Related Party Transactions (Details) (Vornado [member], USD $)	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011
Related Party Transaction [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent	32.40%
Managment and Development Agreement [line items]
Management Fee Agreement Value	$ 3,000,000
Leasing Agreement [Line Items]
Percentage Commissions On Sale Of Assets Under Fifty Million	3.00%
Percentage Commissions On Sale Of Assets Over Fifty Million	1.00%
Leasing services fee and commission on asset sale, annual installment, maximum.	4,000,000
Debt Instrument, Description of Variable Rate Basis	LIBOR
Basis spread over LIBOR	1.00%
Unpaid Balance Effective Interest	2.13%
Other Agreements [Abstract]
Other Supervisory Fees	6.00%
Summary of fees to Vornado [Line Items]
Fees to Related Party	2,828,000	3,579,000
Lexington Avenue Property [Member] \| Office And Retail Space [Member]
Managment and Development Agreement [line items]
Property Management Fee Agreement Price Per Square Foot	0.5
Lexington Avenue Property [Member] \| Common Area [Member]
Managment and Development Agreement [line items]
Property Management Fee Agreement Value	256,000
Property Management Fee Escalation Percentage Per Annum	3.00%
Kings Plaza Regional Shopping Center [Member]
Managment and Development Agreement [line items]
Property Management Fee Agreement Percentage Of Income	3.00%
Rego Park 2 Property [Member]
Managment and Development Agreement [line items]
Property Management Fee Agreement Percentage Of Income	2.00%
Company management fees
Summary of fees to Vornado [Line Items]
Fees to Related Party	750,000	750,000
Development fees
Managment and Development Agreement [line items]
Development fee as percentage of development costs	6.00%
Minimum guaranteed development fee per annum	750,000
Summary of fees to Vornado [Line Items]
Fees to Related Party	188,000	188,000
Leasing Fees
Leasing Agreement [Line Items]
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%
Summary of fees to Vornado [Line Items]
Fees to Related Party	623,000	1,515,000
Fees owed to Vornado	40,064,000
Property Management Fees
Summary of fees to Vornado [Line Items]
Fees to Related Party	1,267,000	1,126,000
Fees owed to Vornado	$ 621,000

Minimum development fee that Vornado will receive per annum, as per the development agreement

No definition available.

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- Definition

Percentage of development costs that the related party will receive as per the Development agreemenent

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Percentage of rent payable to related party for leasing services for the eleventh through twentieth years of the lease

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
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Period Type:	duration

- Definition

Percentage of rent payable to related party for leasing services for the first ten years of the lease

+ References

No definition available.

+ Details

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- Definition

Percentage of rent payable to related party for leasing services for the twenty-first through thirtieth years of the lease

+ References

No definition available.

+ Details

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- Details

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- Definition

Maximum annual installments payable for leasing services and commission on asset sales under the leasing agreement.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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- Definition

The amount of management fee paid to related party to manage corporate activities

+ References

No definition available.

+ Details

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- Definition

The fee charged to supervise cleaning, engineering and security services

+ References

No definition available.

+ Details

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- Definition

Percentage of gross proceeds over $50,000,000 from the sale of any assets, payable to related party

+ References

No definition available.

+ Details

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- Definition

Percentage of gross proceeds under $50,000,000 from the sale of any assets, payable to related party

+ References

No definition available.

+ Details

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- Definition

Percentage of increase in leasing services payable to related party if a real estate broker is used

+ References

No definition available.

+ Details

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- Definition

Percentage of income from property, paid to related party as property management fees

+ References

No definition available.

+ Details

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- Definition

Amount per square foot paid to related party as property management fees

+ References

No definition available.

+ Details

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- Definition

Annual amount paid to related party as property management fees

+ References

No definition available.

+ Details

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- Definition

Annual increase in the amount paid to related party as property management fees

+ References

No definition available.

+ Details

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- Details

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- Definition

Interest rate charged on unpaid commissions as of at end of the current reporting period

+ References

No definition available.

+ Details

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- Definition

The percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

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- Definition

The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

+ References

No definition available.

+ Details

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- Definition

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

+ References

No definition available.

+ Details

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- Definition

Receivables to be collected from (obligations owed to) related parties, net as of the balance sheet date where one party can exercise control or significant influence over another party; including affiliates, owners or officers and their immediate families, pension trusts, and so forth.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 850

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (d)

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 4

-Section 08

-Paragraph k

-Subparagraph 1

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 57

-Paragraph 2

-Subparagraph 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.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(k)(1))

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- Definition

Expenses recognized during the period resulting from transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 57

-Paragraph 2

-Subparagraph c

-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.

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-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

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