Supplemental Disclosures of Cash Flow Information - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Mar. 28, 2019	Jan. 01, 2019	Apr. 30, 2018	Mar. 30, 2018
Supplemental Disclosures of Cash Flow Information
Cash paid for interest	$ 84,100	$ 82,200
Cash paid for income taxes	2,500	$ 1,700
Non-cash activities
Lease liabilities	121,790		$ 122,285		$ 132,000
Right-of-use assets					$ 132,000
Non-refundable deposits from 2019 applied to acquisitions	14,800
Realty Income, L.P.
Non-cash activities
Number of partnership units issued (in units)		89,322		89,322		131,790	242,007
Shares issued in conjunction with acquisitions		$ 6,300
Derivative [Member]
Non-cash activities
Decrease in fair value of net derivative liabilities	$ 16,400