Condensed Consolidated Statements of Changes in Stockholders' Equity (USD $) In Thousands	Total	Share Capital [Member]	Share Capital [Member] Class A Stock [Member]	Contributed Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]	Non-Controlling Interest [Member]
Balance at beginning of period at Dec. 31, 2012		$ 62,181		$ 39,231	$ 399,121	$ 207	$ 4,261
Issuance of Class A non-voting common stock			1,577
Repurchase of Class A non-voting common stock for cancellation			(2,314)
Tax benefit from share-based awards				(92)
Share-based expense				3,863
Vested employee share plan awards				(1,891)
Net income for the period attributable to Oppenheimer Holdings Inc.	11,748				11,748
Dividends paid ($0.33 per share)					(4,494)
Currency translation adjustment	1,156
Total Oppenheimer Holdings Inc. stockholders' equity						510,293
Net income attributable to non-controlling interest, net of tax	(719)						719
Balance at end of period at Sep. 30, 2013	515,273	61,444		41,111	406,375	1,363	4,980
Balance at beginning of period at Jun. 30, 2013
Net income for the period attributable to Oppenheimer Holdings Inc.	5,237
Currency translation adjustment	656
Total Oppenheimer Holdings Inc. stockholders' equity						510,293
Net income attributable to non-controlling interest, net of tax	(271)
Balance at end of period at Sep. 30, 2013	515,273	61,444				1,363
Balance at beginning of period at Dec. 31, 2013	527,871	60,198		42,407	418,204	1,709	5,353
Issuance of Class A non-voting common stock			2,199
Repurchase of Class A non-voting common stock for cancellation			0
Tax benefit from share-based awards				1,275
Share-based expense				4,445
Vested employee share plan awards				(4,177)
Net income for the period attributable to Oppenheimer Holdings Inc.	6,140				6,140
Dividends paid ($0.33 per share)					(4,483)
Currency translation adjustment	(1,356)
Total Oppenheimer Holdings Inc. stockholders' equity	526,561					526,561
Net income attributable to non-controlling interest, net of tax	(652)						652
Balance at end of period at Sep. 30, 2014	532,566	62,397		43,950	419,861	353	6,005
Balance at beginning of period at Jun. 30, 2014
Net income for the period attributable to Oppenheimer Holdings Inc.	4,470
Currency translation adjustment	(1,608)
Total Oppenheimer Holdings Inc. stockholders' equity	526,561					526,561
Net income attributable to non-controlling interest, net of tax	(155)
Balance at end of period at Sep. 30, 2014	$ 532,566	$ 62,397				$ 353