Noncontrolling Interests - Change in Carrying Value (Details) - USD ($) $ in Thousands				3 Months Ended		6 Months Ended
	Mar. 28, 2019	Apr. 30, 2018	Mar. 30, 2018	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Change in the carrying value of all noncontrolling interests
Carrying value at beginning of the period						$ 29,702
Allocation of net income				$ 246	$ 226	562	$ 514
Carrying value at end of the period				$ 29,470		$ 29,470
Realty Income, L.P.
Change in the carrying value of all noncontrolling interests
Number of partnership units issued (in units)	89,322	131,790	242,007				89,322
Number of partnership units outstanding (in units)				463,119		463,119		463,119
Noncontrolling interests
Change in the carrying value of all noncontrolling interests
Carrying value at beginning of the period						$ 29,702
Distributions						(794)
Allocation of net income						562
Carrying value at end of the period				$ 29,470		29,470
Noncontrolling interests | Realty Income, L.P.
Change in the carrying value of all noncontrolling interests
Carrying value at beginning of the period						24,596
Distributions						(647)
Allocation of net income						479
Carrying value at end of the period				24,428		24,428
Noncontrolling interests | Other Noncontrolling Interests
Change in the carrying value of all noncontrolling interests
Carrying value at beginning of the period						5,106
Distributions						(147)
Allocation of net income						83
Carrying value at end of the period				$ 5,042		$ 5,042