| Cover | 12 Months Ended |
| Dec. 31, 2022 | |
| Document Information [Line Items] | |
| Document Type | DEF 14A |
| Amendment Flag | false |
| Entity Information [Line Items] | |
| Entity Registrant Name | Oppenheimer Holdings Inc. |
| Entity Central Index Key | 0000791963 |
| Pay vs Performance Disclosure | 12 Months Ended | ||
| Dec. 31, 2022 USD ($) | Dec. 31, 2021 USD ($) | Dec. 31, 2020 USD ($) | |
| Pay vs Performance Disclosure [Table] | |||
| Pay vs Performance [Table Text Block] | The table below illustrates “Pay Versus Performance” as described in Item 402(v) of Regulation S-K of the Exchange Act, and compares, for each year listed below, the total compensation of our Principal Executive Officer (who is our Chief Executive Officer, “PEO”) and the average total compensation of our Named Executive Officers (“NEOs”) as set forth above in “ Summary Compensation Table” Pay Versus Performance Table Year Summary Compensation Average Average Value of Initial Net Income Total Revenue Total Peer (a) (b) (c) (d) (e) (f) (g) (h) (i) 2022 $ 8,337,803 $ 7,320,256 $ 1,847,292 $ 1,584,637 $ 160 $ 141 $ 32,110,000 $ 1,110,941,000 2021 $ 11,030,203 $ 15,757,927 $ 4,742,450 $ 5,161,976 $ 179 $ 161 $ 158,964,000 $ 1,394,035,000 2020 $ 9,354,240 $ 10,120,442 $ 3,223,373 $ 3,322,821 $ 123 $ 120 $ 122,986,000 $ 1,198,667,000 (1) Amounts represent total compensation paid subject to adjustments for each fiscal year to the amounts listed under the “ Stock Awards Summary Compensation Table | ||
| Company Selected Measure Name | Total Revenue | ||
| Named Executive Officers, Footnote [Text Block] | Our executive officers consist of Mr. A.G. Lowenthal, our Chairman and Chief Executive Officer, and Mr. R.S. Lowenthal, our President, each of whose background is described above, and Mr. Watkins, our Chief Financial Officer and principal financial and accounting officer, whose background is described below. Mr. Watkins joined the Company on August 1, 2022. | ||
| PEO Total Compensation Amount | $ 8,337,803 | $ 11,030,203 | $ 9,354,240 |
| PEO Actually Paid Compensation Amount | 7,320,256 | 15,757,927 | 10,120,442 |
| Non-PEO NEO Average Total Compensation Amount | 1,847,292 | 4,742,450 | 3,223,373 |
| Non-PEO NEO Average Compensation Actually Paid Amount | $ 1,584,637 | 5,161,976 | 3,322,821 |
| Equity Valuation Assumption Difference, Footnote [Text Block] | (1) Amounts represent total compensation paid subject to adjustments for each fiscal year to the amounts listed under the “ Stock Awards Summary Compensation Table | ||
| Compensation Actually Paid vs. Total Shareholder Return [Text Block] | |||
| Compensation Actually Paid vs. Net Income [Text Block] | |||
| Compensation Actually Paid vs. Company Selected Measure [Text Block] | |||
| Tabular List [Table Text Block] | The Compensation Committee, in consultation with the Chief Executive Officer, developed various performance criteria related to incentive compensation for the Named Executive Officers, as further discussed in the “Determination of 2022 Compensation • Total shareholder return; • Net income; and • Total revenue. | ||
| Total Shareholder Return Amount | $ 160 | 179 | 123 |
| Peer Group Total Shareholder Return Amount | 141 | 161 | 120 |
| Net Income (Loss) | $ 32,110,000 | $ 158,964,000 | $ 122,986,000 |
| Company Selected Measure Amount | 1,110,941,000 | 1,394,035,000 | 1,198,667,000 |
| PEO Name | Mr. A.G. Lowenthal | ||
| Measure [Axis]: 1 | |||
| Pay vs Performance Disclosure [Table] | |||
| Measure Name | Total shareholder return | ||
| Measure [Axis]: 2 | |||
| Pay vs Performance Disclosure [Table] | |||
| Measure Name | Net income | ||
| Measure [Axis]: 3 | |||
| Pay vs Performance Disclosure [Table] | |||
| Measure Name | Total revenue | ||
