Document and Entity Information - USD ($)
$ in Millions
12 Months Ended
Sep. 30, 2018
Nov. 26, 2018
Mar. 31, 2018
Document and Entity Information [Abstract]      
Entity Registrant Name META FINANCIAL GROUP INC    
Entity Central Index Key 0000907471    
Current Fiscal Year End Date --09-30    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Filer Category Large Accelerated Filer    
Entity Public Float     $ 979.7
Entity Common Stock, Shares Outstanding   39,406,938  
Document Fiscal Year Focus 2018    
Document Fiscal Period Focus FY    
Document Type 10-K    
Amendment Flag false    
Document Period End Date Sep. 30, 2018    
Entity Small Business false    
Entity Emerging Growth Company false    
Entity Shell Company false