rr_ProspectusLineItems

rr_ObjectiveHeading

Investment Objective

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. Because the fund is new, the fund’s portfolio turnover rate is not available.

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example by, Year, Caption [Text]

rr_ExpenseExampleByYearCaption

The example assumes that you invest $10,000 in the fund for the time periods indicated and then redeem all of your shares at the end of those periods, that you earn a 5% return each year, and that the fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The fund invests in various sectors of the fixed income market holding instruments such as corporate bonds and notes, government securities, securitized credit instruments, and emerging markets debt securities. The portfolio managers select securities using a sector rotation approach that integrates proprietary fundamental research and quantitative model inputs, such as economic activity, inflation and monetary policy, and technical analysis of relative value among various sectors. The fund invests in both investment-grade and high-yield debt securities. Investment grade securities are those that have been rated in one of the top four credit quality categories by an independent rating agency or determined by the advisor to be of comparable credit quality. High-yield securities, which are also known as “junk bonds,” are those that have been rated by an independent rating agency below the highest four categories or determined by the advisor to be of similar quality.

The debt securities in which the fund invests may be payable in U.S. or foreign currencies, including emerging markets currencies. The fund may also invest in certain equity securities such as preferred stock, convertible securities, or equity equivalents provided that such investments are consistent with the fund’s investment objectives. The fund has no average maturity or duration limitations.

In addition to the securities listed above, the fund may also invest in bank loans.

The fund may also utilize derivative instruments provided that such investments are in keeping with the fund’s investment objectives. Such derivative instruments include options, futures contracts, options on futures contracts, and swaps (such as credit default swaps either on a single issuer or a securities index), or in mortgage- or asset-backed securities. The fund may invest in collateralized debt obligations, including collateralized loan obligations, collateralized mortgage obligations, and other similarly structured investments. The fund may use foreign currency exchange contracts to shift investment exposure from one currency into another for hedging purposes or to enhance returns.

To determine whether to buy or sell a security, the portfolio managers consider the fund requirements and standards described above, along with economic conditions, alternative investments and interest rates.

The portfolio managers may engage in hedging of portfolio positions, which usually involves entering into a derivative transaction that has the opposite characteristic of the position being hedged. The net effect of these two positions is intended to reduce or eliminate the exposure created by the first position.

The fund is an actively managed exchange-traded fund (ETF) that does not seek to replicate the performance of a specified index. To determine whether to buy or sell a security, the portfolio managers consider, among other things, various fund requirements and standards, along with economic conditions, alternative investments, interest rates and various credit metrics.

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

•Interest Rate Risk - Investments in debt securities are also sensitive to interest rate changes. Generally, the value of debt securities and the funds that hold them decline as interest rates rise. The fund is more susceptible to interest rate changes than funds that have shorter-weighted average maturities, such as money market and short-term bond funds. A period of rising interest rates may negatively affect the fund’s performance.

•Credit Risk - The inability or perceived inability of a security’s issuer to make interest and principal payments may cause the value of the security to decrease. As a result, the fund’s share price could also decrease. Changes in the credit rating of a debt security held by the fund could have a similar effect.

•High-Yield Risk - Issuers of high-yield securities are more vulnerable to real or perceived economic changes (such as an economic down turn or a prolonged period of rising interest rates), political changes or adverse developments specific to an issuer. These factors may be more likely to cause an issuer of low quality bonds to default on its obligations. Investment in high-yield securities is inherently speculative.

•Foreign Securities Risk - Foreign securities have certain unique risks, such as currency risk, social, political and economic risk, and foreign market and trading risk. Securities of foreign issuers may be less liquid, more volatile and harder to value than U.S. securities.

•Emerging Market Risk – Investing in securities of companies located in emerging market countries generally is also riskier than investing in securities of companies located in foreign developed countries. Emerging market countries may have unstable governments and/or economies that are subject to sudden change. These changes may be magnified by the countries’ emergent financial markets, resulting in significant volatility to investments in these countries. These countries also may lack the legal, business and social framework to support securities markets.

•Derivatives Risk - The use of derivative instruments involves risks different from, or possibly greater than, the risks associated with investing directly in securities. Derivatives are subject to a number of risks, including liquidity, interest rate, market, credit and correlation risk. In addition, derivatives can create economic leverage in the fund’s portfolio, which may result in significant volatility and cause the fund to participate in losses (as well as gains) in an amount that exceeds the fund’s initial investment. Certain derivatives have the potential for unlimited loss, regardless of the size of the initial investment.

Futures contracts may experience dramatic price changes and imperfect correlations between the price of the contract and the underlying security, index or currency.

Swap agreements subject a fund to the risk that the counterparty to the transaction may not meet its obligations. The fund also bears the risk of loss of the amount expected to be received under a swap agreement in the event of the default or bankruptcy of a counterparty. Swap agreements may also be considered illiquid.

Foreign currency forward contracts and other derivatives contracts on foreign currencies involve a risk of loss if currency exchange rates move against the fund’s position.

•Bank Loan Risk – The market for bank loans may not be highly liquid and the fund may have difficulty selling them. In connection with purchasing loan participations, the fund generally will have no right to enforce compliance by borrowers with loan terms nor any set off rights, and the fund may not benefit directly from any posted collateral. As a result, the fund may be subject to the credit risk of both the borrower and the lender selling the participation. Bank loan transactions may take more than seven days to settle, meaning that proceeds would be unavailable to make additional investments or meet redemptions. To the extent the extended loan settlement process gives rise to short-term liquidity needs, such as the need to satisfy redemption requests, the fund may hold cash or sell investments.

•Collateralized Debt Obligations Risk – Collateralized debt obligations and collateralized loan obligations (CLOs) are subject to credit, interest rate, valuation, and prepayment and extension risks. These securities also are subject to risk of default on the underlying asset, particularly during periods of economic downturn. The market value of CLOs may be affected by, among other things, changes in the market value of the underlying assets held by the CLO, changes in the distributions on the underlying assets, defaults and recoveries on the underlying assets, capital gains and losses on the underlying assets, prepayments on underlying assets and the availability, prices and interest rate of underlying assets. Lower rated tranches of such debt are subject to a higher risk of total loss and deferral or nonpayment of interest than the more senior tranches to which they are subordinated.

•Convertible Securities Risk – The value of convertible securities may rise and fall with the market value of the underlying stock or, like a debt security, vary with changes in interest rates and the credit quality of the issuer. A convertible security tends to perform more like a stock when the underlying stock price is high relative to the conversion price and more like a debt security when the underlying stock price is low relative to the conversion price.

•Preferred Securities Risk – Preferred securities combine some of the characteristics of both common stocks and bonds. Preferred securities are typically subordinated to a company’s other debt which subjects them to greater credit risk . Generally, holders of preferred securities have no voting rights. In certain circumstances, an issuer of preferred securities may defer payment on the securities and, in some cases, redeem the securities prior to a specified date. Preferred securities may also be substantially less liquid than other securities and may have less upside potential than common stock.

•Counterparty Risk – If the fund enters into financial contracts, the fund will be subject to the credit risk presented by the counterparties.

•Cash Transactions Risk - The fund may effect its creations and redemptions for cash, rather than for in-kind securities. 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 fund shares may be less tax-efficient than an investment in an ETF that distributes portfolio securities entirely in-kind. Cash transactions may have to be carried out over several days if the securities market is relatively illiquid and may involve considerable brokerage fees and taxes. Brokerage fees and taxes will be higher than if the fund sold and redeemed shares in-kind.

•Liquidity Risk - During periods of market turbulence or unusually low trading activity, it may be necessary for the fund to sell securities at prices that could have an adverse effect on the fund. The market for lower-quality debt securities is generally less liquid than the market for higher-quality securities. Changing regulatory and market conditions, including increases in interest rates and credit spreads may adversely affect the liquidity of the fund’s investments.

•High Portfolio Turnover Risk - The fund may engage in active and frequent trading of its portfolio securities. High portfolio turnover may result in increased transaction costs to the fund, including brokerage commissions, dealer mark-ups and other transaction costs on the sale of the securities and on reinvestment in other securities.

•Market Trading Risk - The fund faces numerous market trading risks, including the potential lack of an active market for fund shares, losses from trading in secondary markets, periods of high volatility and disruption in the creation and/or redemption process of the fund. Any of these factors, among others, may lead to the fund’s shares trading at a premium or discount to NAV. Thus, you may pay more (or less) than NAV when you buy shares of the fund in the secondary market, and you may receive less (or more) than NAV when you sell those shares in the secondary market. The portfolio managers cannot predict whether shares will trade above (premium), below (discount) or at NAV.

•Market Risk - The value of the fund’s shares will go up and down, sometimes rapidly or unpredictably, based on the performance of the issuers whose securities it owns and other factors generally affecting the securities market. Market risks, including political, regulatory, economic and social developments, can affect the value of the fund’s investments. Natural disasters, public health emergencies, terrorism and other unforeseeable events may lead to increased market volatility and may have adverse long-term effects on world economies and markets generally.

•Prepayment and Extension Risk -The fund may invest in debt securities backed by mortgages or other assets. If these underlying assets are prepaid, the fund may benefit less from declining interest rates than funds of similar duration that invest less heavily in mortgage and asset-backed securities. Conversely, an issuer may exercise its right to pay principal on an obligation held by the fund later than expected (extend the obligation) especially in periods of rising interest rates. These events may lengthen the duration (i.e. interest rate sensitivity) and potentially reduce the value of these securities.

•Public Health Emergency Risk - A pandemic, caused by the infectious respiratory illness COVID-19, is causing market disruption and other economic impacts. Markets have experienced volatility, reduced liquidity, and increased trading costs. These events may continue to impact the fund and its underlying investments and could cause increased premiums or discounts to the fund’s NAV.

•Authorized Participant Concentration Risk - Only an authorized participant may engage in creation or redemption transactions directly with the fund. The fund may have a limited number of institutions that act as authorized participants. To the extent that these institutions exit the business or are unable to proceed with creation and/or redemption orders with respect to the fund and no other authorized participant is able to step forward to process creation and/or redemption orders, fund shares may trade at a discount to net asset value (NAV) and possibly face trading halts and/or delisting. This risk may be more pronounced in volatile markets, potentially where there are significant redemptions in ETFs generally.

•Large Shareholder Risk - Certain shareholders, including other funds advised by the advisor, may from time to time own a substantial amount of the shares of the fund. In addition, a third party investor, the advisor or an affiliate of the advisor, an authorized participant, a market maker, or another entity may invest in the fund and hold its investment for a limited period of time solely to facilitate commencement of the fund or to facilitate the fund’s achieving a specified size or scale. 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. In addition, transactions by large shareholders may account for a large percentage of the trading volume on the NYSE Arca, Inc. and may, therefore, have a material upward or downward effect on the market price of the shares.

•Principal Loss Risk - At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund.

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The fund’s performance history is not available as of the date of this prospectus. When the fund has investment results for a full calendar year, this section will feature charts that show annual total returns, highest and lowest quarterly returns and average annual total returns for the fund. This information indicates the volatility of the fund’s historical returns from year to year. For current performance information, please visit americancenturyetfs.com.

Performance information is designed to help you see how fund returns can vary. Keep in mind that past performance (before and after taxes) does not predict how the fund will perform in the future.

Performance One Year or Less [Text]

rr_PerformanceOneYearOrLess

The fund’s performance history is not available as of the date of this prospectus. When the fund has investment results for a full calendar year, this section will feature charts that show annual total returns, highest and lowest quarterly returns and average annual total returns for the fund.

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Keep in mind that past performance (before and after taxes) does not predict how the fund will perform in the future.

Prospectus [Line Items]

rr_ProspectusLineItems

Management Fees (as a percentage of Assets)

rr_ManagementFeesOverAssets

0.35%

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

$ 113

Prospectus [Line Items]

rr_ProspectusLineItems

Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. Because the fund is new, the fund’s portfolio turnover rate is not available.

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example by, Year, Caption [Text]

rr_ExpenseExampleByYearCaption

The example assumes that you invest $10,000 in the fund for the time periods indicated and then redeem all of your shares at the end of those periods, that you earn a 5% return each year, and that the fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

Under normal market conditions, the portfolio managers will invest at least 80% of the fund’s net assets, plus any borrowings for investment purposes, in debt securities related to emerging market countries. Debt securities in which the fund invests include sovereign and quasi-sovereign debt, emerging markets corporate debt securities, and emerging markets debt investments. Emerging markets debt investments include emerging markets derivatives whose reference securities are corporate and sovereign debt securities. Investments are predominantly made in instruments denominated in U.S. dollars but the fund may also invest in securities denominated in local emerging markets currency. The portfolio managers select investments for the fund using proprietary fundamental research, quantitative model inputs and qualitative assessments that consider multiple inputs such as macroeconomic factors, country and fundamental issuer analysis, and market and relative value.

The fund considers an emerging market country to be any country other than a developed country. However, the fund typically invests in the subset of emerging markets countries that comprise the JP Morgan EMBI Global Diversified Index. In determining where a company is located, the portfolio managers will consider various factors, including where the company is headquartered, where the company’s principal operations are located, where a majority of the company’s revenues are derived, where the principal trading market is located and the country in which the company was legally organized. The weight given to each of these factors will vary depending on the circumstances in a given case.

The fund invests in both investment-grade and high-yield debt securities. Investment grade securities are those that have been rated in one of the top four credit quality categories by an independent rating agency or determined by the advisor to be of comparable credit quality. High-yield securities, which are also known as “junk bonds”, are those that have been rated by an independent rating agency below the highest four categories or determined by the advisor to be of similar quality. The fund has no average maturity or duration limitations.

The fund also may invest in derivative instruments such as interest rate futures contracts. The fund may use derivative instruments to earn income, enhance returns, increase liquidity, manage target duration, gain exposure to certain instruments or markets, and/or hedge its exposure to particular investments.

The portfolio managers may engage in hedging of portfolio positions, which usually involves entering into a derivative transaction that has the opposite characteristic of the position being hedged. The net effect of these two positions is intended to reduce or eliminate the exposure created by the first position.

The fund is an actively managed exchange-traded fund (ETF) that does not seek to replicate the performance of a specified index. To determine whether to buy or sell a security, the portfolio managers consider the fund requirements and standards described above, along with economic conditions, alternative investments, interest rates and various credit metrics.

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

•Foreign Securities Risk - Foreign securities have certain unique risks, such as currency risk, social, political and economic risk, and foreign market and trading risk. Securities of foreign issuers may be less liquid, more volatile and harder to value than U.S. securities.

•Emerging Market Risk – Investing in securities of issuers located in emerging market countries generally is riskier than investing in securities of issuers located in foreign developed countries due to lower liquidity, market manipulation concerns, limited reliable access to capital, and differing company organizational structures. Emerging market countries may have unstable governments and/or economies that are subject to sudden change. These changes may be magnified by the countries’ emergent financial markets, resulting in significant volatility to investments in these countries. These countries also may lack the legal, business, and social framework to support securities markets. Additionally, certain jurisdictions do not provide auditors with sufficient access to inspect audit work papers and practices, or otherwise do not cooperate with U.S. regulators, potentially exposing investors in U.S. capital markets to significant risks.

•Currency Risk – Because the fund may invest in securities denominated in foreign currencies, the fund may be subject to currency risk, meaning that the fund could experience gains or losses based solely on changes in the exchange rate between foreign currencies and the U.S. dollar.

•Sovereign Debt Risk – Sovereign debt instruments, which are instruments issued by foreign governmental entities, are subject to the risk that the governmental entity may be unable or unwilling to repay the principal or interest on its sovereign debt due to, among other reasons, cash flow problems, insufficient foreign currency reserves, political considerations, the relative size of the governmental entity’s debt or its failure to implement economic reforms. There is no bankruptcy process for collecting sovereign debt and legal remedies may be limited and onerous to pursue.

•Interest Rate Risk - Investments in debt securities are also sensitive to interest rate changes. Generally, the value of debt securities and the funds that hold them decline as interest rates rise. The fund is more susceptible to interest rate changes than funds that have shorter-weighted average maturities, such as money market and short-term bond funds. A period of rising interest rates may negatively affect the fund’s performance.

•Credit Risk - The inability or perceived inability of a security’s issuer to make interest and principal payments may cause the value of the security to decrease. As a result, the fund’s share price could also decrease. Changes in the credit rating of a debt security held by the fund could have a similar effect.

•High-Yield Risk - Issuers of high-yield securities are more vulnerable to real or perceived economic changes (such as an economic down turn or a prolonged period of rising interest rates), political changes or adverse developments specific to an issuer. These factors may be more likely to cause an issuer of low quality bonds to default on its obligations. Investment in high-yield securities is inherently speculative.

•Derivatives Risk - The use of derivative instruments involves risks different from, or possibly greater than, the risks associated with investing directly in securities and other traditional instruments. Derivatives are subject to a number of risks, including liquidity, interest rate, market, credit and correlation risk. In addition, derivatives can create economic leverage in the fund’s portfolio, which may result in significant volatility and cause the fund to participate in losses (as well as gains) in an amount that exceeds the fund’s initial investment. Certain derivatives have the potential for unlimited loss, regardless of the size of the initial investment. Futures contracts may experience dramatic price changes and imperfect correlations between the price of the contract and the underlying security, index or currency.

•Cash Transactions Risk - The fund may effect its creations and redemptions for cash, rather than for in-kind securities. 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 fund shares may be less tax-efficient than an investment in an ETF that distributes portfolio securities entirely in-kind. Cash transactions may have to be carried out over several days if the securities market is relatively illiquid and may involve considerable brokerage fees and taxes. Brokerage fees and taxes will be higher than if the fund sold and redeemed shares in-kind.

•Liquidity Risk - During periods of market turbulence or unusually low trading activity, it may be necessary for the fund to sell securities at prices that could have an adverse effect on the fund. The market for lower-quality debt securities is generally less liquid than the market for higher-quality securities. Changing regulatory and market conditions, including increases in interest rates and credit spreads may adversely affect the liquidity of the fund’s investments.

•Market Trading Risk - The fund faces numerous market trading risks, including the potential lack of an active market for fund shares, losses from trading in secondary markets, periods of high volatility and disruption in the creation and/or redemption process of the fund. Any of these factors, among others, may lead to the fund’s shares trading at a premium or discount to NAV. Thus, you may pay more (or less) than NAV when you buy shares of the fund in the secondary market, and you may receive less (or more)

than NAV when you sell those shares in the secondary market. The portfolio managers cannot predict whether shares will trade above (premium), below (discount) or at NAV.

•Market Risk - The value of the fund’s shares will go up and down, sometimes rapidly or unpredictably, based on the performance of the issuers whose securities it owns and other factors generally affecting the securities market. Market risks, including political, regulatory, economic and social developments, can affect the value of the fund’s investments. Natural disasters, public health emergencies, terrorism and other unforeseeable events may lead to increased market volatility and may have adverse long-term effects on world economies and markets generally.

•Public Health Emergency Risk - A pandemic, caused by the infectious respiratory illness COVID-19, is causing market disruption and other economic impacts. Markets have experienced volatility, reduced liquidity, and increased trading costs. These events may continue to impact the fund and its underlying investments and could cause increased premiums or discounts to the fund’s NAV.

•Authorized Participant Concentration Risk - Only an authorized participant may engage in creation or redemption transactions directly with the fund. The fund may have a limited number of institutions that act as authorized participants. To the extent that these institutions exit the business or are unable to proceed with creation and/or redemption orders with respect to the fund and no other authorized participant is able to step forward to process creation and/or redemption orders, fund shares may trade at a discount to net asset value (NAV) and possibly face trading halts and/or delisting. This risk may be more pronounced in volatile markets, potentially where there are significant redemptions in ETFs generally.

•Large Shareholder Risk - Certain shareholders, including other funds advised by the advisor, may from time to time own a substantial amount of the shares of the fund. In addition, a third party investor, the advisor or an affiliate of the advisor, an authorized participant, a market maker, or another entity may invest in the fund and hold its investment for a limited period of time solely to facilitate commencement of the fund or to facilitate the fund’s achieving a specified size or scale. 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. In addition, transactions by large shareholders may account for a large percentage of the trading volume on the NYSE Arca, Inc. and may, therefore, have a material upward or downward effect on the market price of the shares.

•Principal Loss Risk - At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund.

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Performance Narrative [Text Block]

rr_PerformanceNarrativeTextBlock

The fund’s performance history is not available as of the date of this prospectus. When the fund has investment results for a full calendar year, this section will feature charts that show annual total returns, highest and lowest quarterly returns and average annual total returns for the fund. This information indicates the volatility of the fund’s historical returns from year to year. For current performance information, please visit americancenturyetfs.com.

Performance information is designed to help you see how fund returns can vary. Keep in mind that past performance (before and after taxes) does not predict how the fund will perform in the future.

Performance One Year or Less [Text]

rr_PerformanceOneYearOrLess

The fund’s performance history is not available as of the date of this prospectus. When the fund has investment results for a full calendar year, this section will feature charts that show annual total returns, highest and lowest quarterly returns and average annual total returns for the fund.

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Keep in mind that past performance (before and after taxes) does not predict how the fund will perform in the future.

Prospectus [Line Items]

rr_ProspectusLineItems

Management Fees (as a percentage of Assets)

rr_ManagementFeesOverAssets

0.39%

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

$ 126

Prospectus [Line Items]

rr_ProspectusLineItems

Objective [Heading]

rr_ObjectiveHeading

Investment Objective

Expense [Heading]

rr_ExpenseHeading

Fees and Expenses

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Text Block]

rr_PortfolioTurnoverTextBlock

The fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. Because the fund is new, the fund’s portfolio turnover rate is not available.

Expense Example [Heading]

rr_ExpenseExampleHeading

Example

Expense Example by, Year, Caption [Text]

rr_ExpenseExampleByYearCaption

The example assumes that you invest $10,000 in the fund for the time periods indicated and then redeem all of your shares at the end of those periods, that you earn a 5% return each year, and that the fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The fund will generally invest in large capitalization companies it believes show sustainable business improvement using a proprietary multi-factor model that combines fundamental measures of a stock’s growth and value potential with environmental, social, and governance (ESG) metrics. The model assigns each security a financial metrics score and an ESG score that are combined on an equal basis to create an overall score.

To measure growth, the managers may use the rate of growth of a company’s earnings and cash flow and changes in its earnings estimates. To measure value, the portfolio managers may use ratios of stock price-to-earnings and stock price-to-cash flow. The model also considers price momentum. The team arrives at an ESG score by evaluating multiple metrics of each ESG characteristic—environmental, social, and governance. The portfolio managers utilize internal data and research, as well as third party commercial data sources and scoring systems, to evaluate each security’s ESG characteristics. For example, portfolio managers will consider, among others, a company’s carbon emission profile (environmental), a company’s employee turnover rates and digital privacy (social), and a company’s corporate leadership, including board chair independence and the independence of audit and compensation committees (governance). If information on a specific metric is unavailable, the security may still be selected for the portfolio if the portfolio managers believe they can evaluate the security qualitatively, or if the financial metrics and remaining ESG scores merit investment.

Final scores for each security are evaluated on a sector-specific basis, and the fund seeks to hold securities with the strongest scores in their respective sectors. Using this process, the portfolio managers attempt to build a portfolio of stocks that has sustainable competitive advantages, provides better returns without taking on significant additional risk, and maintains a stronger ESG profile than the Russell 1000 Growth Index.

Under normal market conditions, the fund will invest at least 80% of its assets in sustainable securities. For this purpose, the advisor defines sustainable securities as those to which the advisor’s proprietary model assigns an ESG score that is in the top three quartiles of the ESG scores the model assigns to all of the securities in the fund’s benchmark, the Russell 1000 Growth Index. The fund will invest principally in exchange-traded common stocks. The fund defines large capitalization companies as companies with capitalizations in the capitalization range of the Russell 1000 Growth Index.

When determining whether to sell a security, the portfolio managers consider among other things, a security’s price, whether a security’s risk parameters outweigh its return opportunities, general market conditions, and whether the security meets their ESG criteria.

The fund is nondiversified and will typically hold 70-90 stocks. The fund is an actively managed, nontransparent exchange-traded fund (ETF) that does not seek to replicate the performance of a specified index. In lieu of publishing its portfolio contents (Actual Portfolio) daily, the fund publishes a proxy portfolio (Proxy Portfolio) each day and on its website. There is no minimum overlap required between the Actual Portfolio and the Proxy Portfolio.

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

•Proxy Portfolio Risk - The goal of the Proxy Portfolio is, during all market conditions, to track closely the daily performance of the Actual Portfolio and minimize intra-day misalignment between the performance of the Proxy Portfolio and the performance of the Actual Portfolio. The Proxy Portfolio is designed to reflect the economic exposures and the risk characteristics of the Actual Portfolio on any given trading day.

◦The Proxy Portfolio methodology is novel and not yet proven as an effective arbitrage mechanism. The effectiveness of the Proxy Portfolio as an arbitrage mechanism is contingent upon, among other things, the fund’s factor model analysis creating a Proxy Portfolio that performs in a manner substantially identical to the performance of the fund’s Actual Portfolio. While the Proxy Portfolio may include some of the fund’s holdings, it is not the fund’s Actual Portfolio. ETFs trading on the basis of a published Proxy Portfolio may exhibit wider premiums and discounts, bid/ask spreads, and tracking error than other ETFs using the same investment strategies that publish their portfolios on a daily basis, especially during periods of market disruption or volatility. Therefore, shares of the fund may cost investors more to trade than shares of a traditional ETF.

◦Each day the fund calculates the overlap between the holdings of the prior Business Day’s Proxy Portfolio compared to the Actual Portfolio (Proxy Overlap) and the difference, in percentage terms, between the Proxy Portfolio per share NAV and that of the Actual Portfolio (Tracking Error). If the Tracking Error becomes large, there is a risk that the performance of the Proxy Portfolio may deviate from the performance of the Actual Portfolio.

◦The fund’s Board of Trustees monitors its Tracking Error and bid/spread. If deviations become too large, the Board will consider the continuing viability of the fund, whether shareholders are being harmed, and what, if any, corrective measures would be appropriate. See the Statement of Additional Information for further discussion of the Board’s monitoring responsibilities.

◦Although the fund seeks to benefit from keeping its portfolio information secret, market participants may attempt to use the Proxy Portfolio to identify a fund’s trading strategy, which if successful, could result in such market participants engaging in certain predatory trading practices that may have the potential to harm the fund and its shareholders.

•Premium/Discount Risk - Publication of the Proxy Portfolio is not the same level of transparency as the publication of the full portfolio by a fully transparent active ETF. Although the Proxy Portfolio is intended to provide investors with enough information to allow for an effective arbitrage mechanism that will keep the market price of the fund at or close to the underlying net asset value (NAV) per share of the fund, there is a risk (which may increase during periods of market disruption or volatility) that market prices will vary significantly from the underlying NAV of the fund. This means the price paid to buy shares on an exchange may not match the value of the fund’s portfolio. The same is true when shares are sold.

•Trading Issues Risk - If securities representing 10% or more of the fund’s Actual Portfolio do not have readily available market quotations, the fund will promptly request that the Exchange halt trading in the fund’s shares. Trading halts may have a greater impact on this fund compared to other ETFs due to the fund’s nontransparent structure. If the trading of a security held in the fund’s Actual Portfolio is halted, or otherwise does not have readily available market quotations, and the Advisor believes that the lack of any such readily available market quotations may affect the reliability of the Proxy Portfolio as an arbitrage vehicle, or otherwise determines it is in the best interest of the fund, the Advisor promptly will disclose on the fund’s website the identity and weighting of such security for so long as such security’s trading is halted or otherwise does not have readily available market quotations and remains in the Actual Portfolio.

•Authorized Participant Concentration Risk - Only an authorized participant may engage in creation or redemption transactions directly with the fund. The fund may have a limited number of institutions that act as authorized participants. To the extent that these institutions exit the business or are unable to proceed with creation and/or redemption orders with respect to the fund and no other authorized participant is able to step forward to process creation and/or redemption orders, fund shares may trade at a discount to net asset value (NAV) and possibly face trading halts and/or delisting. This risk may be more pronounced in volatile markets, potentially where there are significant redemptions in ETFs generally. The fact that the fund is offering a novel and unique structure may affect the number of entities willing to act as Authorized Participants. During times of market stress, Authorized Participants may be more likely to step away from this type of ETF than a traditional ETF.

•ESG Risk - Because the fund considers ESG metrics in addition to fundamental financial metrics when selecting securities, its portfolio may perform differently than funds that do not use ESG metrics. ESG considerations may prioritize long term rather than short term returns. Furthermore, when analyzing ESG criteria for securities, if the portfolio management team relies on the

information and scoring models published by third party sources, there is a risk that this information might be incorrect or only take into account one of many ESG related components of portfolio companies. Moreover, scores and ratings across third party providers may be inconsistent or incomparable.

•Style Risk - If at any time the market is not favoring the fund’s investment process, the fund’s gains may not be as big as, or its losses may be bigger than, those of other equity funds using different investment styles.

•Market Trading Risk - The fund faces numerous market trading risks, including the potential lack of an active market for fund shares, losses from trading in secondary markets, periods of high volatility and disruption in the creation and/or redemption process of the fund. Any of these factors, among others, may lead to the fund’s shares trading at a premium or discount to NAV. Thus, you may pay more (or less) than NAV when you buy shares of the fund in the secondary market, and you may receive less (or more) than NAV when you sell those shares in the secondary market. The portfolio managers cannot predict whether shares will trade above (premium), below (discount) or at NAV.

•Market Risk - The value of the fund’s shares will go up and down based on the performance of the companies whose securities it owns and other factors generally affecting the securities market. Market risks, including political, regulatory, economic and social developments, can affect the value of the fund’s investments. Natural disasters, public health emergencies, terrorism and other unforeseeable events may lead to increased market volatility and may have adverse long-term effects on world economies and markets generally.

•Nondiversification Risk - The fund is classified as nondiversified. A nondiversified fund may invest a greater percentage of its assets in a smaller number of securities than a diversified fund. This gives the portfolio managers the flexibility to hold large positions in a smaller number of securities. If so, a price change in any one of those securities may have a greater impact on the fund’s share price than would be the case in a diversified fund and the fund may be more volatile than if it was diversified.

•Public Health Emergency Risk - A pandemic, caused by the infectious respiratory illness COVID-19, is causing market disruption and other economic impacts. Markets have experienced volatility, reduced liquidity, and increased trading costs. These events may continue to impact the fund and its underlying investments and could cause increased premiums or discounts to the fund’s NAV.

•Large Shareholder Risk - Certain shareholders, including other funds advised by the advisor, may from time to time own a substantial amount of the shares of the fund. In addition, a third party investor, the advisor or an affiliate of the advisor, an authorized participant, a market maker, or another entity may invest in the fund and hold its investment for a limited period of time solely to facilitate commencement of the fund or to facilitate the fund’s achieving a specified size or scale. 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. In addition, transactions by large shareholders may account for a large percentage of the trading volume on the NYSE Arca, Inc. and may, therefore, have a material upward or downward effect on the market price of the shares.

•Principal Loss Risk - At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund.

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Risk Nondiversified Status [Text]

rr_RiskNondiversifiedStatus

The fund is classified as nondiversified. A nondiversified fund may invest a greater percentage of its assets in a smaller number of securities than a diversified fund. This gives the portfolio managers the flexibility to hold large positions in a smaller number of securities. If so, a price change in any one of those securities may have a greater impact on the fund’s share price than would be the case in a diversified fund and the fund may be more volatile than if it was diversified.

Bar Chart and Performance Table [Heading]

rr_BarChartAndPerformanceTableHeading

Fund Performance

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceInformationIllustratesVariabilityOfReturns

Performance information is designed to help you see how fund returns can vary.

Performance Availability Website Address [Text]

rr_PerformanceAvailabilityWebSiteAddress

americancenturyetfs.com

Trading Symbol

dei_TradingSymbol

ESGY

Other Expenses (as a percentage of Assets):

rr_OtherExpensesOverAssets

none

^[3]

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 40