Document and Entity Information - shares
9 Months Ended
Sep. 30, 2019
Oct. 15, 2019
Document and Entity Information    
Entity Registrant Name HARTE HANKS INC  
Entity Central Index Key 0000045919  
Document Type 10-Q  
Document Period End Date Sep. 30, 2019  
Amendment Flag false  
Current Fiscal Year End Date --12-31  
Entity Current Reporting Status Yes  
Entity Filer Category Non-accelerated Filer  
Entity Common Stock, Shares Outstanding   6,300,381
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q3  
Entity Emerging Growth Company false  
Entity Small Business true  
Entity Shell Company false