[Line Items] for Condensed Consolidated financial statements [Table]

No definition available.

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- Definition

The percentage of ownership the holding company owns the guarantors.

+ References

No definition available.

+ Details

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

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Details

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- Details

Name:	us-gaap_DebtInstrumentAxis=opy_A6.75SeniorSecuredNotesMember
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- Details

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Supplemental Guarantor Condensed Consolidated Financial Statements - Additional Information (Narrative) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2018	Jun. 23, 2017	Apr. 12, 2011
Condensed Consolidated financial statements [Line Items]
Interest owned by the holding company	100.00%
Secured Debt [Member] \| 6.75% Senior Secured Notes [Member]
Condensed Consolidated financial statements [Line Items]
Debt Instrument, Face Amount		$ 200.0
Debt Instrument, Interest Rate, Stated Percentage		6.75%
Secured Debt [Member] \| 8.75% Senior Secured Notes [Member]
Condensed Consolidated financial statements [Line Items]
Debt Instrument, Face Amount			$ 200.0
Debt Instrument, Interest Rate, Stated Percentage		8.75%