Commitments and Contingencies (Details) $ in Millions	Dec. 31, 2017 USD ($)
Commitments and Contingencies
Amount of commitments for re-leasing costs, recurring capital expenditures and non-recurring building improvements	$ 13.8
Amount of commitments for construction contracts, which is expected to be paid in next twelve months	64.4
Minimum future rental payments for the next five years and thereafter
2018	15.2
2019	14.9
2020	14.6
2021	14.1
2022	14.0
Thereafter	115.0
Total	187.8
Tenants
Minimum future rental payments for the next five years and thereafter
2018	13.5
2019	13.4
2020	13.2
2021	12.9
2022	12.8
Thereafter	94.1
Total	159.9
Realty Income
Minimum future rental payments for the next five years and thereafter
2018	1.7
2019	1.5
2020	1.4
2021	1.2
2022	1.2
Thereafter	20.9
Total	$ 27.9