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Fair Value Measurements (Details) (USD $) | Jun. 30, 2014 | Dec. 31, 2013
--- | --- | ---
Financial Assets And Liabilities Measured At Fair Value |  |
Marketable securities | $ 35,729,000 | $ 31,522,000
Interest rate cap (included in other assets) | 47,000 |
Total assets | 35,776,000 |
Liabilities measured at fair value | 0 | 0
Carrying Reported Amount Fair Value Disclosure [Member] |  |
Assets |  |
Cash Equivalents | 303,433,000 | 184,796,000
Liabilities |  |
Mortgages Payable Fair Value Disclosure | 1,034,289,000 | 1,049,959,000
Leasing commissions (included in amounts due to Vornado) | 41,279,000 | 42,924,000
Total liabilities not measured at fair value | 1,075,568,000 | 1,092,883,000
Estimate Of Fair Value Fair Value Disclosure [Member] |  |
Assets |  |
Cash Equivalents | 303,433,000 | 184,796,000
Liabilities |  |
Mortgages Payable Fair Value Disclosure | 1,037,000,000 | 1,072,000,000
Leasing commissions (included in amounts due to Vornado) | 41,000,000 | 43,000,000
Total liabilities not measured at fair value | 1,078,000,000 | 1,115,000,000
Fair Value, Inputs, Level 1 [Member] |  |
Financial Assets And Liabilities Measured At Fair Value |  |
Marketable securities | 35,729,000 | 31,522,000
Interest rate cap (included in other assets) | 0 |
Total assets | 35,729,000 |
Fair Value, Inputs, Level 2 [Member] |  |
Financial Assets And Liabilities Measured At Fair Value |  |
Marketable securities | 0 | 0
Interest rate cap (included in other assets) | 47,000 |
Total assets | 47,000 |
Fair Value, Inputs, Level 3 [Member] |  |
Financial Assets And Liabilities Measured At Fair Value |  |
Marketable securities | 0 | 0
Interest rate cap (included in other assets) | 0 |
Total assets | $ 0 |

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- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19207-110258 + Details
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- Definition Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27232-111563 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562 + Details
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- Definition Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Cash -URI http://asc.fasb.org/extlink&oid=6506951 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Cash Equivalents -URI http://asc.fasb.org/extlink&oid=6507016 + Details
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- Definition Fair value of financial and nonfinancial obligations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19207-110258 + 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 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(k)(1)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph k -Subparagraph 1 -Article 4 + Details
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