S000001130 [Member] Expense Example - AMG River Road Small Cap Value Fund |
Oct. 31, 2025
USD ($)
|
|---|---|
| Class N | |
| Prospectus [Line Items] | |
| Expense Example, with Redemption, 1 Year | $ 137 |
| Expense Example, with Redemption, 3 Years | 428 |
| Expense Example, with Redemption, 5 Years | 739 |
| Expense Example, with Redemption, 10 Years | 1,624 |
| Class I | |
| Prospectus [Line Items] | |
| Expense Example, with Redemption, 1 Year | 111 |
| Expense Example, with Redemption, 3 Years | 347 |
| Expense Example, with Redemption, 5 Years | 601 |
| Expense Example, with Redemption, 10 Years | 1,329 |
| Class Z | |
| Prospectus [Line Items] | |
| Expense Example, with Redemption, 1 Year | 102 |
| Expense Example, with Redemption, 3 Years | 318 |
| Expense Example, with Redemption, 5 Years | 552 |
| Expense Example, with Redemption, 10 Years | $ 1,225 |