WASHINGTON MUTUAL INVESTORS FUND Class A Class 529-A Class C Class 529-C Class 529-E Class F-1 Class 529-F-2 Class F-3 Class 529-F-3 Class F-2 R-6 Class R-1 Class R-2 Class R-3 Class R-4 Class R-5 Class R-2E Class R-5E Market conditions [Member] Issuer risks [Member] Investing in income-oriented stocks [Member] Investing in growth-oriented stocks [Member] Management [Member] S&P 500 Index (reflects no deductions for sales charges, account fees, expenses or U.S. federal income taxes) C000025720 Member C000148358 Member S000009388 Member Market Conditions Member C000221715 Member C000025730 Member C000025719 Member Investing In Incomeoriented Stocks Member C000221714 Member Investing In Growthoriented Stocks Member C000164825 Member C000025727 Member C000025722 Member index_ SP_500_ Index_reflects_no_deductions_for_sales_charges_account_fees_expenses_or_ US_federal_income_taxes Member C000025726 Member Issuer Risks Member C000077924 Member C000025721 Member C000025731 Member C000025724 Member C000179991 Member C000025723 Member ManagementMember C000025728 Member C000068526 Member