Noncontrolling Interests (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		12 Months Ended	1 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Jan. 31, 2015	Jun. 22, 2013	Jun. 27, 2013
Noncontrolling interests
Conversion ratio	1
Change in the carrying value of all noncontrolling interests
Carrying value at beginning of the period	$ 27,698	$ 35,911	$ 35,911	$ 27,698
Reallocation of equity	(1,051)		(6,647)
Redemption	(2,120)		(1,032)
Distributions	(418)		(1,839)
Allocation of net income	317	332	1,305
Carrying value at end of the period	24,426		27,698
Carrying value of preferred units			6,750
Tau Operating Partnership, L.P.
Noncontrolling interests
Realty Income partnership units, ownership interest (as a percent)	99.30%
Change in the carrying value of all noncontrolling interests
Carrying value at beginning of the period	13,067	13,489	13,489	13,067
Reallocation of equity	836
Distributions	(180)		(695)
Allocation of net income	73		273
Carrying value at end of the period	13,796		13,067
Units held by third party	317,022		317,022		317,022
Payment rate per annum (as a percent)			2.00%
Partnership preferred units redeemed (in shares)				6,750
Partnership preferred units redemption price (in dollars per unit)				$ 1,000
Realty Income, L.P.
Noncontrolling interests
Third party partnership units, ownership interest (as a percent)	1.70%
Realty Income partnership units, ownership interest (as a percent)	98.30%
Change in the carrying value of all noncontrolling interests
Carrying value at beginning of the period	14,631	22,422	22,422	14,631
Reallocation of equity	(1,887)		(6,647)
Redemption	(2,120)		(1,032)
Distributions	(238)		(1,144)
Allocation of net income	244		1,032
Carrying value at end of the period	$ 10,630		$ 14,631
Units held by third party	419,546		499,546			534,546