GMO Dynamic Allocation ETF Investment Strategy - GMO Dynamic Allocation ETF	Feb. 28, 2026
Prospectus [Line Items]
Strategy [Heading]	<span style="color:#000000;font-family:Times New Roman;font-size:10pt;font-weight:bold;">Principal investment strategies</span>
Strategy Narrative [Text Block]	The Fund is an actively managed ETF that seeks to achieve its investment objective by owning a balanced portfolio of equity investments, fixed-income investments, and liquid alternative strategies. The Fund operates primarily as a fund of funds investing primarily in shares of other investment companies managed by GMO (including other series of GMO ETF Trust) and third parties (collectively, “Underlying Funds”) but is also permitted to invest directly in securities and other investments in lieu of, or in addition to, investing in Underlying Funds.GMO uses its quantitative multi-year forecasts of returns among asset classes, together with its assessment of the relative risks of asset classes and other factors, to determine the asset classes in which the Fund invests and how much the Fund invests in each asset class. An important component of those forecasts is GMO’s expectation that valuations ultimately revert to their fundamental fair (or intrinsic) value over a complete market cycle. GMO changes the Fund’s asset class exposures in response to changes in GMO’s investment outlook and its assessment of market valuations. Under normal circumstances, GMO intends to invest between 40% and 80% of the Fund’s net assets in equity investments, including Underlying Funds that invest primarily in equities. The factors GMO considers and investment methods GMO uses can change over time.The Fund is permitted to invest in any asset class (e.g., U.S., non-U.S., and emerging market equity; U.S., non-U.S., and emerging market fixed income (including asset-backed securities and municipal bonds); and commodities), strategy (e.g., long/short and event-driven strategies), sector, country, or region and at times may have substantial exposure to a single asset class, industry, sector, country, region, issuer, or currency and companies with similar market capitalizations. In addition, the Fund is not restricted in its exposure to any particular market and may invest in securities of companies of any market capitalization and, in the case of debt instruments, of any credit quality (including below investment grade securities, commonly referred to as “high yield” or “junk bonds”), maturity and duration. In addition, the Fund may lend its portfolio securities.In seeking to achieve the Fund’s investment objective, GMO may invest a significant portion of the Fund’s net assets in cash and cash equivalents.The Fund also may invest in GMO U.S. Treasury Fund, a mutual fund advised by GMO, or in money market funds unaffiliated with GMO, and directly in the types of investments typically held by money market funds.

GMO Dynamic Allocation ETF Investment Strategy - GMO Dynamic Allocation ETF

Feb. 28, 2026

<span style="color:#000000;font-family:Times New Roman;font-size:10pt;font-weight:bold;">Principal investment strategies</span>

Strategy Narrative [Text Block]

The Fund is an actively managed ETF that seeks to achieve its investment objective by owning a balanced portfolio of equity investments, fixed-income investments, and liquid alternative strategies. The Fund operates primarily as a fund of funds investing primarily in shares of other investment companies managed by GMO (including other series of GMO ETF Trust) and third parties (collectively, “Underlying Funds”) but is also permitted to invest directly in securities and other investments in lieu of, or in addition to, investing in Underlying Funds.GMO uses its quantitative multi-year forecasts of returns among asset classes, together with its assessment of the relative risks of asset classes and other factors, to determine the asset classes in which the Fund invests and how much the Fund invests in each asset class. An important component of those forecasts is GMO’s expectation that valuations ultimately revert to their fundamental fair (or intrinsic) value over a complete market cycle. GMO changes the Fund’s asset class exposures in response to changes in GMO’s investment outlook and its assessment of market valuations. Under normal circumstances, GMO intends to invest between 40% and 80% of the Fund’s net assets in equity investments, including Underlying Funds that invest primarily in equities. The factors GMO considers and investment methods GMO uses can change over time.The Fund is permitted to invest in any asset class (e.g., U.S., non-U.S., and emerging market equity; U.S., non-U.S., and emerging market fixed income (including asset-backed securities and municipal bonds); and commodities), strategy (e.g., long/short and event-driven strategies), sector, country, or region and at times may have substantial exposure to a single asset class, industry, sector, country, region, issuer, or currency and companies with similar market capitalizations. In addition, the Fund is not restricted in its exposure to any particular market and may invest in securities of companies of any market capitalization and, in the case of debt instruments, of any credit quality (including below investment grade securities, commonly referred to as “high yield” or “junk bonds”), maturity and duration. In addition, the Fund may lend its portfolio securities.In seeking to achieve the Fund’s investment objective, GMO may invest a significant portion of the Fund’s net assets in cash and cash equivalents.The Fund also may invest in GMO U.S. Treasury Fund, a mutual fund advised by GMO, or in money market funds unaffiliated with GMO, and directly in the types of investments typically held by money market funds.