v3.26.3
N-2
Oct. 01, 2026
Cover [Abstract]  
Entity Central Index Key 0002031545
Amendment Flag false
Securities Act File Number 333-298414
Investment Company Act File Number 811-24011
Document Type N-2
Document Registration Statement true
Pre-Effective Amendment false
Post-Effective Amendment true
Post-Effective Amendment Number 1
Investment Company Act Registration true
Entity Registrant Name FT VEST TOTAL RETURN INCOME FUND: SERIES A4
Entity Address, Address Line One 235 West Galena Street
Entity Address, City or Town Milwaukee
Entity Address, State or Province WI
Entity Address, Postal Zip Code 53212
City Area Code 414
Local Phone Number 299-2217
Approximate Date of Commencement of Proposed Sale to Public As soon as practicable after the effective date of this Registration Statement.
Dividend or Interest Reinvestment Plan Only false
Delayed or Continuous Offering true
Primary Shelf [Flag] false
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) true
Exhibits Only, 462(d), File Number 333-298414
Registered Closed-End Fund [Flag] true
Business Development Company [Flag] false
Interval Fund [Flag] false
Primary Shelf Qualified [Flag] false
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 235 West Galena Street
Entity Address, City or Town Milwaukee
Entity Address, State or Province WI
Entity Address, Postal Zip Code 53212
Contact Personnel Name Ann Maurer