ASC 820, Fair Value Measurement and Disclosures defines fair value and establishes a framework for measuring fair value. The objective of fair value is to determine the price that would be received upon the sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (the exit price). 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. Considerable judgment is necessary to interpret Level 2 and 3 inputs in determining the fair value of our financial and non-financial assets and liabilities. Accordingly, our fair value estimates, which are made at the end of each reporting period, may be different than the amounts that may ultimately be realized upon sale or disposition of these assets.

Financial assets and liabilities that are measured at fair value in our consolidated financial statements consist of (i) marketable securities, (ii) derivative positions in marketable equity securities, (iii) the assets of our deferred compensation plan, which are primarily marketable equity securities and equity investments in limited partnerships, (iv) Real Estate Fund investments, and (v) mandatorily redeemable instruments (Series G-1 through G-4 convertible preferred units and Series D-13 cumulative redeemable preferred units). The tables below aggregate the fair values of financial assets and liabilities by the levels in the fair value hierarchy at June 30, 2011 and December 31, 2010, respectively.

			As of June 30, 2011
(Amounts in thousands)			Total		Level 1		Level 2		Level 3
	Marketable securities		$	791,676	$	791,676	$	-	$	-
	Real Estate Fund investments (75% of which is attributable to
		noncontrolling interests)		255,795		-		-		255,795
	Deferred compensation plan assets (included in other assets)			100,374		46,650		-		53,724
	Derivative positions in marketable equity securities
		(included in other assets)		28,017		-		28,017		-
		Total assets	$	1,175,862	$	838,326	$	28,017	$	309,519

	Mandatorily redeemable instruments (included in other liabilities)		$	55,097	$	55,097	$	-	$	-

			As of December 31, 2010
(Amounts in thousands)			Total		Level 1		Level 2		Level 3
	Marketable securities		$	766,116	$	766,116	$	-	$	-
	Real Estate Fund investments (75% of which is attributable to
		noncontrolling interests)		144,423		-		-		144,423
	Deferred compensation plan assets (included in other assets)			91,549		43,699		-		47,850
	Derivative positions in marketable equity securities
		(included in other assets)		17,616		-		17,616		-
		Total assets	$	1,019,704	$	809,815	$	17,616	$	192,273

	Mandatorily redeemable instruments (included in other liabilities)		$	55,097	$	55,097	$	-	$	-

The tables below summarize the changes in the fair value of the Level 3 assets above, by category, for the three and six months ended June 30, 2011 and 2010.

Real Estate Fund Investments:
	For the Three Months Ended June 30,				For the Six Months Ended June 30,
(Amounts in thousands)	2011		2010		2011		2010
Beginning balance	$	230,657	$	-	$	144,423	$	-
Purchases		22,808		-		123,047		-
Sales		(12,831)		-		(12,831)		-
Realized and unrealized gains		15,957		-		16,655		-
Other, net		(796)		-		(15,499)		-
Ending balance	$	255,795	$	-	$	255,795	$	-


Deferred Compensation Plan Assets:
	For the Three Months Ended June 30,				For the Six Months Ended June 30,
(Amounts in thousands)	2011		2010		2011		2010
Beginning balance	$	51,612	$	43,263	$	47,850	$	39,589
Purchases		17,818		3,210		19,104		6,342
Sales		(16,347)		(3,014)		(17,494)		(3,580)
Realized and unrealized gains		594		41		4,217		1,149
Other, net		47		98		47		98
Ending balance	$	53,724	$	43,598	$	53,724	$	43,598

Financial assets and liabilities that are not measured at fair value in our consolidated financial statements include mezzanine loans receivable and debt. Estimates of the fair values of these instruments are based on our assessments of available market information and valuation methodologies, including discounted cash flow analyses. The table below summarizes the carrying amounts and fair values of these financial instruments as of June 30, 2011 and December 31, 2010.

			As of June 30, 2011				As of December 31, 2010
			Carrying		Fair		Carrying		Fair
(Amounts in thousands)			Amount		Value		Amount		Value
	Mezzanine loans receivable		$	155,613	$	149,948	$	202,412	$	197,581
	Debt:
		Notes and mortgages payable	$	8,575,022	$	8,757,884	$	8,259,298	$	8,450,812
		Senior unsecured notes		982,629		1,046,369		1,082,928		1,119,512
		Exchangeable senior debentures		494,403		564,355		491,000		554,355
		Convertible senior debentures due
		to Vornado		187,994		190,391		186,413		191,510
		Revolving credit facility debt		300,000		300,000		874,000		874,000
			$	10,540,048	$	10,858,999	$	10,893,639	$	11,190,189

- 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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6925170&loc=d3e19296-110258

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 159
-Paragraph 17-22, 27, 28
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=6947722&loc=d3e13433-108611

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 107
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Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14064-108612

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-URI http://asc.fasb.org/extlink&oid=6947722&loc=d3e13504-108611

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 107
-Paragraph 15A
-Subparagraph a-d
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
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Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 133
-Paragraph 44A, 44B
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6925170&loc=d3e19207-110258

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-Name Accounting Standards Codification
-Topic 825
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-Name Statement of Financial Accounting Standard (FAS)
-Number 107
-Paragraph 3, 10, 14, 15
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 13: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 107
-Paragraph 15B
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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 14: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 157
-Paragraph 32, 33, 34
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details