Name:	opy_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesIssuances
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Fair value measurement with unobservable inputs reconciliation recurring basis asset sales settlements.

No definition available.

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Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Purchases and Issuances

No definition available.

Name:	opy_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityPurchasesAndIssuances
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Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Sales and Settlements

No definition available.

Name:	opy_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySalesAndSettlements
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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

Name:	us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward
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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

Name:	us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward
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Amount of transfers of financial instrument classified as a liability into level 3 of the fair value hierarchy.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(3)
-URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationLiabilityTransfersIntoLevel3
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Amount of gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258

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Amount of transfer of financial instrument classified as an asset into (out of) level 3 of the fair value hierarchy.

No definition available.

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNet
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Data Type:	xbrli:monetaryItemType
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Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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Amount of gain (loss) recognized in income from liability measured at fair value on recurring basis using unobservable input (level 3).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.