S000023782 [Member] Expense Example - AMG GW&K Small Cap Core Fund |
Dec. 31, 2025
USD ($)
|
|---|---|
| Class N | |
| Prospectus [Line Items] | |
| Expense Example, with Redemption, 1 Year | $ 132 |
| Expense Example, with Redemption, 3 Years | 412 |
| Expense Example, with Redemption, 5 Years | 713 |
| Expense Example, with Redemption, 10 Years | 1,568 |
| Class I | |
| Prospectus [Line Items] | |
| Expense Example, with Redemption, 1 Year | 97 |
| Expense Example, with Redemption, 3 Years | 303 |
| Expense Example, with Redemption, 5 Years | 525 |
| Expense Example, with Redemption, 10 Years | 1,166 |
| Class Z | |
| Prospectus [Line Items] | |
| Expense Example, with Redemption, 1 Year | 92 |
| Expense Example, with Redemption, 3 Years | 287 |
| Expense Example, with Redemption, 5 Years | 498 |
| Expense Example, with Redemption, 10 Years | $ 1,108 |