XML 12 R1.htm IDEA: XBRL DOCUMENT v3.4.0.3
Document and Entity Information - shares
3 Months Ended
Apr. 01, 2016
May. 06, 2016
Document and Entity Information [Abstract]    
Entity Registrant Name HACKETT GROUP, INC.  
Entity Central Index Key 0001057379  
Document Type 10-Q  
Document Period End Date Apr. 01, 2016  
Amendment Flag false  
Document Fiscal Year Focus 2016  
Document Fiscal Period Focus Q1  
Current Fiscal Year End Date --12-30  
Entity Filer Category Accelerated Filer  
Entity Common Stock, Shares Outstanding   28,706,194