The Fund is a diversified fund that, under normal circumstances, invests primarily in equity securities of non-U.S. growth companies. Non-U.S. securities include securities that the Adviser determines are “non-U.S.” based on the consideration of an issuer’s domicile, its principal place of business, its primary stock exchange listing, the source of its revenue or other factors. The Fund seeks to diversify its investments among several developed countries and developing countries throughout the world, although the Fund may only invest up to 35% of its net assets in developing countries. Developing countries include countries in the MSCI Emerging Markets (EM) Index, countries in the MSCI Frontier Markets (FM) Index and other countries determined by the Adviser to be developing countries based on classifications made by the International Monetary Fund or on country characteristics similar to those of the countries in the EM and FM Indexes. The Fund may purchase securities of companies of any market capitalization. The Adviser seeks to invest in businesses it believes have significant opportunities for growth, sustainable competitive advantages, exceptional management, and an attractive valuation.

The Fund’s investments in non-U.S. securities generally are traded in currencies other than U.S. dollars, so the Adviser buys and sells foreign currencies to facilitate transactions in portfolio securities. The Adviser usually does not hedge against possible fluctuations in exchange rates, but exposure to a particular currency that the

Adviser believes is overvalued may be hedged if the Fund has a substantial position in securities traded in that currency. The Fund may buy and sell currencies for cash at current exchange rates, or use an agreement to purchase or sell a specified currency at a specified future date or within a specified time period, at a price set at the time of the contract.

S000024707 [Member] Investment Strategy - Baron International Growth Fund	Dec. 31, 2025
Prospectus [Line Items]
Strategy [Heading]	Investments, Risks, and Performance Principal Investment Strategies of the Fund
Strategy Narrative [Text Block]	The Fund is a diversified fund that, under normal circumstances, invests primarily in equity securities of non-U.S. growth companies. Non-U.S. securities include securities that the Adviser determines are “non-U.S.” based on the consideration of an issuer’s domicile, its principal place of business, its primary stock exchange listing, the source of its revenue or other factors. The Fund seeks to diversify its investments among several developed countries and developing countries throughout the world, although the Fund may only invest up to 35% of its net assets in developing countries. Developing countries include countries in the MSCI Emerging Markets (EM) Index, countries in the MSCI Frontier Markets (FM) Index and other countries determined by the Adviser to be developing countries based on classifications made by the International Monetary Fund or on country characteristics similar to those of the countries in the EM and FM Indexes. The Fund may purchase securities of companies of any market capitalization. The Adviser seeks to invest in businesses it believes have significant opportunities for growth, sustainable competitive advantages, exceptional management, and an attractive valuation. The Fund’s investments in non-U.S. securities generally are traded in currencies other than U.S. dollars, so the Adviser buys and sells foreign currencies to facilitate transactions in portfolio securities. The Adviser usually does not hedge against possible fluctuations in exchange rates, but exposure to a particular currency that the Adviser believes is overvalued may be hedged if the Fund has a substantial position in securities traded in that currency. The Fund may buy and sell currencies for cash at current exchange rates, or use an agreement to purchase or sell a specified currency at a specified future date or within a specified time period, at a price set at the time of the contract.