v2.4.0.6
Document and Entity Information
9 Months Ended
Sep. 28, 2012
Nov. 05, 2012
Document and Entity Information    
Entity Registrant Name Willdan Group, Inc.  
Entity Central Index Key 0001370450  
Document Type 10-Q  
Document Period End Date Sep. 28, 2012  
Amendment Flag false  
Current Fiscal Year End Date --12-31  
Entity Current Reporting Status Yes  
Entity Filer Category Smaller Reporting Company  
Entity Common Stock, Shares Outstanding   7,335,365
Document Fiscal Year Focus 2012  
Document Fiscal Period Focus Q3