v3.26.1
Shareholder Report, Average Annual Return (Details)
 6 Months Ended 12 Months Ended 60 Months Ended 120 Months Ended
Jun. 30, 2026
Jun. 30, 2026
Jun. 30, 2026
Jun. 30, 2026
C000088645        
Average Annual Return [Line Items]        
Line Graph and Table Measure Name The Gabelli Value 25 Fund Inc. - Class AAA      
C000002904        
Average Annual Return [Line Items]        
Line Graph and Table Measure Name The Gabelli Value 25 Fund Inc. - Class C      
Average Annual Return, Percent 8.28% 23.62% 6.74% 7.67%
C000034316        
Average Annual Return [Line Items]        
Line Graph and Table Measure Name The Gabelli Value 25 Fund Inc. - Class I      
C000002902        
Average Annual Return [Line Items]        
Line Graph and Table Measure Name The Gabelli Value 25 Fund Inc. - Class A      
Average Annual Return, Percent 3.42% 18.35% 6.25% 7.82%
Without Sales Load [Member] | C000088645        
Average Annual Return [Line Items]        
Average Annual Return, Percent 9.69% 25.59% 7.52% 8.46%
Without Sales Load [Member] | C000002904        
Average Annual Return [Line Items]        
Average Annual Return, Percent 9.28% 24.62% 6.74% 7.67%
Without Sales Load [Member] | C000034316        
Average Annual Return [Line Items]        
Average Annual Return, Percent 9.97% 26.11% 8.02% 8.94%
Without Sales Load [Member] | C000002902        
Average Annual Return [Line Items]        
Average Annual Return, Percent 9.73% 25.57% 7.52% 8.46%
S&P 500 Index        
Average Annual Return [Line Items]        
Average Annual Return, Percent 10.21% 22.32% 13.41% 15.51%
S&P 500 Index        
Average Annual Return [Line Items]        
Average Annual Return, Percent 10.21% 22.32% 13.41% 15.51%
S&P 500 Index        
Average Annual Return [Line Items]        
Average Annual Return, Percent 10.21% 22.32% 13.41% 15.51%
S&P 500 Index        
Average Annual Return [Line Items]        
Average Annual Return, Percent 10.21% 22.32% 13.41% 15.51%
Russell 1000 Value Index        
Average Annual Return [Line Items]        
Average Annual Return, Percent 16.26% 27.12% 11.17% 11.52%
Russell 1000 Value Index        
Average Annual Return [Line Items]        
Average Annual Return, Percent 16.26% 27.12% 11.17% 11.52%
Russell 1000 Value Index        
Average Annual Return [Line Items]        
Average Annual Return, Percent 16.26% 27.12% 11.17% 11.52%
Russell 1000 Value Index        
Average Annual Return [Line Items]        
Average Annual Return, Percent 16.26% 27.12% 11.17% 11.52%