Document And Entity Information - shares
 6 Months Ended
Mar. 31, 2020
May 22, 2020
Document Information [Line Items]    
Entity Registrant Name ASTA FUNDING INC  
Entity Central Index Key 0001001258  
Trading Symbol asfi  
Current Fiscal Year End Date --09-30  
Entity Filer Category Non-accelerated Filer  
Entity Current Reporting Status Yes  
Entity Emerging Growth Company false  
Entity Small Business true  
Entity Interactive Data Current Yes  
Entity Common Stock, Shares Outstanding (in shares)   6,567,765
Entity Shell Company false  
Document Type 10-Q  
Document Period End Date Mar. 31, 2020  
Document Fiscal Year Focus 2020  
Document Fiscal Period Focus Q2  
Amendment Flag false  
Title of 12(b) Security Common Stock, par value $.01 per share