Commitments and contingencies	12 Months Ended
Commitments and contingencies	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and contingencies	Commitments and contingencies Commitments The Company had capital commitments of $3.0 million with respect to unfunded obligation in private equity funds sponsored by the Company and $40.2 million of commitments related to additional operating leases that have not yet commenced. As of December 31, 2022, the Company had no collateralized or uncollateralized letters of credit outstanding. Contingencies Many aspects of the Company's business involve substantial risks of liability. In the normal course of business, the Company has been named as defendant or co-defendant in various legal actions, including arbitrations, class actions and other litigation, creating substantial exposure and periodic expenses. Certain of the actual or threatened legal matters include claims for substantial compensatory and/or punitive damages or claims for indeterminate amounts of damages. These proceedings arise primarily from securities brokerage, asset management and investment banking activities. The Company is also involved, from time to time, in other reviews, investigations and proceedings (both formal and informal) by governmental and self-regulatory agencies regarding the Company's business, which may result in expenses, adverse judgments, settlements, fines, penalties, injunctions or other relief. The investigations include inquiries from the SEC, the Financial Industry Regulatory Authority ("FINRA") and various state regulators. The Company accrues for estimated loss contingencies related to legal and regulatory matters within Other Expenses in the consolidated income statement when available information indicates that it is probable a liability had been incurred and the Company can reasonably estimate the amount of that loss. In many proceedings, however, it is inherently difficult to determine whether any loss is probable or even possible or to estimate the amount of any loss. In addition, even where a loss is possible or an exposure to loss exists in excess of the liability already accrued with respect to a previously recognized loss contingency, it is often not possible to reasonably estimate the size of the possible loss or range of loss or possible additional losses or range of additional losses. For certain legal and regulatory proceedings, the Company cannot reasonably estimate such losses, particularly for proceedings that are in their early stages of development or where plaintiffs seek substantial, indeterminate or special damages. Counsel may be required to review, analyze and resolve numerous issues, including through potentially lengthy discovery and determination of important factual matters, and by addressing novel or unsettled legal questions relevant to the proceedings in question, before the Company can reasonably estimate a loss or range of loss or additional loss for the proceeding. Even after lengthy review and analysis, the Company, in many legal and regulatory proceedings, may not be able to reasonably estimate possible losses or range of loss. For certain other legal and regulatory proceedings, the Company can estimate possible losses, or range of loss in excess of amounts accrued, but does not believe, based on current knowledge and after consultation with counsel, that such losses individually, or in the aggregate, will have a material adverse effect on the Company's consolidated financial statements as a whole. For legal and regulatory proceedings where there is at least a reasonable possibility that a loss or an additional loss may be incurred, the Company estimates a range of aggregate loss in excess of amounts accrued of up to $40 million. This estimated aggregate range is based upon currently available information for those legal proceedings in which the Company is involved, where the Company can make an estimate for such losses. For certain cases, the Company does not believe that it can make an estimate. The foregoing aggregate estimate is based on various factors, including the varying stages of the proceedings (including the fact that some are currently in preliminary stages), the numerous yet-unresolved issues in many of the proceedings and the attendant uncertainty of the various potential outcomes of such proceedings. Accordingly, the Company's estimate will change from time to time, and actual losses may be more than the current estimate. Beginning on or about August 31, 2021, Oppenheimer has been named as a respondent in thirty-seven arbitrations, many containing multiple claimants, each filed before FINRA, relating to those claimants’ purported investment in Horizon Private Equity, III, LLC (“Horizon”). Horizon is alleged to be a fraudulent scheme involving, among others, a former Oppenheimer employee John Woods. John Woods left Oppenheimer’s employ in 2016 and Oppenheimer never received a complaint or question from any of the investors prior to the Securities and Exchange Commission (“SEC”) bringing a complaint against Woods and his co-conspirators in 2021. Each investor signed a document acknowledging that Horizon was not an approved Oppenheimer product. Over a protracted period of time, Woods made multiple false statements to Oppenheimer, to regulators and to a state court. The claimants are seeking damages based on a number of legal theories, including, without limitation, violations of various state and federal statutes, breach of fiduciary duty, procurement of breach of fiduciary duty, negligent misrepresentation, aiding and abetting fraud, and unjust enrichment. Claimants do not allege Oppenheimer received any of the funds invested in Horizon, but rather that Oppenheimer’s purported failure to properly supervise its employees allowed the alleged scheme to occur and continue. The twenty-six arbitrations still pending claim specific monetary damages allege losses of approximately $36.4 million in the aggregate while a few others claim unspecified damages. Oppenheimer believes these claims to be without merit and intends to defend itself vigorously against these claims. As previously reported Oppenheimer’s motion to vacate the arbitration award in Donald Robinson, Timothy and Sharon Padden, Rhett Rainey, Kelly A. Rainey Trust, Toucan Holdings LP, Robert Goodman, Robert Daniel Burgner, Individually and as Trustee of the Burgner Family Charitable Remainder Trust, Douglas Kasemeier, Wesley Callaway, and Billy Loveless v. Oppenheimer & Co. Inc. (the “Robinson Arbitration”) was denied on January 30, 2023. Oppenheimer has settled, or settled in principle, eleven of the Horizon related arbitrations, including the Robinson Arbitration,with approximately forty-one individual complainants. The aggregate settlement payments for those eleven arbitrations total approximately $48.6 million. On June 30, 2022, the Company received a "Wells Notice" from the SEC requesting that Oppenheimer make a written submission to the SEC to explain why Oppenheimer should not be charged with violations of Section 15c2-12 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and Rule 15c2-12 thereunder as well as Municipal Securities Rulemaking Board Rules G-17 and G-27 in relation to its sales of municipal notes pursuant to an exemption from continuing disclosure contained in Rule 15c2-12. On September 13, 2022, the SEC filed a complaint against Oppenheimer in the United States District Court for the Southern District of New York (the “Court") alleging that Oppenheimer violated Section 15B(c)(1) of the Exchange Act and Rule 15c2-12 thereunder as well as Municipal Securities Rulemaking Board Rules G-17 and G-27 for not having fully complied with the exemption from the continuing disclosure obligations under Rule 15c2-12. The SEC asked the Court to enter an order enjoining Oppenheimer from violating the above referenced rules and requiring it to disgorge approximately $1.9 million plus interest. The Company believes such claim to be without merit and intends to vigorously defend itself against such claim.