Supplemental Disclosures of Cash Flow Information (Details) (USD $)	9 Months Ended			0 Months Ended	9 Months Ended
	Sep. 30, 2013 item	Sep. 30, 2012	Sep. 30, 2013 Realty Income, L.P.	Jan. 22, 2013 ARCT	Sep. 30, 2013 ARCT
Acquisition of American Realty Capital Trust, Inc.
Real estate investments and related intangible assets					$ 3,200,000,000
Other assets					20,000,000
Lines of credit payable					317,200,000
Term loan					235,000,000
Other liabilities				22,820,000	29,600,000
Mortgage notes payable			32,400,000		539,000,000
Number of units issued			534,546
Cash			1,000,000	56,216,000
Acquired lease intangible liabilities					78,700,000
Noncontrolling interests					14,000,000
Real estate acquired					3,200,000,000
Real estate acquired			55,900,000
Cash paid for interest	142,400,000	105,700,000
Interest capitalized to properties under development	579,000	388,000
Cash paid for income taxes	1,500,000	961,000
Non-cash activities
Share-based compensation expense	14,235,000	7,780,000
Mortgages assumed	81,300,000	70,000,000
Net premiums recorded on mortgages assumed	5,700,000	7,100,000
Real estate acquired via exchange of properties	7,400,000
Receivable recorded for the sale of an investment property as a result of an eminent domain action	1,900,000
Number of investment properties sold as a result of an eminent domain action	2
Increase in buildings and improvements and accounts payable	$ 3,000,000