Commitments and Contingencies (Details)	Dec. 31, 2015 USD ($)
Commitments and Contingencies
Amount of commitments for tenant improvements and leasing costs	$ 714,000
Amount of commitments for construction contracts, which is expected to be paid in next twelve months	70,600,000
Minimum future rental payments for the next five years and thereafter under ground leases
2016	14,800,000
2017	14,800,000
2018	14,900,000
2019	14,600,000
2020	14,400,000
Thereafter	142,300,000
Total	215,800,000
Realty Income
Minimum future rental payments for the next five years and thereafter under ground leases
2016	1,500,000
2017	1,500,000
2018	1,600,000
2019	1,400,000
2020	1,400,000
Thereafter	23,300,000
Total	30,700,000
Tenants
Minimum future rental payments for the next five years and thereafter under ground leases
2016	13,300,000
2017	13,300,000
2018	13,300,000
2019	13,200,000
2020	13,000,000
Thereafter	119,000,000
Total	$ 185,100,000