v3.19.2
Document and Entity Information - shares
9 Months Ended
Jun. 30, 2019
Jul. 30, 2019
Document and Entity Information    
Entity Registrant Name LIQUIDITY SERVICES INC  
Entity Central Index Key 0001235468  
Document Type 10-Q  
Document Period End Date Jun. 30, 2019  
Amendment Flag false  
Current Fiscal Year End Date --09-30  
Entity Current Reporting Status Yes  
Entity Filer Category Accelerated Filer  
Entity Common Stock, Shares Outstanding (in shares)   33,651,086
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q3  
Entity Small Business true  
Entity Emerging Growth Company false  
Entity Shell Company false