v2.4.0.6
Document and Entity Information (USD $)
In Millions, except Share data, unless otherwise specified
12 Months Ended
Dec. 31, 2011
Feb. 29, 2012
Jun. 30, 2011
Document and Entity Information      
Entity Registrant Name Celldex Therapeutics, Inc.    
Entity Central Index Key 0000744218    
Document Type 10-K    
Document Period End Date Dec. 31, 2011    
Amendment Flag false    
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     $ 156.1
Entity Common Stock, Shares Outstanding   57,160,636  
Document Fiscal Year Focus 2011    
Document Fiscal Period Focus FY