Distributions Paid and Payable (Details) (USD $)	9 Months Ended		1 Months Ended	9 Months Ended	0 Months Ended	9 Months Ended	1 Months Ended																		9 Months Ended		1 Months Ended	3 Months Ended	9 Months Ended			12 Months Ended		0 Months Ended	1 Months Ended	9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Jun. 30, 2013 Realty Income, L.P. Common Units	Sep. 30, 2013 Realty Income, L.P. Common Units item	Jan. 22, 2013 ARCT	Sep. 30, 2013 ARCT Tau Operating Partnership, L.P. Common Units item	Sep. 30, 2013 Common stock	Aug. 31, 2013 Common stock	Jul. 31, 2013 Common stock	Jun. 30, 2013 Common stock	May 31, 2013 Common stock	Apr. 30, 2013 Common stock	Mar. 31, 2013 Common stock	Feb. 28, 2013 Common stock	Jan. 31, 2013 Common stock	Sep. 30, 2012 Common stock	Aug. 31, 2012 Common stock	Jul. 31, 2012 Common stock	Jun. 30, 2012 Common stock	May 31, 2012 Common stock	Apr. 30, 2012 Common stock	Mar. 31, 2012 Common stock	Feb. 29, 2012 Common stock	Jan. 31, 2012 Common stock	Sep. 30, 2013 Common stock	Sep. 30, 2012 Common stock	Mar. 31, 2012 Class D Cumulative Redeemable Preferred Stock	Mar. 31, 2012 Class D Cumulative Redeemable Preferred Stock	Sep. 30, 2013 Class D Cumulative Redeemable Preferred Stock	Sep. 30, 2013 Class E Cumulative Redeemable Preferred Stock M	Sep. 30, 2012 Class E Cumulative Redeemable Preferred Stock M	Dec. 31, 2006 Class E Cumulative Redeemable Preferred Stock	Dec. 07, 2011 Class E Cumulative Redeemable Preferred Stock	Mar. 15, 2012 Class F Cumulative Redeemable Preferred Stock	Feb. 29, 2012 Class F Cumulative Redeemable Preferred Stock	Sep. 30, 2013 Class F Cumulative Redeemable Preferred Stock M	Sep. 30, 2012 Class F Cumulative Redeemable Preferred Stock M	Apr. 30, 2012 Class F Cumulative Redeemable Preferred Stock
Distributions paid and payable
Dividends paid per common share (in dollars per share)							$ 0.1815417	$ 0.1815417	$ 0.1815417	$ 0.1812292	$ 0.1812292	$ 0.1812292	$ 0.1809167	$ 0.1809167	$ 0.1517500	$ 0.1511250	$ 0.1461250	$ 0.1461250	$ 0.1458125	$ 0.1458125	$ 0.1458125	$ 0.1455000	$ 0.1455000	$ 0.1455000	$ 1.6018961	$ 1.3173125
Monthly distributions payable (in dollars per share)							$ 0.1818542																		$ 0.1818542					$ 0.140625						$ 0.138021
Units issued in connection with acquisition (in shares)			534,546		45,573,144	317,022
Preferred stock redeemed (in shares)					208,709																						5,100,000
Preferred stock, dividend rate (as a percent)																											7.375%		7.375%	6.75%	6.75%	6.75%			6.625%	6.625%	6.625%
Dividends paid per preferred share (in dollars per share)																												$ 0.3841147		$ 1.265625	$ 1.265625					$ 1.242189	$ 0.9983517
Preferred stock dividends paid																												$ 2,000,000		$ 11,100,000	$ 11,100,000					$ 20,300,000	$ 15,900,000
Period for which dividends are paid																														9	9					9	7
Preferred stock, shares issued	25,150,000	25,150,000																														8,800,000			14,950,000			1,400,000
Preferred stock, redemption price per share (in dollars per share)																											$ 25	$ 25					$ 25			$ 25
Preferred stock, issuance price per share (in dollars per share)																																$ 25			$ 25			$ 25.2863
Number of monthly distributions paid				3		8
Distributions paid per unit (in dollars per share)				$ 0.5446251		$ 1.4501461
Distributions paid (in dollars)	$ 751,000			$ 291,000		$ 460,000
Monthly distributions payable (in dollars per share)				$ 0.1818542		$ 0.1818542
Period when initial dividend payments were made																																		37 days