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Number of financing receivables held that have been modified by troubled debt restructurings.

No definition available.

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Represents the period during which a loan is contractually past due to be considered in payment default under the modified terms.

No definition available.

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Data Type:	xbrli:durationItemType
Balance Type:	na
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The percentage of disbursement to unsecured creditors by an illusory company in liquidation in order to explain the proper use of the doubtful category.

No definition available.

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

The percentage of loans classified in rating category depending upon the probability of loan collection in the example used to explain the proper use of the doubtful category.

No definition available.

Name:	ovly_FinancingReceivableRatingExamplePercentageOfLoansClassifiedInRatingCategory
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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Represents the percentage of total loans segregated by class of loan portfolio.

No definition available.

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Data Type:	num:percentItemType
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Period Type:	instant

The percentage of the loan amount for which cash collateral must be equal to or greater than in order for the loan to properly margined.

No definition available.

Name:	ovly_LoansAndLeasesReceivableMinimumCashCollateralPercent
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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Represents the percentage of outstanding principal balance of the loans secured by owner-occupied properties.

No definition available.

Name:	ovly_LoansAndLeasesReceivablePercentageOfOutstandingPrincipalBalanceSecuredByOwnerOccupiedProperties
Namespace Prefix:	ovly_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Represents the housing percentage as per the underwriting standards.

No definition available.

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Represents the loan-to-value percentage as per the underwriting standards.

No definition available.

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Represents the total debt ratio as per the underwriting standards.

No definition available.

Name:	ovly_UnderwritingStandardsTotalDebtRatio
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Data Type:	num:percentItemType
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Period Type:	instant

Amount of the collateral pledged in support of federal home loan bank advances outstanding.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822

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Number of financing receivables that have been modified by troubled debt restructurings.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953676-111524

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The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
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-Section 50
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Number of financing receivables that have been modified by troubled debt restructurings within the previous 12 months and for which there was a payment default.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953682-111524

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Data Type:	xbrli:integerItemType
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Period Type:	duration

Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5212-111524

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Data Type:	xbrli:monetaryItemType
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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=82891408&loc=d3e4428-111522

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Reflects the unfunded portion of contractual agreements to lend funds to borrowers for loans whose terms have been modified by troubled debt restructuring.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
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-URI http://asc.fasb.org/extlink&oid=82895541&loc=d3e18794-111554

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Reflects the amount of additional interest income that would have been recorded if impaired or nonperforming loans were instead current, in compliance with their original terms, and outstanding throughout the reporting period or since origination (if held for part of the period).

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Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_DoubtfulMember
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Data Type:	na
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Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_UnlikelyToBeCollectedFinancingReceivableMember
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Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialRealEstatePortfolioSegmentMember
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