S000056045 [Member] Investment Strategy - AMG Yacktman Global Fund	Dec. 31, 2025
Prospectus [Line Items]
Strategy [Heading]	Principal Investment Strategies
Strategy Narrative [Text Block]	The Fund invests primarily in domestic and foreign equity securities. The Fund’s investments in foreign equity securities may include emerging market securities. The Fund also may invest in debt securities. The Fund’s investments in equity securities may include common stocks, preferred stocks, convertible preferred stocks, warrants, options and American Depositary Receipts (“ADRs”). Some, but not all, of the equity securities will pay a dividend. The Fund’s investments in debt securities may include U.S. Treasury notes and bonds, investment grade corporate debt securities, convertible debt securities and debt securities below investment grade (high yield or junk bonds). For hedging and investment purposes, the Fund may engage in short sales of securities, including short sales of securities the Fund does not own. At times, depending on market and other conditions, and in the sole discretion of the Fund’s subadviser, Yacktman Asset Management LP (“Yacktman” or the “Subadviser”), the Fund will focus a substantial portion of its assets in a small number of issuers, business sectors or industries. The Fund is non-diversified. Under normal circumstances, the Fund invests at least 35% (or if conditions are not favorable, in the view of Yacktman, at least 25%) of its net assets in investments economically tied to countries other than the U.S., and the Fund will hold investments economically tied to a minimum of three countries other than the U.S. The Fund considers an investment to be economically tied to a country other than the U.S. if it provides investment exposure to a non-U.S. issuer. The Fund considers a company to be a non-U.S. issuer if (i) it is organized outside the U.S. or maintains a principal place of business outside the U.S., (ii) its securities are traded principally outside the U.S., or (iii) during its most recent fiscal year, it derived at least 50% of its revenues or profits from goods produced or sold, investments made, or services performed outside the U.S. or it has at least 50% of its assets outside the U.S.

The Fund invests primarily in domestic and foreign equity securities. The Fund’s investments in foreign equity securities may include emerging market securities. The Fund also may invest in debt securities.

The Fund’s investments in equity securities may include common stocks, preferred stocks, convertible preferred stocks, warrants, options and American Depositary Receipts (“ADRs”). Some, but not all, of the equity securities will pay a dividend.

The Fund’s investments in debt securities may include U.S. Treasury notes and bonds, investment grade corporate debt securities, convertible debt securities and debt securities below investment grade (high yield or junk bonds).

At times, depending on market and other conditions, and in the sole discretion of the Fund’s subadviser, Yacktman Asset Management LP (“Yacktman” or the “Subadviser”), the Fund will focus a substantial portion of its assets in a small number of issuers, business sectors or industries. The Fund is non-diversified.

Under normal circumstances, the Fund invests at least 35% (or if conditions are not favorable, in the view of Yacktman, at least 25%) of its net assets in investments economically tied to countries other than the U.S., and the Fund will hold investments economically tied to a minimum of three countries other than the U.S. The Fund considers an investment to be economically tied to a country other than the U.S. if it provides investment exposure to a non-U.S. issuer. The Fund considers a company to be a non-U.S. issuer if (i) it is organized outside the U.S. or maintains a principal place of business outside the U.S., (ii) its securities are traded principally outside the U.S., or (iii) during its most recent fiscal year, it derived at least 50% of its revenues or profits from goods produced or sold, investments made, or services performed outside the U.S. or it has at least 50% of its assets outside the U.S.