v3.25.4
Annual Total Returns
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Hennessy Energy Transition Fund - Investor Class                    
Prospectus [Line Items]                    
Annual Return [Percent] 12.48% 13.49% 3.72% 47.53% 55.42% (25.72%) 5.74% (31.16%) 1.89% 42.96%
Hennessy Midstream Fund - Investor Class                    
Prospectus [Line Items]                    
Annual Return [Percent] (0.74%) 35.94% 23.39% 28.82% 35.93% (31.28%) 11.76% (21.20%) (4.97%) 21.55%
Hennessy Technology Fund - Investor Class                    
Prospectus [Line Items]                    
Annual Return [Percent] 15.38% 17.35% 35.95% (26.28%) 13.37% 32.98% 39.10% (1.82%) 20.20% 2.03%
Hennessy Sustainable ETF [Member]                    
Prospectus [Line Items]                    
Annual Return [Percent] 10.18% 8.94% 11.40% (12.78%)            
Hennessy Cornerstone Growth Fund - Investor Class                    
Prospectus [Line Items]                    
Annual Return [Percent] 4.78% 31.64% 19.58% (4.93%) 28.89% 17.73% 20.70% (21.22%) 16.60% 8.37%
Hennessy Focus Fund - Investor Class                    
Prospectus [Line Items]                    
Annual Return [Percent] 26.73% 14.79% 20.85% (24.99%) 31.55% 5.49% 34.86% (10.47%) 19.27% 7.16%
Hennessy Cornerstone Mid Cap 30 Fund - Investor Class                    
Prospectus [Line Items]                    
Annual Return [Percent] 2.68% 34.29% 30.78% 2.79% 27.22% 23.37% 15.76% (22.78%) 20.51% 5.82%
Hennessy Cornerstone Large Growth Fund - Investor Class                    
Prospectus [Line Items]                    
Annual Return [Percent] 7.41% 4.40% 21.71% (13.31%) 34.66% 5.49% 27.53% (8.98%) 17.08% 14.69%
Hennessy Cornerstone Value Fund - Investor Class                    
Prospectus [Line Items]                    
Annual Return [Percent] 18.27% 9.59% 5.81% 6.13% 29.91% (6.38%) 20.79% (9.34%) 19.16% 17.25%
Hennessy Total Return Fund - Investor Class                    
Prospectus [Line Items]                    
Annual Return [Percent] 14.29% 2.89% 8.02% 1.39% 11.81% (4.83%) 12.56% 0.11% 11.17% 12.92%
Hennessy Equity and Income Fund - Investor Class                    
Prospectus [Line Items]                    
Annual Return [Percent] 6.73% 10.23% 10.43% (13.85%) 16.71% 8.97% 15.99% (4.33%) 13.51% 5.73%
Hennessy Balanced Fund - Investor Class                    
Prospectus [Line Items]                    
Annual Return [Percent] 9.89% 3.24% 5.24% (1.20%) 7.99% (2.98%) 9.69% 0.10% 8.35% 9.15%
Hennessy Gas Utility Fund - Investor Class                    
Prospectus [Line Items]                    
Annual Return [Percent] 10.40% 24.95% 0.27% 6.15% 19.52% (9.32%) 20.78% (3.51%) 7.03% 20.70%
Hennessy Japan Fund - Investor Class                    
Prospectus [Line Items]                    
Annual Return [Percent] 14.50% 18.72% 22.85% (30.65%) (3.07%) 25.52% 18.04% (6.57%) 32.04% 11.26%
Hennessy Japan Small Cap Fund - Investor Class                    
Prospectus [Line Items]                    
Annual Return [Percent] 28.89% 8.23% 16.29% (16.34%) (4.65%) 13.43% 19.95% (12.51%) 49.58% 8.52%
Hennessy Large Cap Financial Fund - Investor Class                    
Prospectus [Line Items]                    
Annual Return [Percent] 22.00% 28.46% 4.57% (24.88%) 18.80% 16.55% 29.75% (11.73%) 19.38% 14.96%
Hennessy Small Cap Financial Fund - Investor Class                    
Prospectus [Line Items]                    
Annual Return [Percent] 12.78% 10.82% 4.58% (11.16%) 42.75% 2.58% 19.88% (15.86%) (0.20%) 33.41%