Earnings Per Share - Summary of Earnings Per Share (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2014	Mar. 31, 2013
Earnings Per Share [Abstract]
Basic weighted average number of shares outstanding	13,536,805	13,607,998
Net dilutive effect of warrant, treasury method
Net dilutive effect of share-based awards, treasury method	578,152	420,717
Diluted weighted average number of shares outstanding	14,114,957	14,028,715
Net income for the period	$ 3,420	$ 3,893
Net income attributable to non-controlling interest, net of tax	196	230
Net income attributable to Oppenheimer Holdings Inc.	$ 3,224	$ 3,663
Basic earnings per share	$ 0.24	$ 0.27
Diluted earnings per share	$ 0.23	$ 0.26

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The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of call options and warrants using the treasury stock method.

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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Amount of Net Income (Loss) attributable to noncontrolling interest.

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