v3.26.1
Expense Example, No Redemption - Eaton Vance AMT-Free Municipal Income Fund
Sep. 30, 2025
USD ($)
Eaton Vance AMT-Free Municipal Income Fund Class A  
Prospectus [Line Items]  
Expense Example, No Redemption, 1 Year $ 407
Expense Example, No Redemption, 3 Years 598
Expense Example, No Redemption, 5 Years 805
Expense Example, No Redemption, 10 Years 1,401
Eaton Vance AMT-Free Municipal Income Fund Class C  
Prospectus [Line Items]  
Expense Example, No Redemption, 1 Year 161
Expense Example, No Redemption, 3 Years 516
Expense Example, No Redemption, 5 Years 895
Expense Example, No Redemption, 10 Years 1,759
Eaton Vance AMT-Free Municipal Income Fund Class I  
Prospectus [Line Items]  
Expense Example, No Redemption, 1 Year 59
Expense Example, No Redemption, 3 Years 203
Expense Example, No Redemption, 5 Years 360
Expense Example, No Redemption, 10 Years $ 815