v3.25.2
Shareholder Report, Average Annual Return (Details)
 6 Months Ended 12 Months Ended 60 Months Ended 120 Months Ended
Jun. 30, 2025
Jun. 30, 2025
Jun. 30, 2025
Jun. 30, 2025
C000002943        
Average Annual Return [Line Items]        
Line Graph and Table Measure Name The Gabelli Asset Fund - Class AAA      
C000002942        
Average Annual Return [Line Items]        
Line Graph and Table Measure Name The Gabelli Asset Fund - Class C      
Average Annual Return, Percent 5.59% 11.65% 10.47% 7.04%
C000034307        
Average Annual Return [Line Items]        
Line Graph and Table Measure Name The Gabelli Asset Fund - Class I      
C000002940        
Average Annual Return [Line Items]        
Line Graph and Table Measure Name The Gabelli Asset Fund - Class A      
Average Annual Return, Percent 0.85% 6.97% 9.98% 7.21%
Without Sales Load [Member] | C000002943        
Average Annual Return [Line Items]        
Average Annual Return, Percent 7.01% 13.52% 11.30% 7.85%
Without Sales Load [Member] | C000002942        
Average Annual Return [Line Items]        
Average Annual Return, Percent 6.59% 12.65% 10.47% 7.04%
Without Sales Load [Member] | C000034307        
Average Annual Return [Line Items]        
Average Annual Return, Percent 7.12% 13.76% 11.57% 8.11%
Without Sales Load [Member] | C000002940        
Average Annual Return [Line Items]        
Average Annual Return, Percent 7.00% 13.49% 11.29% 7.85%
S&P 500 Index        
Average Annual Return [Line Items]        
Average Annual Return, Percent 6.20% 15.16% 16.64% 13.65%
S&P 500 Index        
Average Annual Return [Line Items]        
Average Annual Return, Percent 6.20% 15.16% 16.64% 13.65%
S&P 500 Index        
Average Annual Return [Line Items]        
Average Annual Return, Percent 6.20% 15.16% 16.64% 13.65%
S&P 500 Index        
Average Annual Return [Line Items]        
Average Annual Return, Percent 6.20% 15.16% 16.64% 13.65%
Dow Jones Industrial Average (DJIA)        
Average Annual Return [Line Items]        
Average Annual Return, Percent 4.55% 14.72% 13.51% 12.05%
Dow Jones Industrial Average (DJIA)        
Average Annual Return [Line Items]        
Average Annual Return, Percent 4.55% 14.72% 13.51% 12.05%
Dow Jones Industrial Average (DJIA)        
Average Annual Return [Line Items]        
Average Annual Return, Percent 4.55% 14.72% 13.51% 12.05%
Dow Jones Industrial Average (DJIA)        
Average Annual Return [Line Items]        
Average Annual Return, Percent 4.55% 14.72% 13.51% 12.05%