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]	Parent [Member]	Non-Controlling Interest [Member]
Adjustments to Additional Paid in Capital, Income Tax Deficiency from Share-based Compensation				$ (321)
Balance at beginning of period at Dec. 31, 2014		$ 62,397		45,118	$ 421,047	$ (918)		$ 6,088
Issuance of Class A non-voting common stock			$ 2,889
Repurchase of Class A non-voting common stock for cancellation			0
Share-based expense				898
Vested employee share plan awards				(4,572)
Net income (loss) attributable to Oppenheimer Holdings Inc.	$ 5,719				5,719
Dividends paid ($0.11 per share)					(1,511)
Currency translation adjustment	(567)					(567)
Net income (loss) attributable to noncontrolling interest	(402)							402
Balance at end of period at Mar. 31, 2015	536,669	65,286		41,123	425,255	(1,485)	$ 530,179	6,490
Balance at beginning of period at Dec. 31, 2014		62,397		45,118	421,047	(918)		6,088
Balance at end of period at Dec. 31, 2015	525,082	57,520		44,438	417,001	(901)		7,024
Adjustments to Additional Paid in Capital, Income Tax Deficiency from Share-based Compensation				(741)
Issuance of Class A non-voting common stock			5,463
Repurchase of Class A non-voting common stock for cancellation			$ 3,634
Share-based expense				1,492
Vested employee share plan awards				(6,804)
Net income (loss) attributable to Oppenheimer Holdings Inc.	(3,847)				(3,847)
Dividends paid ($0.11 per share)					(1,476)
Currency translation adjustment	873					873
Net income (loss) attributable to noncontrolling interest	62							(62)
Balance at end of period at Mar. 31, 2016	$ 516,346	$ 59,349		$ 38,385	$ 411,678	$ (28)	$ 509,384	$ 6,962