Basis of Presentation	3 Months Ended
Mar. 31, 2012
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]	Note 2. Basis of Presentation Our interim consolidated financial statements have been prepared, without audit, in accordance with the instructions to Form 10-Q and, therefore, do not necessarily include all information and footnotes necessary for a fair statement of our consolidated financial position, results of operations and cash flows in accordance with accounting principles generally accepted in the U.S. (“GAAP”). In the opinion of management, the unaudited financial information for the interim periods presented in this Report reflects all normal and recurring adjustments necessary for a fair statement of results of operations, financial position and cash flows. Our interim consolidated financial statements should be read in conjunction with our audited consolidated financial statements and accompanying notes for the year ended December 31, 2011, which are included in our 2011 Annual Report, as certain disclosures that would substantially duplicate those contained in the audited consolidated financial statements have not been included in this Report. Operating results for interim periods are not necessarily indicative of operating results for an entire fiscal year. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts and the disclosure of contingent amounts in our consolidated financial statements and the accompanying notes. Actual results could differ from those estimates. The unaudited consolidated financial statements included in this Report have been retrospectively adjusted to reflect the disposition (or planned disposition) of certain properties as discontinued operations for all periods presented. Basis of Consolidation The consolidated financial statements reflect all of our accounts, including those of our majority-owned and/or controlled subsidiaries. The portion of equity in a subsidiary that is not attributable, directly or indirectly, to us is presented as noncontrolling interests. All significant intercompany accounts and transactions have been eliminated. We have investments in tenancy-in-common interests in various domestic and international properties. Consolidation of these investments is not required as they do not qualify as VIEs and do not meet the control requirement required for consolidation. Accordingly, we account for these investments using the equity method of accounting under current authoritative accounting guidance. We use the equity method of accounting because the shared decision-making involved in a tenancy-in-common interest investment creates an opportunity for us to have significant influence on the operating and financial decisions of these investments and thereby creates some responsibility by us to achieve a return on our investment. Additionally, we own interests in single-tenant net leased properties leased to corporations through noncontrolling interests in partnerships and limited liability companies that we do not control but over which we exercise significant influence. We account for these investments under the equity method of accounting. At times the carrying value of our equity investments may fall below zero for certain investments. We intend to fund our share of the investments' future operating deficits should the need arise. However, we have no legal obligation to pay for any of the liabilities of such investments nor do we have any legal obligation to fund operating deficits. Counterparty Credit Risk Portfolio Exception Election Effective January 1, 2011, or the “effective date,” we have made an accounting policy election to use the exception in Accounting Standards Codification 820-10-35-18D, the “portfolio exception,” with respect to measuring counterparty credit risk for derivative instruments, consistent with the guidance in 820-10-35-18G. We manage credit risk for our derivative positions on a counterparty-by-counterparty basis (that is, on the basis of its net portfolio exposure with each counterparty), consistent with our risk management strategy for such transactions. We manage credit risk by considering indicators of risk such as credit ratings, and by negotiating terms in our International Swaps and Derivatives Association, Inc. (“ISDA”) master netting arrangements with each individual counterparty. Credit risk plays a central role in the decision of which counterparties to consider for such relationships and when deciding with whom it will enter into derivative transactions. Since the effective date, we have monitored and measured credit risk and calculated credit valuation adjustments for our derivative transactions on the basis of its relationships at ISDA master netting arrangement level. We receive reports from an independent third-party valuation specialist on quarterly basis providing the credit valuation adjustments at the counterparty portfolio level for purposes of reviewing and managing our credit risk exposures. Since the portfolio exception applies only to the fair value measurement and not to financial statement presentation, the portfolio-level adjustments are then allocated in a reasonable and consistent manner each period to the individual assets or liabilities that make up the group, in accordance with other applicable accounting guidance and our accounting policy elections. Derivative transactions are measured at fair value in the statement of financial position each reporting period. We note that key market participants take into account the existence of such arrangements that mitigate credit risk exposure in the event of default. As such, we elect to apply the portfolio exception in 820-10-35-18D with respect to measuring counterparty credit risk for all of our derivative transactions subject to master netting arrangements.

Basis of Presentation

3 Months Ended

Mar. 31, 2012

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]

Note 2. Basis of Presentation

Our interim consolidated financial statements have been prepared, without audit, in accordance with the instructions to Form 10-Q and, therefore, do not necessarily include all information and footnotes necessary for a fair statement of our consolidated financial position, results of operations and cash flows in accordance with accounting principles generally accepted in the U.S. (“GAAP”).

In the opinion of management, the unaudited financial information for the interim periods presented in this Report reflects all normal and recurring adjustments necessary for a fair statement of results of operations, financial position and cash flows. Our interim consolidated financial statements should be read in conjunction with our audited consolidated financial statements and accompanying notes for the year ended December 31, 2011, which are included in our 2011 Annual Report, as certain disclosures that would substantially duplicate those contained in the audited consolidated financial statements have not been included in this Report. Operating results for interim periods are not necessarily indicative of operating results for an entire fiscal year.

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts and the disclosure of contingent amounts in our consolidated financial statements and the accompanying notes. Actual results could differ from those estimates. The unaudited consolidated financial statements included in this Report have been retrospectively adjusted to reflect the disposition (or planned disposition) of certain properties as discontinued operations for all periods presented.

Basis of Consolidation

The consolidated financial statements reflect all of our accounts, including those of our majority-owned and/or controlled subsidiaries. The portion of equity in a subsidiary that is not attributable, directly or indirectly, to us is presented as noncontrolling interests. All significant intercompany accounts and transactions have been eliminated.

We have investments in tenancy-in-common interests in various domestic and international properties. Consolidation of these investments is not required as they do not qualify as VIEs and do not meet the control requirement required for consolidation. Accordingly, we account for these investments using the equity method of accounting under current authoritative accounting guidance. We use the equity method of accounting because the shared decision-making involved in a tenancy-in-common interest investment creates an opportunity for us to have significant influence on the operating and financial decisions of these investments and thereby creates some responsibility by us to achieve a return on our investment. Additionally, we own interests in single-tenant net leased properties leased to corporations through noncontrolling interests in partnerships and limited liability companies that we do not control but over which we exercise significant influence. We account for these investments under the equity method of accounting. At times the carrying value of our equity investments may fall below zero for certain investments. We intend to fund our share of the investments' future operating deficits should the need arise. However, we have no legal obligation to pay for any of the liabilities of such investments nor do we have any legal obligation to fund operating deficits.

Counterparty Credit Risk Portfolio Exception Election

Effective January 1, 2011, or the “effective date,” we have made an accounting policy election to use the exception in Accounting Standards Codification 820-10-35-18D, the “portfolio exception,” with respect to measuring counterparty credit risk for derivative instruments, consistent with the guidance in 820-10-35-18G. We manage credit risk for our derivative positions on a counterparty-by-counterparty basis (that is, on the basis of its net portfolio exposure with each counterparty), consistent with our risk management strategy for such transactions. We manage credit risk by considering indicators of risk such as credit ratings, and by negotiating terms in our International Swaps and Derivatives Association, Inc. (“ISDA”) master netting arrangements with each individual counterparty. Credit risk plays a central role in the decision of which counterparties to consider for such relationships and when deciding with whom it will enter into derivative transactions. Since the effective date, we have monitored and measured credit risk and calculated credit valuation adjustments for our derivative transactions on the basis of its relationships at ISDA master netting arrangement level. We receive reports from an independent third-party valuation specialist on quarterly basis providing the credit valuation adjustments at the counterparty portfolio level for purposes of reviewing and managing our credit risk exposures. Since the portfolio exception applies only to the fair value measurement and not to financial statement presentation, the portfolio-level adjustments are then allocated in a reasonable and consistent manner each period to the individual assets or liabilities that make up the group, in accordance with other applicable accounting guidance and our accounting policy elections. Derivative transactions are measured at fair value in the statement of financial position each reporting period. We note that key market participants take into account the existence of such arrangements that mitigate credit risk exposure in the event of default. As such, we elect to apply the portfolio exception in 820-10-35-18D with respect to measuring counterparty credit risk for all of our derivative transactions subject to master netting arrangements.