View Filing Data

Document and Entity Information - shares	3 Months Ended
Document and Entity Information - shares	Mar. 31, 2017	Apr. 30, 2017
Document and Entity Information [Abstract]
Entity Registrant Name	ALEXANDERS INC
Entity Central Index Key	0000003499
Document Type	10-Q
Document Period End Date	Mar. 31, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q1
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		5,107,290
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Trading Symbol	alx

Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Real estate, at cost:
Land	$ 44,971	$ 44,971
Buildings and leasehold improvements	987,165	985,800
Development and construction in progress	2,913	2,780
Total	1,035,049	1,033,551
Accumulated depreciation and amortization	(259,655)	(252,737)
Real estate, net	775,394	780,814
Cash and cash equivalents	306,530	288,926
Restricted cash	85,496	85,752
Marketable securities	34,471	37,918
Tenant and other receivables, net of allowance for doubtful accounts of $1,778 and $1,473, respectively	2,549	3,056
Receivable arising from the straight-lining of rents	177,940	179,010
Deferred leasing costs, net, including unamortized leasing fees to Vornado of $36,087 and $36,960, respectively	47,271	48,387
Other assets	14,281	27,367
Total assets	1,443,932	1,451,230
LIABILITIES AND EQUITY
Mortgages payable, net of deferred debt issuance costs	1,051,973	1,052,359
Amounts due to Vornado	542	897
Accounts payable and accrued expenses	39,111	42,200
Other liabilities	2,922	2,929
Total liabilities	1,094,548	1,098,385
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 and 5,106,196 shares, respectively	5,173	5,173
Additional capital	31,183	31,189
Retained earnings	308,925	308,995
Accumulated other comprehensive income	4,471	7,862
Equity before treasury stock	349,752	353,219
Treasury stock: 66,160 shares and 67,254 shares, respectively, at cost	(368)	(374)
Total equity	349,384	352,845
Total liabilities and equity	$ 1,443,932	$ 1,451,230

Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Assets
Allowance for doubtful accounts (in US dollars)	$ 1,778	$ 1,473
Unamortized leasing fees to Vornado (in US dollars)	$ 36,087	$ 36,960
Preferred stock: par value per share (in dollars per share)	$ 1	$ 1
Preferred stock: authorized shares	3,000,000	3,000,000
Preferred stock: issued shares	0	0
Preferred stock: outstanding shares	0	0
Common stock: par value per share (in dollars per share)	$ 1	$ 1
Common stock: authorized shares	10,000,000	10,000,000
Common stock: issued shares	5,173,450	5,173,450
Common stock: outstanding shares	5,107,290	5,106,196
Treasury stock: shares	66,160	67,254

Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended
Consolidated Statements of Income - USD ($) $ in Thousands	Mar. 31, 2017	Mar. 31, 2016
REVENUES
Property rentals	$ 38,273	$ 36,653
Expense reimbursements	18,956	18,905
Total revenues	57,229	55,558
EXPENSES
Operating, including fees to Vornado of $1,128 and $1,255, respectively	20,921	19,654
Depreciation and amortization	8,045	8,333
General and administrative, including management fees to Vornado of $595 in each period	1,156	1,235
Total expenses	30,122	29,222
OPERATING INCOME	27,107	26,336
Interest and other income, net	727	1,091
Interest and debt expense	(6,160)	(5,406)
Income before income taxes	21,674	22,021
Income tax expense	(7)	(2)
Net income	$ 21,667	$ 22,019
Income per common share- basic and diluted:
Net income per common share- basic and diluted (in dollars per share)	$ 4.24	$ 4.31
Weighted average shares outstanding - basic and diluted (in shares)	5,114,701	5,113,077
Dividends per common share (in dollars per share)	$ 4.25	$ 4

Consolidated Statements of Income (Parentheticals) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Consolidated Statements of Income
Fees to Vornado	$ 1,128	$ 1,255
Management fees to Vornado	$ 595	$ 595

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Statements of Comprehensive Income
Net income	$ 21,667	$ 22,019
Other comprehensive (loss) income:
Change in unrealized net gain on available-for-sale securities	(3,447)	(777)
Change in value of interest rate cap	56	16
Comprehensive income	$ 18,276	$ 21,258

Consolidated Statements of Changes in Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Capital	Retained Earnings	Accumulated Other Comprehensive Income	Treasury Stock
Opening Balance, at Dec. 31, 2015	$ 352,880	$ 5,173	$ 30,739	$ 304,340	$ 13,002	$ (374)
Opening Balance (in shares) at Dec. 31, 2015		5,173,000
Net income	22,019			22,019
Dividends paid	(20,452)			(20,452)
Change in unrealized net gain on available-for-sale securities	(777)				(777)
Change in value of interest rate cap	16				16
Closing Balance (in shares) at Mar. 31, 2016		5,173,000
Closing Balance, at Mar. 31, 2016	353,686	$ 5,173	30,739	305,907	12,241	(374)
Opening Balance, at Dec. 31, 2016	$ 352,845	$ 5,173	31,189	308,995	7,862	(374)
Opening Balance (in shares) at Dec. 31, 2016	5,173,450	5,173,000
Net income	$ 21,667			21,667
Dividends paid	(21,737)			(21,737)
Change in unrealized net gain on available-for-sale securities	(3,447)				(3,447)
Change in value of interest rate cap	56				56
Other	$ 0		(6)			6
Closing Balance (in shares) at Mar. 31, 2017	5,173,450	5,173,000
Closing Balance, at Mar. 31, 2017	$ 349,384	$ 5,173	$ 31,183	$ 308,925	$ 4,471	$ (368)

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 21,667	$ 22,019
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization, including amortization of debt issuance costs	8,569	8,974
Straight-lining of rental income	1,070	(44)
Changes in operating assets and liabilities:
Tenant and other receivables, net	507	705
Other assets	13,131	5,548
Amounts due to Vornado	(353)	(2,318)
Accounts payable and accrued expenses	(2,961)	10,499
Other liabilities	(7)	(7)
Net cash provided by operating activities	41,623	45,376
CASH FLOWS FROM INVESTING ACTIVITIES
Construction in progress and real estate additions	(1,628)	(8,853)
Net cash used in investing activities	(1,628)	(8,853)
CASH FLOWS FROM FINANCING ACTIVITIES
Debt repayments	(901)	(836)
Dividends paid	(21,737)	(20,452)
Debt issuance costs	(9)	(16)
Net cash used in financing activities	(22,647)	(21,304)
Net increase in cash and cash equivalents and restricted cash	17,348	15,219
Cash and cash equivalents and restricted cash at beginning of period	374,678	344,656
Cash and cash equivalents and restricted cash at end of period	392,026	359,875
RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH
Cash and cash equivalents at beginning of year	288,926	259,349
Restricted cash at beginning of period	85,752	85,307
Cash and cash equivalents and restricted cash at beginning of period	374,678	344,656
Cash and cash equivalents at end of year	306,530	276,234
Restricted cash at end of period	85,496	83,641
Cash and cash equivalents and restricted cash at end of period	392,026	359,875
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Cash payments for interest	5,386	4,676
NON-CASH TRANSACTIONS
Liability for real estate additions, including $52 and $36 for development fees due to Vornado in 2017 and 2016, respectively	192	1,931
Write-off of fully amortized and/or depreciated assets	0	12
Change in unrealized net gain on available-for-sale securities	$ (3,447)	$ (777)

Consolidated Statements of Cash Flows (Parentheticals) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Liability for real estate additions due to Vornado	$ 192	$ 1,931
Vornado \| Development fees
Liability for real estate additions due to Vornado	$ 52	$ 36

Organization	3 Months Ended
Organization	Mar. 31, 2017
Organization and Basis of Presentation [Abstract]
Organization	1. Organization Alexander’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 seven properties in the greater New York City metropolitan area.

Basis of Presentation	3 Months Ended
Basis of Presentation	Mar. 31, 2017
Organization and Basis of Presentation [Abstract]
Basis of Presentation	2. Basis of Presentation The accompanying consolidated financial statements are unaudited and include the accounts of Alexander’s and its consolidated subsidiaries. All intercompany amounts have been eliminated. In our opinion, 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 condensed 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, 2016, 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 months ended March 31, 2017 are not necessarily indicative of the operating results for the full year. We currently operate in one business segment.

Recently Issued Accounting Literature

3 Months Ended

Mar. 31, 2017

Recently Issued Accounting Literature [Abstract]

Recently Issued Accounting Literature

3. Recently Issued Accounting Literature

In May 2014, the Financial Accounting Standards Board (“FASB”) issued an update ("ASU 2014-09") establishing Accounting Standards Codification (“ASC”) Topic 606, Revenue from Contracts with Customers (“ASC 606”). ASU 2014-09, as amended by subsequent ASUs on the topic, establishes a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most of the existing revenue recognition guidance. This standard, which is effective for interim and annual reporting periods in fiscal years that begin after December 15, 2017, requires an entity to recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services and also requires certain additional disclosures. When adopting this standard, we are permitted to use either the full retrospective method or the modified retrospective method. We will adopt this standard effective as of January 1, 2018 and currently expect to utilize the modified retrospective method of adoption. We have commenced the execution of our project plan for adopting this standard, which consists of gathering and evaluating the inventory of our revenue streams. We expect this standard will have an impact on the presentation of certain lease and non-lease components of revenue from leases upon the adoption of (“ASU 2016-02”) Leases with no impact on “total revenues.” We also expect this standard will have an impact on the timing of gains on certain sales of real estate. We are continuing to evaluate the impact of this standard on our consolidated financial statements.

In January 2016, the FASB issued an update (“ASU 2016-01”) Recognition and Measurement of Financial Assets and Financial Liabilities to ASC Topic 825, Financial Instruments. ASU 2016-01 amends certain aspects of recognition, measurement, presentation and disclosure of financial instruments. ASU 2016-01 is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017. While the adoption of this standard requires us to continue to measure “marketable securities” at fair value at each reporting date, the changes in fair value will be recognized in current period earnings as opposed to “other comprehensive income.”

In February 2016, the FASB issued an update ASU 2016-02 establishing ASC Topic 842, Leases, which sets out the principles for the recognition, measurement, presentation and disclosure of leases for both lessees and lessors. ASU 2016-02 requires lessees to apply a dual approach, classifying leases as either finance or operating leases based on the principle of whether or not the lease is effectively a financed purchase. Lessees are required to record a right-of-use asset and a lease liability for all leases with a term of greater than 12 months. Leases with a term of 12 months or less will be accounted for similar to existing guidance for operating leases. Lessees will recognize expense based on the effective interest method for finance leases or on a straight-line basis for operating leases. ASU 2016-02 is effective for reporting periods beginning after December 15, 2018, with early adoption permitted. We are currently evaluating the overall impact of the adoption of ASU 2016-02 on our consolidated financial statements, including the timing of adopting this standard. ASU 2016-02 will more significantly impact the accounting for leases in which we are a lessee. Upon adoption of this standard, we will be required to record a right-of-use asset and lease liability for our Flushing property ground lease, equal to the present value of the remaining minimum lease payments. We also expect that this standard will have an impact on the presentation of certain lease and non-lease components of revenue from leases with no impact on “total revenues.” In particular, lease components, such as reimbursable real estate taxes and insurance expenses, will be presented in “property rentals” and non-lease components, such as reimbursable operating expenses, will be presented in “expense reimbursements” on our consolidated statements of income.

In March 2016, the FASB issued an update (“ASU 2016-09”) Improvements to Employee Share-Based Payment Accounting to ASC Topic 718, Compensation – Stock Compensation. ASU 2016-09 amends several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. ASU 2016-09 is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2016. The adoption of this update as of January 1, 2017, did not have any impact on our consolidated financial statements.

In August 2016, the FASB issued an update (“ASU 2016-15”) Classification of Certain Cash Receipts and Cash Payments to ASC Topic 230, Statement of Cash Flows. ASU 2016-15 clarifies guidance on the classification of certain cash receipts and payments in the statement of cash flows to reduce diversity in practice with respect to (i) debt prepayment or debt extinguishment costs, (ii) settlement of zero-coupon debt instruments or other debt instruments with coupon interest rates that are insignificant in relation to the effective interest rate of the borrowing, (iii) contingent consideration payments made after a business combination, (iv) proceeds from the settlement of insurance claims, (v) proceeds from the settlement of corporate-owned life insurance policies, including bank-owned life insurance policies, (vi) distributions received from equity method investees, (vii) beneficial interests in securitization transactions, and (viii) separately identifiable cash flows and application of the predominance principle. ASU 2016-15 is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017, with early adoption permitted. We elected to early adopt ASU 2016-15 effective January 1, 2017. The adoption of this update did not have a material impact on our consolidated financial statements.

In November 2016, the FASB issued an update (“ASU 2016-18”) Restricted Cash to ASC Topic 230, Statement of Cash Flows. ASU 2016-18 requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents and amounts generally described as restricted cash or restricted cash equivalents. Restricted cash and restricted cash equivalents will be included with cash and cash equivalents when reconciling the beginning of period and end of period balances on the statement of cash flows upon adoption of this standard. ASU 2016-18 is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017, with early adoption permitted. We elected to early adopt ASU 2016-18 effective January 1, 2017, with retrospective application to our consolidated statements of cash flows. Accordingly, the consolidated statements of cash flows present a reconciliation of the changes in cash and cash equivalents and restricted cash. Restricted cash primarily consists of cash held in a non-interest bearing escrow account in connection with our Rego Park I 100% cash collateralized mortgage, as well as security deposits and other cash escrowed under loan agreements for debt service, real estate taxes, property insurance and capital improvements.

In February 2017, the FASB issued an update (“ASU 2017-05”) Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets to ASC Subtopic 610-20, Other Income–Gains and Losses from the Derecognition of Nonfinancial Assets. ASU 2017-05 clarifies the scope of recently established guidance on nonfinancial asset derecognition as well as the accounting for partial sales of nonfinancial assets. This update conforms the derecognition guidance on nonfinancial assets with the model for transactions in ASC 606. ASU 2017-05 is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017. The adoption of this standard is not expected to have an impact on our consolidated financial statements.

- Definition

The entire disclosure of changes in accounting principles, including adoption of new accounting pronouncements, that describes the new methods, amount and effects on financial statement line items.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Change in Accounting Principle
-URI http://asc.fasb.org/extlink&oid=6507316

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Direct Effects of a Change in Accounting Principle
-URI http://asc.fasb.org/extlink&oid=66092750

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=64853466&loc=d3e22583-107794

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Indirect Effects of a Change in Accounting Principle
-URI http://asc.fasb.org/extlink&oid=6515603

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64853466&loc=d3e22580-107794

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 270
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.10-01.(b)(6))
-URI http://asc.fasb.org/extlink&oid=27015980&loc=d3e46468-122699

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Accounting Change
-URI http://asc.fasb.org/extlink&oid=6503790

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=64853466&loc=d3e22499-107794

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Retrospective Application
-URI http://asc.fasb.org/extlink&oid=6523989

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 270
-SubTopic 10
-Section 45
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=68064558&loc=d3e765-108305

Reference 11: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 270
-SubTopic 10
-Section 45
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=68064558&loc=d3e725-108305

+ Details

Related Party Transactions

3 Months Ended

Mar. 31, 2017

Related Party Transactions

4. Related Party Transactions

Vornado

As of March 31, 2017, 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) $297,000, 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 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.

Other Agreements

We also have agreements with Building Maintenance Services, a wholly owned subsidiary of Vornado, to supervise (i) cleaning, engineering and security services at our 731 Lexington Avenue property and (ii) security services at our Rego Park I and Rego Park II properties.

The following is a summary of fees to Vornado under the various agreements discussed above.


		Three Months Ended
		March 31,
(Amounts in thousands)		2017		2016
Company management fees		$	700	$	700
Development fees			28		44
Leasing fees			11		6,458
Property management fees and payments for cleaning, engineering
	and security services		988		1,115
		$	1,727	$	8,317

4. Related Party Transactions – continued

As of March 31, 2017, the amounts due to Vornado were $52,000 for development fees; $489,000 for management, property management, cleaning and security fees; and $1,000 for leasing fees. As of December 31, 2016, the amounts due to Vornado were $54,000 for development fees; $428,000 for management, property management, cleaning and security fees; and $415,000 for leasing fees. In January 2016, we paid an $8,916,000 leasing commission related to the Bloomberg lease amendment, of which $7,200,000 was to a third party broker and $1,716,000 was to Vornado. In March 2016, we paid Vornado a development fee of $5,784,000 related to The Alexander apartment tower.

Toys “R” Us (“Toys”)

As of March 31, 2017, our affiliate, Vornado owned 32.5% of Toys. Toys leases approximately 47,000 square feet of retail space at our Rego Park II shopping center. Joseph Macnow, our Executive Vice President and Chief Financial Officer, and Vornado’s Executive Vice President and Chief Financial Officer and Wendy A. Silverstein, a member of our Board of Directors, represent Vornado as members of Toys’ Board of Directors. We recognized $884,000 and $713,000 of revenue related to the space leased by Toys for the three months ended March 31, 2017 and 2016, respectively.

Marketable Securities	3 Months Ended
Marketable Securities	Mar. 31, 2017
Marketable Securities [Abstract]
Marketable Securities	5. Marketable Securities As of March 31, 2017 and December 31, 2016, we owned 535,265 common shares of The Macerich Company (“Macerich”) (NYSE: MAC). These shares have an economic cost of $56.05 per share, or $30,000,000 in the aggregate. As of March 31, 2017 and December 31, 2016, the fair value of these shares was $34,471,000 and $37,918,000, respectively, based on Macerich’s closing share price of $64.40 per share and $70.84 per share, respectively. These shares are included in “marketable securities” on our consolidated balance sheets and are classified as available-for-sale. Available-for-sale securities are presented at fair value and unrealized gains and losses resulting from the mark-to-market of these securities are included in “other comprehensive income.”

- Definition

The entire disclosure for investments in certain debt and equity securities.

+ References + Details

Significant Tenants	3 Months Ended
Significant Tenants	Mar. 31, 2017
Significant Tenants [Abstract]
Significant Tenants	6. Significant Tenants Bloomberg L.P. (“Bloomberg”) accounted for revenue of $26,010,000 and $26,506,000, representing approximately 45% and 48% of our total revenues for the three months ended March 31, 2017 and 2016, respectively. No other tenant accounted for more than 10% of our total 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.

Mortgages Payable

3 Months Ended

Mar. 31, 2017

Mortgages Payable [Abstract]

Mortgages Payable

7. Mortgages Payable

The following is a summary of our outstanding mortgages payable as of March 31, 2017 and December 31, 2016.

					Balance as of
			Interest Rate as of		March 31,		December 31,
(Amounts in thousands)		Maturity⁽¹⁾	March 31, 2017		2017		2016
First mortgages secured by:
	Rego Park I shopping center (100% cash
	collateralized)⁽²⁾	Mar. 2018	0.35	%	$	78,246	$	78,246
	Paramus	Oct. 2018	2.90	%		68,000		68,000
	Rego Park II shopping center⁽³⁾	Nov. 2018	2.83	%		259,000		259,901
	731 Lexington Avenue, office space⁽⁴⁾	Mar. 2021	1.86	%		300,000		300,000
	731 Lexington Avenue, retail space⁽⁵⁾	Aug. 2022	2.23	%		350,000		350,000
	Total					1,055,246		1,056,147
	Deferred debt issuance costs, net of accumulated
amortization of $7,348 and $6,824 respectively						(3,273)		(3,788)
					$	1,051,973	$	1,052,359


(1)	Represents the extended maturity where we have the unilateral right to extend.
(2)	Extended in March 2016 for two years.
(3)	Interest at LIBOR plus 1.85%.
(4)	Interest at LIBOR plus 0.95%.
(5)	Interest at LIBOR plus 1.40%.

Fair Value Measurements

3 Months Ended

Mar. 31, 2017

Fair Value Measurements [Abstract]

Fair Value Measurements

8. Fair Value Measurements

ASC 820, Fair Value Measurements and Disclosures 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; 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 sheets as of March 31, 2017 and December 31, 2016, consist of marketable securities, which are presented in the table below based on their level in the fair value hierarchy, and an interest rate cap which fair value was insignificant, as of March 31, 2017 and December 31, 2016. There were no financial liabilities measured at fair value as of March 31, 2017 and December 31, 2016.


		As of March 31, 2017
(Amounts in thousands)		Total		Level 1		Level 2		Level 3
	Marketable securities	$	34,471	$	34,471	$	-	$	-


		As of December 31, 2016
(Amounts in thousands)		Total		Level 1		Level 2		Level 3
	Marketable securities	$	37,918	$	37,918	$	-	$	-

8. Fair Value Measurements – continued

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. 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. The fair value of cash equivalents is classified as Level 1 and the fair values of mortgages payable are classified as Level 2. The table below summarizes the carrying amounts and fair value of these financial instruments as of March 31, 2017 and December 31, 2016.

		As of March 31, 2017				As of December 31, 2016
		Carrying		Fair		Carrying		Fair
(Amounts in thousands)		Amount		Value		Amount		Value
Assets:
	Cash equivalents	$	273,477	$	273,477	$	256,730	$	256,730

Liabilities:
	Mortgages payable (excluding deferred debt issuance costs)	$	1,055,246	$	1,042,000	$	1,056,147	$	1,045,000

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Commitments and Contingencies

3 Months Ended

Mar. 31, 2017

Commitments and Contingencies [Abstract]

Commitments and Contingencies

9. Commitments and Contingencies

Insurance

We maintain general liability insurance with limits of $300,000,000 per occurrence and per property, 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.

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 Program Reauthorization Act, which expires in December 2020. 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 $293,000 deductible and 17% of the balance of a covered loss, and the Federal government is responsible for the remaining 83% 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. However, we cannot anticipate what coverage will be available on commercially reasonable terms in the future. We are responsible for deductibles and losses in excess of our insurance coverage, which could be material.

Our mortgage loans are non-recourse to us and 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 our properties.

Tenant Matters

In April 2017, Sears closed its 195,000 square foot store it leases from us at our Rego Park I property. Annual revenue, including reimbursements, is approximately $10,337,000, under a lease which expires in March of 2021. There is a straight-line rent receivable of approximately $4,757,000 and unamortized deferred leasing costs of approximately $499,000 on our consolidated balance sheet as of March 31, 2017. In its 2016 annual report on Form 10-K, Sears indicated that substantial doubt exists related to its ability to continue as a going concern.

9. Commitments and Contingencies – continued

Rego Park I Litigation

On June 24, 2014, Sears Roebuck and Co. (“Sears”) filed a lawsuit in the Supreme Court of the State of New York against Vornado and us (and certain of our subsidiaries) with regard to space that Sears leases at our Rego Park I property alleging that the defendants are liable for harm that Sears has suffered as a result of (a) water intrusions into the premises, (b) two fires in February 2014 that caused damages to those premises, and (c) alleged violations of the Americans with Disabilities Act in the premises’ parking garage. Sears asserted various causes of actions for damages and sought to compel compliance with landlord’s obligations to repair the premises and to provide security, and to compel us to abate a nuisance that Sears claims was a cause of the water intrusions into its premises. In addition to injunctive relief, Sears sought, among other things, damages of not less than $4 million and future damages it estimated would not be less than $25 million. In March 2016, Sears withdrew its claim for future damages leaving a remaining claim for property damages, which we estimate to be approximately $650,000 based on information provided by Sears. We intend to defend the remaining claim vigorously. The amount or range of reasonably possible losses, if any, is not expected to be greater than $650,000.

Paramus

In 2001, we leased 30.3 acres of land located in Paramus, New Jersey to IKEA Property, Inc. The lease has a purchase option in 2021 for $75,000,000. The property is encumbered by a $68,000,000 interest-only mortgage loan with a fixed rate of 2.90%, which matures in October 2018. The annual triple-net rent is the sum of $700,000 plus the amount of debt service on the mortgage loan. If the purchase option is exercised, we will receive net cash proceeds of approximately $7,000,000 and recognize a gain on sale of land of approximately $60,000,000. If the purchase option is not exercised, the triple-net rent for the last 20 years would include debt service sufficient to fully amortize $68,000,000 over the remaining 20-year lease term.

Letters of Credit

Approximately $2,074,000 of standby letters of credit were outstanding as of March 31, 2017.

Other

On October 15, 2015, the New York City Department of Finance (“NYC DOF”) issued a Notice of Determination to us assessing an additional $21,700,000 of transfer taxes (including interest and penalties as of March 31, 2017) in connection with the sale of Kings Plaza Regional Shopping Center in 2012. We believe that the NYC DOF’s claim is without merit and intend to vigorously contest this assessment. We have determined that the likelihood of a loss related to this issue is not probable and, after consultation with legal counsel, that the outcome of this assessment is not expected to have a material adverse effect on our financial position, results of operations or cash flows.

There are various other legal actions against us in the ordinary course of business. In our opinion, the outcome of such matters in the aggregate will not have a material effect on our financial position, results of operations or cash flows.

Earnings Per Share

3 Months Ended

Mar. 31, 2017

Earnings Per Share

Earnings Per Share

10. 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 outstanding during the period. Diluted income per share is determined using the weighted average shares of common stock 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 months ended March 31, 2017 and 2016.

		Three Months Ended
		March 31,
(Amounts in thousands, except share and per share amounts)		2017		2016
	Net income	$	21,667	$	22,019

	Weighted average shares outstanding – basic and diluted		5,114,701		5,113,077

	Net income per common share – basic and diluted	$	4.24	$	4.31

Summary of Significant Accounting Policies (Policies)	3 Months Ended
Summary of Significant Accounting Policies (Policies)	Mar. 31, 2017
Summary Of Significant Accounting Policies [Abstract]
Basis of Presentation	The accompanying consolidated financial statements are unaudited and include the accounts of Alexander’s and its consolidated subsidiaries. All intercompany amounts have been eliminated. In our opinion, 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 condensed 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, 2016, 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 months ended March 31, 2017 are not necessarily indicative of the operating results for the full year. We currently operate in one business segment.
Recently Issued Accounting Literature	In February 2017, the FASB issued an update (“ASU 2017-05”) Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets to ASC Subtopic 610-20, Other Income–Gains and Losses from the Derecognition of Nonfinancial Assets. ASU 2017-05 clarifies the scope of recently established guidance on nonfinancial asset derecognition as well as the accounting for partial sales of nonfinancial assets. This update conforms the derecognition guidance on nonfinancial assets with the model for transactions in ASC 606. ASU 2017-05 is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017. The adoption of this standard is not expected to have an impact on our consolidated financial statements.
Revenue Recognition	In May 2014, the Financial Accounting Standards Board (“FASB”) issued an update ("ASU 2014-09") establishing Accounting Standards Codification (“ASC”) Topic 606, Revenue from Contracts with Customers (“ASC 606”). ASU 2014-09, as amended by subsequent ASUs on the topic, establishes a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most of the existing revenue recognition guidance. This standard, which is effective for interim and annual reporting periods in fiscal years that begin after December 15, 2017, requires an entity to recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services and also requires certain additional disclosures. When adopting this standard, we are permitted to use either the full retrospective method or the modified retrospective method. We will adopt this standard effective as of January 1, 2018 and currently expect to utilize the modified retrospective method of adoption. We have commenced the execution of our project plan for adopting this standard, which consists of gathering and evaluating the inventory of our revenue streams. We expect this standard will have an impact on the presentation of certain lease and non-lease components of revenue from leases upon the adoption of (“ASU 2016-02”) Leases with no impact on “total revenues.” We also expect this standard will have an impact on the timing of gains on certain sales of real estate. We are continuing to evaluate the impact of this standard on our consolidated financial statements.
Fair value of financial instruments	In January 2016, the FASB issued an update (“ASU 2016-01”) Recognition and Measurement of Financial Assets and Financial Liabilities to ASC Topic 825, Financial Instruments. ASU 2016-01 amends certain aspects of recognition, measurement, presentation and disclosure of financial instruments. ASU 2016-01 is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017. While the adoption of this standard requires us to continue to measure “marketable securities” at fair value at each reporting date, the changes in fair value will be recognized in current period earnings as opposed to “other comprehensive income.”
Lessee leases	In February 2016, the FASB issued an update ASU 2016-02 establishing ASC Topic 842, Leases, which sets out the principles for the recognition, measurement, presentation and disclosure of leases for both lessees and lessors. ASU 2016-02 requires lessees to apply a dual approach, classifying leases as either finance or operating leases based on the principle of whether or not the lease is effectively a financed purchase. Lessees are required to record a right-of-use asset and a lease liability for all leases with a term of greater than 12 months. Leases with a term of 12 months or less will be accounted for similar to existing guidance for operating leases. Lessees will recognize expense based on the effective interest method for finance leases or on a straight-line basis for operating leases. ASU 2016-02 is effective for reporting periods beginning after December 15, 2018, with early adoption permitted. We are currently evaluating the overall impact of the adoption of ASU 2016-02 on our consolidated financial statements, including the timing of adopting this standard. ASU 2016-02 will more significantly impact the accounting for leases in which we are a lessee. Upon adoption of this standard, we will be required to record a right-of-use asset and lease liability for our Flushing property ground lease, equal to the present value of the remaining minimum lease payments. We also expect that this standard will have an impact on the presentation of certain lease and non-lease components of revenue from leases with no impact on “total revenues.” In particular, lease components, such as reimbursable real estate taxes and insurance expenses, will be presented in “property rentals” and non-lease components, such as reimbursable operating expenses, will be presented in “expense reimbursements” on our consolidated statements of income.
Share-based Compensation, Option and Incentive Plans	In March 2016, the FASB issued an update (“ASU 2016-09”) Improvements to Employee Share-Based Payment Accounting to ASC Topic 718, Compensation – Stock Compensation. ASU 2016-09 amends several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. ASU 2016-09 is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2016. The adoption of this update as of January 1, 2017, did not have any impact on our consolidated financial statements.
Cash and Cash Equivalents	In August 2016, the FASB issued an update (“ASU 2016-15”) Classification of Certain Cash Receipts and Cash Payments to ASC Topic 230, Statement of Cash Flows. ASU 2016-15 clarifies guidance on the classification of certain cash receipts and payments in the statement of cash flows to reduce diversity in practice with respect to (i) debt prepayment or debt extinguishment costs, (ii) settlement of zero-coupon debt instruments or other debt instruments with coupon interest rates that are insignificant in relation to the effective interest rate of the borrowing, (iii) contingent consideration payments made after a business combination, (iv) proceeds from the settlement of insurance claims, (v) proceeds from the settlement of corporate-owned life insurance policies, including bank-owned life insurance policies, (vi) distributions received from equity method investees, (vii) beneficial interests in securitization transactions, and (viii) separately identifiable cash flows and application of the predominance principle. ASU 2016-15 is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017, with early adoption permitted. We elected to early adopt ASU 2016-15 effective January 1, 2017. The adoption of this update did not have a material impact on our consolidated financial statements.
Restricted Cash	In November 2016, the FASB issued an update (“ASU 2016-18”) Restricted Cash to ASC Topic 230, Statement of Cash Flows. ASU 2016-18 requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents and amounts generally described as restricted cash or restricted cash equivalents. Restricted cash and restricted cash equivalents will be included with cash and cash equivalents when reconciling the beginning of period and end of period balances on the statement of cash flows upon adoption of this standard. ASU 2016-18 is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017, with early adoption permitted. We elected to early adopt ASU 2016-18 effective January 1, 2017, with retrospective application to our consolidated statements of cash flows. Accordingly, the consolidated statements of cash flows present a reconciliation of the changes in cash and cash equivalents and restricted cash. Restricted cash primarily consists of cash held in a non-interest bearing escrow account in connection with our Rego Park I 100% cash collateralized mortgage, as well as security deposits and other cash escrowed under loan agreements for debt service, real estate taxes, property insurance and capital improvements.
Marketable Securities	Available-for-sale securities are presented at fair value and unrealized gains and losses resulting from the mark-to-market of these securities are included in “other comprehensive income.”
Fair Value Measurement	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.

Related Party Transactions (Tables)

3 Months Ended

Mar. 31, 2017

Summary of Fees to Vornado

The following is a summary of fees to Vornado under the various agreements discussed above.


		Three Months Ended
		March 31,
(Amounts in thousands)		2017		2016
Company management fees		$	700	$	700
Development fees			28		44
Leasing fees			11		6,458
Property management fees and payments for cleaning, engineering
	and security services		988		1,115
		$	1,727	$	8,317

Mortgages Payable (Tables)

3 Months Ended

Mar. 31, 2017

Mortgages Payable [Abstract]

Summary of Notes and Mortgages Payable

The following is a summary of our outstanding mortgages payable as of March 31, 2017 and December 31, 2016.

					Balance as of
			Interest Rate as of		March 31,		December 31,
(Amounts in thousands)		Maturity⁽¹⁾	March 31, 2017		2017		2016
First mortgages secured by:
	Rego Park I shopping center (100% cash
	collateralized)⁽²⁾	Mar. 2018	0.35	%	$	78,246	$	78,246
	Paramus	Oct. 2018	2.90	%		68,000		68,000
	Rego Park II shopping center⁽³⁾	Nov. 2018	2.83	%		259,000		259,901
	731 Lexington Avenue, office space⁽⁴⁾	Mar. 2021	1.86	%		300,000		300,000
	731 Lexington Avenue, retail space⁽⁵⁾	Aug. 2022	2.23	%		350,000		350,000
	Total					1,055,246		1,056,147
	Deferred debt issuance costs, net of accumulated
amortization of $7,348 and $6,824 respectively						(3,273)		(3,788)
					$	1,051,973	$	1,052,359


(1)	Represents the extended maturity where we have the unilateral right to extend.
(2)	Extended in March 2016 for two years.
(3)	Interest at LIBOR plus 1.85%.
(4)	Interest at LIBOR plus 0.95%.
(5)	Interest at LIBOR plus 1.40%.

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21475-112644

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(e),(f))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21538-112644

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21506-112644

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28541-108399

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21521-112644

+ Details

Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2017

Fair Value Measurements [Abstract]

Fair Value, Assets Measured on Recurring Basis


		As of March 31, 2017
(Amounts in thousands)		Total		Level 1		Level 2		Level 3
	Marketable securities	$	34,471	$	34,471	$	-	$	-


		As of December 31, 2016
(Amounts in thousands)		Total		Level 1		Level 2		Level 3
	Marketable securities	$	37,918	$	37,918	$	-	$	-

Fair Value, by Balance Sheet Grouping

The table below summarizes the carrying amounts and fair value of these financial instruments as of March 31, 2017 and December 31, 2016.

		As of March 31, 2017				As of December 31, 2016
		Carrying		Fair		Carrying		Fair
(Amounts in thousands)		Amount		Value		Amount		Value
Assets:
	Cash equivalents	$	273,477	$	273,477	$	256,730	$	256,730

Liabilities:
	Mortgages payable (excluding deferred debt issuance costs)	$	1,055,246	$	1,042,000	$	1,056,147	$	1,045,000

Earnings Per Share (Tables)

3 Months Ended

Mar. 31, 2017

Earnings Per Share

Schedule of Earnings Per Share, Basic and Diluted

		Three Months Ended
		March 31,
(Amounts in thousands, except share and per share amounts)		2017		2016
	Net income	$	21,667	$	22,019

	Weighted average shares outstanding – basic and diluted		5,114,701		5,113,077

	Net income per common share – basic and diluted	$	4.24	$	4.31

Organization (Details)	Mar. 31, 2017 property
Operating property
Operating Properties
Number of properties in greater New York City metropolitan area (in property)	7

Basis of Presentation (Details)	3 Months Ended
Basis of Presentation (Details)	Mar. 31, 2017 Segment
Organization and Basis of Presentation [Abstract]
Number of Reportable Segments	1

Recently Issued Accounting Literature (Details)	Mar. 31, 2017
Rego Park I
New Accounting Pronouncement Early Adoption
Percentage of cash mortgage collateralized	100.00%

Related Party Transactions (Details) ft² in Thousands	1 Months Ended	3 Months Ended
Related Party Transactions (Details) ft² in Thousands	Jan. 31, 2016 USD ($)	Mar. 31, 2017 USD ($) ft² $ / ft²	Mar. 31, 2016 USD ($)	Dec. 31, 2016 USD ($)
Other Agreements
Property rentals		$ 38,273,000	$ 36,653,000
Rego Park II \| Retail space \| Toys R Us
Other Agreements
Area of property (in square feet) \| ft²		47
Property rentals		$ 884,000	713,000
Bloomberg \| Lease amendment
Other Agreements
Leasing commission	$ 8,916,000
Bloomberg \| Lease amendment \| Third party broker
Other Agreements
Leasing commission	7,200,000
Vornado
Related Party Transaction [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent		32.40%
Vornado \| Toys R Us
Related Party Transaction [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent		32.50%
Vornado \| 731 Lexington Avenue \| Common Area
Management and Development Agreements
Property Management Fee Agreement Value (in US dollars)		$ 297,000
Vornado \| Bloomberg \| Lease amendment
Other Agreements
Leasing commission	$ 1,716,000
Vornado \| Development fees
Management and Development Agreements
Development fee as percentage of development costs		6.00%
Other Agreements
Amount Due to / (Fees paid to) related party (in US dollars)		$ 52,000		$ 54,000
Vornado \| Development fees \| Alexander apartment tower
Other Agreements
Amount Due to / (Fees paid to) related party (in US dollars)			$ (5,784,000)
Vornado \| Leasing Fees
Leasing Agreements
Lease Fee Percentage Of Rent One To Ten Years		3.00%
Lease Fee Percentage Of Rent Eleven To Twenty Years		2.00%
Lease Fee Percentage Of Rent Twenty First To Thirty Years		1.00%
Percentage Increase Lease Fee If Broker Used		1.00%
Asset Sale Commission Threshold (in US dollars)		$ 50,000,000
Percentage Commissions On Sale Of Assets Under Fifty Million		3.00%
Percentage Commissions On Sale Of Assets Over Fifty Million		1.00%
Other Agreements
Amount Due to / (Fees paid to) related party (in US dollars)		$ 1,000		415,000
Vornado \| Property Management Fees
Management and Development Agreements
Management Fee Agreement Value (in US dollars)		$ 2,800,000
Vornado \| Property Management Fees \| 731 Lexington Avenue \| Office And Retail Space
Management and Development Agreements
Property Management Fee Agreement Price Per Square Foot \| $ / ft²		0.5
Vornado \| Property Management Fees \| 731 Lexington Avenue \| Common Area
Management and Development Agreements
Property Management Fee Agreement Value (in US dollars)		$ 297,000
Property Management Fee Escalation Percentage Per Annum		3.00%
Vornado \| Property Management Fees \| Rego Park II \| Retail space
Management and Development Agreements
Property Management Fee Agreement Percentage Of Income		2.00%
Vornado \| Management, property management, cleaning and security fees
Other Agreements
Amount Due to / (Fees paid to) related party (in US dollars)		$ 489,000		$ 428,000

Related Party Transactions (Fees to Vornado) (Details) - Vornado - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Summary of fees to Vornado
Fees to related party (in US dollars)	$ 1,727	$ 8,317
Company management fees
Summary of fees to Vornado
Fees to related party (in US dollars)	700	700
Development fees
Summary of fees to Vornado
Fees to related party (in US dollars)	28	44
Leasing Fees
Summary of fees to Vornado
Fees to related party (in US dollars)	11	6,458
Property Management Fees
Summary of fees to Vornado
Fees to related party (in US dollars)	$ 988	$ 1,115

Marketable Securities (Details) - USD ($)	Mar. 31, 2017	Dec. 31, 2016
Marketable Securities
Marketable securities	$ 34,471,000	$ 37,918,000
Fair Value	$ 34,471,000	$ 37,918,000
Macerich interest
Marketable Securities
Macerich Common Shares	535,265	535,265
Economic basis per share (in dollars per share)	$ 56.05
GAAP Cost	$ 30,000,000
Fair Value	$ 34,471,000	$ 37,918,000
Closing share price (in dollars per share)	$ 64.4	$ 70.84

Significant Tenants (Details) - USD ($) $ in Thousands	3 Months Ended
Significant Tenants (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Mar. 31, 2016
Real Estate Properties [Line Items]
Real estate revenue, net (in dollars)	$ 57,229	$ 55,558
Bloomberg \| Customer Concentration Risk \| Sales Revenue Services Net
Real Estate Properties [Line Items]
Real estate revenue, net (in dollars)	$ 26,010	$ 26,506
Percentage Rent Contributed By Tenant	45.00%	48.00%
Percentage Of Minimum Revenue Threshold Contributed By One Tenant (in percentage)	10.00%

Mortgages Payable (Outstanding mortgages payable) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Mortgage Loans on Real Estate
Notes Payable (in US dollars)	$ 1,051,973	$ 1,052,359
Rego Park I
Mortgage Loans on Real Estate
Percentage of cash mortgage collateralized	100.00%
Mortgages \| Secured loan
Mortgage Loans on Real Estate
Mortgage payable gross	$ 1,055,246	1,056,147
Deferred debt issuance costs, net of accumulated amortization of $7,348 and $6,824 respectively	(3,273)	(3,788)
Notes Payable (in US dollars)	1,051,973	1,052,359
Deferred debt issuance costs, accumulated amortization (in US dollars)	$ 7,348	6,824
Mortgages \| Secured loan \| Rego Park I \| Retail space
Mortgage Loans on Real Estate
Maturity date	Mar. 10, 2018
Interest rate (in percentage)	0.35%
Percentage of cash mortgage collateralized	100.00%
Mortgage payable gross	$ 78,246	78,246
Mortgage loan extension date	2016-03
Duration Of Mortgage Loan Extension	2 years
Mortgages \| Secured loan \| Rego Park II \| Retail space
Mortgage Loans on Real Estate
Maturity date	Nov. 30, 2018
Interest rate (in percentage)	2.83%
Debt Instrument, Description of Variable Rate Basis	LIBOR
Mortgage payable gross	$ 259,000	259,901
Mortgages \| Secured loan \| Rego Park II \| Retail space \| LIBOR
Mortgage Loans on Real Estate
Basis spread over LIBOR (in percentage)	1.85%
Mortgages \| Secured loan \| 731 Lexington Avenue \| Office space
Mortgage Loans on Real Estate
Maturity date	Mar. 11, 2021
Interest rate (in percentage)	1.86%
Debt Instrument, Description of Variable Rate Basis	LIBOR
Mortgage payable gross	$ 300,000	300,000
Mortgages \| Secured loan \| 731 Lexington Avenue \| Office space \| LIBOR
Mortgage Loans on Real Estate
Basis spread over LIBOR (in percentage)	0.95%
Mortgages \| Secured loan \| 731 Lexington Avenue \| Retail space
Mortgage Loans on Real Estate
Maturity date	Aug. 31, 2022
Interest rate (in percentage)	2.23%
Debt Instrument, Description of Variable Rate Basis	LIBOR
Mortgage payable gross	$ 350,000	350,000
Mortgages \| Secured loan \| 731 Lexington Avenue \| Retail space \| LIBOR
Mortgage Loans on Real Estate
Basis spread over LIBOR (in percentage)	1.40%
Mortgages \| Secured loan \| Paramus
Mortgage Loans on Real Estate
Maturity date	Oct. 05, 2018
Interest rate (in percentage)	2.90%
Mortgage payable gross	$ 68,000	$ 68,000

Fair Value Measurements (Financial Assets and Liabilities Measured at Fair Value) (Details) - Recurring - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Financial Assets And Liabilities Measured At Fair Value
Marketable securities	$ 34,471	$ 37,918
Liabilities measured at fair value	0	0
Level 1
Financial Assets And Liabilities Measured At Fair Value
Marketable securities	34,471	37,918
Level 2
Financial Assets And Liabilities Measured At Fair Value
Marketable securities	0	0
Level 3
Financial Assets And Liabilities Measured At Fair Value
Marketable securities	$ 0	$ 0

- Definition

Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(12))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Trading Securities
-URI http://asc.fasb.org/extlink&oid=6526789

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(5))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(6))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 35
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=27723805&loc=d3e24584-111560

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(2))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 25
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=65884222&loc=d3e22054-111558

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(1))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Available-for-Sale Securities
-URI http://asc.fasb.org/extlink&oid=6505594

+ Details

Fair Value Measurements (Financial Assets and Liabilities Not Measured at Fair Value) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Carrying Amount
Assets
Cash Equivalents	$ 273,477	$ 256,730
Liabilities
Mortgages payable (excluding deferred debt issuance costs, net)	1,055,246	1,056,147
Fair Value \| Level 1
Assets
Cash Equivalents	273,477	256,730
Fair Value \| Level 2
Liabilities
Mortgages payable (excluding deferred debt issuance costs, net)	$ 1,042,000	$ 1,045,000

Commitments and Contingencies (Insurance) (Details)	3 Months Ended
Commitments and Contingencies (Insurance) (Details)	Mar. 31, 2017 USD ($)
General Liability
Insurance
Insurance Maximum Coverage Per occurrence	$ 300,000,000
Insurance Maximum Coverage Per Property	300,000,000
All Risk Property And Rental Value
Insurance
Insurance Maximum Coverage Per occurrence	1,700,000,000
Terrorism Coverage Including NBCR
Insurance
Insurance Maximum Coverage Per occurrence	1,700,000,000
Insurance Maximum Coverage In Aggregate	$ 1,700,000,000
NBCR
Insurance
Insurance Coverage End Date	December 2020
Self Insured Responsibility (in percentage)	17.00%
Federal Government Responsibility (in percentage)	83.00%
FNSIC \| NBCR
Insurance
Insurance Deductible	$ 293,000

Commitments and Contingencies (Litigation and contingencies) (Details) ft² in Thousands, $ in Thousands			1 Months Ended	3 Months Ended		12 Months Ended
	Oct. 15, 2015 USD ($)	Jun. 24, 2014 USD ($)	Feb. 28, 2014 Fires	Mar. 31, 2017 USD ($) ft²	Mar. 31, 2016 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2001 a
Loss Contingency
Property rentals				$ 38,273	$ 36,653
Deferred leasing cost, net				47,271			$ 48,387
Standby letters of credit, outstanding				2,074
Mortgages payable, net of deferred debt issuance costs				1,051,973			$ 1,052,359
Rego Park I \| Sears
Loss Contingency
Number Of Fires \| Fires			2
Property rentals				10,337
Deferred leasing cost, net				$ 499
Lease expiration date				March 2021
Straight line rent receivable				$ 4,757
Paramus Property
Area of property (in square feet) \| ft²				195
Rego Park I \| Sears \| Minimum
Loss Contingency
Loss Contingency, Damages Sought, Value		$ 4,000
Rego Park I \| Sears \| Estimated Future Damages
Loss Contingency
Loss Contingency, Damages Sought, Value				$ 650	$ 650
Rego Park I \| Sears \| Estimated Future Damages \| Minimum
Loss Contingency
Loss Contingency, Damages Sought, Value		$ 25,000
Paramus \| Tenant Occupant \| Ikea
Loss Contingency
Area Of Land \| a								30.3
Mortgages payable, net of deferred debt issuance costs				$ 68,000
Paramus Property
Fixed interest rate on the debt (in percentage)				2.90%
Debt instrument maturity date				October 2018
Triple-net rent, annual amount				$ 700
Paramus \| Tenant Occupant \| Ikea \| Forecast
Paramus Property
Property purchase option exercisable be leasee with purchase option in 2021						$ 75,000
Purchase option exercised, net cash proceeds from sale of land						7,000
Purchase option excercised, gain on sale of land						60,000
Purchase option not excercised amount included in triple net rent over remainder of lease						$ 68,000
Loan Amortization Period						20 years
Lease term range as Lessor						20 years
The Kings Plaza Regional Shopping Center
Loss Contingency
Loss Contingency, Damages Sought, Value	$ 21,700

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Earnings Per Share
Net income	$ 21,667	$ 22,019
Weighted average shares outstanding - basic and diluted (in shares)	5,114,701	5,113,077
Net income per common share (in dollars per share)	$ 4.24	$ 4.31