v3.26.3
Average Annual Total Returns
 12 Months Ended 60 Months Ended 105 Months Ended 107 Months Ended 120 Months Ended 196 Months Ended 197 Months Ended
Sep. 30, 2026
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
AMERICAN FUNDS SHORT-TERM TAX-EXEMPT BOND FUND (Class A, Class F-1, Class F-2, Class F-3) | Class A                  
Prospectus [Line Items]                  
Average Annual Return, Percent   1.77% 0.84%     1.26%   1.31%  
Performance Inception Date Aug. 07, 2009                
AMERICAN FUNDS SHORT-TERM TAX-EXEMPT BOND FUND (Class A, Class F-1, Class F-2, Class F-3) | Class F-1                  
Prospectus [Line Items]                  
Average Annual Return, Percent   4.18% 1.16%     1.32% 1.26%    
Performance Inception Date Aug. 27, 2009                
AMERICAN FUNDS SHORT-TERM TAX-EXEMPT BOND FUND (Class A, Class F-1, Class F-2, Class F-3) | Class F-2                  
Prospectus [Line Items]                  
Average Annual Return, Percent   4.50% 1.47%     1.61%     1.54%
Performance Inception Date Aug. 12, 2009                
AMERICAN FUNDS SHORT-TERM TAX-EXEMPT BOND FUND (Class A, Class F-1, Class F-2, Class F-3) | Class F-2 | After Taxes on Distributions                  
Prospectus [Line Items]                  
Average Annual Return, Percent   4.50% 1.45%     1.59%      
AMERICAN FUNDS SHORT-TERM TAX-EXEMPT BOND FUND (Class A, Class F-1, Class F-2, Class F-3) | Class F-2 | After Taxes on Distributions and Sales                  
Prospectus [Line Items]                  
Average Annual Return, Percent   3.88% 1.55%     1.61%      
AMERICAN FUNDS SHORT-TERM TAX-EXEMPT BOND FUND (Class A, Class F-1, Class F-2, Class F-3) | Class F-3                  
Prospectus [Line Items]                  
Average Annual Return, Percent   4.58% 1.54%   1.84%        
Performance Inception Date Jan. 27, 2017                
AMERICAN FUNDS SHORT-TERM TAX-EXEMPT BOND FUND (Class A, Class F-1, Class F-2, Class F-3) | Bloomberg Municipal Bond Index (reflects no deductions for sales charges, account fees, expenses or U.S. federal income taxes)                  
Prospectus [Line Items]                  
Average Annual Return, Percent   4.25% 0.80%     2.34%     3.44%
AMERICAN FUNDS SHORT-TERM TAX-EXEMPT BOND FUND (Class A, Class F-1, Class F-2, Class F-3) | Bloomberg Municipal Short 1-5 Years Index (reflects no deductions for sales charges, account fees, expenses or U.S. federal income taxes)                  
Prospectus [Line Items]                  
Average Annual Return, Percent   4.11% 1.36%     1.67%     1.76%
AMERICAN FUNDS SHORT-TERM TAX-EXEMPT BOND FUND (Class R-6) | Class R-6                  
Prospectus [Line Items]                  
Average Annual Return, Percent   4.58% 1.54% 1.84%          
Performance Inception Date Mar. 17, 2017                
AMERICAN FUNDS SHORT-TERM TAX-EXEMPT BOND FUND (Class R-6) | Class R-6 | After Taxes on Distributions                  
Prospectus [Line Items]                  
Average Annual Return, Percent   4.58% 1.52% 1.82%          
AMERICAN FUNDS SHORT-TERM TAX-EXEMPT BOND FUND (Class R-6) | Class R-6 | After Taxes on Distributions and Sales                  
Prospectus [Line Items]                  
Average Annual Return, Percent   3.95% 1.63% 1.81%          
AMERICAN FUNDS SHORT-TERM TAX-EXEMPT BOND FUND (Class R-6) | Bloomberg Municipal Bond Index (reflects no deductions for sales charges, account fees, expenses or U.S. federal income taxes)                  
Prospectus [Line Items]                  
Average Annual Return, Percent   4.25% 0.80% 2.55%          
AMERICAN FUNDS SHORT-TERM TAX-EXEMPT BOND FUND (Class R-6) | Bloomberg Municipal Short 1-5 Years Index (reflects no deductions for sales charges, account fees or U.S. federal income taxes)                  
Prospectus [Line Items]                  
Average Annual Return, Percent   4.11% 1.36% 1.78%