Commitments and Contingencies - Minimum Future Rental Payments Due on Ground Leases (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019
Minimum Future Rental Payments Due
2019	$ 3,800
2020	15,000
2021	14,500
2022	14,300
2023	14,300
Thereafter	102,000
Total	163,900
Present value adjustment for remaining lease payments	(39,600)
Lease liability - operating leases, net	$ 124,349	$ 132,000
Weighted average discount rate (percent)	4.29%
Weighted average remaining lease term	12 years 6 months
Ground Leases Paid by Realty Income
Minimum Future Rental Payments Due
2019	$ 400
2020	1,500
2021	1,300
2022	1,200
2023	1,200
Thereafter	19,900
Total	25,500
Ground Leases Paid by Our Tenants
Minimum Future Rental Payments Due
2019	3,400
2020	13,500
2021	13,200
2022	13,100
2023	13,100
Thereafter	82,100
Total	$ 138,400
Minimum
Minimum Future Rental Payments Due
Discount rate used to present value lease payments (percent)	3.09%
Maximum
Minimum Future Rental Payments Due
Discount rate used to present value lease payments (percent)	5.50%