XML 31 R1.htm IDEA: XBRL DOCUMENT v2.4.0.6
Document and Entity Information (USD $)
In Millions, except Share data, unless otherwise specified
 12 Months Ended
Dec. 31, 2011
Jun. 30, 2011
Feb. 28, 2012
Class A non-voting common stock
Feb. 28, 2012
Class B voting common stock
Entity Information [Line Items]        
Entity Registrant Name OPPENHEIMER HOLDINGS INC      
Entity Central Index Key 0000791963      
Document Type 10-K      
Document Period End Date Dec. 31, 2011      
Amendment Flag false      
Document Fiscal Year Focus 2011      
Document Fiscal Period Focus FY      
Current Fiscal Year End Date --12-31      
Entity Well-known Seasoned Issuer No      
Entity Voluntary Filers No      
Entity Current Reporting Status Yes      
Entity Filer Category Accelerated Filer      
Entity Public Float   $ 382.8    
Entity Common Stock, Shares Outstanding     13,589,062 99,680