Document and Entity Information
6 Months Ended
Dec. 31, 2011
Jan. 31, 2012
Document and Entity Information [Abstract]    
Entity Registrant Name QUINSTREET, INC  
Entity Central Index Key 0001117297  
Document Type 10-Q  
Document Period End Date Dec. 31, 2011  
Amendment Flag false  
Document Fiscal Year Focus 2012  
Document Fiscal Period Focus Q2  
Current Fiscal Year End Date --06-30  
Entity Filer Category Accelerated Filer  
Entity Common Stock, Shares Outstanding   45,153,228