Net Assets Investment Company, Portfolio Turnover C000024463 [Member] Capital Income Builder - Class A Investment Type [Axis] Bonds Notes And Other Debt Instruments [Member] Bonds, notes & other debt instruments [Member] Financial Services Sector [Member] Healthcare Sector [Member] Investment funds [Member] Investment funds [Member] Other securities [Member] Short Term Securities And Other Assets Less Liabilities [Member] Short-term securities & other assets less liabilities [Member] Energy Sector [Member] C000024470 [Member] Capital Income Builder - Class C C000189419 [Member] Capital Income Builder - Class T C000024471 [Member] Capital Income Builder - Class F-1 C000068596 [Member] Capital Income Builder - F2 C000180006 [Member] Capital Income Builder - Class F-3 C000024472 [Member] Capital Income Builder - Class 529-A C000024474 [Member] Capital Income Builder - Class 529-C C000024475 [Member] Capital Income Builder - Class 529-E C000189418 [Member] Capital Income Builder - Class 529-T C000024476 [Member] Capital Income Builder - Class 529-F-1 C000224565 [Member] Capital Income Builder - Class 529-F-2 C000224566 [Member] Capital Income Builder - Class 529-F-3 C000024464 [Member] Capital Income Builder - Class R-1 C000024465 [Member] Capital Income Builder - Class R-2 C000148440 [Member] Capital Income Builder - Class R-2E C000024466 [Member] Capital Income Builder - Class R-3 C000024467 [Member] Capital Income Builder - Class R-4 C000164810 [Member] Capital Income Builder - Class R-5E C000024468 [Member] Capital Income Builder - Class R-5 C000077881 [Member] Capital Income Builder - Class R-6