Commitments And Contingencies	12 Months Ended
Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]
Commitments And Contingencies	Commitments and Contingencies General In the normal course of business, the Company guarantees its performance of services or indemnifies third parties against its negligence. In addition, in the normal course of business, the Company guarantees to certain tenants the obligations of its subsidiaries for the payment of tenant improvement allowances and brokerage commissions in connection with their leases and limited costs arising from delays in delivery of their premises. The Company has letter of credit and performance obligations of approximately $13.9 million related to lender and development requirements. Certain of the Company’s joint venture agreements include provisions whereby, at certain specified times, each partner has the right to initiate a purchase or sale of the property or its interest in the joint ventures. Under these provisions, the Company is not compelled to purchase the interest of its outside joint venture partners. See also Noncontrolling Interest—Redeemable Interest in Property Partnership in Note 11. In connection with the assumption of 767 Fifth Avenue's (the General Motors Building) secured loan by the Company’s consolidated joint venture, 767 Venture, LLC, the Company guaranteed the consolidated joint venture’s obligation to fund various escrows, including tenant improvements, taxes and insurance in lieu of cash deposits. As of December 31, 2013, the maximum funding obligation under the guarantee was approximately $24.1 million. The Company earns a fee from the joint venture for providing the guarantee and has an agreement with the outside partners to reimburse the joint venture for their share of any payments made under the guarantee. In connection with the mortgage financing collateralized by the Company's John Hancock Tower property located in Boston, Massachusetts, the Company has agreed to guarantee approximately $15.9 million related to its obligation to provide funds for certain tenant re-leasing costs. The mortgage financing matures on January 6, 2017. From time to time, the Company (or the applicable joint venture) has also agreed to guarantee portions of the principal, interest or other amounts in connection with other unconsolidated joint venture borrowings. In addition to the financial guarantees referenced above, the Company has agreed to customary environmental indemnifications and nonrecourse carve-outs (e.g., guarantees against fraud, misrepresentation and bankruptcy) on certain of its unconsolidated joint venture loans. Concentrations of Credit Risk Management of the Company performs ongoing credit evaluations of tenants and may require tenants to provide some form of credit support such as corporate guarantees and/or other financial guarantees. Although the Company’s properties are geographically diverse and the tenants operate in a variety of industries, to the extent the Company has a significant concentration of rental revenue from any single tenant, the inability of that tenant to make its lease payments could have an adverse effect on the Company. Some potential losses are not covered by insurance. The Company carries insurance coverage on its properties of types and in amounts and with deductibles that it believes are in line with coverage customarily obtained by owners of similar properties. In response to the uncertainty in the insurance market following the terrorist attacks of September 11, 2001, the Federal Terrorism Risk Insurance Act (as amended, “TRIA”) was enacted in November 2002 to require regulated insurers to make available coverage for “certified” acts of terrorism (as defined by the statute). The expiration date of TRIA was extended to December 31, 2014 by the Terrorism Risk Insurance Program Reauthorization Act of 2007 (“TRIPRA”) and the Company can provide no assurance that it will be extended further. Currently, the Company’s property insurance program per occurrence limits are $1.0 billion for its portfolio insurance program, including coverage for acts of terrorism certified under TRIA other than nuclear, biological, chemical or radiological terrorism (“Terrorism Coverage”). The Company also carries $250 million of Terrorism Coverage for 601 Lexington Avenue, New York, New York (“601 Lexington Avenue”) in excess of the $1.0 billion of coverage in the Company’s property insurance program which is provided by IXP, LLC (“IXP”) as a direct insurer. Certain properties, including the General Motors Building located at 767 Fifth Avenue in New York, New York (“767 Fifth Avenue”), are currently insured in separate insurance programs. The property insurance program per occurrence limits for 767 Fifth Avenue are $1.625 billion, including Terrorism Coverage, with $1.375 billion of Terrorism Coverage in excess of $250 million being provided by NYXP, LLC (“NYXP”), as a direct insurer. The Company also currently carries nuclear, biological, chemical and radiological terrorism insurance coverage for acts of terrorism certified under TRIA (“NBCR Coverage”), which is provided by IXP as a direct insurer, for the properties in our portfolio, including 767 Fifth Avenue, but excluding certain other properties owned in joint ventures with third parties or which the Company manages. The per occurrence limit for NBCR Coverage is $1.0 billion. Under TRIA, after the payment of the required deductible and coinsurance, the additional Terrorism Coverage provided by IXP for 601 Lexington Avenue, the NBCR Coverage provided by IXP and the Terrorism Coverage provided by NYXP are backstopped by the Federal Government if the aggregate industry insured losses resulting from a certified act of terrorism exceed a “program trigger.” The program trigger is $100.0 million and the coinsurance is 15%. Under TRIPRA, if the Federal Government pays out for a loss under TRIA, it is mandatory that the Federal Government recoup the full amount of the loss from insurers offering TRIA coverage after the payment of the loss pursuant to a formula in TRIPRA. The Company may elect to terminate the NBCR Coverage if the Federal Government seeks recoupment for losses paid under TRIA, if there is a change in its portfolio or for any other reason. In the event TRIPRA is not extended beyond December 31, 2014, (i) the Company will evaluate alternative approaches to secure coverage for acts of terrorism thereby potentially increasing its overall cost of insurance, (ii) if such insurance is not available at commercially reasonable rates with limits equal to its current coverage or at all, the Company may not continue to have full occurrence limit coverage for acts of terrorism, (iii) the Company may not satisfy the insurance requirements under existing or future debt financings secured by individual properties, (iv) the Company may not be able to obtain future debt financings secured by individual properties and (v) the Company may cancel the insurance policies issued by IXP for the NBCR Coverage and the additional Terrorism Coverage for 601 Lexington Avenue and by NYXP for the Terrorism Coverage for 767 Fifth Avenue. The Company intends to continue to monitor the scope, nature and cost of available terrorism insurance and maintain terrorism insurance in amounts and on terms that are commercially reasonable. The Company also currently carries earthquake insurance on its properties located in areas known to be subject to earthquakes in an amount and subject to self-insurance that the Company believes are commercially reasonable. In addition, this insurance is subject to a deductible in the amount of 5% of the value of the affected property. Specifically, the Company currently carries earthquake insurance which covers its San Francisco region (excluding 535 Mission Street and the below grade improvements for Transbay Tower) with a $120 million per occurrence limit and a $120 million annual aggregate limit, $20 million of which is provided by IXP, as a direct insurer. The builders risk policy maintained for the development of 535 Mission Street in San Francisco includes a $15 million per occurrence and annual aggregate limit of earthquake coverage. In addition, the builders risk policy maintained for the development of the below grade improvements of the Transbay Tower in San Francisco includes a $15 million per occurrence and annual aggregate limit of earthquake coverage. The amount of the Company’s earthquake insurance coverage may not be sufficient to cover losses from earthquakes. In addition, the amount of earthquake coverage could impact the Company’s ability to finance properties subject to earthquake risk. The Company may discontinue earthquake insurance or change the structure of its earthquake insurance program on some or all of its properties in the future if the premiums exceed the Company’s estimation of the value of the coverage. IXP, a captive insurance company which is a wholly-owned subsidiary of the Company, acts as a direct insurer with respect to a portion of the Company’s earthquake insurance coverage for its Greater San Francisco properties, the additional Terrorism Coverage for 601 Lexington Avenue and the Company’s NBCR Coverage. The additional Terrorism Coverage provided by IXP for 601 Lexington Avenue only applies to losses which exceed the program trigger under TRIA. NYXP, a captive insurance company which is a wholly-owned subsidiary of the Company, acts as a direct insurer with respect to a portion of the Company’s Terrorism Coverage for 767 Fifth Avenue. Currently, NYXP only insures losses which exceed the program trigger under TRIA and NYXP reinsures with a third-party insurance company any coinsurance payable under TRIA. Insofar as the Company owns IXP and NYXP, it is responsible for their liquidity and capital resources, and the accounts of IXP and NYXP are part of the Company’s consolidated financial statements. In particular, if a loss occurs which is covered by the Company’s NBCR Coverage but is less than the applicable program trigger under TRIA, IXP would be responsible for the full amount of the loss without any backstop by the Federal Government. IXP and NYXP would also be responsible for any recoupment charges by the Federal Government in the event losses are paid out and their insurance policies are maintained after the payout by the Federal Government. If the Company experiences a loss and IXP or NYXP are required to pay under their insurance policies, the Company would ultimately record the loss to the extent of the required payment. Therefore, insurance coverage provided by IXP and NYXP should not be considered as the equivalent of third-party insurance, but rather as a modified form of self-insurance. In addition, the Operating Partnership has issued a guarantee to cover liabilities of IXP in the amount of $20.0 million. The mortgages on the Company's properties typically contain requirements concerning the financial ratings of the insurers who provide policies covering the property. The Company provides the lenders on a regular basis with the identity of the insurance companies in the Company's insurance programs. The ratings of some of the Company's insurers are below the rating requirements in some of the Company's loan agreements and the lenders for these loans could attempt to claim that an event of default has occurred under the loan. The Company believes it could obtain insurance with insurers which satisfy the rating requirements. Additionally, in the future, the Company's ability to obtain debt financing secured by individual properties, or the terms of such financing, may be adversely affected if lenders generally insist on ratings for insurers or amounts of insurance which are difficult to obtain or which result in a commercially unreasonable premium. There can be no assurance that a deficiency in the financial ratings of one or more of the Company's insurers will not have a material adverse effect on the Company. The Company continues to monitor the state of the insurance market in general, and the scope and costs of coverage for acts of terrorism and California earthquake risk in particular, but the Company cannot anticipate what coverage will be available on commercially reasonable terms in future policy years. There are other types of losses, such as from wars, for which the Company cannot obtain insurance at all or at a reasonable cost. With respect to such losses and losses from acts of terrorism, earthquakes or other catastrophic events, if the Company experiences a loss that is uninsured or that exceeds policy limits, the Company could lose the capital invested in the damaged properties, as well as the anticipated future revenues from those properties. Depending on the specific circumstances of each affected property, it is possible that the Company could be liable for mortgage indebtedness or other obligations related to the property. Any such loss could materially and adversely affect the Company's business and financial condition and results of operations. Legal Matters The Company is subject to various legal proceedings and claims that arise in the ordinary course of business. These matters are generally covered by insurance. Management believes that the final outcome of such matters will not have a material adverse effect on the financial position, results of operations or liquidity of the Company. State and Local Tax Matters Because the Company is organized and qualifies as a REIT, it is generally not subject to federal income taxes, but is subject to certain state and local taxes. In the normal course of business, certain entities through which the Company owns real estate either have undergone, or are currently undergoing, tax audits. Although the Company believes that it has substantial arguments in favor of its positions in the ongoing audits, in some instances there is no controlling precedent or interpretive guidance on the specific point at issue. Collectively, tax deficiency notices received to date from the jurisdictions conducting the ongoing audits have not been material. However, there can be no assurance that future audits will not occur with increased frequency or that the ultimate result of such audits will not have a material adverse effect on the Company’s results of operations. Environmental Matters It is the Company’s policy to retain independent environmental consultants to conduct or update Phase I environmental assessments (which generally do not involve invasive techniques such as soil or ground water sampling) and asbestos surveys in connection with the Company’s acquisition of properties. These pre-purchase environmental assessments have not revealed environmental conditions that the Company believes will have a material adverse effect on its business, assets, financial condition, results of operations or liquidity, and the Company is not otherwise aware of environmental conditions with respect to its properties that the Company believes would have such a material adverse effect. However, from time to time environmental conditions at the Company’s properties have required and may in the future require environmental testing and/or regulatory filings, as well as remedial action. In February 1999, the Company (through a joint venture) acquired from Exxon Corporation a property in Massachusetts that was formerly used as a petroleum bulk storage and distribution facility and was known by the state regulatory authority to contain soil and groundwater contamination. The Company developed an office park on the property. The Company engaged a specially licensed environmental consultant to oversee the management of contaminated soil and groundwater that was disturbed in the course of construction. Under the property acquisition agreement, Exxon agreed to (1) bear the liability arising from releases or discharges of oil and hazardous substances which occurred at the site prior to the Company’s ownership, (2) continue monitoring and/or remediating such releases and discharges as necessary and appropriate to comply with applicable requirements, and (3) indemnify the Company for certain losses arising from preexisting site conditions. Any indemnity claim may be subject to various defenses, and there can be no assurance that the amounts paid under the indemnity, if any, would be sufficient to cover the liabilities arising from any such releases and discharges. Environmental investigations at some of the Company’s properties and certain properties owned by affiliates of the Company have identified groundwater contamination migrating from off-site source properties. In each case the Company engaged a licensed environmental consultant to perform the necessary investigations and assessments and to prepare any required submittals to the regulatory authorities. In each case the environmental consultant concluded that the properties qualify under the regulatory program or the regulatory practice for a status which eliminates certain deadlines for conducting response actions at a site. The Company also believes that these properties qualify for liability relief under certain statutory provisions or regulatory practices regarding upgradient releases. Although the Company believes that the current or former owners of the upgradient source properties may bear responsibility for some or all of the costs of addressing the identified groundwater contamination, the Company will take such further response actions (if any) that it deems necessary or advisable. Other than periodic testing at some of these properties, no such additional response actions are anticipated at this time. Some of the Company’s properties and certain properties owned by the Company’s affiliates are located in urban, industrial and other previously developed areas where fill or current or historical uses of the areas have caused site contamination. Accordingly, it is sometimes necessary to institute special soil and/or groundwater handling procedures and/or include particular building design features in connection with development, construction and other property operations in order to achieve regulatory closure and/or ensure that contaminated materials are addressed in an appropriate manner. In these situations it is the Company’s practice to investigate the nature and extent of detected contamination and estimate the costs of required response actions and special handling procedures. The Company then uses this information as part of its decision-making process with respect to the acquisition and/or development of the property. For example, the Company owns a parcel in Massachusetts which was formerly used as a quarry/asphalt batching facility. Pre-purchase testing indicated that the site contained relatively low levels of certain contaminants. The Company has developed an office park on this property. Prior to and during redevelopment activities, the Company engaged a specially licensed environmental consultant to monitor environmental conditions at the site and prepare necessary regulatory submittals based on the results of an environmental risk characterization. A submittal has been made to the regulatory authorities in order to achieve regulatory closure at this site. The submittal included an environmental deed restriction that mandates compliance with certain protective measures in a portion of the site where low levels of residual soil contamination have been left in place in accordance with applicable laws. The Company expects that resolution of the environmental matters relating to the above will not have a material impact on its business, assets, financial condition, results of operations or liquidity. However, the Company cannot assure you that it has identified all environmental liabilities at its properties, that all necessary remediation actions have been or will be undertaken at the Company’s properties or that the Company will be indemnified, in full or at all, in the event that such environmental liabilities arise. Tax Protection Obligations In connection with the acquisition or contribution of three properties, the Company entered into agreements for the benefit of the selling or contributing parties which specifically state that until such time as the contributors do not hold at least a specified percentage of the OP Units owned by such person following the contribution of the properties, or until June 9, 2017 for 767 Fifth Avenue (the General Motors Building), the Operating Partnership will not sell or otherwise transfer the properties in a taxable transaction. If the Company does sell or transfer the properties in a taxable transaction, it would be liable to the contributors for contractual damages.

Commitments and Contingencies

General

In the normal course of business, the Company guarantees its performance of services or indemnifies third parties against its negligence. In addition, in the normal course of business, the Company guarantees to certain tenants the obligations of its subsidiaries for the payment of tenant improvement allowances and brokerage commissions in connection with their leases and limited costs arising from delays in delivery of their premises.

The Company has letter of credit and performance obligations of approximately $13.9 million related to lender and development requirements.

Certain of the Company’s joint venture agreements include provisions whereby, at certain specified times, each partner has the right to initiate a purchase or sale of the property or its interest in the joint ventures. Under these provisions, the Company is not compelled to purchase the interest of its outside joint venture partners. See also Noncontrolling Interest—Redeemable Interest in Property Partnership in Note 11.

In connection with the assumption of 767 Fifth Avenue's (the General Motors Building) secured loan by the Company’s consolidated joint venture, 767 Venture, LLC, the Company guaranteed the consolidated joint venture’s obligation to fund various escrows, including tenant improvements, taxes and insurance in lieu of cash deposits. As of December 31, 2013, the maximum funding obligation under the guarantee was approximately $24.1 million. The Company earns a fee from the joint venture for providing the guarantee and has an agreement with the outside partners to reimburse the joint venture for their share of any payments made under the guarantee.

In connection with the mortgage financing collateralized by the Company's John Hancock Tower property located in Boston, Massachusetts, the Company has agreed to guarantee approximately $15.9 million related to its obligation to provide funds for certain tenant re-leasing costs. The mortgage financing matures on January 6, 2017.

From time to time, the Company (or the applicable joint venture) has also agreed to guarantee portions of the principal, interest or other amounts in connection with other unconsolidated joint venture borrowings. In addition to the financial guarantees referenced above, the Company has agreed to customary environmental indemnifications and nonrecourse carve-outs (e.g., guarantees against fraud, misrepresentation and bankruptcy) on certain of its unconsolidated joint venture loans.

Concentrations of Credit Risk

Management of the Company performs ongoing credit evaluations of tenants and may require tenants to provide some form of credit support such as corporate guarantees and/or other financial guarantees. Although the Company’s properties are geographically diverse and the tenants operate in a variety of industries, to the extent the Company has a significant concentration of rental revenue from any single tenant, the inability of that tenant to make its lease payments could have an adverse effect on the Company.

Some potential losses are not covered by insurance.

The Company carries insurance coverage on its properties of types and in amounts and with deductibles that it believes are in line with coverage customarily obtained by owners of similar properties. In response to the uncertainty in the insurance market following the terrorist attacks of September 11, 2001, the Federal Terrorism Risk Insurance Act (as amended, “TRIA”) was enacted in November 2002 to require regulated insurers to make available coverage for “certified” acts of terrorism (as defined by the statute). The expiration date of TRIA was extended to December 31, 2014 by the Terrorism Risk Insurance Program Reauthorization Act of 2007 (“TRIPRA”) and the Company can provide no assurance that it will be extended further. Currently, the Company’s property insurance program per occurrence limits are $1.0 billion for its portfolio insurance program, including coverage for acts of terrorism certified under TRIA other than nuclear, biological, chemical or radiological terrorism (“Terrorism Coverage”). The Company also carries $250 million of Terrorism Coverage for 601 Lexington Avenue, New York, New York (“601 Lexington Avenue”) in excess of the $1.0 billion of coverage in the Company’s property insurance program which is provided by IXP, LLC (“IXP”) as a direct insurer. Certain properties, including the General Motors Building located at 767 Fifth Avenue in New York, New York (“767 Fifth Avenue”), are currently insured in separate insurance programs. The property insurance program per occurrence limits for 767 Fifth Avenue are $1.625 billion, including Terrorism Coverage, with $1.375 billion of Terrorism Coverage in excess of $250 million being provided by NYXP, LLC (“NYXP”), as a direct insurer. The Company also currently carries nuclear, biological, chemical and radiological terrorism insurance coverage for acts of terrorism certified under TRIA (“NBCR Coverage”), which is provided by IXP as a direct insurer, for the properties in our portfolio, including 767 Fifth Avenue, but excluding certain other properties owned in joint ventures with third parties or which the Company manages. The per occurrence limit for NBCR Coverage is $1.0 billion. Under TRIA, after the payment of the required deductible and coinsurance, the additional Terrorism Coverage provided by IXP for 601 Lexington Avenue, the NBCR Coverage provided by IXP and the Terrorism Coverage provided by NYXP are backstopped by the Federal Government if the aggregate industry insured losses resulting from a certified act of terrorism exceed a “program trigger.” The program trigger is $100.0 million and the coinsurance is 15%. Under TRIPRA, if the Federal Government pays out for a loss under TRIA, it is mandatory that the Federal Government recoup the full amount of the loss from insurers offering TRIA coverage after the payment of the loss pursuant to a formula in TRIPRA. The Company may elect to terminate the NBCR Coverage if the Federal Government seeks recoupment for losses paid under TRIA, if there is a change in its portfolio or for any other reason. In the event TRIPRA is not extended beyond December 31, 2014, (i) the Company will evaluate alternative approaches to secure coverage for acts of terrorism thereby potentially increasing its overall cost of insurance, (ii) if such insurance is not available at commercially reasonable rates with limits equal to its current coverage or at all, the Company may not continue to have full occurrence limit coverage for acts of terrorism, (iii) the Company may not satisfy the insurance requirements under existing or future debt financings secured by individual properties, (iv) the Company may not be able to obtain future debt financings secured by individual properties and (v) the Company may cancel the insurance policies issued by IXP for the NBCR Coverage and the additional Terrorism Coverage for 601 Lexington Avenue and by NYXP for the Terrorism Coverage for 767 Fifth Avenue. The Company intends to continue to monitor the scope, nature and cost of available terrorism insurance and maintain terrorism insurance in amounts and on terms that are commercially reasonable.

The Company also currently carries earthquake insurance on its properties located in areas known to be subject to earthquakes in an amount and subject to self-insurance that the Company believes are commercially reasonable. In addition, this insurance is subject to a deductible in the amount of 5% of the value of the affected property. Specifically, the Company currently carries earthquake insurance which covers its San Francisco region (excluding 535 Mission Street and the below grade improvements for Transbay Tower) with a $120 million per occurrence limit and a $120 million annual aggregate limit, $20 million of which is provided by IXP, as a direct insurer. The builders risk policy maintained for the development of 535 Mission Street in San Francisco includes a $15 million per occurrence and annual aggregate limit of earthquake coverage. In addition, the builders risk policy maintained for the development of the below grade improvements of the Transbay Tower in San Francisco includes a $15 million per occurrence and annual aggregate limit of earthquake coverage. The amount of the Company’s earthquake insurance coverage may not be sufficient to cover losses from earthquakes. In addition, the amount of earthquake coverage could impact the Company’s ability to finance properties subject to earthquake risk. The Company may discontinue earthquake insurance or change the structure of its earthquake insurance program on some or all of its properties in the future if the premiums exceed the Company’s estimation of the value of the coverage.

IXP, a captive insurance company which is a wholly-owned subsidiary of the Company, acts as a direct insurer with respect to a portion of the Company’s earthquake insurance coverage for its Greater San Francisco properties, the additional Terrorism Coverage for 601 Lexington Avenue and the Company’s NBCR Coverage. The additional Terrorism Coverage provided by IXP for 601 Lexington Avenue only applies to losses which exceed the program trigger under TRIA. NYXP, a captive insurance company which is a wholly-owned subsidiary of the Company, acts as a direct insurer with respect to a portion of the Company’s Terrorism Coverage for 767 Fifth Avenue. Currently, NYXP only insures losses which exceed the program trigger under TRIA and NYXP reinsures with a third-party insurance company any coinsurance payable under TRIA. Insofar as the Company owns IXP and NYXP, it is responsible for their liquidity and capital resources, and the accounts of IXP and NYXP are part of the Company’s consolidated financial statements. In particular, if a loss occurs which is covered by the Company’s NBCR Coverage but is less than the applicable program trigger under TRIA, IXP would be responsible for the full amount of the loss without any backstop by the Federal Government. IXP and NYXP would also be responsible for any recoupment charges by the Federal Government in the event losses are paid out and their insurance policies are maintained after the payout by the Federal Government. If the Company experiences a loss and IXP or NYXP are required to pay under their insurance policies, the Company would ultimately record the loss to the extent of the required payment. Therefore, insurance coverage provided by IXP and NYXP should not be considered as the equivalent of third-party insurance, but rather as a modified form of self-insurance. In addition, the Operating Partnership has issued a guarantee to cover liabilities of IXP in the amount of $20.0 million.

The mortgages on the Company's properties typically contain requirements concerning the financial ratings of the insurers who provide policies covering the property. The Company provides the lenders on a regular basis with the identity of the insurance companies in the Company's insurance programs. The ratings of some of the Company's insurers are below the rating requirements in some of the Company's loan agreements and the lenders for these loans could attempt to claim that an event of default has occurred under the loan. The Company believes it could obtain insurance with insurers which satisfy the rating requirements. Additionally, in the future, the Company's ability to obtain debt financing secured by individual properties, or the terms of such financing, may be adversely affected if lenders generally insist on ratings for insurers or amounts of insurance which are difficult to obtain or which result in a commercially unreasonable premium. There can be no assurance that a deficiency in the financial ratings of one or more of the Company's insurers will not have a material adverse effect on the Company.

The Company continues to monitor the state of the insurance market in general, and the scope and costs of coverage for acts of terrorism and California earthquake risk in particular, but the Company cannot anticipate what coverage will be available on commercially reasonable terms in future policy years. There are other types of losses, such as from wars, for which the Company cannot obtain insurance at all or at a reasonable cost. With respect to such losses and losses from acts of terrorism, earthquakes or other catastrophic events, if the Company experiences a loss that is uninsured or that exceeds policy limits, the Company could lose the capital invested in the damaged properties, as well as the anticipated future revenues from those properties. Depending on the specific circumstances of each affected property, it is possible that the Company could be liable for mortgage indebtedness or other obligations related to the property. Any such loss could materially and adversely affect the Company's business and financial condition and results of operations.

Legal Matters

The Company is subject to various legal proceedings and claims that arise in the ordinary course of business. These matters are generally covered by insurance. Management believes that the final outcome of such matters will not have a material adverse effect on the financial position, results of operations or liquidity of the Company.

State and Local Tax Matters

Because the Company is organized and qualifies as a REIT, it is generally not subject to federal income taxes, but is subject to certain state and local taxes. In the normal course of business, certain entities through which the Company owns real estate either have undergone, or are currently undergoing, tax audits. Although the Company believes that it has substantial arguments in favor of its positions in the ongoing audits, in some instances there is no controlling precedent or interpretive guidance on the specific point at issue. Collectively, tax deficiency notices received to date from the jurisdictions conducting the ongoing audits have not been material. However, there can be no assurance that future audits will not occur with increased frequency or that the ultimate result of such audits will not have a material adverse effect on the Company’s results of operations.

Environmental Matters

It is the Company’s policy to retain independent environmental consultants to conduct or update Phase I environmental assessments (which generally do not involve invasive techniques such as soil or ground water sampling) and asbestos surveys in connection with the Company’s acquisition of properties. These pre-purchase environmental assessments have not revealed environmental conditions that the Company believes will have a material adverse effect on its business, assets, financial condition, results of operations or liquidity, and the Company is not otherwise aware of environmental conditions with respect to its properties that the Company believes would have such a material adverse effect. However, from time to time environmental conditions at the Company’s properties have required and may in the future require environmental testing and/or regulatory filings, as well as remedial action.

In February 1999, the Company (through a joint venture) acquired from Exxon Corporation a property in Massachusetts that was formerly used as a petroleum bulk storage and distribution facility and was known by the state regulatory authority to contain soil and groundwater contamination. The Company developed an office park on the property. The Company engaged a specially licensed environmental consultant to oversee the management of contaminated soil and groundwater that was disturbed in the course of construction. Under the property acquisition agreement, Exxon agreed to (1) bear the liability arising from releases or discharges of oil and hazardous substances which occurred at the site prior to the Company’s ownership, (2) continue monitoring and/or remediating such releases and discharges as necessary and appropriate to comply with applicable requirements, and (3) indemnify the Company for certain losses arising from preexisting site conditions. Any indemnity claim may be subject to various defenses, and there can be no assurance that the amounts paid under the indemnity, if any, would be sufficient to cover the liabilities arising from any such releases and discharges.

Environmental investigations at some of the Company’s properties and certain properties owned by affiliates of the Company have identified groundwater contamination migrating from off-site source properties. In each case the Company engaged a licensed environmental consultant to perform the necessary investigations and assessments and to prepare any required submittals to the regulatory authorities. In each case the environmental consultant concluded that the properties qualify under the regulatory program or the regulatory practice for a status which eliminates certain deadlines for conducting response actions at a site. The Company also believes that these properties qualify for liability relief under certain statutory provisions or regulatory practices regarding upgradient releases. Although the Company believes that the current or former owners of the upgradient source properties may bear responsibility for some or all of the costs of addressing the identified

groundwater contamination, the Company will take such further response actions (if any) that it deems necessary or advisable. Other than periodic testing at some of these properties, no such additional response actions are anticipated at this time.

Some of the Company’s properties and certain properties owned by the Company’s affiliates are located in urban, industrial and other previously developed areas where fill or current or historical uses of the areas have caused site contamination. Accordingly, it is sometimes necessary to institute special soil and/or groundwater handling procedures and/or include particular building design features in connection with development, construction and other property operations in order to achieve regulatory closure and/or ensure that contaminated materials are addressed in an appropriate manner. In these situations it is the Company’s practice to investigate the nature and extent of detected contamination and estimate the costs of required response actions and special handling procedures. The Company then uses this information as part of its decision-making process with respect to the acquisition and/or development of the property. For example, the Company owns a parcel in Massachusetts which was formerly used as a quarry/asphalt batching facility. Pre-purchase testing indicated that the site contained relatively low levels of certain contaminants. The Company has developed an office park on this property. Prior to and during redevelopment activities, the Company engaged a specially licensed environmental consultant to monitor environmental conditions at the site and prepare necessary regulatory submittals based on the results of an environmental risk characterization. A submittal has been made to the regulatory authorities in order to achieve regulatory closure at this site. The submittal included an environmental deed restriction that mandates compliance with certain protective measures in a portion of the site where low levels of residual soil contamination have been left in place in accordance with applicable laws.

The Company expects that resolution of the environmental matters relating to the above will not have a material impact on its business, assets, financial condition, results of operations or liquidity. However, the Company cannot assure you that it has identified all environmental liabilities at its properties, that all necessary remediation actions have been or will be undertaken at the Company’s properties or that the Company will be indemnified, in full or at all, in the event that such environmental liabilities arise.

Tax Protection Obligations

In connection with the acquisition or contribution of three properties, the Company entered into agreements for the benefit of the selling or contributing parties which specifically state that until such time as the contributors do not hold at least a specified percentage of the OP Units owned by such person following the contribution of the properties, or until June 9, 2017 for 767 Fifth Avenue (the General Motors Building), the Operating Partnership will not sell or otherwise transfer the properties in a taxable transaction. If the Company does sell or transfer the properties in a taxable transaction, it would be liable to the contributors for contractual damages.