Annual report pursuant to Section 13 and 15(d)

Document and Entity Information

Document and Entity Information - USD ($)
12 Months Ended
Sep. 30, 2017
Nov. 06, 2017
Mar. 31, 2017
Document and Entity Information      
Entity Registrant Name MAXIMUS INC    
Entity Central Index Key 0001032220    
Document Type 10-K    
Document Period End Date Sep. 30, 2017    
Amendment Flag false    
Current Fiscal Year End Date --09-30    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Filer Category Large Accelerated Filer    
Entity Public Float     $ 3,963,270,858
Entity Common Stock, Shares Outstanding   65,136,568  
Document Fiscal Year Focus 2017    
Document Fiscal Period Focus FY