Alger Capital Appreciation Institutional Fund Average Annual Total Returns - Class Z2 Shares [Member] |
12 Months Ended | 60 Months Ended | 111 Months Ended | 113 Months Ended | |
|---|---|---|---|---|---|
Oct. 31, 2025 |
Dec. 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% | 19.29% | ||
| S&P 500 Index (reflects no deductions for fees, expenses or taxes)[Member] | |||||
| Prospectus [Line Items] | |||||
| Average Annual Return, Percent | 17.88% | 14.42% | 15.43% | 14.92% | |
| Class Z-2 | |||||
| Prospectus [Line Items] | |||||
| Average Annual Return, Percent | 32.44% | 16.42% | 19.80% | ||
| Performance Inception Date | Oct. 14, 2016 | ||||
| Class Z-2 | After Taxes on Distributions | |||||
| Prospectus [Line Items] | |||||
| Average Annual Return, Percent | 30.17% | 13.89% | 17.11% | ||
| Class Z-2 | After Taxes on Distributions and Sales | |||||
| Prospectus [Line Items] | |||||
| Average Annual Return, Percent | 20.35% | 12.49% | 15.79% |