Real Estate Investments - Purchase Price Allocation of Properties Acquired (Details) - Acquisitions in 2021 $ in Thousands	Dec. 31, 2021 USD ($)
Assets
Land	$ 46,958
Building and improvements	89,147
Acquired lease intangible asset	7,697
Deferred charges	3,873
Assets acquired	147,675
Liabilities
Acquired lease intangible liability	22,185
Liabilities assumed	$ 22,185

Asset Acquisition, Recognized Identifiable Assets Acquired And Liabilities Assumed, Lease Intangible Liability

No definition available.

Name:	roic_AssetAcquisitionRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLeaseIntangibleLiability
Namespace Prefix:	roic_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant