v3.26.1
Fees and Expenses - WASHINGTON MUTUAL INVESTORS FUND
Jun. 30, 2026
USD ($)
Prospectus [Line Items]  
Expense Heading [Optional Text] Fees and expenses of the fund
Expense Narrative [Text Block]

This table describes the fees and expenses that you may pay if you buy, hold and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. For example, in addition to the fees and expenses described below, you may also be required to pay brokerage commissions on purchases and sales of Class F-2, F-3, 529-F-2 or 529-F-3 shares of the fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in American Funds and Capital Group KKR Public-Private+ Funds (collectively “Capital Group Funds”) ($250,000 for Class 529-A shares). More information about these and other discounts is available from your financial professional, in the “Sales charge reductions and waivers” sections on page 34 of the prospectus and on page 66 of the fund’s statement of additional information, and in the sales charge waiver appendix to the prospectus.
Expense Breakpoint Discounts [Text] You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in American Funds and Capital Group KKR Public-Private+ Funds (collectively “Capital Group Funds”) ($250,000 for Class 529-A shares).
Expense Breakpoint, Minimum Investment Required [Amount] $ 25,000
Shareholder Fees Caption [Optional Text] Shareholder fees (fees paid directly from your investment)
Shareholder Fees [Table]
             
Shareholder fees (fees paid directly from your investment)
Share class: A 529-A C and
529-C		 529-E All F and 529-F share classes All R
share
classes
Maximum sales charge (load) imposed on purchases (as a percentage of offering price) 5.75% 3.50% none none none none
Maximum deferred sales charge (load) (as a percentage of the amount redeemed) 1.00* 1.00* 1.00% none none none
Maximum sales charge (load) imposed on reinvested dividends none none none none none none
Redemption or exchange fees none none none none none none
Operating Expenses Caption [Optional Text] Annual fund operating expenses (expenses that you pay each year as a percentage of the net asset value of your investment)
Annual Fund Operating Expenses [Table]
             
Annual fund operating expenses (expenses that you pay each year as a percentage of the net asset value of your investment)
Share class: A C F-1 F-2 F-3 529-A
Management fees 0.22% 0.22% 0.22% 0.22% 0.22% 0.22%
Distribution and/or service (12b-1) fees 0.24 1.00 0.25 none none 0.23
Other expenses 0.09 0.09 0.15 0.15 0.04 0.13
Total annual fund operating expenses 0.55 1.31 0.62 0.37 0.26 0.58
             
Share class: 529-C 529-E 529-F-2 529-F-3 R-1 R-2
Management fees 0.22% 0.22% 0.22% 0.22% 0.22% 0.22%
Distribution and/or service (12b-1) fees 1.00 0.50 none none 1.00 0.75
Other expenses 0.14 0.12 0.13 0.09 0.13 0.38
Total annual fund operating expenses 1.36 0.84 0.35 0.31 1.35 1.35
             
Share class: R-2E R-3 R-4 R-5E R-5 R-6
Management fees 0.22% 0.22% 0.22% 0.22% 0.22% 0.22%
Distribution and/or service (12b-1) fees 0.60 0.50 0.25 none none none
Other expenses 0.24 0.19 0.14 0.19 0.09 0.04
Total annual fund operating expenses 1.06 0.91 0.61 0.41 0.31 0.26

*  A contingent deferred sales charge of 1.00% applies on certain redemptions made within 18 months following purchases of $1 million or more made without an initial sales charge. Contingent deferred sales charge is calculated based on the lesser of the offering price and market value of shares being sold.
Expenses Deferred Charges [Text Block] A contingent deferred sales charge of 1.00% applies on certain redemptions made within 18 months following purchases of $1 million or more made without an initial sales charge. Contingent deferred sales charge is calculated based on the lesser of the offering price and market value of shares being sold.
Expense Example [Heading] Example
Expense Example Narrative [Text Block]

This example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds.

The example assumes that you invest $10,000 in the fund for the time periods indicated and then redeem or hold all of your shares at the end of those periods. The example also assumes that your investment has a 5% return each year and that the fund’s operating expenses remain the same. You may be required to pay brokerage commissions on your purchases and sales of Class F-2, F-3, 529-F-2 or 529-F-3 shares of the fund, which are not reflected in the example.

Expense Example by, Year, Caption [Text] Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Expense Example, With Redemption [Table]
                         
Share class: A C F-1 F-2 F-3 529-A 529-C 529-E 529-F-2 529-F-3 R-1 R-2
1 year $628 $233 $63 $38 $27 $407 $238 $86 $36 $32 $137 $137
3 years 741 415 199 119 84 529 431 268 113 100 428 428
5 years 865 718 346 208 146 662 745 466 197 174 739 739
10 years 1,225 1,369 774 468 331 1,050 1,132 1,037 443 393 1,624 1,624
                     
Share class: R-2E R-3 R-4 R-5E R-5 R-6 For the share classes listed to the right, you would pay the following if you did not redeem your shares: Share class: C 529-C
1 year $108 $93 $62 $42 $32 $27 1 year $133 $138
3 years 337 290 195 132 100 84 3 years 415 431
5 years 585 504 340 230 174 146 5 years 718 745
10 years 1,294 1,120 762 518 393 331 10 years 1,369 1,132
Expense Example, No Redemption, By Year, Caption [Text] For the share classes listed to the right, you would pay the following if you did not redeem your shares:
Expense Example, No Redemption [Table]
                     
Share class: R-2E R-3 R-4 R-5E R-5 R-6 For the share classes listed to the right, you would pay the following if you did not redeem your shares: Share class: C 529-C
1 year $108 $93 $62 $42 $32 $27 1 year $133 $138
3 years 337 290 195 132 100 84 3 years 415 431
5 years 585 504 340 230 174 146 5 years 718 745
10 years 1,294 1,120 762 518 393 331 10 years 1,369 1,132
Portfolio Turnover [Heading] Portfolio turnover
Portfolio Turnover [Text Block]

The fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s investment results. During the most recent fiscal year, the fund’s portfolio turnover rate was 32% of the average value of its portfolio.
Portfolio Turnover, Rate 32.00%