Investment Risks - WASHINGTON MUTUAL INVESTORS FUND	Jun. 30, 2026
Risk Lose Money [Member]
Prospectus [Line Items]
Risk [Text Block]	You may lose money by investing in the fund.
Risk Not Insured [Member]
Prospectus [Line Items]
Risk [Text Block]	Your investment in the fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency, entity or person.
Market conditions [Member]
Prospectus [Line Items]
Risk [Text Block]	Market conditions — The prices of, and the income generated by, the common stocks and other securities held by the fund may decline – sometimes rapidly or unpredictably – due to various factors, including events or conditions affecting the general economy or particular industries or companies; overall market changes; local, regional or global political, social or economic instability; governmental, governmental agency or central bank responses to economic conditions; levels of public debt and deficits; changes in inflation rates; and currency exchange rate, interest rate and commodity price fluctuations. Economies and financial markets throughout the world are highly interconnected. Economic, financial or political events, trading and tariff arrangements, wars, terrorism, cybersecurity events, natural disasters, public health emergencies (such as the spread of infectious disease), bank failures and other circumstances in one country or region, including actions taken by governmental or quasi-governmental authorities in response to any of the foregoing, could have impacts on global economies or markets. As a result, whether or not the fund invests in securities of issuers located in or with significant exposure to the countries affected, the value and liquidity of the fund’s investments may be negatively affected by developments in other countries and regions.
Issuer risks [Member]
Prospectus [Line Items]
Risk [Text Block]	Issuer risks — The prices of, and the income generated by, securities held by the fund may decline in response to various factors directly related to the issuers of such securities, including reduced demand for an issuer’s goods or services, poor management performance, major litigation, investigations or other controversies related to the issuer, changes in the issuer’s financial condition or credit rating, changes in government regulations affecting the issuer or its competitive environment and strategic initiatives such as mergers, acquisitions or dispositions and the market response to any such initiatives. An individual security may also be affected by factors relating to the industry or sector of the issuer or the securities markets as a whole, and conversely an industry or sector or the securities markets may be affected by a change in financial condition or other event affecting a single issuer.
Investing in income-oriented stocks [Member]
Prospectus [Line Items]
Risk [Text Block]	Investing in income-oriented stocks — The value of the fund’s securities and income provided by the fund may be reduced by changes in the dividend policies of, and the capital resources available for dividend payments at, the companies in which the fund invests.
Investing in growth-oriented stocks [Member]
Prospectus [Line Items]
Risk [Text Block]	Investing in growth-oriented stocks — Growth-oriented common stocks and other equity-type securities (such as preferred stocks, convertible preferred stocks and convertible bonds) may involve larger price swings and greater potential for loss than other types of investments.
Management [Member]
Prospectus [Line Items]
Risk [Text Block]	Management — The investment adviser to the fund actively manages the fund’s investments. Consequently, the fund is subject to the risk that the methods and analyses, including models, tools and data, employed by the investment adviser in this process may be flawed or incorrect and may not produce the desired results. This could cause the fund to lose value or its investment results to lag relevant benchmarks or other funds with similar objectives.

Investment Risks - WASHINGTON MUTUAL INVESTORS FUND

Jun. 30, 2026

You may lose money by investing in the fund.

Your investment in the fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency, entity or person.

Market conditions [Member]

Prospectus [Line Items]

Risk [Text Block]

Market conditions — The prices of, and the income generated by, the common stocks and other securities held by the fund may decline – sometimes rapidly or unpredictably – due to various factors, including events or conditions affecting the general economy or particular industries or companies; overall market changes; local, regional or global political, social or economic instability; governmental, governmental agency or central bank responses to economic conditions; levels of public debt and deficits; changes in inflation rates; and currency exchange rate, interest rate and commodity price fluctuations.

Economies and financial markets throughout the world are highly interconnected. Economic, financial or political events, trading and tariff arrangements, wars, terrorism, cybersecurity events, natural disasters, public health emergencies (such as the spread of infectious disease), bank failures and other circumstances in one country or region, including actions taken by governmental or quasi-governmental authorities in response to any of the foregoing, could have impacts on global economies or markets. As a result, whether or not the fund invests in securities of issuers located in or with significant exposure to the countries affected, the value and liquidity of the fund’s investments may be negatively affected by developments in other countries and regions.

Issuer risks [Member]

Prospectus [Line Items]

Risk [Text Block]

Issuer risks — The prices of, and the income generated by, securities held by the fund may decline in response to various factors directly related to the issuers of such securities, including reduced demand for an issuer’s goods or services, poor management performance, major litigation, investigations or other controversies related to the issuer, changes in the issuer’s financial condition or credit rating, changes in government regulations affecting the issuer or its competitive environment and strategic initiatives such as mergers, acquisitions or dispositions and the market response to any such initiatives. An individual security may also be affected by factors relating to the industry or sector of the issuer or the securities markets as a whole, and conversely an industry or sector or the securities markets may be affected by a change in financial condition or other event affecting a single issuer.

Investing in income-oriented stocks [Member]

Prospectus [Line Items]

Risk [Text Block]

Investing in income-oriented stocks — The value of the fund’s securities and income provided by the fund may be reduced by changes in the dividend policies of, and the capital resources available for dividend payments at, the companies in which the fund invests.

Investing in growth-oriented stocks [Member]

Prospectus [Line Items]

Risk [Text Block]

Investing in growth-oriented stocks — Growth-oriented common stocks and other equity-type securities (such as preferred stocks, convertible preferred stocks and convertible bonds) may involve larger price swings and greater potential for loss than other types of investments.

Management [Member]

Prospectus [Line Items]

Risk [Text Block]

Management — The investment adviser to the fund actively manages the fund’s investments. Consequently, the fund is subject to the risk that the methods and analyses, including models, tools and data, employed by the investment adviser in this process may be flawed or incorrect and may not produce the desired results. This could cause the fund to lose value or its investment results to lag relevant benchmarks or other funds with similar objectives.