Alger Focus Equity Fund Average Annual Total Returns - Class Y Shares [Member] |
12 Months Ended | 60 Months Ended | 106 Months Ended | |
|---|---|---|---|---|
Oct. 31, 2025 |
Dec. 31, 2025 |
Dec. 31, 2025 |
Dec. 31, 2025 |
|
| Russell 1000 Growth Index (reflects no deductions for fees, expenses or taxes)[Member] | ||||
| Prospectus [Line Items] | ||||
| Average Annual Return, Percent | 18.56% | 15.32% | 18.82% | |
| S&P 500 Index (reflects no deductions for fees, expenses or taxes)[Member] | ||||
| Prospectus [Line Items] | ||||
| Average Annual Return, Percent | 17.88% | 14.42% | 14.69% | |
| Class Y | ||||
| Prospectus [Line Items] | ||||
| Average Annual Return, Percent | 40.42% | 19.01% | 22.16% | |
| Performance Inception Date | Feb. 28, 2017 | |||
| Class Y | After Taxes on Distributions | ||||
| Prospectus [Line Items] | ||||
| Average Annual Return, Percent | 37.05% | 17.65% | 20.72% | |
| Class Y | After Taxes on Distributions and Sales | ||||
| Prospectus [Line Items] | ||||
| Average Annual Return, Percent | 24.60% | 14.94% | 18.34% |