Document and Entity Information	9 Months Ended
	Sep. 30, 2014	Oct. 31, 2014 Class A Stock [Member]	Oct. 31, 2014 Class B Stock [Member]
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2014
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	Q3
Entity Registrant Name	OPPENHEIMER HOLDINGS INC
Entity Central Index Key	0000791963
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		13,530,688	99,680