Summary of significant accounting policies	6 Months Ended
Jun. 30, 2011
Summary of significant accounting policies [Abstract]
Summary of significant accounting policies	1. Summary of significant accounting policies Oppenheimer Holdings Inc. (“OPY”) is incorporated under the laws of the State of Delaware. The consolidated financial statements include the accounts of OPY and its subsidiaries (together, the “Company”). The principal subsidiaries of OPY are Oppenheimer & Co. Inc. (“Oppenheimer”), a registered broker dealer in securities, Oppenheimer Asset Management Inc. (“OAM”) and its wholly owned subsidiary, Oppenheimer Investment Management Inc. (“OIM”), both registered investment advisors under the Investment Advisors Act of 1940, Oppenheimer Trust Company, a limited purpose trust company chartered by the State of New Jersey to provide fiduciary services such as trust and estate administration and investment management, Oppenheimer Multifamily Housing and Healthcare Finance, Inc. (formerly Evanston Financial Corporation) (“OMHHF”), which is engaged in mortgage brokerage and servicing, and OPY Credit Corp., which offers syndication as well as trading of issued corporate loans. Oppenheimer Europe Ltd. (formerly Oppenheimer E.U. Ltd.) (“Oppenheimer Europe”), based in the United Kingdom, provides institutional equities and fixed income brokerage and corporate financial services and is regulated by the Financial Services Authority. Oppenheimer Investments Asia Limited, based in Hong Kong, China, provides assistance in accessing the U.S. equities markets and limited mergers and acquisitions advisory services to Asia-based companies. Oppenheimer operates as Fahnestock & Co. Inc. in Latin America. Oppenheimer owns Freedom Investments, Inc. (“Freedom”), a registered broker dealer in securities, which also operates as the BUYandHOLD division of Freedom, offering on-line discount brokerage and dollar-based investing services, and Oppenheimer Israel (OPCO) Ltd., which is engaged in offering investment services in the State of Israel as a local broker dealer. The Company’s condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). These accounting principles are set out in the notes to the Company’s consolidated financial statements for the year ended December 31, 2010 included in its Annual Report on Form 10-K for the year then ended. Accounting standards require the Company to present non-controlling interests (previously referred to as minority interests) as a separate component of stockholders’ equity on the Company’s condensed consolidated balance sheet. As of June 30, 2011, the Company owns 67.34% of OMHHF and the non-controlling interest recorded in the condensed consolidated balance sheet was $4.5 million. The condensed consolidated financial statements include all adjustments, which in the opinion of management are normal and recurring and necessary for a fair statement of the results of operations, financial position and cash flows for the interim periods presented. The nature of the Company’s business is such that the results of operations for the interim periods are not necessarily indicative of the results to be expected for a full year. Disclosures reflected in these condensed consolidated financial statements comply in all material respects with those required pursuant to the rules and regulations of the United States Securities and Exchange Commission (“SEC”) with respect to quarterly financial reporting. Certain prior period amounts appearing in the notes to the condensed consolidated financial statements pertaining to the fair value measurement of derivative contracts have been reclassified to conform with current presentation.

1. Summary of significant accounting policies

Oppenheimer Holdings Inc. (“OPY”) is incorporated under the laws of the State of Delaware. The consolidated financial statements include the accounts of OPY and its subsidiaries (together, the “Company”). The principal subsidiaries of OPY are Oppenheimer & Co. Inc. (“Oppenheimer”), a registered broker dealer in securities, Oppenheimer Asset Management Inc. (“OAM”) and its wholly owned subsidiary, Oppenheimer Investment Management Inc. (“OIM”), both registered investment advisors under the Investment Advisors Act of 1940, Oppenheimer Trust Company, a limited purpose trust company chartered by the State of New Jersey to provide fiduciary services such as trust and estate administration and investment management, Oppenheimer Multifamily Housing and Healthcare Finance, Inc. (formerly Evanston Financial Corporation) (“OMHHF”), which is engaged in mortgage brokerage and servicing, and OPY Credit Corp., which offers syndication as well as trading of issued corporate loans. Oppenheimer Europe Ltd. (formerly Oppenheimer E.U. Ltd.) (“Oppenheimer Europe”), based in the United Kingdom, provides institutional equities and fixed income brokerage and corporate financial services and is regulated by the Financial Services Authority. Oppenheimer Investments Asia Limited, based in Hong Kong, China, provides assistance in accessing the U.S. equities markets and limited mergers and acquisitions advisory services to Asia-based companies. Oppenheimer operates as Fahnestock & Co. Inc. in Latin America. Oppenheimer owns Freedom Investments, Inc. (“Freedom”), a registered broker dealer in securities, which also operates as the BUYandHOLD division of Freedom, offering on-line discount brokerage and dollar-based investing services, and Oppenheimer Israel (OPCO) Ltd., which is engaged in offering investment services in the State of Israel as a local broker dealer.

The Company’s condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). These accounting principles are set out in the notes to the Company’s consolidated financial statements for the year ended December 31, 2010 included in its Annual Report on Form 10-K for the year then ended.

Accounting standards require the Company to present non-controlling interests (previously referred to as minority interests) as a separate component of stockholders’ equity on the Company’s condensed consolidated balance sheet. As of June 30, 2011, the Company owns 67.34% of OMHHF and the non-controlling interest recorded in the condensed consolidated balance sheet was $4.5 million.

The condensed consolidated financial statements include all adjustments, which in the opinion of management are normal and recurring and necessary for a fair statement of the results of operations, financial position and cash flows for the interim periods presented. The nature of the Company’s business is such that the results of operations for the interim periods are not necessarily indicative of the results to be expected for a full year.

Disclosures reflected in these condensed consolidated financial statements comply in all material respects with those required pursuant to the rules and regulations of the United States Securities and Exchange Commission (“SEC”) with respect to quarterly financial reporting.

Certain prior period amounts appearing in the notes to the condensed consolidated financial statements pertaining to the fair value measurement of derivative contracts have been reclassified to conform with current presentation.