Commitments and Contingencies (Details) $ in Millions	Sep. 30, 2015 USD ($)
Commitments and Contingencies.
Amount of commitments for re-leasing costs, recurring capital expenditures and non-recurring building improvements	$ 2.3
Amount of commitments for construction contracts, which is expected to be paid in next twelve months	$ 58.4

The amount of contingent payments for re-leasing costs, recurring capital expenditures and non-recurring building improvements.

No definition available.

Name:	o_ReleasingCostsRecurringCapitalExpendituresAndNonRecurringBuildingImprovementsContingentPayments
Namespace Prefix:	o_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant