v3.26.3
Expense Example - AMERICAN HIGH-INCOME MUNICIPAL BOND FUND
Sep. 30, 2026
USD ($)
AMERICAN HIGH-INCOME MUNICIPAL BOND FUND (Class A, Class C, Class F-1, Class F-2, Class F-3) | Class A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year $ 441
Expense Example, with Redemption, 3 Years 581
Expense Example, with Redemption, 5 Years 734
Expense Example, with Redemption, 10 Years 1,178
AMERICAN HIGH-INCOME MUNICIPAL BOND FUND (Class A, Class C, Class F-1, Class F-2, Class F-3) | Class C  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 239
Expense Example, with Redemption, 3 Years 434
Expense Example, with Redemption, 5 Years 750
Expense Example, with Redemption, 10 Years 1,454
AMERICAN HIGH-INCOME MUNICIPAL BOND FUND (Class A, Class C, Class F-1, Class F-2, Class F-3) | Class F-1  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 72
Expense Example, with Redemption, 3 Years 224
Expense Example, with Redemption, 5 Years 390
Expense Example, with Redemption, 10 Years 871
AMERICAN HIGH-INCOME MUNICIPAL BOND FUND (Class A, Class C, Class F-1, Class F-2, Class F-3) | Class F-2  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 45
Expense Example, with Redemption, 3 Years 141
Expense Example, with Redemption, 5 Years 246
Expense Example, with Redemption, 10 Years 555
AMERICAN HIGH-INCOME MUNICIPAL BOND FUND (Class A, Class C, Class F-1, Class F-2, Class F-3) | Class F-3  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 34
Expense Example, with Redemption, 3 Years 106
Expense Example, with Redemption, 5 Years 185
Expense Example, with Redemption, 10 Years 418
AMERICAN HIGH-INCOME MUNICIPAL BOND FUND (Class R6) | Class R-6  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 34
Expense Example, with Redemption, 3 Years 106
Expense Example, with Redemption, 5 Years 185
Expense Example, with Redemption, 10 Years $ 418