S000009876 [Member] Expense Example - AMG TimesSquare Mid Cap Growth Fund |
Dec. 31, 2025
USD ($)
|
|---|---|
| Class Z | |
| Prospectus [Line Items] | |
| Expense Example, with Redemption, 1 Year | $ 88 |
| Expense Example, with Redemption, 3 Years | 274 |
| Expense Example, with Redemption, 5 Years | 477 |
| Expense Example, with Redemption, 10 Years | 1,061 |
| Class N | |
| Prospectus [Line Items] | |
| Expense Example, with Redemption, 1 Year | 108 |
| Expense Example, with Redemption, 3 Years | 337 |
| Expense Example, with Redemption, 5 Years | 585 |
| Expense Example, with Redemption, 10 Years | 1,294 |
| Class I | |
| Prospectus [Line Items] | |
| Expense Example, with Redemption, 1 Year | 93 |
| Expense Example, with Redemption, 3 Years | 290 |
| Expense Example, with Redemption, 5 Years | 504 |
| Expense Example, with Redemption, 10 Years | $ 1,120 |