Receivable from and Payable to Brokers, Dealers and Clearing Organizations (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Receivable from brokers, dealers and clearing organizations consist of:
Securities borrowed	$ 242,172	$ 274,127
Receivable from brokers	38,149us-gaap_DueFromCorrespondentBrokers	23,384us-gaap_DueFromCorrespondentBrokers
Securities failed to deliver	11,055us-gaap_SecuritiesFailedToDeliver	9,628us-gaap_SecuritiesFailedToDeliver
Clearing organizations	21,106	26,446
Omnibus accounts	0opy_OmnibusAccounts	18,086opy_OmnibusAccounts
Other	1,993	13,202
Receivables from broker, dealers and clearing organizations	314,475	364,873
Payable to brokers, dealers and clearing organizations consist of:
Securities loaned	137,892	211,621
Securities failed to receive	23,573us-gaap_SecuritiesFailedToReceive	5,346us-gaap_SecuritiesFailedToReceive
Clearing organizations and other	95,696	6,348
Payable to brokers, dealers and clearing organizations	$ 257,161	$ 223,315

Omnibus accounts.

No definition available.

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- Definition

This is the amount of cash advanced as security in return for borrowing securities from another party.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 6

-Article 9

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount of cash received as security in return for loaning securities to another party.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 16

-Article 9

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.12)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Amount receivable from correspondent broker-dealer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=28367877&loc=d3e4428-111522

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 940

-SubTopic 20

-Section 25

-URI http://asc.fasb.org/section&trid=2176260

+ Details

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Balance Type:	debit
Period Type:	instant

- Definition

Amount of other payables due to broker-dealer.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of other receivables due from broker-dealer.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount payable to broker-dealers and clearing organizations, including, but not limited to, securities failed-to-receive, certain deposits received for securities loaned, open transactions, and floor-brokerage payables.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 940

-SubTopic 20

-Section 45

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6475717&loc=d3e41645-110958

+ Details

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Period Type:	instant

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- Definition

Amount receivable from broker-dealers and clearing organizations, including, but not limited to, securities failed-to-deliver, certain deposits for securities borrowed, open transactions, good faith and margin deposits, commissions and floor brokerage receivables.

+ References

+ Details

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- Definition

Amount of right to receive cash and securities on deposit with clearing organizations. Clearing organizations perform post trade processing and trade comparisons among numerous broker-dealers and act as settlement agents between buying and selling broker-dealers.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount receivable as the result of a fail-to-deliver. A fail-to-deliver is a securities sale to another broker-dealer that has not been delivered to buying broker-dealer by the close of business on the settlement date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Fail-to-Deliver

-URI http://asc.fasb.org/extlink&oid=6512414

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount payable as the result of fail-to-receive. A fail-to-receive is a securities purchase from another broker-dealer not received from the selling broker-dealer by the close of business on the settlement date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Fail-to-Receive

-URI http://asc.fasb.org/extlink&oid=6512444

+ Details

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