Tax Credit Transactions	12 Months Ended
Dec. 31, 2011
Income Tax Disclosure [Abstract]
TAX CREDIT TRANSACTIONS	TAX CREDIT TRANSACTIONS Historic Tax Credit Transaction On November 17, 2008, the Company closed a transaction with US Bancorp (“USB”) related to the historic rehabilitation of the IRS Philadelphia Campus, a 862,692 square foot office building that is 100% leased to the IRS. On August 27, 2010, the Company completed the development of the IRS Philadelphia Campus and the IRS lease commenced. USB agreed to contribute approximately $64.1 million of project costs and advanced $10.2 million of that amount contemporaneously with the closing of the transaction. USB subsequently advanced an additional $27.4 million and $23.8 million in June 2010 and December 2009, respectively. On October 19, 2011, the Company received the remaining $2.7 million of the total contributions upon its completion of certain items and compliance with the federal rehabilitation regulations. In exchange for its contributions into the development of IRS Philadelphia Campus, USB is entitled to substantially all of the benefits derived from the tax rehabilitation credits available under section 47 of the Internal Revenue Code. USB does not have a material interest in the underlying economics of the property. This transaction includes a put/call provision whereby the Company may be obligated or entitled to repurchase USB’s interest in the IRS Philadelphia Campus. The Company believes the put will be exercised and the amount attributed to that puttable non-controlling interest obligation is included in other liabilities and is being accreted to the expected fixed put price. Based on the contractual arrangements that obligate the Company to deliver tax benefits and provide other guarantees to USB and that entitle the Company through fee arrangements to receive substantially all available cash flow from the IRS Philadelphia Campus, the Company concluded that the IRS Philadelphia Campus should be consolidated. The Company also concluded that capital contributions received from USB, in substance, are consideration that the Company receives in exchange for its obligation to deliver tax credits and other tax benefits to USB. These receipts other than the amounts allocated to the put obligation will be recognized as historic tax credit transaction income in the consolidated financial statements beginning when the obligation to USB is relieved which occurs upon delivery of the expected tax benefits net of any associated costs. The tax credit is subject to 20% recapture per year beginning one year after the completion of the IRS Philadelphia Campus. The total USB contributions presented within deferred income in the Company's consolidated balance sheet amounted to to $51.6 million as of December 31, 2011 and $61.4 million as of December 31, 2010, respectively. The contributions were recorded net of the amount allocated to non-controlling interest as described above of $2.4 million and $2.1 million at December 31, 2011 and December 31, 2010, respectively. Beginning in September 2011 to September 2015, the Company recognized and will recognize the cash received as revenue net of allocated expenses over the five year credit recapture period as defined in the Internal Revenue Code within other income (expense) in its consolidated statements of operations. During the year ended December 31, 2011, the Company recognized $12.0 million of the cash received as revenue net of $0.5 million of allocated expenses within other income (expense) in its consolidated statements of operations. Direct and incremental costs incurred in structuring the transaction are deferred and will be recognized as expense in the consolidated financial statements upon the recognition of the related revenue as discussed above. The deferred costs at December 31, 2011 and 2010 are $2.1 million and $4.3 million, respectively, and are included in other assets on the Company’s consolidated balance sheet. Amounts included in interest expense related to the accretion of the non-controlling interest liability and the 2% return expected to be paid to USB on its non-controlling interest aggregate to $1.3 million, $1.1 million and $0.2 million for years ended December 31, 2011, 2010 and 2009, respectively. New Markets Tax Credit Transaction On December 30, 2008, the Company entered into a transaction with USB related to the Cira South Garage in Philadelphia, Pennsylvania and expects to receive a net benefit of $7.8 million under a qualified New Markets Tax Credit Program (“NMTC”). The NMTC was provided for in the Community Renewal Tax Relief Act of 2000 (the “Act”) and is intended to induce investment capital in underserved and impoverished areas of the United States. The Act permits taxpayers (whether companies or individuals) to claim credits against their Federal income taxes for up to 39% of qualified investments in qualified, active low-income businesses or ventures. USB contributed $13.3 million into the development of the Cira South Garage and as such it is entitled to substantially all of the benefits derived from the tax credit, but it does not have a material interest in the underlying economics of the Cira South Garage. This transaction also includes a put/call provision whereby the Company may be obligated or entitled to repurchase USB’s interest. The Company believes the put will be exercised and an amount attributed to that obligation is included in other liabilities and is being accreted to the expected fixed put price. The said put price is insignificant. Based on the contractual arrangements that obligate the Company to deliver tax benefits and provide various other guarantees to USB, the Company concluded that the investment entities established to facilitate the NMTC transaction should be consolidated. The USB contribution of $13.3 million is included in deferred income on the Company’s consolidated balance sheet at December 31, 2011 and December 31, 2010. The USB contribution other than the amount allocated to the put obligation will be recognized as income in the consolidated financial statements when the tax benefits are delivered without risk of recapture to the tax credit investors and the Company’s obligation is relieved. The Company anticipates that it will recognize the net cash received as revenue within other income/expense in the year ended December 31, 2015. The NMTC is subject to 100% recapture for a period of seven years as provided in the Internal Revenue Code. The Company expects that the put/call provision will be exercised in December 2015 when the recapture period ends. Direct and incremental costs incurred in structuring the transaction are deferred and will be recognized as expense in the consolidated financial statements upon the recognition of the related revenue as discussed above. The deferred cost at December 31, 2011 and 2010 is $5.3 million and is included in other assets on the Company’s consolidated balance sheet.

TAX CREDIT TRANSACTIONS

Historic Tax Credit Transaction

On November 17, 2008, the Company closed a transaction with US Bancorp (“USB”) related to the historic rehabilitation of the IRS Philadelphia Campus, a 862,692 square foot office building that is 100% leased to the IRS. On August 27, 2010, the Company completed the development of the IRS Philadelphia Campus and the IRS lease commenced. USB agreed to contribute approximately $64.1 million of project costs and advanced $10.2 million of that amount contemporaneously with the closing of the transaction. USB subsequently advanced an additional $27.4 million and $23.8 million in June 2010 and December 2009, respectively. On October 19, 2011, the Company received the remaining $2.7 million of the total contributions upon its completion of certain items and compliance with the federal rehabilitation regulations.

In exchange for its contributions into the development of IRS Philadelphia Campus, USB is entitled to substantially all of the benefits derived from the tax rehabilitation credits available under section 47 of the Internal Revenue Code. USB does not have a material interest in the underlying economics of the property. This transaction includes a put/call provision whereby the Company may be obligated or entitled to repurchase USB’s interest in the IRS Philadelphia Campus. The Company believes the put will be exercised and the amount attributed to that puttable non-controlling interest obligation is included in other liabilities and is being accreted to the expected fixed put price.

Based on the contractual arrangements that obligate the Company to deliver tax benefits and provide other guarantees to USB and that entitle the Company through fee arrangements to receive substantially all available cash flow from the IRS Philadelphia Campus, the Company concluded that the IRS Philadelphia Campus should be consolidated. The Company also concluded that capital contributions received from USB, in substance, are consideration that the Company receives in exchange for its obligation to deliver tax credits and other tax benefits to USB. These receipts other than the amounts allocated to the put obligation will be recognized as historic tax credit transaction income in the consolidated financial statements beginning when the obligation to USB is relieved which occurs upon delivery of the expected tax benefits net of any associated costs. The tax credit is subject to 20% recapture per year beginning one year after the completion of the IRS Philadelphia Campus. The total USB contributions presented within deferred income in the Company's consolidated balance sheet amounted to to $51.6 million as of December 31, 2011 and $61.4 million as of December 31, 2010, respectively. The contributions were recorded net of the amount allocated to non-controlling interest as described above of $2.4 million and $2.1 million at December 31, 2011 and December 31, 2010, respectively. Beginning in September 2011 to September 2015, the Company recognized and will recognize the cash received as revenue net of allocated expenses over the five year credit recapture period as defined in the Internal Revenue Code within other income (expense) in its consolidated statements of operations. During the year ended December 31, 2011, the Company recognized $12.0 million of the cash received as revenue net of $0.5 million of allocated expenses within other income (expense) in its consolidated statements of operations.

Direct and incremental costs incurred in structuring the transaction are deferred and will be recognized as expense in the consolidated financial statements upon the recognition of the related revenue as discussed above. The deferred costs at December 31, 2011 and 2010 are $2.1 million and $4.3 million, respectively, and are included in other assets on the Company’s consolidated balance sheet. Amounts included in interest expense related to the accretion of the non-controlling interest liability and the 2% return expected to be paid to USB on its non-controlling interest aggregate to $1.3 million, $1.1 million and $0.2 million for years ended December 31, 2011, 2010 and 2009, respectively.

New Markets Tax Credit Transaction

On December 30, 2008, the Company entered into a transaction with USB related to the Cira South Garage in Philadelphia, Pennsylvania and expects to receive a net benefit of $7.8 million under a qualified New Markets Tax Credit Program (“NMTC”). The NMTC was provided for in the Community Renewal Tax Relief Act of 2000 (the “Act”) and is intended to induce investment capital in underserved and impoverished areas of the United States. The Act permits taxpayers (whether companies or individuals) to claim credits against their Federal income taxes for up to 39% of qualified investments in qualified, active low-income businesses or ventures.

USB contributed $13.3 million into the development of the Cira South Garage and as such it is entitled to substantially all of the benefits derived from the tax credit, but it does not have a material interest in the underlying economics of the Cira South Garage. This transaction also includes a put/call provision whereby the Company may be obligated or entitled to repurchase USB’s interest. The Company believes the put will be exercised and an amount attributed to that obligation is included in other liabilities and is being accreted to the expected fixed put price. The said put price is insignificant.

Based on the contractual arrangements that obligate the Company to deliver tax benefits and provide various other guarantees to USB, the Company concluded that the investment entities established to facilitate the NMTC transaction should be consolidated. The USB contribution of $13.3 million is included in deferred income on the Company’s consolidated balance sheet at December 31, 2011 and December 31, 2010. The USB contribution other than the amount allocated to the put obligation will be recognized as income in the consolidated financial statements when the tax benefits are delivered without risk of recapture to the tax credit investors and the Company’s obligation is relieved. The Company anticipates that it will recognize the net cash received as revenue within other income/expense in the year ended December 31, 2015. The NMTC is subject to 100% recapture for a period of seven years as provided in the Internal Revenue Code. The Company expects that the put/call provision will be exercised in December 2015 when the recapture period ends.