XML 22 R1.htm IDEA: XBRL DOCUMENT v2.4.0.6
Document and Entity Information
 3 Months Ended
Mar. 31, 2012
Apr. 30, 2012
Class A non-voting common stock
Apr. 30, 2012
Class B voting common stock
Entity Information [Line Items]      
Entity Registrant Name OPPENHEIMER HOLDINGS INC    
Entity Central Index Key 0000791963    
Document Type 10-Q    
Document Period End Date Mar. 31, 2012    
Amendment Flag false    
Document Fiscal Year Focus 2011    
Document Fiscal Period Focus Q1    
Current Fiscal Year End Date --12-31    
Entity Filer Category Accelerated Filer    
Entity Common Stock, Shares Outstanding   13,489,162 99,680