Net Assets Investment Company, Portfolio Turnover C000024003 [Member] AMCAP Fund® - Class A Investment Type [Axis] Short term securities and other assets less liabilities [Member] Short-term securities & other assets less liabilities [Member] Healthcare Sector [Member] Financial Services Sector [Member] Other Securities [Member] C000024010 [Member] AMCAP Fund® - Class C C000024011 [Member] AMCAP Fund® - Class F-1 C000068557 [Member] AMCAP Fund® - Class F-2 C000179992 [Member] AMCAP Fund® - Class F-3 C000024012 [Member] AMCAP Fund® - Class 529-A C000024014 [Member] AMCAP Fund® - Class 529-C C000024015 [Member] AMCAP Fund® - Class 529-E C000220528 [Member] AMCAP Fund® - Class 529-F-2 C000220529 [Member] AMCAP Fund® - Class 529-F-3 C000024004 [Member] AMCAP Fund® - Class R-1 C000024005 [Member] AMCAP Fund® - Class R-2 C000148384 [Member] AMCAP Fund® - Class R-2E C000024006 [Member] AMCAP Fund® - Class R-3 C000024007 [Member] AMCAP Fund® - Class R-4 C000164827 [Member] AMCAP Fund® - Class R-5E C000024008 [Member] AMCAP Fund® - Class R-5 C000076711 [Member] AMCAP Fund® - Class R-6