XML 46 R36.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Summary of Significant Accounting Policies - Additional Information (Narrative) (Details) - USD ($) | 3 Months Ended |
--- | --- | ---
Mar. 31, 2018 | Dec. 31, 2017
Summary Of Significant Accounting Policies [Line Items] |  |
Noncontrolling Interest, Ownership Percentage by Parent | 83.68% |
Non-controlling interest | $ 365,000 | $ 361,000
Minimum [Member] |  |
Summary Of Significant Accounting Policies [Line Items] |  |
Number of business days for related transactions | 1 day |
Maximum [Member] |  |
Summary Of Significant Accounting Policies [Line Items] |  |
Number of business days for related transactions | 2 days |

X
- Definition Summary Of Significant Accounting Policies [Line Items] + References No definition available. + Details
Name: | opy_SummaryOfSignificantAccountingPoliciesLineItems
Namespace Prefix: | opy_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Transaction Settlement Period + References No definition available. + Details
Name: | opy_TransactionSettlementPeriod
Namespace Prefix: | opy_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which is directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent (that is, noncontrolling interest, previously referred to as minority interest). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(22)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(24)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.31) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_MinorityInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Percentage of subsidiary's or equity method investee's stock owned by parent immediately after all stock transactions. + References No definition available. + Details
Name: | us-gaap_SubsidiaryOrEquityMethodInvesteeCumulativePercentageOwnershipAfterAllTransactions
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |