v3.19.1
Document and Entity Information - shares
6 Months Ended
Mar. 31, 2019
May 06, 2019
Document and Entity Information    
Entity Registrant Name LIQUIDITY SERVICES INC  
Entity Central Index Key 0001235468  
Document Type 10-Q  
Document Period End Date Mar. 31, 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)   33,496,398
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q2