| Cover | Feb. 22, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Feb. 22, 2021 |
| Entity File Number | 001-13779 |
| Entity Registrant Name | W. P. Carey Inc. |
| Entity Central Index Key | 0001025378 |
| Entity Tax Identification Number | 45-4549771 |
| Entity Incorporation, State or Country Code | MD |
| Entity Address, Address Line One | One Manhattan West |
| Entity Address, Address Line Two | 395 9th Avenue |
| Entity Address, Address Line Three | 58th Floor |
| Entity Address, City or Town | New York |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 10001 |
| City Area Code | 212 |
| Local Phone Number | 492-1100 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $0.001 Par Value |
| Trading Symbol | WPC |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
