Alger Weatherbie Specialized Growth Fund Average Annual Total Returns - Class I Shares [Member] |
12 Months Ended | 21 Months Ended | 60 Months Ended | 79 Months Ended | 120 Months Ended | |
|---|---|---|---|---|---|---|
Oct. 31, 2025 |
Dec. 31, 2025 |
Dec. 31, 2025 |
Dec. 31, 2025 |
Dec. 31, 2025 |
Dec. 31, 2025 |
|
| Russell 2500 Growth Index (reflects no deductions for fees, expenses or taxes)[Member] | ||||||
| Prospectus [Line Items] | ||||||
| Average Annual Return, Percent | 10.31% | 2.98% | 10.55% | |||
| S&P 500 Index (reflects no deductions for fees, expenses or taxes)[Member] | ||||||
| Prospectus [Line Items] | ||||||
| Average Annual Return, Percent | 17.88% | 19.32% | 14.42% | 15.89% | 14.82% | |
| Class I | ||||||
| Prospectus [Line Items] | ||||||
| Average Annual Return, Percent | 0.42% | (3.66%) | 9.52% | |||
| Performance Inception Date | Aug. 05, 2007 | |||||
| Class I | After Taxes on Distributions | ||||||
| Prospectus [Line Items] | ||||||
| Average Annual Return, Percent | 0.42% | (4.92%) | 7.58% | |||
| Class I | After Taxes on Distributions and Sales | ||||||
| Prospectus [Line Items] | ||||||
| Average Annual Return, Percent | 0.25% | (2.92%) | 7.19% |