Cover Page - shares	9 Months Ended
	Sep. 30, 2019	Oct. 29, 2019
Cover page.
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2019
Document Transition Report	false
Entity File Number	1-13374
Entity Registrant Name	REALTY INCOME CORPORATION
Entity Central Index Key	0000726728
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Incorporation, State or Country Code	MD
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
Title of 12(b) Security	Common Stock, $0.01 Par Value
Trading Symbol	O
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		325,919,119