S000020207 [Member] Expense Example - AMG GW&K Small Cap Value Fund |
Dec. 31, 2025
USD ($)
|
|---|---|
| Class N | |
| Prospectus [Line Items] | |
| Expense Example, with Redemption, 1 Year | $ 117 |
| Expense Example, with Redemption, 3 Years | 376 |
| Expense Example, with Redemption, 5 Years | 655 |
| Expense Example, with Redemption, 10 Years | 1,450 |
| Class I | |
| Prospectus [Line Items] | |
| Expense Example, with Redemption, 1 Year | 97 |
| Expense Example, with Redemption, 3 Years | 313 |
| Expense Example, with Redemption, 5 Years | 548 |
| Expense Example, with Redemption, 10 Years | 1,220 |
| Class Z | |
| Prospectus [Line Items] | |
| Expense Example, with Redemption, 1 Year | 92 |
| Expense Example, with Redemption, 3 Years | 298 |
| Expense Example, with Redemption, 5 Years | 521 |
| Expense Example, with Redemption, 10 Years | $ 1,162 |