S000001125 [Member] Expense Example - AMG River Road Mid Cap Value Fund |
Oct. 31, 2025
USD ($)
|
|---|---|
| CLASS N SHARES | |
| Prospectus [Line Items] | |
| Expense Example, with Redemption, 1 Year | $ 113 |
| Expense Example, with Redemption, 3 Years | 359 |
| Expense Example, with Redemption, 5 Years | 625 |
| Expense Example, with Redemption, 10 Years | 1,383 |
| CLASS I SHARES | |
| Prospectus [Line Items] | |
| Expense Example, with Redemption, 1 Year | 83 |
| Expense Example, with Redemption, 3 Years | 265 |
| Expense Example, with Redemption, 5 Years | 463 |
| Expense Example, with Redemption, 10 Years | 1,034 |
| Class Z Shares | |
| Prospectus [Line Items] | |
| Expense Example, with Redemption, 1 Year | 78 |
| Expense Example, with Redemption, 3 Years | 249 |
| Expense Example, with Redemption, 5 Years | 436 |
| Expense Example, with Redemption, 10 Years | $ 975 |