Commitments and Contingencies (Details) (USD $)	Dec. 31, 2012
Commitments and Contingencies
Amount of contingent payments for tenant improvements and leasing costs	$ 944,000
Amount of commitments for construction contracts, which is expected to be paid in next twelve months	16,000,000
Minimum future rental payments for the next five years and thereafter under ground leases
2013	4,430,000
2014	4,300,000
2015	4,265,000
2016	4,239,000
2017	4,154,000
Thereafter	49,193,000
Total	70,581,000
Realty Income
Minimum future rental payments for the next five years and thereafter under ground leases
2013	181,000
2014	189,000
2015	191,000
2016	201,000
2017	210,000
Thereafter	424,000
Total	1,396,000
Tenants
Minimum future rental payments for the next five years and thereafter under ground leases
2013	4,249,000
2014	4,111,000
2015	4,074,000
2016	4,038,000
2017	3,944,000
Thereafter	48,769,000
Total	$ 69,185,000