| Cover Page Document | Sep. 17, 2020 |
| Cover page. | |
| Document Type | 8-K |
| Document Period End Date | Sep. 17, 2020 |
| Entity Registrant Name | W. P. Carey Inc. |
| Entity Incorporation, State or Country Code | MD |
| Entity File Number | 001-13779 |
| Entity Tax Identification Number | 45-4549771 |
| Entity Address, Street Address | 50 Rockefeller Plaza, |
| Entity Address, City | New York, |
| Entity Address, State | NY |
| Entity Address, Postal Zip Code | 10020 |
| City Area Code | 212 |
| Local Phone Number | 492-1100 |
| Title of each class | Common Stock, $0.001 Par Value |
| Trading Symbol | WPC |
| Name of each exchange on which registered | NYSE |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0001025378 |
| Amendment Flag | false |
