Quarterly report pursuant to Section 13 or 15(d)

Cover Page

Cover Page - shares
9 Months Ended
Jun. 30, 2020
Aug. 03, 2020
Cover [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2020  
Document Transition Report false  
Entity File Number 1-12997  
Entity Registrant Name Maximus, Inc.  
Entity Incorporation, State or Country Code VA  
Entity Tax Identification Number 54-1000588  
Entity Address, Address Line One 1891 Metro Center Drive  
Entity Address, City or Town Reston  
Entity Address, State or Province VA  
Entity Address, Postal Zip Code 20190  
City Area Code 703  
Local Phone Number 251-8500  
Title of 12(b) Security Common Stock, no par value  
Trading Symbol MMS  
Security Exchange Name NYSE  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Large Accelerated Filer  
Entity Small Reporting Company false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   61,312,619
Entity Central Index Key 0001032220  
Current Fiscal Year End Date --09-30  
Document Fiscal Year Focus 2020  
Document Fiscal Period Focus Q3  
Amendment Flag false