v3.25.1
Shareholder Report, Line Graph (Details) - USD ($)
 6 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Mar. 31, 2023
Mar. 31, 2022
Mar. 31, 2021
Mar. 31, 2020
Mar. 31, 2019
Mar. 31, 2018
Mar. 31, 2017
Mar. 31, 2016
Mar. 31, 2015
C000085566                      
Account Value [Line Items]                      
Line Graph and Table Measure Name The Gabelli Enterprise Mergers and Acquisitions Fund - Class AAA                    
C000049132                      
Account Value [Line Items]                      
Line Graph and Table Measure Name The Gabelli Enterprise Mergers and Acquisitions Fund - Class C                    
C000049133                      
Account Value [Line Items]                      
Line Graph and Table Measure Name The Gabelli Enterprise Mergers and Acquisitions Fund - Class Y                    
C000049130                      
Account Value [Line Items]                      
Line Graph and Table Measure Name The Gabelli Enterprise Mergers and Acquisitions Fund - Class A                    
S&P 500 Index                      
Account Value [Line Items]                      
Account Value $ 32,480 $ 30,004 $ 23,101 $ 25,037 $ 21,649 $ 13,846 $ 14,885 $ 13,594 $ 11,926 $ 10,178 $ 10,000
S&P 500 Index                      
Account Value [Line Items]                      
Account Value 32,480 30,004 23,101 25,037 21,649 13,846 14,885 13,594 11,926 10,178 10,000
S&P 500 Index                      
Account Value [Line Items]                      
Account Value 32,480 30,004 23,101 25,037 21,649 13,846 14,885 13,594 11,926 10,178 10,000
S&P 500 Index                      
Account Value [Line Items]                      
Account Value 32,480 30,004 23,101 25,037 21,649 13,846 14,885 13,594 11,926 10,178 10,000
Lipper U.S. Treasury Money-Market Fund Average                      
Account Value [Line Items]                      
Account Value 11,735 11,206 10,670 10,424 10,423 10,418 10,249 10,073 10,009 10,001 10,000
S&P Merger Arbitrage Index                      
Account Value [Line Items]                      
Account Value 13,912 12,926 11,971 12,527 12,124 11,061 10,950 10,150 9,996 10,419 10,000
Lipper U.S. Treasury Money-Market Fund Average                      
Account Value [Line Items]                      
Account Value 11,735 11,206 10,670 10,424 10,423 10,418 10,249 10,073 10,009 10,001 10,000
S&P Merger Arbitrage Index                      
Account Value [Line Items]                      
Account Value 13,912 12,926 11,971 12,527 12,124 11,061 10,950 10,150 9,996 10,419 10,000
Lipper U.S. Treasury Money-Market Fund Average                      
Account Value [Line Items]                      
Account Value 11,735 11,206 10,670 10,424 10,423 10,418 10,249 10,073 10,009 10,001 10,000
S&P Merger Arbitrage Index                      
Account Value [Line Items]                      
Account Value 13,912 12,926 11,971 12,527 12,124 11,061 10,950 10,150 9,996 10,419 10,000
Lipper U.S. Treasury Money-Market Fund Average                      
Account Value [Line Items]                      
Account Value 11,735 11,206 10,670 10,424 10,423 10,418 10,249 10,073 10,009 10,001 10,000
S&P Merger Arbitrage Index                      
Account Value [Line Items]                      
Account Value $ 13,912 $ 12,926 $ 11,971 $ 12,527 $ 12,124 $ 11,061 $ 10,950 $ 10,150 $ 9,996 $ 10,419 $ 10,000