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

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Charges

No definition available.

Name:	roic_BusinessCombinationRecognizedIdentifiableAssetsAcquiredandLiabilitiesAssumedDeferredCharges
Namespace Prefix:	roic_
Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Amount of acquisition cost of a business combination allocated to buildings and improvements included in real estate.

No definition available.

Name:	roic_BusinessacquisitionPurchasePriceAllocationBuildingsAndImprovements
Namespace Prefix:	roic_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount of assets acquired at the acquisition date.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=73530397&loc=d3e4845-128472

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- References

No definition available.

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Amount of intangible assets, excluding goodwill, acquired at the acquisition date.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Amount of real estate acquired, at the acquisition date.

Name:	us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLand
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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Amount of liabilities assumed at the acquisition date.

Name:	us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities
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Data Type:	xbrli:monetaryItemType
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- References

No definition available.

Name:	us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract
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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Amount of long-term debt due after one year or the normal operating cycle, if longer, assumed at the acquisition date.