Noncontrolling Interests - Change in Carrying Value (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Mar. 28, 2019	Apr. 30, 2018	Mar. 30, 2018
Change in the carrying value of all noncontrolling interests
Carrying value at beginning of the period	$ 29,702
Allocation of net income	316	$ 288
Carrying value at end of the period	$ 29,624
Realty Income, L.P.
Change in the carrying value of all noncontrolling interests
Number of partnership units issued (in units)		89,322		89,322	131,790	242,007
Number of partnership units outstanding (in units)	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	(394)
Allocation of net income	316
Carrying value at end of the period	29,624
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	(323)
Allocation of net income	277
Carrying value at end of the period	24,550
Noncontrolling interests | Other Noncontrolling Interests
Change in the carrying value of all noncontrolling interests
Carrying value at beginning of the period	5,106
Distributions	(71)
Allocation of net income	39
Carrying value at end of the period	$ 5,074