v3.26.3
Shareholder Report, Average Annual Return (Details)
 12 Months Ended 23 Months Ended
Aug. 31, 2026
Aug. 31, 2026
American Funds® U.S. Small and Mid Cap Equity Fund - Class A    
Average Annual Return [Line Items]    
Line Graph and Table Measure Name American Funds U.S. Small and Mid Cap Equity Fund — Class A (with sales charge)  
Average Annual Return, Percent [1] 7.31% 9.75% [2]
American Funds® U.S. Small and Mid Cap Equity Fund - Class C    
Average Annual Return [Line Items]    
Line Graph and Table Measure Name American Funds U.S. Small and Mid Cap Equity Fund — Class C (with sales charge)  
Average Annual Return, Percent [1] 12.85% 13.17% [3]
American Funds® U.S. Small and Mid Cap Equity Fund - Class F-1    
Average Annual Return [Line Items]    
Line Graph and Table Measure Name American Funds U.S. Small and Mid Cap Equity Fund — Class F-1  
Average Annual Return, Percent [1] 13.88% 13.18% [4]
American Funds® U.S. Small and Mid Cap Equity Fund - Class F-2    
Average Annual Return [Line Items]    
Line Graph and Table Measure Name American Funds U.S. Small and Mid Cap Equity Fund — Class F-2  
Average Annual Return, Percent [1] 13.85% 13.17% [5]
American Funds® U.S. Small and Mid Cap Equity Fund - Class F-3    
Average Annual Return [Line Items]    
Line Graph and Table Measure Name American Funds U.S. Small and Mid Cap Equity Fund — Class F-3  
Average Annual Return, Percent [1] 14.12% 13.45% [6]
American Funds® U.S. Small and Mid Cap Equity Fund - Class 529-A    
Average Annual Return [Line Items]    
Line Graph and Table Measure Name American Funds U.S. Small and Mid Cap Equity Fund — Class 529-A (with sales charge)  
Average Annual Return, Percent [1] 9.72% 11.01% [7]
American Funds® U.S. Small and Mid Cap Equity Fund - Class 529-C    
Average Annual Return [Line Items]    
Line Graph and Table Measure Name American Funds U.S. Small and Mid Cap Equity Fund — Class 529-C (with sales charge)  
Average Annual Return, Percent [1] 12.70% 13.08% [8]
American Funds® U.S. Small and Mid Cap Equity Fund - Class 529-E    
Average Annual Return [Line Items]    
Line Graph and Table Measure Name American Funds U.S. Small and Mid Cap Equity Fund — Class 529-E  
Average Annual Return, Percent [1] 13.70% 13.09% [9]
American Funds® U.S. Small and Mid Cap Equity Fund - Class 529-F-2    
Average Annual Return [Line Items]    
Line Graph and Table Measure Name American Funds U.S. Small and Mid Cap Equity Fund — Class 529-F-2  
Average Annual Return, Percent [1] 13.68% 13.07% [10]
American Funds® U.S. Small and Mid Cap Equity Fund - Class 529-F-3    
Average Annual Return [Line Items]    
Line Graph and Table Measure Name American Funds U.S. Small and Mid Cap Equity Fund — Class 529-F-3  
Average Annual Return, Percent [1] 13.97% 13.37% [11]
American Funds® U.S. Small and Mid Cap Equity Fund - Class R-1    
Average Annual Return [Line Items]    
Line Graph and Table Measure Name American Funds U.S. Small and Mid Cap Equity Fund — Class R-1  
Average Annual Return, Percent [1] 14.10% 13.45% [12]
American Funds® U.S. Small and Mid Cap Equity Fund - Class R-2    
Average Annual Return [Line Items]    
Line Graph and Table Measure Name American Funds U.S. Small and Mid Cap Equity Fund — Class R-2  
Average Annual Return, Percent [1] 14.13% 13.42% [13]
American Funds® U.S. Small and Mid Cap Equity Fund - Class R-2E    
Average Annual Return [Line Items]    
Line Graph and Table Measure Name American Funds U.S. Small and Mid Cap Equity Fund — Class R-2E  
Average Annual Return, Percent [1] 14.13% 13.44% [14]
American Funds® U.S. Small and Mid Cap Equity Fund - Class R-3    
Average Annual Return [Line Items]    
Line Graph and Table Measure Name American Funds U.S. Small and Mid Cap Equity Fund — Class R-3  
Average Annual Return, Percent [1] 14.12% 13.45% [15]
American Funds® U.S. Small and Mid Cap Equity Fund - Class R-4    
Average Annual Return [Line Items]    
Line Graph and Table Measure Name American Funds U.S. Small and Mid Cap Equity Fund — Class R-4  
Average Annual Return, Percent [1] 14.11% 13.45% [16]
American Funds® U.S. Small and Mid Cap Equity Fund - Class R-5E    
Average Annual Return [Line Items]    
Line Graph and Table Measure Name American Funds U.S. Small and Mid Cap Equity Fund — Class R-5E  
Average Annual Return, Percent [1] 14.12% 13.45% [17]
American Funds® U.S. Small and Mid Cap Equity Fund - Class R-5    
Average Annual Return [Line Items]    
Line Graph and Table Measure Name American Funds U.S. Small and Mid Cap Equity Fund — Class R-5  
Average Annual Return, Percent [1] 14.11% 13.45% [18]
American Funds® U.S. Small and Mid Cap Equity Fund - Class R-6    
Average Annual Return [Line Items]    
Line Graph and Table Measure Name American Funds U.S. Small and Mid Cap Equity Fund — Class R-6  
Average Annual Return, Percent [1] 14.14% 13.47% [19]
Without Sales Load [Member] | American Funds® U.S. Small and Mid Cap Equity Fund - Class A    
Average Annual Return [Line Items]    
Line Graph and Table Measure Name American Funds U.S. Small and Mid Cap Equity Fund — Class A (without sales charge)  
Average Annual Return, Percent [1] 13.86% 13.17% [2],[20]
Without Sales Load [Member] | American Funds® U.S. Small and Mid Cap Equity Fund - Class C    
Average Annual Return [Line Items]    
Line Graph and Table Measure Name American Funds U.S. Small and Mid Cap Equity Fund — Class C (without sales charge)  
Average Annual Return, Percent [1] 13.85% 13.17% [3]
Without Sales Load [Member] | American Funds® U.S. Small and Mid Cap Equity Fund - Class 529-A    
Average Annual Return [Line Items]    
Line Graph and Table Measure Name American Funds U.S. Small and Mid Cap Equity Fund — Class 529-A (without sales charge)  
Average Annual Return, Percent [1] 13.70% 13.08% [7]
Without Sales Load [Member] | American Funds® U.S. Small and Mid Cap Equity Fund - Class 529-C    
Average Annual Return [Line Items]    
Line Graph and Table Measure Name American Funds U.S. Small and Mid Cap Equity Fund — Class 529-C (without sales charge)  
Average Annual Return, Percent [1] 13.70% 13.08% [8]
Russell 3000 Index [Member]    
Average Annual Return [Line Items]    
Line Graph and Table Measure Name Russell 3000 Index  
Average Annual Return, Percent [20] 20.10% 17.68% [2],[3],[4],[5],[6],[7],[8],[9],[10],[11],[12],[13],[14],[15],[16],[17],[18],[19]
Russell 2500 Index [Member]    
Average Annual Return [Line Items]    
Line Graph and Table Measure Name Russell 2500 Index  
Average Annual Return, Percent [20] 25.54% 17.46% [2],[3],[4],[5],[6],[7],[8],[9],[10],[11],[12],[13],[14],[15],[16],[17],[18],[19]
Russell Midcap Index [Member]    
Average Annual Return [Line Items]    
Line Graph and Table Measure Name Russell Midcap Index  
Average Annual Return, Percent [20] 17.94% 14.63% [2],[3],[4],[5],[6],[7],[8],[9],[10],[11],[12],[13],[14],[15],[16],[17],[18],[19]
[1] Investment results assume all distributions are reinvested and reflect applicable fees and expenses. When applicable, results reflect fee waivers and/or expense reimbursements, without which they would have been lower.
[2] Class A shares were first offered on September 27, 2024.
[3] Class C shares were first offered on September 27, 2024.
[4] Class F-1 shares were first offered on September 27, 2024.
[5] Class F-2 shares were first offered on September 27, 2024.
[6] Class F-3 shares were first offered on September 27, 2024.
[7] Class 529-A shares were first offered on September 27, 2024.
[8] Class 529-C shares were first offered on September 27, 2024.
[9] Class 529-E shares were first offered on September 27, 2024.
[10] Class 529-F-2 shares were first offered on September 27, 2024.
[11] Class 529-F-3 shares were first offered on September 27, 2024.
[12] Class R-1 shares were first offered on September 27, 2024.
[13] Class R-2 shares were first offered on September 27, 2024.
[14] Class R-2E shares were first offered on September 27, 2024.
[15] Class R-3 shares were first offered on September 27, 2024.
[16] Class R-4 shares were first offered on September 27, 2024.
[17] Class R-5E shares were first offered on September 27, 2024.
[18] Class R-5 shares were first offered on September 27, 2024.
[19] Class R-6 shares were first offered on September 27, 2024.
[20] Results assume all distributions are reinvested. Any market index shown is unmanaged, and therefore, has no expenses. Investors cannot invest directly in an index. Source(s): London Stock Exchange Group.