v3.26.3
N-2
Oct. 07, 2026
Cover [Abstract]  
Entity Central Index Key 0000844790
Amendment Flag true
Amendment Description EXPLANATORY NOTE The purpose of this Pre-Effective Amendment No. 2 to the Registration Statement under the Securities Act of 1933, as amended, on Form N-2, is to revise Item 25 of Part C of the Registration Statement filed on October 2, 2026. Accordingly, this Pre-Effective Amendment No. 2 consists only of the facing page, this explanatory note and Part C of the Registration Statement. The prospectus and financial statements are unchanged and have been omitted.
Entity Inv Company Type N-2
Securities Act File Number 333-298053
Investment Company Act File Number 811-05740
Document Type N-2/A
Document Registration Statement true
Pre-Effective Amendment true
Pre-Effective Amendment Number 2
Post-Effective Amendment false
Investment Company Act Registration true
Investment Company Registration Amendment true
Investment Company Registration Amendment Number 12
Entity Registrant Name Franklin Managed Municipal Income Trust
Entity Address, Address Line One 100 Federal Street
Entity Address, City or Town Boston
Entity Address, State or Province MA
Entity Address, Postal Zip Code 02110
City Area Code 617
Local Phone Number 292-1000
Approximate Date of Commencement of Proposed Sale to Public From time to time after the effective date of this Registration Statement.
Dividend or Interest Reinvestment Plan Only false
Delayed or Continuous Offering true
Primary Shelf [Flag] true
Effective Upon Filing, 462(e) false
Additional Securities Effective, 413(b) false
Effective when Declared, Section 8(c) false
New Effective Date for Previous Filing false
Additional Securities. 462(b) false
No Substantive Changes, 462(c) false
Exhibits Only, 462(d) false
Registered Closed-End Fund [Flag] true
Business Development Company [Flag] false
Interval Fund [Flag] false
Primary Shelf Qualified [Flag] true
Entity Well-known Seasoned Issuer No
Entity Emerging Growth Company false
New CEF or BDC Registrant [Flag] false
Business Contact [Member]  
Cover [Abstract]  
Entity Address, Address Line One One Madison Avenue
Entity Address, Address Line Two 17th Floor
Entity Address, City or Town New York
Entity Address, State or Province NY
Entity Address, Postal Zip Code 10010
Contact Personnel Name Franklin Templeton