XML 77 R61.htm IDEA: XBRL DOCUMENT
v3.20.4

Fair Value Measurements - Investments in Company-Sponsored Funds (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019
Investment Holdings [Line Items] |  |
Fair Value | $ 4,836 | $ 5,816
Unfunded Commitments | 1,238 | 1,339
Hedge Funds [Member] |  |
Investment Holdings [Line Items] |  |
Fair Value | 1,126 | 1,589
Unfunded Commitments | $ 0 | $ 0
Redemption Frequency | Quarterly - Annually | Quarterly - Annually
Investment Redemption Notice Period Minimum | 30 days |
Investment Redemption Notice Period Maximum | 120 days |
Private Equity Funds |  |
Investment Holdings [Line Items] |  |
Fair Value | $ 3,710 | $ 4,227
Unfunded Commitments | $ 1,238 | $ 1,339

X
- Definition Investment redemption frequency. + References No definition available. + Details
Name: | opy_InvestmentRedemptionFrequency
Namespace Prefix: | opy_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Investment redemption notice period maximum. + References No definition available. + Details
Name: | opy_InvestmentRedemptionNoticePeriodMaximum
Namespace Prefix: | opy_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Investment redemption notice period minimum. + References No definition available. + Details
Name: | opy_InvestmentRedemptionNoticePeriodMinimum
Namespace Prefix: | opy_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of unfunded commitments for which the entity is obligated, to those certain investments for which net asset value per share is calculated (including by unit, membership interest, or other equity (ownership interest) unit measure) (alternative investments). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 6A -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=117815213&loc=SL6742756-110258 + Details
Name: | us-gaap_FairValueInvestmentsEntitiesThatCalculateNetAssetValuePerShareUnfundedCommittments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_InvestmentHoldingsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
Name: | us-gaap_InvestmentsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_HedgeFundsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_PrivateEquityFundsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |