v3.26.3
Document And Entity Information - shares
 9 Months Ended
Sep. 26, 2026
Oct. 20, 2026
Document Information [Line Items]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Sep. 26, 2026  
Document Transition Report false  
Entity File Number 001-04298  
Entity Registrant Name COHU, INC.  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 95-1934119  
Entity Address, Address Line One 17087 Via Del Campo  
Entity Address, City or Town San Diego  
Entity Address, State or Province CA  
Entity Address, Postal Zip Code 92127-1711  
City Area Code 858  
Local Phone Number 848-8100  
Title of 12(b) Security Common Stock, $1.00 par value  
Trading Symbol COHU  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding (in shares)   47,346,050
Entity Central Index Key 0000021535  
Current Fiscal Year End Date --12-26  
Document Fiscal Year Focus 2026  
Document Fiscal Period Focus Q3  
Amendment Flag false