v2.4.0.8
Document and Entity Information
9 Months Ended
Sep. 26, 2014
Nov. 04, 2014
Document and Entity Information    
Entity Registrant Name Willdan Group, Inc.  
Entity Central Index Key 0001370450  
Document Type 10-Q  
Document Period End Date Sep. 26, 2014  
Amendment Flag false  
Current Fiscal Year End Date --01-02  
Entity Current Reporting Status Yes  
Entity Filer Category Smaller Reporting Company  
Entity Common Stock, Shares Outstanding   7,627,025
Document Fiscal Year Focus 2014  
Document Fiscal Period Focus Q3