Noncontrolling Interests (Details) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017 USD ($) shares	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($) shares	Sep. 30, 2016 USD ($)	Dec. 31, 2016 USD ($) property item shares	Jun. 27, 2013 shares	Jan. 22, 2013 shares
Noncontrolling interests
Conversion ratio			1
Number of properties acquired | property					2
Number of joint ventures controlling interest acquired | item					2
Change in the carrying value of all noncontrolling interests
Carrying value at beginning of the period			$ 20,249
Reallocation of equity			485
Distributions			(1,656)
Allocation of net income	$ 133	$ 130	420	$ 623
Carrying value at end of the period	$ 19,498		$ 19,498		$ 20,249
Joint Venture One
Noncontrolling interests
Ownership interest (as a percent)	95.00%		95.00%
Joint Venture Two
Noncontrolling interests
Ownership interest (as a percent)	74.00%		74.00%
Tau Operating Partnership
Noncontrolling interests
Realty Income partnership units, ownership interest (as a percent)	99.40%		99.40%
Change in the carrying value of all noncontrolling interests
Carrying value at beginning of the period			$ 13,405
Reallocation of equity			492
Distributions			(602)
Allocation of net income			189
Carrying value at end of the period	$ 13,484		$ 13,484		$ 13,405
Units held by third party | shares	317,022		317,022		317,022		317,022
Realty Income, L.P.
Noncontrolling interests
Third party partnership units, ownership interest (as a percent)	0.40%		0.40%
Realty Income partnership units, ownership interest (as a percent)	99.60%		99.60%
Change in the carrying value of all noncontrolling interests
Carrying value at beginning of the period			$ 2,216
Reallocation of equity			(26)
Distributions			(167)
Allocation of net income			151
Carrying value at end of the period	$ 2,174		$ 2,174		$ 2,216
Units held by third party | shares	88,182		88,182		88,182	534,546
Other Noncontrolling Interests
Change in the carrying value of all noncontrolling interests
Carrying value at beginning of the period			$ 4,628
Reallocation of equity			19
Distributions			(887)
Allocation of net income			80
Carrying value at end of the period	$ 3,840		$ 3,840		$ 4,628