v2.4.0.6
Document and Entity Information (USD $)
12 Months Ended
Dec. 31, 2011
Feb. 10, 2012
Jun. 24, 2011
Document and Entity Information [Abstract]      
Entity Registrant Name COHU INC    
Entity Central Index Key 0000021535    
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     $ 164,000,000
Entity Common Stock, Shares Outstanding   24,355,295