XML 127 R74.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Bank Call Loans - Additional Information (Detail) (USD $) | 12 Months Ended
--- | ---
Dec. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2011
Brokers And Dealers [Abstract] |  |  |
Broker call rate | 2.00% | 2.00% |
Interest expense on bank call loans | $ 2,200,000 | $ 996,200.0 | $ 1,200,000

X
- Definition Broker call rate as of the balance sheet date. + References No definition available. + Details
Name: | opy_BrokerCallRate
Namespace Prefix: | opy_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Interest expense on bank call loans. + References No definition available. + Details
Name: | opy_InterestExpenseOnBankCallLoans
Namespace Prefix: | opy_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_BrokersAndDealersAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration