| Cover | Oct. 22, 2021 |
| Entity Information [Line Items] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Oct. 22, 2021 |
| Entity File Number | 1-13374 |
| Entity Registrant Name | REALTY INCOME CORPORATION |
| Entity Central Index Key | 0000726728 |
| Entity Tax Identification Number | 33-0580106 |
| Entity Incorporation, State or Country Code | MD |
| 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 |
| Common Stock [Member] | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | Common Stock, $0.01 Par value |
| Trading Symbol | O |
| Security Exchange Name | NYSE |
| 1.125% Notes due 2027 [Member] | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | 1.125% Notes due 2027 |
| Trading Symbol | O27A |
| Security Exchange Name | NYSE |
| 1.625% Notes due 2030 [Member] | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | 1.625% Notes due 2030 |
| Trading Symbol | O30 |
| Security Exchange Name | NYSE |
| 1.750% Notes due 2033 [Member] | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | 1.750% Notes due 2033 |
| Trading Symbol | O33A |
| Security Exchange Name | NYSE |
