Supplemental Disclosures of Cash Flow Information (Details) (USD $)	6 Months Ended
	Jun. 30, 2014 item	Jun. 30, 2013
Business acquisitions
Cash paid for interest	$ 104,200,000	$ 78,600,000
Interest capitalized to properties under development	220,000	369,000
Cash paid for income taxes	2,900,000	1,500,000
Non-cash investing and financing activities
Share-based compensation expense	5,449,000	7,498,000
Mortgages assumed	159,700,000	113,700,000
Interest rate swap agreement acquired	901,000
Net premiums recorded on mortgages assumed	718,000	5,700,000
Loans receivable	48,900,000
Number of acquired properties by applying loans receivable to the purchase price	5
Increase in buildings and improvements and accounts payable	3,900,000	836,000
Realty Income, L.P.
Business acquisitions
Mortgage notes payable		32,400,000
Real estate acquired		55,900,000
Number of units issued		534,546
Cash		1,000,000
ARCT
Business acquisitions
Real estate investments and related intangible assets		3,200,000,000
Other assets		19,500,000
Lines of credit payable		317,200,000
Term loan		235,000,000
Mortgage notes payable		539,000,000
Acquired lease intangible liabilities		79,700,000
Other liabilities		29,000,000
Noncontrolling interests		$ 14,000,000