Business and Organization	6 Months Ended
Jun. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Business and Organization	Business and Organization W. P. Carey Inc., or W. P. Carey, is, together with its consolidated subsidiaries, a REIT that provides long-term financing via sale-leaseback and build-to-suit transactions for companies worldwide and manages a global investment portfolio. We invest primarily in commercial properties domestically and internationally. We earn revenue principally by leasing the properties we own to single corporate tenants, on a triple-net lease basis, which generally requires each tenant to pay the costs associated with operating and maintaining the property. Originally founded in 1973, we reorganized as a REIT in September 2012 in connection with our merger with Corporate Property Associates 15 Incorporated. We refer to that merger as the CPA^®:15 Merger. On January 31, 2014, Corporate Property Associates 16 – Global Incorporated, or CPA^®:16 – Global, merged with and into us, which we refer to as the CPA^®:16 Merger. Our shares of common stock are listed on the New York Stock Exchange under the symbol “WPC.” We have elected to be taxed as a REIT under Section 856 through 860 of the Internal Revenue Code. As a REIT, we are not generally subject to United States federal income taxation other than from our taxable REIT subsidiaries, or TRSs, as long as we satisfy certain requirements, principally relating to the nature of our income and the level of our distributions, as well as other factors. We also own real property in jurisdictions outside the United States through foreign subsidiaries and are subject to income taxes on our pre-tax income earned from properties in such countries. We hold all of our real estate assets attributable to our Owned Real Estate segment under the REIT structure, while the activities conducted by our Investment Management segment subsidiaries have been organized under TRSs. Through our TRSs, we also earn revenue as the advisor to publicly owned, non-listed REITs, which are sponsored by us under the Corporate Property Associates, or CPA^®,brand name and invest in similar properties. At June 30, 2017, we were the advisor to Corporate Property Associates 17 – Global Incorporated, or CPA^®:17 – Global, and Corporate Property Associates 18 – Global Incorporated, or CPA^®:18 – Global. We refer to CPA^®:17 – Global and CPA^®:18 – Global together as the CPA^® REITs. At June 30, 2017, we were also the advisor to Carey Watermark Investors Incorporated, or CWI 1, and Carey Watermark Investors 2 Incorporated, or CWI 2, two publicly owned, non-listed REITs that invest in lodging and lodging-related properties. We refer to CWI 1 and CWI 2 together as the CWI REITs and, together with the CPA^® REITs, as the Managed REITs (Note 3). At June 30, 2017, we also served as the advisor to Carey Credit Income Fund, or CCIF, and its feeder funds, or the CCIF Feeder Funds, each of which is a business development company, or BDC (Note 3). We refer to CCIF and the CCIF Feeder Funds collectively as the Managed BDCs. At June 30, 2017, we were also the advisor to Carey European Student Housing Fund I, L.P., or CESH I, a limited partnership formed for the purpose of developing, owning, and operating student housing properties and similar investments in Europe. We refer to the Managed REITs, Managed BDCs, and CESH I collectively as the Managed Programs. On June 15, 2017, our board of directors, or the Board, approved a plan to exit all non-traded retail fundraising activities carried out by our wholly-owned broker-dealer subsidiary, Carey Financial LLC, or Carey Financial, as of June 30, 2017. We currently expect to continue to manage all existing Managed Programs through the end of their natural life cycles (Note 3). Reportable Segments As a result of our Board’s decision to exit all non-traded retail fundraising activities, described above, we have revised how we view and present a component of our two reportable segments. As such, effective for the second quarter of 2017, we include equity income generated through our (i) ownership of shares and limited partnership units of the Managed REITs and CESH I and (ii) special member interests in the operating partnerships of the Managed REITs in our Investment Management segment. Previously, these items were recognized within our Owned Real Estate segment. We also include our equity investments in the Managed REITs and CESH I in our Investment Management segment. Both (i) equity in earnings of our equity method investment in CCIF and (ii) our equity investment in CCIF continue to be included in our Investment Management segment. Results of operations and assets by segment for prior periods have been reclassified to conform to the current period presentation. Owned Real Estate — We own and invest in commercial properties principally in North America, Europe, Australia, and Asia that are then leased to companies, primarily on a triple-net lease basis. We also own two hotels, which are considered operating properties. We earn lease revenues from our wholly-owned and co-owned real estate investments that we control. In addition, we generate equity income through co-owned real estate investments that we do not control (Note 7). At June 30, 2017, our owned portfolio was comprised of our full or partial ownership interests in 895 properties, totaling approximately 86.6 million square feet, substantially all of which were net leased to 214 tenants, with an occupancy rate of 99.3%. Investment Management — Through our TRSs, we structure and negotiate investments and debt placement transactions for the Managed REITs and CESH I, for which we earn structuring revenue, and manage their portfolios of real estate investments, for which we earn asset management revenue. We also earn asset management revenue from CCIF based on the average of its gross assets at fair value. We may earn disposition revenue when we negotiate and structure the sale of properties on behalf of the Managed REITs, and we may also earn incentive revenue and receive other compensation through our advisory agreements with certain of the Managed Programs, including in connection with providing liquidity events for the Managed REITs’ stockholders. In addition, we generate equity income through our ownership of shares and limited partnership units of the Managed Programs (Note 7). Through our special member interests in the operating partnerships of the Managed REITs, we also participate in their cash flows (Note 3). Our Board’s decision to exit all non-traded retail fundraising activities through Carey Financial as of June 30, 2017, as discussed above, will not affect the continuation of these current revenue streams. At June 30, 2017, the CPA^®REITs collectively owned all or a portion of 461 properties (including certain properties in which we have an ownership interest), totaling approximately 54.1 million square feet, substantially all of which were net leased to 210 tenants, with an occupancy rate of approximately 99.8%. The Managed REITs and CESH I also had interests in 164 operating properties, totaling approximately 19.7 million square feet in the aggregate.

Business and Organization

W. P. Carey Inc., or W. P. Carey, is, together with its consolidated subsidiaries, a REIT that provides long-term financing via sale-leaseback and build-to-suit transactions for companies worldwide and manages a global investment portfolio. We invest primarily in commercial properties domestically and internationally. We earn revenue principally by leasing the properties we own to single corporate tenants, on a triple-net lease basis, which generally requires each tenant to pay the costs associated with operating and maintaining the property.

Originally founded in 1973, we reorganized as a REIT in September 2012 in connection with our merger with Corporate Property Associates 15 Incorporated. We refer to that merger as the CPA^®:15 Merger. On January 31, 2014, Corporate Property Associates 16 – Global Incorporated, or CPA^®:16 – Global, merged with and into us, which we refer to as the CPA^®:16 Merger. Our shares of common stock are listed on the New York Stock Exchange under the symbol “WPC.”

We have elected to be taxed as a REIT under Section 856 through 860 of the Internal Revenue Code. As a REIT, we are not generally subject to United States federal income taxation other than from our taxable REIT subsidiaries, or TRSs, as long as we satisfy certain requirements, principally relating to the nature of our income and the level of our distributions, as well as other factors. We also own real property in jurisdictions outside the United States through foreign subsidiaries and are subject to income taxes on our pre-tax income earned from properties in such countries. We hold all of our real estate assets attributable to our Owned Real Estate segment under the REIT structure, while the activities conducted by our Investment Management segment subsidiaries have been organized under TRSs.

Through our TRSs, we also earn revenue as the advisor to publicly owned, non-listed REITs, which are sponsored by us under the Corporate Property Associates, or CPA^®,brand name and invest in similar properties. At June 30, 2017, we were the advisor to Corporate Property Associates 17 – Global Incorporated, or CPA^®:17 – Global, and Corporate Property Associates 18 – Global Incorporated, or CPA^®:18 – Global. We refer to CPA^®:17 – Global and CPA^®:18 – Global together as the CPA^® REITs.

At June 30, 2017, we were also the advisor to Carey Watermark Investors Incorporated, or CWI 1, and Carey Watermark Investors 2 Incorporated, or CWI 2, two publicly owned, non-listed REITs that invest in lodging and lodging-related properties. We refer to CWI 1 and CWI 2 together as the CWI REITs and, together with the CPA^® REITs, as the Managed REITs (Note 3).

At June 30, 2017, we also served as the advisor to Carey Credit Income Fund, or CCIF, and its feeder funds, or the CCIF Feeder Funds, each of which is a business development company, or BDC (Note 3). We refer to CCIF and the CCIF Feeder Funds collectively as the Managed BDCs.

At June 30, 2017, we were also the advisor to Carey European Student Housing Fund I, L.P., or CESH I, a limited partnership formed for the purpose of developing, owning, and operating student housing properties and similar investments in Europe. We refer to the Managed REITs, Managed BDCs, and CESH I collectively as the Managed Programs.

On June 15, 2017, our board of directors, or the Board, approved a plan to exit all non-traded retail fundraising activities carried out by our wholly-owned broker-dealer subsidiary, Carey Financial LLC, or Carey Financial, as of June 30, 2017. We currently expect to continue to manage all existing Managed Programs through the end of their natural life cycles (Note 3).

Reportable Segments

As a result of our Board’s decision to exit all non-traded retail fundraising activities, described above, we have revised how we view and present a component of our two reportable segments. As such, effective for the second quarter of 2017, we include equity income generated through our (i) ownership of shares and limited partnership units of the Managed REITs and CESH I and (ii) special member interests in the operating partnerships of the Managed REITs in our Investment Management segment. Previously, these items were recognized within our Owned Real Estate segment. We also include our equity investments in the Managed REITs and CESH I in our Investment Management segment. Both (i) equity in earnings of our equity method investment in CCIF and (ii) our equity investment in CCIF continue to be included in our Investment Management segment. Results of operations and assets by segment for prior periods have been reclassified to conform to the current period presentation.

Owned Real Estate — We own and invest in commercial properties principally in North America, Europe, Australia, and Asia that are then leased to companies, primarily on a triple-net lease basis. We also own two hotels, which are considered operating properties. We earn lease revenues from our wholly-owned and co-owned real estate investments that we control. In addition, we generate equity income through co-owned real estate investments that we do not control (Note 7). At June 30, 2017, our owned portfolio was comprised of our full or partial ownership interests in 895 properties, totaling approximately 86.6 million square feet, substantially all of which were net leased to 214 tenants, with an occupancy rate of 99.3%.

Investment Management — Through our TRSs, we structure and negotiate investments and debt placement transactions for the Managed REITs and CESH I, for which we earn structuring revenue, and manage their portfolios of real estate investments, for which we earn asset management revenue. We also earn asset management revenue from CCIF based on the average of its gross assets at fair value. We may earn disposition revenue when we negotiate and structure the sale of properties on behalf of the Managed REITs, and we may also earn incentive revenue and receive other compensation through our advisory agreements with certain of the Managed Programs, including in connection with providing liquidity events for the Managed REITs’ stockholders.

In addition, we generate equity income through our ownership of shares and limited partnership units of the Managed Programs (Note 7). Through our special member interests in the operating partnerships of the Managed REITs, we also participate in their cash flows (Note 3). Our Board’s decision to exit all non-traded retail fundraising activities through Carey Financial as of June 30, 2017, as discussed above, will not affect the continuation of these current revenue streams. At June 30, 2017, the CPA^®REITs collectively owned all or a portion of 461 properties (including certain properties in which we have an ownership interest), totaling approximately 54.1 million square feet, substantially all of which were net leased to 210 tenants, with an occupancy rate of approximately 99.8%. The Managed REITs and CESH I also had interests in 164 operating properties, totaling approximately 19.7 million square feet in the aggregate.