Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
REVENUE
Commissions									$ 377,317	$ 417,559	$ 469,829
Advisory fees									269,119	280,247	281,680
Investment banking									81,011	102,540	125,598
Interest									47,649	49,032	47,505
Principal transactions, net									20,481	15,180	27,515
Other									62,202	33,243	29,008
Total revenue	$ 218,945	$ 211,804	$ 212,074	$ 214,956	$ 225,189	$ 207,478	$ 227,959	$ 237,175	857,779	897,801	981,135
EXPENSES
Compensation and related expenses									584,710	610,820	654,396
Communications and technology									70,390	66,549	66,750
Occupancy and equipment costs									60,791	62,842	62,671
Clearing and exchange fees									25,126	26,022	24,709
Interest									19,437	16,329	16,956
Other									119,217	117,667	138,463
Total expenses	226,441	213,614	217,320	222,296	229,757	210,051	229,060	231,361	879,671	900,229	963,945
Income (loss) before income taxes from continuing operations	(7,496)	(1,810)	(5,246)	(7,340)	(4,568)	(2,573)	(1,101)	5,814	(21,892)	(2,428)	17,190
Current and Deferred Income Tax Expense (Benefit) from Continuing Operations									(12,262)	406	12,134
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	(2,424)	(1,059)	(2,619)	(3,528)	(3,856)	(1,136)	(1,501)	3,659	(9,630)	(2,834)	5,056
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax									17,339	9,139	8,546
Discontinued Operation, Tax Effect of Discontinued Operation									7,218	3,407	4,041
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	759	413	9,330	(381)	765	359	2,146	2,462	10,121	5,732	4,505
Net income	(1,665)	(646)	6,711	(3,909)	(3,091)	(777)	645	6,121	491	2,898	9,561
Less net income attributable to noncontrolling interest, net of tax	125	66	1,523	(62)	53	131	350	402	1,652	936	735
Net income (loss) attributable to Oppenheimer Holdings Inc.	$ (1,790)	$ (712)	$ 5,188	$ (3,847)	$ (3,144)	$ (908)	$ 295	$ 5,719	$ (1,161)	$ 1,962	$ 8,826
Basic net income (loss) per share attributable to Oppenheimer Holdings Inc.
Income (Loss) from Continuing Operations, Per Basic Share	$ (0.28)	$ (0.08)	$ (0.20)	$ (0.27)	$ (0.28)	$ (0.08)	$ (0.11)	$ 0.27	$ (0.72)	$ (0.21)	$ 0.37
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share	0.05	0.03	0.59	(0.02)	0.05	0.01	0.13	0.15	0.63	0.35	0.28
Net income (loss) per share	(0.23)	(0.05)	0.39	(0.29)	0	0	0	0	(0.09)	0.14	0.65
Income (Loss) from Continuing Operations, Per Diluted Share	(0.28)	(0.08)	(0.20)	(0.27)	(0.28)	(0.08)	(0.11)	0.26	(0.72)	(0.21)	0.36
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share	0.05	0.03	0.59	(0.02)	0.05	0.01	0.13	0.14	0.63	0.35	0.26
Earnings Per Share, Diluted	$ (0.23)	$ (0.05)	$ 0.39	$ (0.29)	$ 0	$ 0	$ 0	$ 0	$ (0.09)	$ 0.14	$ 0.62
Weighted average shares
Basic									13,368,768	13,640,610	13,604,258
Diluted									13,368,768	13,640,610	14,250,663