S000001114 [Member] Expense Example - AMG GW&K Small Cap Growth Fund |
Oct. 31, 2025
USD ($)
|
|---|---|
| CLASS N SHARES | |
| Prospectus [Line Items] | |
| Expense Example, with Redemption, 1 Year | $ 92 |
| Expense Example, with Redemption, 3 Years | 300 |
| Expense Example, with Redemption, 5 Years | 525 |
| Expense Example, with Redemption, 10 Years | 1,173 |
| CLASS I SHARES | |
| Prospectus [Line Items] | |
| Expense Example, with Redemption, 1 Year | 75 |
| Expense Example, with Redemption, 3 Years | 246 |
| Expense Example, with Redemption, 5 Years | 433 |
| Expense Example, with Redemption, 10 Years | 972 |
| CLASS Z SHARES | |
| Prospectus [Line Items] | |
| Expense Example, with Redemption, 1 Year | 68 |
| Expense Example, with Redemption, 3 Years | 227 |
| Expense Example, with Redemption, 5 Years | 400 |
| Expense Example, with Redemption, 10 Years | $ 901 |