Supplemental Disclosures of Cash Flow Information (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2018 USD ($) shares	Jun. 30, 2017 USD ($) building	Apr. 30, 2018 shares	Mar. 30, 2018 shares	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Jun. 27, 2013 shares
Supplemental Disclosures of Cash Flow Information
Cash paid for interest	$ 111,900	$ 107,300
Cash paid for income taxes	2,900	$ 3,300
Non-cash activities
Non-refundable escrow deposits for pending acquisitions	0				$ 7,500
Number of buildings damaged | building		2
Damaged buildings insurance receivables		$ 10,700
Reconciliation of cash and cash equivalents
Cash and cash equivalents shown in the consolidated balance sheets	30,717	10,945			6,898
Restricted escrow deposits	7,054	8,550			679
Impounds related to mortgages payable	7,029	2,916			4,565
Total cash, cash equivalents, and restricted cash shown in the consolidated statements of cash flows	44,800	22,411			$ 12,142	$ 15,681
Properties under development
Supplemental Disclosures of Cash Flow Information
Interest capitalized to properties under development	$ 130	$ 272
Realty Income, L.P.
Non-cash activities
Number of partnership units issued | shares	373,797		131,790	242,007			534,546
Value of partnership units issued	$ 18,800