| Cover | Jan. 25, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Jan. 25, 2021 |
| Entity Registrant Name | REALTY INCOME CORPORATION |
| Entity Central Index Key | 0000726728 |
| Amendment Flag | false |
| Entity Incorporation, State or Country Code | MD |
| Entity File Number | 1-13374 |
| Entity Tax Identification Number | 33-0580106 |
| Entity Address, Address Line One | 11995 El Camino Real |
| Entity Address, City or Town | San Diego |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 92130 |
| City Area Code | 858 |
| Local Phone Number | 284-5000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Entity Listings [Line Items] | |
| Document Type | 8-K |
| Document Period End Date | Jan. 25, 2021 |
| Common Stock, $0.01 Par Value | |
| Entity Listings [Line Items] | |
| Title of 12(b) Security | Common Stock, $0.01 Par Value |
| Trading Symbol | O |
| Security Exchange Name | NYSE |
| 1.625% Notes due 2030 | |
| Entity Listings [Line Items] | |
| Title of 12(b) Security | 1.625% Notes due 2030 |
| Trading Symbol | O30 |
| Security Exchange Name | NYSE |
