Net Assets Investment Company, Portfolio Turnover C000025050 [Member] Fundamental Investors Class A - ANCFX C000077853 [Member] Fundamental Investors Class R-6 - RFNGX C000164826 [Member] Fundamental Investors Class R-5E - RFNHX C000025055 [Member] Fundamental Investors Class R-5 - RFNFX C000025052 [Member] Fundamental Investors Class R-2 - RFNBX C000148457 [Member] Fundamental Investors Class R-2E - RFEBX C000025053 [Member] Fundamental Investors Class R-3 - RFNCX C000025054 [Member] Fundamental Investors Class R-4 - RFNEX C000025057 [Member] Fundamental Investors Class C - AFICX C000025058 [Member] Fundamental Investors Class F-1 - AFIFX C000068558 [Member] Fundamental Investors Class F-2 - FINFX C000179985 [Member] Fundamental Investors Class F-3 - FUNFX C000025059 [Member] Fundamental Investors Class 529-A - CFNAX C000025061 [Member] Fundamental Investors Class 529-C - CFNCX C000025062 [Member] Fundamental Investors Class 529-E - CFNEX C000224623 [Member] Fundamental Investors Class 529-F-2 - FFXFX C000224624 [Member] Fundamental Investors Class 529-F-3 - FEEFX C000025051 [Member] Fundamental Investors Class R-1 - RFNAX Investment Type [Axis] Financial Services Sector [Member] Healthcare Sector [Member] Other securities [Member] Short-term securities and other assets less liabilities [Member]