Common Stock Incentive Plan	9 Months Ended
Common Stock Incentive Plan	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Common Stock Incentive Plan	Common Stock Incentive Plan In 2012, our Board of Directors adopted and stockholders approved the Realty Income Corporation 2012 Incentive Award Plan, or the 2012 Plan, to enable us to motivate, attract and retain the services of directors and employees considered essential to our long-term success. The 2012 Plan offers our directors and employees an opportunity to own our stock or rights that will reflect our growth, development and financial success. Under the terms of the 2012 plan, the aggregate number of shares of our common stock subject to options, restricted stock, stock appreciation rights, restricted stock units and other awards, will be no more than 3,985,734 shares. The 2012 Plan has a term of ten years from the date it was adopted by our Board of Directors. The amount of share-based compensation costs recognized in general and administrative expense on our consolidated statements of income was $3.9 million during the third quarter of 2018, $3.4 million during the third quarter of 2017, $12.5 million during the first nine months of 2018 and $10.6 million during the first nine months of 2017. A. Restricted Stock During the first nine months of 2018, we granted 147,000 shares of common stock under the 2012 Plan. This included an annual grant of 28,000 shares of common stock to the independent members of our Board of Directors in May 2018, of which 20,000 shares vested immediately, 4,000 shares vest in equal parts over a three-year service period, and 4,000 shares vest in equal parts over a two-year service period. In addition, in July 2018, we granted 8,000 shares of common stock to our two newly appointed independent directors of our Board of Directors, which vest in equal parts over a three-year service period. With the exception of shares granted to our independent directors, shares granted to employees typically vest in equal parts over a four-year service period. As of September 30, 2018, the remaining unamortized share-based compensation expense related to restricted stock totaled $16.7 million, which is being amortized on a straight-line basis over the service period of each applicable award. The amount of share-based compensation is based on the fair value of the stock at the grant date. We define the grant date as the date the recipient and Realty Income have a mutual understanding of the key terms and conditions of the award, and the recipient of the grant begins to benefit from, or be adversely affected by, subsequent changes in the price of the shares. B. Performance Shares and Restricted Stock Units During the first nine months of 2018, we granted 190,449 performance shares, as well as dividend equivalent rights, to our executive officers. The performance shares are earned based on our Total Shareholder Return (TSR) performance relative to select industry indices and peer groups as well as achievement of certain operating metrics, and vest 50% on the first and second January 1 after the end of the three year performance period, subject to continued service. During the first nine months of 2018, we also granted 8,383 restricted stock units, all of which vest over a four-year service period. These restricted stock units have the same economic rights as shares of restricted stock. As of September 30, 2018, the remaining share-based compensation expense related to the performance shares and restricted stock units totaled $13.6 million. The fair value of the performance shares were estimated on the date of grant using a Monte Carlo Simulation model. The performance shares are being recognized on a tranche-by-tranche basis over the service period. The amount of share-based compensation for the restricted stock units is based on the fair value of our common stock at the grant date. The restricted stock units are being recognized on a straight-line basis over the service period.