Investment Strategy - American Funds U.S. Small & Mid Cap Equity Fund	Oct. 30, 2026
Prospectus [Line Items]
Strategy [Heading]	Principal investment strategies
Strategy Narrative [Text Block]	Under normal market conditions, the fund invests at least 80% of its net assets in common stocks and other equity-type securities of small and mid-capitalization companies in the United States. For purposes of this policy, equity-type securities are securities that exhibit ownership characteristics, including common and preferred stock, securities convertible into common and preferred stock and depository receipts representing ownership in common and preferred stock. The investment adviser currently defines “small and mid-capitalization companies” to be companies whose market capitalizations typically fall within the range of the Russell 2500 Index or the Russell Midcap Index. As of June 30, 2026, the largest company for the Russell 2500 Index had a market capitalization of approximately $30.6 billion and the largest company for the Russell Midcap Index had a market capitalization of approximately $92.7 billion. The market capitalization of the companies included in the Russell 2500 Index and the Russell Midcap Index will change with market conditions. The fund strives to maintain a fully invested portfolio. The fund is nondiversified, which allows it to invest a greater percentage of its assets in any one issuer than would otherwise be the case. The investment adviser uses a system of multiple portfolio managers in managing the fund’s assets. Under this approach, a portfolio is divided into segments managed by individual managers. For more information regarding the investment process of the fund, see the “Management and organization” section of this prospectus. The fund relies on the professional judgment of its investment adviser to make decisions about the fund’s portfolio investments. The basic investment philosophy of the investment adviser is to seek to invest in attractively valued companies that, in its opinion, represent good, long-term investment opportunities. Securities may be sold when the investment adviser believes that they no longer represent relatively attractive investment opportunities.
Summary of Definition of Rule 35d-1 Term in Fund Name [Text Block]	For purposes of this policy, equity-type securities are securities that exhibit ownership characteristics, including common and preferred stock, securities convertible into common and preferred stock and depository receipts representing ownership in common and preferred stock. The investment adviser currently defines “small and mid-capitalization companies” to be companies whose market capitalizations typically fall within the range of the Russell 2500 Index or the Russell Midcap Index.
Summary of Selection Criteria for Rule 35d-1 Term in Fund Name [Text Block]	For purposes of this policy, equity-type securities are securities that exhibit ownership characteristics, including common and preferred stock, securities convertible into common and preferred stock and depository receipts representing ownership in common and preferred stock. The investment adviser currently defines “small and mid-capitalization companies” to be companies whose market capitalizations typically fall within the range of the Russell 2500 Index or the Russell Midcap Index.
Rule 35d-1 Eighty Percent Investment Policy [Text Block]	Under normal market conditions, the fund invests at least 80% of its net assets in common stocks and other equity-type securities of small and mid-capitalization companies in the United States.

Investment Strategy - American Funds U.S. Small & Mid Cap Equity Fund

Oct. 30, 2026

Principal investment strategies

Under normal market conditions, the fund invests at least 80% of its net assets in common stocks and other equity-type securities of small and mid-capitalization companies in the United States. For purposes of this policy, equity-type securities are securities that exhibit ownership characteristics, including common and preferred stock, securities convertible into common and preferred stock and depository receipts representing ownership in common and preferred stock. The investment adviser currently defines “small and mid-capitalization companies” to be companies whose market capitalizations typically fall within the range of the Russell 2500 Index or the Russell Midcap Index. As of June 30, 2026, the largest company for the Russell 2500 Index had a market capitalization of approximately $30.6 billion and the largest company for the Russell Midcap Index had a market capitalization of approximately $92.7 billion. The market capitalization of the companies included in the Russell 2500 Index and the Russell Midcap Index will change with market conditions. The fund strives to maintain a fully invested portfolio.

The fund is nondiversified, which allows it to invest a greater percentage of its assets in any one issuer than would otherwise be the case.

The investment adviser uses a system of multiple portfolio managers in managing the fund’s assets. Under this approach, a portfolio is divided into segments managed by individual managers. For more information regarding the investment process of the fund, see the “Management and organization” section of this prospectus.

The fund relies on the professional judgment of its investment adviser to make decisions about the fund’s portfolio investments. The basic investment philosophy of the investment adviser is to seek to invest in attractively valued companies that, in its opinion, represent good, long-term investment opportunities. Securities may be sold when the investment adviser believes that they no longer represent relatively attractive investment opportunities.

Summary of Definition of Rule 35d-1 Term in Fund Name [Text Block]

For purposes of this policy, equity-type securities are securities that exhibit ownership characteristics, including common and preferred stock, securities convertible into common and preferred stock and depository receipts representing ownership in common and preferred stock. The investment adviser currently defines “small and mid-capitalization companies” to be companies whose market capitalizations typically fall within the range of the Russell 2500 Index or the Russell Midcap Index.

Summary of Selection Criteria for Rule 35d-1 Term in Fund Name [Text Block]

Rule 35d-1 Eighty Percent Investment Policy [Text Block]

Under normal market conditions, the fund invests at least 80% of its net assets in common stocks and other equity-type securities of small and mid-capitalization companies in the United States.