Notes Payable - Narrative (Details) - Notes and bonds payable	6 Months Ended
Jun. 30, 2020
Debt
Weighted average interest rate (as a percent)	3.80%
Weighted average remaining years until maturity	8 years 3 months 18 days

Weighted average remaining period until maturity of the debt instrument, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

Name:	o_DebtInstrumentWeightedAverageRemainingMaturity
Namespace Prefix:	o_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration