at beginning of period	214,478	483,505
Cash and cash equivalents and restricted cash at end of period	529,081	284,391
RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH
Cash and cash equivalents at beginning of period	194,933	463,539
Restricted cash at beginning of period	19,545	19,966
Cash and cash equivalents and restricted cash at beginning of period	214,478	483,505
Cash and cash equivalents at end of period	507,918	264,872
Restricted cash at end of period	21,163	19,519
Cash and cash equivalents and restricted cash at end of period	529,081	284,391
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Cash payments for interest (net of amounts capitalized)	38,399	15,808
NON-CASH TRANSACTIONS
Liability for real estate additions, including $3 for development fees due to Vornado in 2022	652	2,277
Write-off of fully depreciated assets	$ 5,964	$ 23

Consolidated Statements of Ca_2

Consolidated Statements of Cash Flows (Parenthetical) $ in Thousands	9 Months Ended
	Sep. 30, 2022 USD ($)
Liability for real estate additions due to Vornado	$ 2,277
Development fees | Vornado
Liability for real estate additions due to Vornado	$ 3

Organization

Organization	9 Months Ended
	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	OrganizationAlexander’s, Inc. (NYSE: ALX) is a real estate investment trust (“REIT”), incorporated in Delaware, engaged in leasing, managing, developing and redeveloping its properties. All references to “we,” “us,” “our,” “Company” and “Alexander’s” refer to Alexander’s, Inc. and its consolidated subsidiaries. We are managed by, and our properties are leased and developed by, Vornado Realty Trust (“Vornado”) (NYSE: VNO). We have five properties in New York City.

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements are unaudited and include the accounts of Alexander’s and its consolidated subsidiaries. All adjustments (which include only normal recurring adjustments) necessary to present fairly the financial position, results of operations and changes in cash flows have been made. Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) have been condensed or omitted. These consolidated financial statements have been prepared in accordance with the instructions to Form 10-Q of the Securities and Exchange Commission (the “SEC”) and should be read in conjunction with the consolidated financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2022, as filed with the SEC. We have made estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from those estimates. The results of operations for the three and nine months ended September 30, 2023 are not necessarily indicative of the operating results for the full year.

Recently Issued Accounting Lite

Recently Issued Accounting Literature	9 Months Ended
	Sep. 30, 2023
Accounting Standards Update and Change in Accounting Principle [Abstract]
Recently Issued Accounting Literature	Recently Issued Accounting Literature In March 2020, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2020-04 establishing Accounting Standards Codification (“ASC”) Topic 848, Reference Rate Reform, and in January 2021, the FASB issued ASU 2021-01, Reference Rate Reform (Topic 848) : Scope (collectively, “ASC 848”). ASC 848 contains practical expedients for reference rate reform related activities that impact debt, leases, derivatives and other contracts. The guidance in ASC 848 is optional and may be elected over time as reference rate reform activities occur. We have elected to apply the hedge accounting expedients related to probability and the assessments of effectiveness for future LIBOR-indexed cash flows to assume that the index upon which future hedged transactions will be based matches the index on the corresponding derivatives. Application of these expedients preserves the presentation of derivatives consistent with past presentation. In December 2022, the FASB issued ASU 2022-06, Deferral of the Sunset Date of Topic 848

Revenue Recognition

Revenue Recognition	9 Months Ended
	Sep. 30, 2023
Revenue from Contract with Customer [Abstract]
Revenue Recognition	Revenue Recognition The following is a summary of revenue sources for the three and nine months ended September 30, 2023 and 2022. For the Three Months Ended September 30, For the Nine Months Ended September 30, (Amounts in thousands) 2023 2022 2023 2022 Lease revenues $ 52,954 $ 51,921 $ 155,502 $ 146,440 Parking revenue 1,090 1,189 3,300 3,582 Tenant services 1,369 619 3,225 2,746 Rental revenues $ 55,413 $ 53,729 $ 162,027 $ 152,768 The components of lease revenues for the three and nine months ended September 30, 2023 and 2022 are as follows: For the Three Months Ended September 30, For the Nine Months Ended September 30, (Amounts in thousands) 2023 2022 2023 2022 Fixed lease revenues $ 34,926 $ 35,847 $ 104,489 $ 101,468 Variable lease revenues 18,028 16,074 51,013 44,972 Lease revenues $ 52,954 $ 51,921 $ 155,502 $ 146,440 Bloomberg L.P. (“Bloomberg”) accounted for revenue of $89,863,000 and $81,536,000 for the nine months ended September 30, 2023 and 2022, respectively, representing approximately 55% and 53% of our rental revenues in each period, respectively. No other tenant accounted for more than 10% of our rental revenues. If we were to lose Bloomberg as a tenant, or if Bloomberg were to be unable to fulfill its obligations under its lease, it would adversely affect our results of operations and financial condition. In order to assist us in our continuing assessment of Bloomberg’s creditworthiness, we receive certain confidential financial information and metrics from Bloomberg. In addition, we access and evaluate financial information regarding Bloomberg from other private sources, as well as publicly available data. On December 3, 2022, IKEA closed its 112,000 square foot store at our Rego Park I property under a lease that was set to expire in December 2030. The lease included a right to terminate effective no earlier than March 16, 2026, subject to payment of rent through the termination date and an additional termination payment equal to the lesser of $10,000,000 or the amount of rent due under the remaining term. On September 27, 2023, we entered into a lease modification agreement with IKEA which accelerates its lease termination date to April 1, 2024. Under the lease modification agreement, IKEA will pay its remaining rent due through March 16, 2026 and the $10,000,000 termination payment over the modified lease term.

Real Estate Sale

Real Estate Sale	9 Months Ended
	Sep. 30, 2023
Real Estate [Abstract]
Real Estate Sale	Real Estate SaleOn May 19, 2023, we sold the Rego Park III land parcel in Queens, New York, for $71,060,000 inclusive of consideration for Brownfield tax benefits and reimbursement of costs for plans, specifications and improvements to date. Net proceeds from the sale were $67,821,000 after closing costs and the financial statement gain was $53,952,000

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2023
Related Party Transactions [Abstract]
Related Party Transactions	Vornado As of September 30, 2023, Vornado owned 32.4% of our outstanding common stock. We are managed by, and our properties are leased and developed by, Vornado, pursuant to the agreements described below, which expire in March of each year and are automatically renewable. Management and Development Agreements We pay Vornado an annual management fee equal to the sum of (i) $2,800,000, (ii) 2% of gross revenue from the Rego Park II shopping center, (iii) $0.50 per square foot of the tenant-occupied office and retail space at 731 Lexington Avenue, and (iv) $365,000, escalating at 3% per annum, for managing the common area of 731 Lexington Avenue. Vornado is also entitled to a development fee equal to 6% of development costs, as defined. Leasing and Other Agreements Vornado also provides us with leasing services for a fee of 3% of rent for the first ten years of a lease term, 2% of rent for the eleventh through the twentieth year of a lease term, and 1% of rent for the twenty-first through thirtieth year of a lease term, subject to the payment of rents by tenants. In the event third-party real estate brokers are used, the fees to Vornado increase by 1% and Vornado is responsible for the fees to the third-party real estate brokers. Vornado is also entitled to a commission upon the sale of any of our assets equal to 3% of gross proceeds, as defined, for asset sales less than $50,000,000 and 1% of gross proceeds, as defined, for asset sales of $50,000,000 or more (the “Sales Agreement”). Pursuant to the Sales Agreement, we paid a $711,000 sales commission to Vornado in the second quarter of 2023 related to the sale of the Rego Park III land parcel. We also have agreements with Building Maintenance Services, a wholly owned subsidiary of Vornado, to supervise (i) cleaning, engineering and security services at our Lexington Avenue property and (ii) security services at our Rego Park I and Rego Park II properties and The Alexander apartment tower. We also have an agreement with a wholly owned subsidiary of Vornado to manage the parking garages at our Rego Park I and Rego Park II properties. The following is a summary of fees earned by Vornado under the various agreements discussed above. For the Three Months Ended September 30, For the Nine Months Ended September 30, (Amounts in thousands) 2023 2022 2023 2022 Company management fees $ 700 $ 700 $ 2,100 $ 2,100 Development fees — — — 3 Leasing fees 974 58 1,144 1,376 Commission on sale of real estate — — 711 — Property management, cleaning, engineering, parking and security fees 1,442 1,358 4,401 4,174 $ 3,116 $ 2,116 $ 8,356 $ 7,653 As of September 30, 2023, the amounts due to Vornado were $974,000 for leasing fees and $526,000 for management, property management, cleaning, engineering and security fees. As of December 31, 2022, the amounts due to Vornado were $742,000 for management, property management, cleaning, engineering and security fees and $59,000 for leasing fees.

Mortgages Payable

Mortgages Payable	9 Months Ended
	Sep. 30, 2023
Debt Disclosure [Abstract]
Mortgages Payable	Mortgages Payable On June 9, 2023, we exercised our remaining one-year extension option on the $500,000,000 interest-only mortgage loan on the office condominium of our 731 Lexington Avenue property. The interest rate on the loan remained at LIBOR plus 0.90% through July 15, 2023 and thereafter at the Prime Rate through loan maturity on June 11, 2024. In June 2023, we purchased an interest rate cap for $11,258,000, which capped LIBOR at 6.00% through July 15, 2023 and caps the Prime Rate (8.50% as of September 30, 2023) at 6.00% through loan maturity. The following is a summary of our outstanding mortgages payable as of September 30, 2023 and December 31, 2022. We may refinance our maturing debt as it comes due or choose to pay it down. Interest Rate at September 30, 2023 Balance as of (Amounts in thousands) Maturity September 30, 2023 December 31, 2022 First mortgages secured by: 731 Lexington Avenue, office condominium (1) Jun. 11, 2024 6.00% $ 500,000 $ 500,000 731 Lexington Avenue, retail condominium (2)(3) Aug. 05, 2025 1.76% 300,000 300,000 Rego Park II shopping center (2)(4) Dec. 12, 2025 5.60% 202,544 202,544 The Alexander apartment tower Nov. 01, 2027 2.63% 94,000 94,000 Total 1,096,544 1,096,544 Deferred debt issuance costs, net of accumulated amortization of $17,246 and $16,071, respectively (4,419) (5,493) $ 1,092,125 $ 1,091,051 (1) Interest at the Prime Rate (capped at 6.00% through loan maturity). (2) Interest rate listed represents the rate in effect as of September 30, 2023 based on SOFR as of contractual reset date plus contractual spread, adjusted for hedging instruments as applicable. (3) Interest at SOFR plus 1.51% which was swapped to a fixed rate of 1.76% through May 2025. (4) Interest at SOFR plus 1.45% (SOFR is capped at 4.15% through November 2024).

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation We account for stock-based compensation in accordance with ASC Topic 718, Compensation – Stock Compensation (“ASC 718”). Our 2016 Omnibus Stock Plan (the “Plan”) provides for grants of incentive and non-qualified stock options, restricted stock, stock appreciation rights, deferred stock units (“DSUs”) and performance shares, as defined, to the directors, officers and employees of the Company and Vornado. In May 2023, we granted each of the members of our Board of Directors 449 DSUs with a market value of $75,000 per grant. The grant date fair value of these awards was $56,250 per grant, or $450,000 in the aggregate, in accordance with ASC 718. The DSUs entitle the holders to receive shares of the Company’s common stock without the payment of any consideration. The DSUs vested immediately and accordingly, were expensed on the date of grant, but the shares of common stock underlying the DSUs are not deliverable to the grantee until the grantee is no longer serving on the Company’s Board of Directors. As of September 30, 2023, there were 23,388 DSUs outstanding and 482,399 shares were available for future grant under the Plan.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements ASC Topic 820, Fair Value Measurement (“ASC 820”) defines fair value and establishes a framework for measuring fair value. ASC 820 establishes a fair value hierarchy that prioritizes observable and unobservable inputs used to measure fair value into three levels: Level 1 – quoted prices (unadjusted) in active markets that are accessible at the measurement date for assets or liabilities as well as certain U.S. Treasury securities that are highly liquid and are actively traded in secondary markets; Level 2 – observable prices that are based on inputs not quoted in active markets, but corroborated by market data; and Level 3 – unobservable inputs that are used when little or no market data is available. The fair value hierarchy gives the highest priority to Level 1 inputs and the lowest priority to Level 3 inputs. In determining fair value, we utilize valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible, as well as consider counterparty credit risk in our assessment of fair value. Financial Assets and Liabilities Measured at Fair Value Financial assets measured at fair value on our consolidated balance sheet as of September 30, 2023 consisted of interest rate derivatives, which are presented in the table below based on their level in the fair value hierarchy. There were no financial liabilities measured at fair value as of September 30, 2023. As of September 30, 2023 (Amounts in thousands) Total Level 1 Level 2 Level 3 Interest rate derivatives (included in other assets) $ 33,694 $ — $ 33,694 $ — Financial assets measured at fair value on our consolidated balance sheet as of December 31, 2022 consisted of U.S. Treasury bills (classified as available-for-sale) and interest rate derivatives, which are presented in the table below based on their level in the fair value hierarchy. There were no financial liabilities measured at fair value as of December 31, 2022. As of December 31, 2022 (Amounts in thousands) Total Level 1 Level 2 Level 3 Investments in U.S. Treasury bills $ 266,963 $ 266,963 $ — $ — Interest rate derivatives (included in other assets) 29,351 — 29,351 — $ 296,314 $ 266,963 $ 29,351 $ — 9. Fair Value Measurements - continued Interest Rate Derivatives We recognize the fair value of all interest rate derivatives in “other assets” or “other liabilities” on our consolidated balance sheets and since all of our interest rate derivatives have been designated as cash flow hedges, changes in the fair value are recognized in other comprehensive income. The table below summarizes our interest rate derivatives, all of which hedge the interest rate risk attributable to the variable rate debt noted as of September 30, 2023 and December 31, 2022, respectively. Fair Value as of As of September 30, 2023 (Amounts in thousands) September 30, 2023 December 31, 2022 Notional Amount Rate Expiration Date Interest rate swap related to: 731 Lexington Avenue mortgage loan, retail condominium $ 22,249 $ 26,718 $ 300,000 1.76% 05/25 Interest rate caps related to: Rego Park II shopping center mortgage loan 2,764 2,622 202,544 (1) 11/24 731 Lexington Avenue mortgage loan, office condominium 8,681 11 500,000 (2) 06/24 Included in other assets $ 33,694 $ 29,351 (1) SOFR cap strike rate of 4.15%. (2) In June 2023, we purchased an interest rate cap for $11,258, which capped LIBOR at 6.00% through July 15, 2023 and caps the Prime Rate (8.50% as of September 30, 2023) at 6.00% through loan maturity. See Note 7 - Mortgages Payable for further information. Financial Assets and Liabilities not Measured at Fair Value Financial assets and liabilities that are not measured at fair value on our consolidated balance sheets include cash equivalents and mortgages payable. Cash equivalents are carried at cost, which approximates fair value due to their short-term maturities and are classified as Level 1. The fair value of our mortgages payable is calculated by discounting the future contractual cash flows of these instruments using current risk-adjusted rates available to borrowers with similar credit ratings, which are provided by a third-party specialist, and is classified as Level 2. The table below summarizes the carrying amount and fair value of these financial instruments as of September 30, 2023 and December 31, 2022. As of September 30, 2023 As of December 31, 2022 (Amounts in thousands) Carrying Fair Carrying Fair Assets: Cash equivalents $ 356,391 $ 356,391 $ 47,852 $ 47,852 Liabilities: Mortgages payable (excluding deferred debt issuance costs, net) $ 1,096,544 $ 1,064,832 $ 1,096,544 $ 1,061,221

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Insurance We maintain general liability insurance with limits of $300,000,000 per occurrence and per property, of which the first $30,000,000 includes communicable disease coverage, and all-risk property and rental value insurance coverage with limits of $1.7 billion per occurrence, including coverage for acts of terrorism, with sub-limits for certain perils such as floods and earthquakes on each of our properties and excluding communicable disease coverage. Fifty Ninth Street Insurance Company, LLC (“FNSIC”), our wholly owned consolidated subsidiary, acts as a direct insurer for coverage for acts of terrorism, including nuclear, biological, chemical and radiological (“NBCR”) acts, as defined by the Terrorism Risk Insurance Act of 2002, as amended to date and which has been extended through December 2027. Coverage for acts of terrorism (including NBCR acts) is up to $1.7 billion per occurrence and in the aggregate. Coverage for acts of terrorism (excluding NBCR acts) is fully reinsured by third party insurance companies and the Federal government with no exposure to FNSIC. For NBCR acts, FNSIC is responsible for a $316,000 deductible and 20% of the balance of a covered loss, and the Federal government is responsible for the remaining 80% of a covered loss. We are ultimately responsible for any loss incurred by FNSIC. We continue to monitor the state of the insurance market and the scope and costs of coverage for acts of terrorism or other events. However, we cannot anticipate what coverage will be available on commercially reasonable terms in the future. We are responsible for uninsured losses and for deductibles and losses in excess of our insurance coverage, which could be material. The principal amounts of our mortgage loans are non-recourse to us and the loans contain customary covenants requiring us to maintain insurance. Although we believe that we have adequate insurance coverage for purposes of these agreements, we may not be able to obtain an equivalent amount of coverage at reasonable costs in the future. If lenders insist on greater coverage than we are able to obtain, it could adversely affect our ability to finance or refinance our properties. Letters of Credit Approximately $900,000 of standby letters of credit were issued and outstanding as of September 30, 2023. Other

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share The following table sets forth the computation of basic and diluted income per share, including a reconciliation of net income and the number of shares used in computing basic and diluted income per share. Basic income per share is determined using the weighted average shares of common stock (including deferred stock units) outstanding during the period. Diluted income per share is determined using the weighted average shares of common stock (including deferred stock units) outstanding during the period, and assumes all potentially dilutive securities were converted into common shares at the earliest date possible. There were no potentially dilutive securities outstanding during the three and nine months ended September 30, 2023 and 2022. For the Three Months Ended September 30, For the Nine Months Ended September 30, (Amounts in thousands, except share and per share amounts) 2023 2022 2023 2022 Net income $ 10,754 $ 15,109 $ 86,127 $ 44,455 Weighted average shares outstanding – basic and diluted 5,130,678 5,127,086 5,128,875 5,125,768 Net income per common share – basic and diluted $ 2.10 $ 2.95 $ 16.79 $ 8.67

Basis of Presentation (Policies

Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	The accompanying consolidated financial statements are unaudited and include the accounts of Alexander’s and its consolidated subsidiaries. All adjustments (which include only normal recurring adjustments) necessary to present fairly the financial position, results of operations and changes in cash flows have been made. Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) have been condensed or omitted. These consolidated financial statements have been prepared in accordance with the instructions to Form 10-Q of the Securities and Exchange Commission (the “SEC”) and should be read in conjunction with the consolidated financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2022, as filed with the SEC. We have made estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from those estimates. The results of operations for the three and nine months ended September 30, 2023 are not necessarily indicative of the operating results for the full year.
Recently Issued Accounting Literature	In March 2020, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2020-04 establishing Accounting Standards Codification (“ASC”) Topic 848, Reference Rate Reform, and in January 2021, the FASB issued ASU 2021-01, Reference Rate Reform (Topic 848) : Scope (collectively, “ASC 848”). ASC 848 contains practical expedients for reference rate reform related activities that impact debt, leases, derivatives and other contracts. The guidance in ASC 848 is optional and may be elected over time as reference rate reform activities occur. We have elected to apply the hedge accounting expedients related to probability and the assessments of effectiveness for future LIBOR-indexed cash flows to assume that the index upon which future hedged transactions will be based matches the index on the corresponding derivatives. Application of these expedients preserves the presentation of derivatives consistent with past presentation. In December 2022, the FASB issued ASU 2022-06, Deferral of the Sunset Date of Topic 848
Stock-Based Compensation	We account for stock-based compensation in accordance with ASC Topic 718, Compensation – Stock Compensation (“ASC 718”). Our 2016 Omnibus Stock Plan (the “Plan”) provides for grants of incentive and non-qualified stock options, restricted stock, stock appreciation rights, deferred stock units (“DSUs”) and performance shares, as defined, to the directors, officers and employees of the Company and Vornado.
Fair Value Measurement	ASC Topic 820, Fair Value Measurement (“ASC 820”) defines fair value and establishes a framework for measuring fair value. ASC 820 establishes a fair value hierarchy that prioritizes observable and unobservable inputs used to measure fair value into three levels: Level 1 – quoted prices (unadjusted) in active markets that are accessible at the measurement date for assets or liabilities as well as certain U.S. Treasury securities that are highly liquid and are actively traded in secondary markets; Level 2 – observable prices that are based on inputs not quoted in active markets, but corroborated by market data; and Level 3 – unobservable inputs that are used when little or no market data is available. The fair value hierarchy gives the highest priority to Level 1 inputs and the lowest priority to Level 3 inputs. In determining fair value, we utilize valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible, as well as consider counterparty credit risk in our assessment of fair value.

Revenue Recognition (Tables)

Revenue Recognition (Tables)	9 Months Ended
	Sep. 30, 2023
Revenue from Contract with Customer [Abstract]
Schedule of Disaggregation of Revenue	The following is a summary of revenue sources for the three and nine months ended September 30, 2023 and 2022. For the Three Months Ended September 30, For the Nine Months Ended September 30, (Amounts in thousands) 2023 2022 2023 2022 Lease revenues $ 52,954 $ 51,921 $ 155,502 $ 146,440 Parking revenue 1,090 1,189 3,300 3,582 Tenant services 1,369 619 3,225 2,746 Rental revenues $ 55,413 $ 53,729 $ 162,027 $ 152,768
Schedule of Components of Lease Revenue	The components of lease revenues for the three and nine months ended September 30, 2023 and 2022 are as follows: For the Three Months Ended September 30, For the Nine Months Ended September 30, (Amounts in thousands) 2023 2022 2023 2022 Fixed lease revenues $ 34,926 $ 35,847 $ 104,489 $ 101,468 Variable lease revenues 18,028 16,074 51,013 44,972 Lease revenues $ 52,954 $ 51,921 $ 155,502 $ 146,440

Related Party Transactions (Tab

Related Party Transactions (Tables)	9 Months Ended
	Sep. 30, 2023
Related Party Transactions [Abstract]
Schedule of Fees to Vornado	The following is a summary of fees earned by Vornado under the various agreements discussed above. For the Three Months Ended September 30, For the Nine Months Ended September 30, (Amounts in thousands) 2023 2022 2023 2022 Company management fees $ 700 $ 700 $ 2,100 $ 2,100 Development fees — — — 3 Leasing fees 974 58 1,144 1,376 Commission on sale of real estate — — 711 — Property management, cleaning, engineering, parking and security fees 1,442 1,358 4,401 4,174 $ 3,116 $ 2,116 $ 8,356 $ 7,653

Mortgages Payable (Tables)

Mortgages Payable (Tables)	9 Months Ended
	Sep. 30, 2023
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments	The following is a summary of our outstanding mortgages payable as of September 30, 2023 and December 31, 2022. We may refinance our maturing debt as it comes due or choose to pay it down. Interest Rate at September 30, 2023 Balance as of (Amounts in thousands) Maturity September 30, 2023 December 31, 2022 First mortgages secured by: 731 Lexington Avenue, office condominium (1) Jun. 11, 2024 6.00% $ 500,000 $ 500,000 731 Lexington Avenue, retail condominium (2)(3) Aug. 05, 2025 1.76% 300,000 300,000 Rego Park II shopping center (2)(4) Dec. 12, 2025 5.60% 202,544 202,544 The Alexander apartment tower Nov. 01, 2027 2.63% 94,000 94,000 Total 1,096,544 1,096,544 Deferred debt issuance costs, net of accumulated amortization of $17,246 and $16,071, respectively (4,419) (5,493) $ 1,092,125 $ 1,091,051 (1) Interest at the Prime Rate (capped at 6.00% through loan maturity). (2) Interest rate listed represents the rate in effect as of September 30, 2023 based on SOFR as of contractual reset date plus contractual spread, adjusted for hedging instruments as applicable. (3) Interest at SOFR plus 1.51% which was swapped to a fixed rate of 1.76% through May 2025. (4) Interest at SOFR plus 1.45% (SOFR is capped at 4.15% through November 2024).

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	Financial assets measured at fair value on our consolidated balance sheet as of September 30, 2023 consisted of interest rate derivatives, which are presented in the table below based on their level in the fair value hierarchy. There were no financial liabilities measured at fair value as of September 30, 2023. As of September 30, 2023 (Amounts in thousands) Total Level 1 Level 2 Level 3 Interest rate derivatives (included in other assets) $ 33,694 $ — $ 33,694 $ — Financial assets measured at fair value on our consolidated balance sheet as of December 31, 2022 consisted of U.S. Treasury bills (classified as available-for-sale) and interest rate derivatives, which are presented in the table below based on their level in the fair value hierarchy. There were no financial liabilities measured at fair value as of December 31, 2022. As of December 31, 2022 (Amounts in thousands) Total Level 1 Level 2 Level 3 Investments in U.S. Treasury bills $ 266,963 $ 266,963 $ — $ — Interest rate derivatives (included in other assets) 29,351 — 29,351 — $ 296,314 $ 266,963 $ 29,351 $ —
Schedule of Interest Rate Derivatives	The table below summarizes our interest rate derivatives, all of which hedge the interest rate risk attributable to the variable rate debt noted as of September 30, 2023 and December 31, 2022, respectively. Fair Value as of As of September 30, 2023 (Amounts in thousands) September 30, 2023 December 31, 2022 Notional Amount Rate Expiration Date Interest rate swap related to: 731 Lexington Avenue mortgage loan, retail condominium $ 22,249 $ 26,718 $ 300,000 1.76% 05/25 Interest rate caps related to: Rego Park II shopping center mortgage loan 2,764 2,622 202,544 (1) 11/24 731 Lexington Avenue mortgage loan, office condominium 8,681 11 500,000 (2) 06/24 Included in other assets $ 33,694 $ 29,351 (1) SOFR cap strike rate of 4.15%. (2) In June 2023, we purchased an interest rate cap for $11,258, which capped LIBOR at 6.00% through July 15, 2023 and caps the Prime Rate (8.50% as of September 30, 2023) at 6.00% through loan maturity. See Note 7 - Mortgages Payable
Schedule of Fair Value, by Balance Sheet Grouping	The table below summarizes the carrying amount and fair value of these financial instruments as of September 30, 2023 and December 31, 2022. As of September 30, 2023 As of December 31, 2022 (Amounts in thousands) Carrying Fair Carrying Fair Assets: Cash equivalents $ 356,391 $ 356,391 $ 47,852 $ 47,852 Liabilities: Mortgages payable (excluding deferred debt issuance costs, net) $ 1,096,544 $ 1,064,832 $ 1,096,544 $ 1,061,221

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	There were no potentially dilutive securities outstanding during the three and nine months ended September 30, 2023 and 2022. For the Three Months Ended September 30, For the Nine Months Ended September 30, (Amounts in thousands, except share and per share amounts) 2023 2022 2023 2022 Net income $ 10,754 $ 15,109 $ 86,127 $ 44,455 Weighted average shares outstanding – basic and diluted 5,130,678 5,127,086 5,128,875 5,125,768 Net income per common share – basic and diluted $ 2.10 $ 2.95 $ 16.79 $ 8.67

Organization (Details)

Organization (Details)	Sep. 30, 2023 property
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of properties	5

Basis of Presentation (Details)

Basis of Presentation (Details)	9 Months Ended
	Sep. 30, 2023 segment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of reportable segments	1

Revenue Recognition - Disaggreg

Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation of Revenue [Line Items]
Lease revenues	$ 52,954	$ 51,921	$ 155,502	$ 146,440
Rental revenues	55,413	53,729	162,027	152,768
Parking revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,090	1,189	3,300	3,582
Tenant services
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 1,369	$ 619	$ 3,225	$ 2,746

Revenue Recognition - Component

Revenue Recognition - Components of Lease Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Revenue from Contract with Customer [Abstract]
Fixed lease revenues	$ 34,926	$ 35,847	$ 104,489	$ 101,468
Variable lease revenues	18,028	16,074	51,013	44,972
Lease revenues	$ 52,954	$ 51,921	$ 155,502	$ 146,440

Revenue Recognition - Additiona

Revenue Recognition - Additional Information (Details) ft² in Thousands, $ in Thousands		3 Months Ended		9 Months Ended
	Sep. 27, 2023 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Dec. 03, 2022 ft²
Disaggregation of Revenue [Line Items]
Rental revenues		$ 55,413	$ 53,729	$ 162,027	$ 152,768
IKEA | Anchor | Rego Park1 Property
Disaggregation of Revenue [Line Items]
Area of property (in sqft.) | ft²						112
Payment for termination of lease	$ 10,000
Customer Concentration Risk | Revenue | Bloomberg
Disaggregation of Revenue [Line Items]
Rental revenues				$ 89,863	$ 81,536
Percentage rent contributed by tenant				55%	53%

Real Estate Sale (Details)

Real Estate Sale (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	May 19, 2023	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Real Estate [Line Items]
Proceeds from sale of real estate				$ 67,821	$ 0
Net gain on sale of real estate		$ 0	$ 0	$ 53,952	$ 0
Rego Park III Land Parcel
Real Estate [Line Items]
Proceeds from sale of real estate	$ 71,060
Net proceeds from sale of land	67,821
Net gain on sale of real estate	$ 53,952

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details)	3 Months Ended			9 Months Ended
	Sep. 30, 2023 USD ($)	Jun. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) $ / ft²	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)
Related Party Transaction [Line Items]
Related party transaction, amounts of transaction	$ 3,116,000		$ 2,116,000	$ 8,356,000	$ 7,653,000
Amounts due to Vornado	1,500,000			1,500,000		$ 801,000
Management And Development Agreement, Base Management Fee | 731 Lexington Avenue | Common Area
Related Party Transaction [Line Items]
Related party transaction, amounts of transaction				$ 365,000
Leasing and Other Agreements, Percentage of Gross Proceeds Used for Commission for Sales Less Than Fifty Million
Related Party Transaction [Line Items]
Related party transaction, rate				3%
Asset sale commission threshold				$ 50,000,000
Leasing and Other Agreements, Percentage of Gross Proceeds Used For Commission for Sales Greater Than Fifty Million
Related Party Transaction [Line Items]
Related party transaction, rate				1%
Asset sale commission threshold				$ 50,000,000
Leasing fees
Related Party Transaction [Line Items]
Related party transaction, amounts of transaction	974,000		$ 58,000	1,144,000	$ 1,376,000
Related Party | Rego Park III Land Parcel
Related Party Transaction [Line Items]
Payments for commissions		$ 711,000
Related Party | Management and Development Agreement
Related Party Transaction [Line Items]
Annual management fee				$ 2,800,000
Related Party | Management and Development Agreement | 731 Lexington Avenue | Office and Retail Space
Related Party Transaction [Line Items]
Property management fee agreement, price per square foot | $ / ft²				0.50
Related Party | Management and Development Agreement, Percentage of Gross Revenue | Rego Park II | Retail Space
Related Party Transaction [Line Items]
Property management fee agreement percentage of gross revenue				2%
Related Party | Management and Development Agreement, Annualized Management Fee | 731 Lexington Avenue | Common Area
Related Party Transaction [Line Items]
Property management fee agreement percentage of gross revenue				3%
Related Party | Management and Development Agreement, Development Fee
Related Party Transaction [Line Items]
Property management fee agreement percentage of gross revenue				6%
Related Party | Leasing and Other Agreements, Percentage of Rent for First Ten Years
Related Party Transaction [Line Items]
Service fees, rate				3%
Related Party | Leasing and Other Agreements, Percentage of Rent for Eleventh Through Twentieth Year
Related Party Transaction [Line Items]
Service fees, rate				2%
Related Party | Leasing and Other Agreements, Percentage of Rent for the Twenty-First Through the Thirtieth Year
Related Party Transaction [Line Items]
Service fees, rate				1%
Related Party | Leasing and Other Agreements, Percentage Increase in Fee if Third Party is Used
Related Party Transaction [Line Items]
Service fees, rate				1%
Related Party | Leasing fees
Related Party Transaction [Line Items]
Amounts due to Vornado	974,000			$ 974,000		59,000
Related Party | Management, property management, cleaning, engineering and security fees
Related Party Transaction [Line Items]
Amounts due to Vornado	$ 526,000			$ 526,000		$ 742,000
Vornado | Alexander's Inc. | Related Party
Related Party Transaction [Line Items]
Ownership percentage by noncontrolling owners	32.40%			32.40%

Related Party Transactions - Su

Related Party Transactions - Summary of Fees to Vornado (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Related Party Transaction [Line Items]
Fees to related party	$ 3,116	$ 2,116	$ 8,356	$ 7,653
Company management fees
Related Party Transaction [Line Items]
Fees to related party	700	700	2,100	2,100
Development fees
Related Party Transaction [Line Items]
Fees to related party	0	0	0	3
Leasing fees
Related Party Transaction [Line Items]
Fees to related party	974	58	1,144	1,376
Commission on sale of real estate
Related Party Transaction [Line Items]
Fees to related party	0	0	711	0
Property management, cleaning, engineering, parking and security fees
Related Party Transaction [Line Items]
Fees to related party	$ 1,442	$ 1,358	$ 4,401	$ 4,174

Mortgages Payable - Additional

Mortgages Payable - Additional Information (Details) - 731 Lexington Avenue - USD ($) $ in Thousands	1 Months Ended	6 Months Ended
	Jul. 15, 2023	Jun. 30, 2023	Sep. 30, 2023	Jun. 09, 2023
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Payments for derivative instrument		$ 11,258
Mortgages
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Mortgage loans, extension option				1 year
Mortgage loans				$ 500,000
Mortgages | LIBOR
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Basis spread over LIBOR	0.90%
Interest cap rate	6%	6%
Mortgages | Prime Rate
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest rate			8.50%

Mortgages Payable - Schedule of

Mortgages Payable - Schedule of Long-term Debt Instruments (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Notes payable	$ 1,092,125	$ 1,091,051
Mortgages
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Mortgage payable gross	1,096,544	1,096,544
Deferred debt issuance costs, net of accumulated amortization of $17,246 and $16,071, respectively	(4,419)	(5,493)
Notes payable	1,092,125	1,091,051
Deferred debt issuance costs, accumulated amortization	$ 17,246	16,071
Mortgages | 731 Lexington Avenue | Prime Rate
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest rate	8.50%
Mortgages | 731 Lexington Avenue | Office Space
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest rate (in percentage)	6%
Mortgage payable gross	$ 500,000	500,000
Mortgages | 731 Lexington Avenue | Office Space | Prime Rate
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest rate	6%
Mortgages | 731 Lexington Avenue | Retail Space
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest rate (in percentage)	1.76%
Mortgage payable gross	$ 300,000	300,000
Mortgages | 731 Lexington Avenue | Retail Space | Secured Overnight Financing Rate (SOFR)
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Basis spread over SOFR	1.51%
Mortgages | Rego Park II | Retail Space
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest rate (in percentage)	5.60%
Mortgage payable gross	$ 202,544	202,544
Mortgages | Rego Park II | Retail Space | Secured Overnight Financing Rate (SOFR)
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Basis spread over SOFR	1.45%
Mortgages | Rego Park II | Retail Space | Secured Overnight Financing Rate (SOFR) | Maximum
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest cap rate	4.15%
Mortgages | Alexander Apartment Tower | Apartment Building
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest rate (in percentage)	2.63%
Mortgage payable gross	$ 94,000	$ 94,000

Stock-Based Compensation (Detai

Stock-Based Compensation (Details) - 2016 Omnibus Stock Plan - Director - Deferred Stock Units - USD ($)	1 Months Ended
	May 31, 2023	Sep. 30, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non option equity instruments granted per director (in shares)	449
Non option equity instruments market value	$ 75,000
Non option equity instruments grant date fair value per grant	56,250
Non option equity instruments grant date fair value total	$ 450,000
Non option equity instruments, outstanding, number (in shares)		23,388
Shares available for future grant under the plan (in shares)		482,399

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value, Assets and Liabilities Measured on Recurring Basis (Details) - Recurring - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
ASSETS
Total assets		$ 296,314
US Treasury Bill Securities
ASSETS
Investments in U.S. Treasury bills		266,963
Interest rate derivatives (included in other assets)
ASSETS
Interest rate derivatives (included in other assets)	$ 33,694	29,351
Level 1
ASSETS
Total assets		266,963
Level 1 | US Treasury Bill Securities
ASSETS
Investments in U.S. Treasury bills		266,963
Level 1 | Interest rate derivatives (included in other assets)
ASSETS
Interest rate derivatives (included in other assets)	0	0
Level 2
ASSETS
Total assets		29,351
Level 2 | US Treasury Bill Securities
ASSETS
Investments in U.S. Treasury bills		0
Level 2 | Interest rate derivatives (included in other assets)
ASSETS
Interest rate derivatives (included in other assets)	33,694	29,351
Level 3
ASSETS
Total assets		0
Level 3 | US Treasury Bill Securities
ASSETS
Investments in U.S. Treasury bills		0
Level 3 | Interest rate derivatives (included in other assets)
ASSETS
Interest rate derivatives (included in other assets)	$ 0	$ 0

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Interest Rate Derivatives (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Sep. 30, 2023	Jul. 16, 2023	Jul. 15, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Included in other assets		$ 33,694			$ 29,351
731 Lexington Avenue Mortgage Loan, Retail Condominium | Interest rate derivatives (included in other assets) | Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Included in other assets		22,249			26,718
Notional Amount		$ 300,000
Swapped Rate		1.76%
Rego Park II Shopping Center Mortgage Loan | Interest rate derivatives (included in other assets) | Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Included in other assets		$ 2,764			2,622
Notional Amount		$ 202,544
Rego Park II Shopping Center Mortgage Loan | Interest rate derivatives (included in other assets) | Designated as Hedging Instrument | SOFR
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest cap rate		4.15%
731 Lexington Avenue Mortgage Loan, Office Condominium | Interest rate derivatives (included in other assets) | Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Included in other assets		$ 8,681			$ 11
Notional Amount		$ 500,000
Payments for derivative instrument	$ 11,258
731 Lexington Avenue Mortgage Loan, Office Condominium | Interest rate derivatives (included in other assets) | Designated as Hedging Instrument | LIBOR
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest cap rate				6%
731 Lexington Avenue Mortgage Loan, Office Condominium | Interest rate derivatives (included in other assets) | Designated as Hedging Instrument | Prime Rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest cap rate			6%
Interest rate		8.50%

Fair Value Measurements - Fai_2

Fair Value Measurements - Fair Value, by Balance Sheet Grouping (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Carrying Amount
Assets:
Cash equivalents	$ 356,391	$ 47,852
Liabilities:
Mortgages payable (excluding deferred debt issuance costs, net)	1,096,544	1,096,544
Fair Value | Level 1
Assets:
Cash equivalents	356,391	47,852
Fair Value | Level 2
Liabilities:
Mortgages payable (excluding deferred debt issuance costs, net)	$ 1,064,832	$ 1,061,221

Commitments and Contingencies (

Commitments and Contingencies (Details)	9 Months Ended
	Sep. 30, 2023 USD ($)
Loss Contingencies [Line Items]
Standby letters of credit, outstanding	$ 900,000
All Risk Property and Rental Value
Loss Contingencies [Line Items]
Insurance maximum coverage per occurrence	1,700,000,000
Terrorism Coverage Including NBCR
Loss Contingencies [Line Items]
Insurance maximum coverage per occurrence	1,700,000,000
Insurance maximum coverage in aggregate	$ 1,700,000,000
NBCR
Loss Contingencies [Line Items]
Federal government responsibility	80%
NBCR | FNSIC
Loss Contingencies [Line Items]
Insurance deductible	$ 316,000
Self insured responsibility	20%
General Liability
Loss Contingencies [Line Items]
Insurance maximum coverage per property	$ 300,000,000
Insurance maximum coverage per occurrence	300,000,000
Disease Coverage
Loss Contingencies [Line Items]
Insurance maximum coverage per occurrence	$ 30,000,000

Earnings Per Share - Additional

Earnings Per Share - Additional Information (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Earnings Per Share [Abstract]
Potentially dilutive securities outstanding	0	0	0	0

Earnings Per Share - Schedule o

Earnings Per Share - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Earnings Per Share [Abstract]
Net income	$ 10,754	$ 15,109	$ 86,127	$ 44,455
Weighted average shares outstanding - basic (in shares)	5,130,678	5,127,086	5,128,875	5,125,768
Weighted average shares outstanding - diluted (in shares)	5,130,678	5,127,086	5,128,875	5,125,768
Net income per common share - basic (in usd per share)	$ 2.10	$ 2.95	$ 16.79	$ 8.67
Net income per common share - diluted (in usd per share)	$ 2.10	$ 2.95	$ 16.79	$ 8.67