v3.26.1
Shareholder Report, Average Annual Return (Details) 74200001190_Franklin Natural Resources Fund_Advisor Class_TSR Annual {Advisor Class}
12 Months Ended 60 Months Ended 120 Months Ended
Apr. 30, 2026
Apr. 30, 2026
Apr. 30, 2026
Advisor Class      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Advisor Class    
Average Annual Return, Percent 65.18% 20.52% 8.42%
Russell 3000 Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name Russell 3000 Index    
Average Annual Return, Percent 31.01% 11.91% 14.76%
S&P North American Natural Resources Sector Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name S&P North American Natural Resources Sector Index    
Average Annual Return, Percent 53.73% 20.81% 10.34%
S&P Global Natural Resources Index [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name S&P Global Natural Resources Index    
Average Annual Return, Percent 49.88% 12.01% 10.96%