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S000096483 [Member] Investment Risks - Baron SMID Cap ETF
Dec. 31, 2025
Growth Investing [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Growth Investing. Growth stocks can react differently to issuer, political, market and economic developments than the market as a whole and other types of stocks. Growth stocks tend to be more expensive relative to their earnings or assets compared to other types of stocks. As a result, because growth stocks tend to be sensitive to changes in their earnings and to increasing interest rates and inflation, they tend to be more volatile than other types of stocks. In response, from time to time, growth investing as an investment style may go out of favor with investors.
Small and Mid Sized Companies [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Small‑ and Mid-Sized Companies. The Adviser believes there is more potential for capital appreciation in small‑ and mid-sized companies, but there also may be more risk. Securities of small‑ and mid-sized companies may not be well known to most investors, and the securities may be less actively traded than those of large businesses. The securities of small‑ and mid-sized companies may fluctuate in price more widely than the stock market generally, and they may be more difficult to sell during market downturns. Small‑ and mid-sized companies rely more on the skills of management and on their continued tenure. Investing in small‑ and mid-sized companies requires a long‑term outlook and may require shareholders to assume more risk and to have more patience than investing in the securities of larger, more established companies.
Special Situations [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Special Situations. The Funds may invest in “special situations.” A special situation arises when, in the opinion of the Adviser, the securities of a company will be recognized and appreciate in value due to a specific anticipated development at that company. Such developments might include a new product, a management change, an acquisition or a technological advancement. The risk of investing in special situations is that the anticipated development does not occur or its impact is not what the Adviser expected.
ETF Structure Risks [Member]  
Prospectus [Line Items]  
Risk [Text Block]
ETF Structure Risks.
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Authorized Participant Concentration Risk. Only an authorized participant may engage in creation or redemption transactions directly with the Fund. The Fund has a limited number of intermediaries that act as authorized participants and none of these authorized participants is or will be obligated to engage in creation or redemption transactions. There can be no assurance that an active trading market for the Fund’s shares will develop or be maintained. To the extent that these intermediaries exit the business or are unable to or choose not to proceed with creation and/or redemption orders with respect to the Fund, such as during periods of market stress, and no other authorized participant creates or redeems, shares may trade at a discount to NAV per share and possibly face trading halts and/or delisting. Authorized participant concentration risk may be heightened to the extent the Fund invests in securities issued by non‑U.S. issuers or other securities or instruments that have lower trading volumes.
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Cash Transactions Risk. Unlike certain ETFs, the Fund may effect creations and redemptions in cash or partially in cash. Therefore, it may be required to sell portfolio securities and subsequently recognize gains on such sales that the Fund might not have recognized if it were to distribute portfolio securities in‑kind. As such, investments in shares may be less tax‑efficient than an investment in an ETF that distributes portfolio securities entirely in‑ kind.
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Trading Risk. The market prices of shares are expected to fluctuate, in some cases materially, in response to changes in the Fund’s NAV, the intra‑day value of the Fund’s holdings, and supply and demand for shares. The Adviser cannot predict whether shares will trade above, below or at their NAV. Disruptions to creations and redemptions, the existence of significant market volatility or potential lack of an active trading market for the shares (including through a trading halt), as well as other factors, may result in the shares trading significantly above (at a premium) or below (at a discount) to NAV or to the intraday value of the Fund’s holdings. You may pay significantly more or receive significantly less than the Fund’s NAV per share during periods when there is a significant premium or discount. Buying or selling shares in the secondary market may require paying brokerage commissions or other charges imposed by brokers as determined by that broker. Brokerage commissions are often a fixed amount and may be a significant proportional cost when seeking to buy or sell relatively small amounts of shares. In addition, the market price of shares, like the price of any exchange-traded security, includes a “bid‑ask spread” charged by the market makers or other participants that trade the particular security. The spread of the Fund’s shares varies over time based on the Fund’s trading volume and market liquidity and may increase if the Fund’s trading volume, the spread of the Fund’s underlying securities, or market liquidity decrease. In addition, the securities held by the Fund may be traded in markets that close at a different time than the Fund’s listing exchange. Liquidity in those securities may be reduced after the applicable closing times. Accordingly, during the time when the Fund’s listing exchange is open but after the applicable market closing, fixing or settlement times, bid‑ask spreads on the Fund’s listing exchange and the corresponding premium or discount to the shares’ NAV may widen.
Limited Operating History Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Limited Operating History Risk. The Fund has a limited operating history. As a result, prospective investors would not have a track record or history on which to base their investment decisions. In addition, until the Fund achieves a certain size, the performance of certain of its investments may disproportionately impact the performance of the Fund, which may be subject to heightened volatility. In addition, there can be no assurance that the Fund will grow to or maintain an economically viable size.
Large Shareholder Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Large Shareholder Risk. Certain shareholders, including other funds advised by the Adviser, may from time to time own a substantial amount of the Fund’s Shares. In addition, a third party investor, the Adviser or an affiliate of the Adviser, an authorized participant, a lead market maker, or another entity (i.e., a seed investor) may invest in the Fund and hold its investment solely to facilitate commencement of the Fund or to facilitate the Fund’s achieving a specified size or scale. Any such investment may be held for a limited period of time. There can be no assurance that any large shareholder would not redeem its investment, that the size of the Fund would be maintained at such levels or that the Fund would continue to meet applicable listing requirements. Redemptions by large shareholders could have a significant negative impact on the Fund, including on the Fund’s liquidity. In addition, transactions by large shareholders may account for a large percentage of the trading volume on the New York Stock Exchange (“NYSE”) and may, therefore, have a material upward or downward effect on the market price of the Shares.
General Stock Market [Member]  
Prospectus [Line Items]  
Risk [Text Block]
General Stock Market. Fund losses may be incurred due to declines in one or more markets in which Fund investments are made. These declines may be the result of, among other things, political, regulatory, market, economic or social developments affecting the relevant market(s). In addition, turbulence has recently been experienced, caused, among other reasons, by increased inflation, tightening monetary policy and interest rate increases by the US Federal Reserve or similar international bodies, and reduced liquidity in financial markets may continue to negatively affect many issuers, which could have an adverse effect on your Fund investment. Events involving limited liquidity, defaults, non‑performance or other adverse developments that affect one industry, such as the financial services industry, or concerns or rumors about any events of these kinds, have in the past and may in the future lead to market-wide liquidity problems, may spread to other industries, and could negatively affect the value and liquidity of the Fund’s investments. Global economies and financial markets are increasingly interconnected, and conditions and events in one country, region or financial market, such as Russia’s invasion of Ukraine in February 2022 and the world-wide response to it, have and may continue to adversely impact issuers and markets worldwide. The active and expanding conflict in the Middle East between Israel and Hamas presents considerable market risks. Raising the ceiling on U.S. government debt has become increasingly politicized. Any failure to increase the total amount that the U.S. government is authorized to borrow could lead to a default on U.S. government obligations, with unpredictable consequences for economies and markets in the U.S. and elsewhere.
Risk Lose Money [Member]  
Prospectus [Line Items]  
Risk [Text Block] Fund losses may be incurred due to declines in one or more markets in which Fund investments are made.