v3.26.1
Shareholder Report, Holdings (Details)
Apr. 30, 2026
Washington Mutual Investors Fund - Class A | Consumer Discretionary Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.91%
Washington Mutual Investors Fund - Class A | Consumer Staples Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.54%
Washington Mutual Investors Fund - Class A | Financial Services Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.96%
Washington Mutual Investors Fund - Class A | Healthcare Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.85%
Washington Mutual Investors Fund - Class A | Information Technology Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 21.93%
Washington Mutual Investors Fund - Class A | Unclassified Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 13.57%
Washington Mutual Investors Fund - Class A | Industrial Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.46%
Washington Mutual Investors Fund - Class A | Communications Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.13%
Washington Mutual Investors Fund - Class A | Other securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.87%
Washington Mutual Investors Fund - Class A | Short Term Securities And Other Assets Less Liabilities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.78%
Washington Mutual Investors Fund - Class C | Consumer Discretionary Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.91%
Washington Mutual Investors Fund - Class C | Consumer Staples Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.54%
Washington Mutual Investors Fund - Class C | Financial Services Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.96%
Washington Mutual Investors Fund - Class C | Healthcare Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.85%
Washington Mutual Investors Fund - Class C | Information Technology Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 21.93%
Washington Mutual Investors Fund - Class C | Unclassified Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 13.57%
Washington Mutual Investors Fund - Class C | Industrial Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.46%
Washington Mutual Investors Fund - Class C | Communications Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.13%
Washington Mutual Investors Fund - Class C | Other securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.87%
Washington Mutual Investors Fund - Class C | Short Term Securities And Other Assets Less Liabilities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.78%
Washington Mutual Investors Fund - Class T | Consumer Discretionary Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.91%
Washington Mutual Investors Fund - Class T | Consumer Staples Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.54%
Washington Mutual Investors Fund - Class T | Financial Services Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.96%
Washington Mutual Investors Fund - Class T | Healthcare Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.85%
Washington Mutual Investors Fund - Class T | Information Technology Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 21.93%
Washington Mutual Investors Fund - Class T | Unclassified Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 13.57%
Washington Mutual Investors Fund - Class T | Industrial Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.46%
Washington Mutual Investors Fund - Class T | Communications Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.13%
Washington Mutual Investors Fund - Class T | Other securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.87%
Washington Mutual Investors Fund - Class T | Short Term Securities And Other Assets Less Liabilities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.78%
Washington Mutual Investors Fund - Class F-1 | Consumer Discretionary Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.91%
Washington Mutual Investors Fund - Class F-1 | Consumer Staples Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.54%
Washington Mutual Investors Fund - Class F-1 | Financial Services Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.96%
Washington Mutual Investors Fund - Class F-1 | Healthcare Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.85%
Washington Mutual Investors Fund - Class F-1 | Information Technology Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 21.93%
Washington Mutual Investors Fund - Class F-1 | Unclassified Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 13.57%
Washington Mutual Investors Fund - Class F-1 | Industrial Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.46%
Washington Mutual Investors Fund - Class F-1 | Communications Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.13%
Washington Mutual Investors Fund - Class F-1 | Other securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.87%
Washington Mutual Investors Fund - Class F-1 | Short Term Securities And Other Assets Less Liabilities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.78%
Washington Mutual Investors Fund - Class F-2 | Consumer Discretionary Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.91%
Washington Mutual Investors Fund - Class F-2 | Consumer Staples Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.54%
Washington Mutual Investors Fund - Class F-2 | Financial Services Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.96%
Washington Mutual Investors Fund - Class F-2 | Healthcare Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.85%
Washington Mutual Investors Fund - Class F-2 | Information Technology Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 21.93%
Washington Mutual Investors Fund - Class F-2 | Unclassified Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 13.57%
Washington Mutual Investors Fund - Class F-2 | Industrial Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.46%
Washington Mutual Investors Fund - Class F-2 | Communications Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.13%
Washington Mutual Investors Fund - Class F-2 | Other securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.87%
Washington Mutual Investors Fund - Class F-2 | Short Term Securities And Other Assets Less Liabilities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.78%
Washington Mutual Investors Fund - Class F-3 | Consumer Discretionary Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.91%
Washington Mutual Investors Fund - Class F-3 | Consumer Staples Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.54%
Washington Mutual Investors Fund - Class F-3 | Financial Services Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.96%
Washington Mutual Investors Fund - Class F-3 | Healthcare Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.85%
Washington Mutual Investors Fund - Class F-3 | Information Technology Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 21.93%
Washington Mutual Investors Fund - Class F-3 | Unclassified Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 13.57%
Washington Mutual Investors Fund - Class F-3 | Industrial Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.46%
Washington Mutual Investors Fund - Class F-3 | Communications Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.13%
Washington Mutual Investors Fund - Class F-3 | Other securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.87%
Washington Mutual Investors Fund - Class F-3 | Short Term Securities And Other Assets Less Liabilities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.78%
Washington Mutual Investors Fund - Class 529-A | Consumer Discretionary Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.91%
Washington Mutual Investors Fund - Class 529-A | Consumer Staples Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.54%
Washington Mutual Investors Fund - Class 529-A | Financial Services Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.96%
Washington Mutual Investors Fund - Class 529-A | Healthcare Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.85%
Washington Mutual Investors Fund - Class 529-A | Information Technology Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 21.93%
Washington Mutual Investors Fund - Class 529-A | Unclassified Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 13.57%
Washington Mutual Investors Fund - Class 529-A | Industrial Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.46%
Washington Mutual Investors Fund - Class 529-A | Communications Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.13%
Washington Mutual Investors Fund - Class 529-A | Other securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.87%
Washington Mutual Investors Fund - Class 529-A | Short Term Securities And Other Assets Less Liabilities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.78%
Washington Mutual Investors Fund - Class 529-C | Consumer Discretionary Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.91%
Washington Mutual Investors Fund - Class 529-C | Consumer Staples Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.54%
Washington Mutual Investors Fund - Class 529-C | Financial Services Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.96%
Washington Mutual Investors Fund - Class 529-C | Healthcare Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.85%
Washington Mutual Investors Fund - Class 529-C | Information Technology Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 21.93%
Washington Mutual Investors Fund - Class 529-C | Unclassified Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 13.57%
Washington Mutual Investors Fund - Class 529-C | Industrial Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.46%
Washington Mutual Investors Fund - Class 529-C | Communications Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.13%
Washington Mutual Investors Fund - Class 529-C | Other securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.87%
Washington Mutual Investors Fund - Class 529-C | Short Term Securities And Other Assets Less Liabilities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.78%
Washington Mutual Investors Fund - Class 529-E | Consumer Discretionary Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.91%
Washington Mutual Investors Fund - Class 529-E | Consumer Staples Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.54%
Washington Mutual Investors Fund - Class 529-E | Financial Services Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.96%
Washington Mutual Investors Fund - Class 529-E | Healthcare Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.85%
Washington Mutual Investors Fund - Class 529-E | Information Technology Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 21.93%
Washington Mutual Investors Fund - Class 529-E | Unclassified Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 13.57%
Washington Mutual Investors Fund - Class 529-E | Industrial Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.46%
Washington Mutual Investors Fund - Class 529-E | Communications Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.13%
Washington Mutual Investors Fund - Class 529-E | Other securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.87%
Washington Mutual Investors Fund - Class 529-E | Short Term Securities And Other Assets Less Liabilities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.78%
Washington Mutual Investors Fund - Class 529-T | Consumer Discretionary Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.91%
Washington Mutual Investors Fund - Class 529-T | Consumer Staples Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.54%
Washington Mutual Investors Fund - Class 529-T | Financial Services Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.96%
Washington Mutual Investors Fund - Class 529-T | Healthcare Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.85%
Washington Mutual Investors Fund - Class 529-T | Information Technology Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 21.93%
Washington Mutual Investors Fund - Class 529-T | Unclassified Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 13.57%
Washington Mutual Investors Fund - Class 529-T | Industrial Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.46%
Washington Mutual Investors Fund - Class 529-T | Communications Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.13%
Washington Mutual Investors Fund - Class 529-T | Other securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.87%
Washington Mutual Investors Fund - Class 529-T | Short Term Securities And Other Assets Less Liabilities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.78%
Washington Mutual Investors Fund - Class 529-F-1 | Consumer Discretionary Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.91%
Washington Mutual Investors Fund - Class 529-F-1 | Consumer Staples Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.54%
Washington Mutual Investors Fund - Class 529-F-1 | Financial Services Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.96%
Washington Mutual Investors Fund - Class 529-F-1 | Healthcare Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.85%
Washington Mutual Investors Fund - Class 529-F-1 | Information Technology Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 21.93%
Washington Mutual Investors Fund - Class 529-F-1 | Unclassified Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 13.57%
Washington Mutual Investors Fund - Class 529-F-1 | Industrial Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.46%
Washington Mutual Investors Fund - Class 529-F-1 | Communications Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.13%
Washington Mutual Investors Fund - Class 529-F-1 | Other securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.87%
Washington Mutual Investors Fund - Class 529-F-1 | Short Term Securities And Other Assets Less Liabilities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.78%
Washington Mutual Investors Fund - Class 529-F-2 | Consumer Discretionary Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.91%
Washington Mutual Investors Fund - Class 529-F-2 | Consumer Staples Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.54%
Washington Mutual Investors Fund - Class 529-F-2 | Financial Services Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.96%
Washington Mutual Investors Fund - Class 529-F-2 | Healthcare Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.85%
Washington Mutual Investors Fund - Class 529-F-2 | Information Technology Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 21.93%
Washington Mutual Investors Fund - Class 529-F-2 | Unclassified Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 13.57%
Washington Mutual Investors Fund - Class 529-F-2 | Industrial Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.46%
Washington Mutual Investors Fund - Class 529-F-2 | Communications Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.13%
Washington Mutual Investors Fund - Class 529-F-2 | Other securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.87%
Washington Mutual Investors Fund - Class 529-F-2 | Short Term Securities And Other Assets Less Liabilities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.78%
Washington Mutual Investors Fund - Class 529-F-3 | Consumer Discretionary Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.91%
Washington Mutual Investors Fund - Class 529-F-3 | Consumer Staples Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.54%
Washington Mutual Investors Fund - Class 529-F-3 | Financial Services Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.96%
Washington Mutual Investors Fund - Class 529-F-3 | Healthcare Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.85%
Washington Mutual Investors Fund - Class 529-F-3 | Information Technology Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 21.93%
Washington Mutual Investors Fund - Class 529-F-3 | Unclassified Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 13.57%
Washington Mutual Investors Fund - Class 529-F-3 | Industrial Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.46%
Washington Mutual Investors Fund - Class 529-F-3 | Communications Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.13%
Washington Mutual Investors Fund - Class 529-F-3 | Other securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.87%
Washington Mutual Investors Fund - Class 529-F-3 | Short Term Securities And Other Assets Less Liabilities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.78%
WASHINGTON MUTUAL INVESTORS FUND Class R-1 | Consumer Discretionary Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.91%
WASHINGTON MUTUAL INVESTORS FUND Class R-1 | Consumer Staples Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.54%
WASHINGTON MUTUAL INVESTORS FUND Class R-1 | Financial Services Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.96%
WASHINGTON MUTUAL INVESTORS FUND Class R-1 | Healthcare Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.85%
WASHINGTON MUTUAL INVESTORS FUND Class R-1 | Information Technology Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 21.93%
WASHINGTON MUTUAL INVESTORS FUND Class R-1 | Unclassified Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 13.57%
WASHINGTON MUTUAL INVESTORS FUND Class R-1 | Industrial Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.46%
WASHINGTON MUTUAL INVESTORS FUND Class R-1 | Communications Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.13%
WASHINGTON MUTUAL INVESTORS FUND Class R-1 | Other securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.87%
WASHINGTON MUTUAL INVESTORS FUND Class R-1 | Short Term Securities And Other Assets Less Liabilities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.78%
Washington Mutual Investors Fund - Class R-2 | Consumer Discretionary Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.91%
Washington Mutual Investors Fund - Class R-2 | Consumer Staples Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.54%
Washington Mutual Investors Fund - Class R-2 | Financial Services Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.96%
Washington Mutual Investors Fund - Class R-2 | Healthcare Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.85%
Washington Mutual Investors Fund - Class R-2 | Information Technology Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 21.93%
Washington Mutual Investors Fund - Class R-2 | Unclassified Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 13.57%
Washington Mutual Investors Fund - Class R-2 | Industrial Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.46%
Washington Mutual Investors Fund - Class R-2 | Communications Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.13%
Washington Mutual Investors Fund - Class R-2 | Other securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.87%
Washington Mutual Investors Fund - Class R-2 | Short Term Securities And Other Assets Less Liabilities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.78%
Washington Mutual Investors Fund - Class R-2E | Consumer Discretionary Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.91%
Washington Mutual Investors Fund - Class R-2E | Consumer Staples Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.54%
Washington Mutual Investors Fund - Class R-2E | Financial Services Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.96%
Washington Mutual Investors Fund - Class R-2E | Healthcare Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.85%
Washington Mutual Investors Fund - Class R-2E | Information Technology Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 21.93%
Washington Mutual Investors Fund - Class R-2E | Unclassified Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 13.57%
Washington Mutual Investors Fund - Class R-2E | Industrial Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.46%
Washington Mutual Investors Fund - Class R-2E | Communications Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.13%
Washington Mutual Investors Fund - Class R-2E | Other securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.87%
Washington Mutual Investors Fund - Class R-2E | Short Term Securities And Other Assets Less Liabilities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.78%
Washington Mutual Investors Fund - Class R-3 | Consumer Discretionary Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.91%
Washington Mutual Investors Fund - Class R-3 | Consumer Staples Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.54%
Washington Mutual Investors Fund - Class R-3 | Financial Services Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.96%
Washington Mutual Investors Fund - Class R-3 | Healthcare Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.85%
Washington Mutual Investors Fund - Class R-3 | Information Technology Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 21.93%
Washington Mutual Investors Fund - Class R-3 | Unclassified Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 13.57%
Washington Mutual Investors Fund - Class R-3 | Industrial Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.46%
Washington Mutual Investors Fund - Class R-3 | Communications Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.13%
Washington Mutual Investors Fund - Class R-3 | Other securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.87%
Washington Mutual Investors Fund - Class R-3 | Short Term Securities And Other Assets Less Liabilities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.78%
Washington Mutual Investors Fund Class R-4 | Consumer Discretionary Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.91%
Washington Mutual Investors Fund Class R-4 | Consumer Staples Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.54%
Washington Mutual Investors Fund Class R-4 | Financial Services Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.96%
Washington Mutual Investors Fund Class R-4 | Healthcare Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.85%
Washington Mutual Investors Fund Class R-4 | Information Technology Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 21.93%
Washington Mutual Investors Fund Class R-4 | Unclassified Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 13.57%
Washington Mutual Investors Fund Class R-4 | Industrial Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.46%
Washington Mutual Investors Fund Class R-4 | Communications Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.13%
Washington Mutual Investors Fund Class R-4 | Other securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.87%
Washington Mutual Investors Fund Class R-4 | Short Term Securities And Other Assets Less Liabilities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.78%
Washington Mutual Investors Fund Class R-5E | Consumer Discretionary Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.91%
Washington Mutual Investors Fund Class R-5E | Consumer Staples Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.54%
Washington Mutual Investors Fund Class R-5E | Financial Services Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.96%
Washington Mutual Investors Fund Class R-5E | Healthcare Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.85%
Washington Mutual Investors Fund Class R-5E | Information Technology Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 21.93%
Washington Mutual Investors Fund Class R-5E | Unclassified Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 13.57%
Washington Mutual Investors Fund Class R-5E | Industrial Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.46%
Washington Mutual Investors Fund Class R-5E | Communications Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.13%
Washington Mutual Investors Fund Class R-5E | Other securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.87%
Washington Mutual Investors Fund Class R-5E | Short Term Securities And Other Assets Less Liabilities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.78%
Washington Mutual Investors Fund - Class R-5 | Consumer Discretionary Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.91%
Washington Mutual Investors Fund - Class R-5 | Consumer Staples Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.54%
Washington Mutual Investors Fund - Class R-5 | Financial Services Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.96%
Washington Mutual Investors Fund - Class R-5 | Healthcare Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.85%
Washington Mutual Investors Fund - Class R-5 | Information Technology Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 21.93%
Washington Mutual Investors Fund - Class R-5 | Unclassified Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 13.57%
Washington Mutual Investors Fund - Class R-5 | Industrial Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.46%
Washington Mutual Investors Fund - Class R-5 | Communications Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.13%
Washington Mutual Investors Fund - Class R-5 | Other securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.87%
Washington Mutual Investors Fund - Class R-5 | Short Term Securities And Other Assets Less Liabilities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.78%
Washington Mutual Investors Fund - Class R-6 | Consumer Discretionary Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.91%
Washington Mutual Investors Fund - Class R-6 | Consumer Staples Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 8.54%
Washington Mutual Investors Fund - Class R-6 | Financial Services Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 14.96%
Washington Mutual Investors Fund - Class R-6 | Healthcare Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 10.85%
Washington Mutual Investors Fund - Class R-6 | Information Technology Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 21.93%
Washington Mutual Investors Fund - Class R-6 | Unclassified Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 13.57%
Washington Mutual Investors Fund - Class R-6 | Industrial Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 12.46%
Washington Mutual Investors Fund - Class R-6 | Communications Sector [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 6.13%
Washington Mutual Investors Fund - Class R-6 | Other securities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 0.87%
Washington Mutual Investors Fund - Class R-6 | Short Term Securities And Other Assets Less Liabilities [Member]  
Holdings [Line Items]  
Percent of Net Asset Value 3.78%