v3.26.1
Shareholder Fees
Mar. 31, 2026
Eaton Vance National Ultra-Short Municipal Income Fund | Eaton Vance National Ultra-Short Municipal Income Fund | Advisers Class  
Prospectus [Line Items]  
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) 0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price) 0.00%
Eaton Vance National Ultra-Short Municipal Income Fund | Eaton Vance National Ultra-Short Municipal Income Fund | Class A  
Prospectus [Line Items]  
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) 2.25%
Maximum Deferred Sales Charge (as a percentage of Offering Price) 0.00% [1]
Eaton Vance National Ultra-Short Municipal Income Fund | Eaton Vance National Ultra-Short Municipal Income Fund | Class I  
Prospectus [Line Items]  
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) 0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price) 0.00%
Eaton Vance National Limited Maturity Municipal Income Fund | Eaton Vance National Limited Maturity Municipal Income Fund | Class A  
Prospectus [Line Items]  
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) 3.25%
Maximum Deferred Sales Charge (as a percentage of Offering Price) 0.00% [2]
Eaton Vance National Limited Maturity Municipal Income Fund | Eaton Vance National Limited Maturity Municipal Income Fund | Class C  
Prospectus [Line Items]  
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) 0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price) 1.00%
Eaton Vance National Limited Maturity Municipal Income Fund | Eaton Vance National Limited Maturity Municipal Income Fund | Class I  
Prospectus [Line Items]  
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) 0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price) 0.00%
Eaton Vance Short Duration Municipal Opportunities Fund | Eaton Vance Short Duration Municipal Opportunities Fund | Class A  
Prospectus [Line Items]  
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) 3.25%
Maximum Deferred Sales Charge (as a percentage of Offering Price) 0.00% [3]
Eaton Vance Short Duration Municipal Opportunities Fund | Eaton Vance Short Duration Municipal Opportunities Fund | Class C  
Prospectus [Line Items]  
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) 0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price) 1.00%
Eaton Vance Short Duration Municipal Opportunities Fund | Eaton Vance Short Duration Municipal Opportunities Fund | Class I  
Prospectus [Line Items]  
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) 0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price) 0.00%
[1]
1 Class A shares purchased at net asset value in amounts of $250,000 or more are subject to a 0.25% contingent deferred sales charge if redeemed within 12 months of purchase.
[2]
1 Class A shares purchased at net asset value in amounts of $500,000 or more are subject to a 0.75% contingent deferred sales charge if redeemed within 12 months of purchase.
[3]
1 Class A shares purchased at net asset value in amounts of $500,000 or more are subject to a 0.75% contingent deferred sales charge if redeemed within 12 months of purchase.