v3.25.2
Label Element Value
Franklin Dynamic Municipal Bond ETF  
Risk/Return: oef_RiskReturnAbstract  
Risk/Return [Heading] oef_RiskReturnHeading Franklin Dynamic Municipal Bond ETF
Objective [Heading] oef_ObjectiveHeading Investment Goal
Objective, Primary [Text Block] oef_ObjectivePrimaryTextBlock

A high level of current income that is exempt from federal income taxes.

Expense Heading [Optional Text] oef_ExpenseHeading Fees and Expenses of the Fund
Expense Narrative [Text Block] oef_ExpenseNarrativeTextBlock

The following table describes the fees and expenses that you will incur if you buy, hold and sell shares of the Fund. You may also incur other fees, such as usual and customary brokerage commissions and other fees to financial intermediaries, which are not reflected in the table and the Example that follows.

Operating Expenses Caption [Optional Text] oef_OperatingExpensesCaption Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Portfolio Turnover [Heading] oef_PortfolioTurnoverHeading Portfolio Turnover
Portfolio Turnover [Text Block] oef_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. During the most recent fiscal year, the Fund's portfolio turnover rate was 49.83% of the average value of its portfolio.

Portfolio Turnover, Rate oef_PortfolioTurnoverRate 49.83%
Expense Example [Heading] oef_ExpenseExampleHeading Example
Expense Example Narrative [Text Block] oef_ExpenseExampleNarrativeTextBlock

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then sell all of your shares at the end of the period. The Example also assumes that your investment has 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 [Heading] oef_StrategyHeading Principal Investment Strategies
Strategy Narrative [Text Block] oef_StrategyNarrativeTextBlock

Under normal market conditions, the Fund invests at least 80% of its net assets in municipal securities whose interest is free from federal income taxes, including the federal alternative minimum tax. Although the Fund tries to invest all of its assets in tax-free securities, it is possible that up to 20% of the Fund’s net assets may be in securities that pay interest that may be subject to the federal alternative minimum tax and in securities that pay interest subject to other federal or state income taxes.

The Fund may invest in debt and fixed income securities of any maturity. Under normal market conditions, the Fund seeks to maintain an average effective duration of two to eight years. Effective duration seeks to measure the expected sensitivity of market price to changes in interest rates, taking into account the anticipated effects of structural complexities (for example, some bonds can be prepaid by the issuer). The Fund may invest in municipal securities that are issued on a when-issued or delayed delivery basis.

The Fund may invest in municipal securities rated in any rating category by U.S. nationally recognized rating services (or unrated or short-term rated securities of comparable quality), including below investment grade (also known as "junk bonds") and defaulted securities.

The Fund also may invest in insured municipal securities, municipal lease obligations, variable and floating rate securities (primarily variable rate demand notes), zero coupon securities and deferred interest securities.

Although the investment manager will search for investments across a large number of municipal securities that finance different types of projects, from time to time, based on economic conditions, the Fund may have significant positions in municipal securities that finance similar types of projects.

The Fund may invest in municipal securities that are covered by insurance policies that guarantee the timely payment of principal and interest.

The investment manager selects securities that it believes will provide the best balance between risk and return within the Fund's range of allowable investments and typically invests with a long-term time horizon. This means it generally holds securities in the Fund's portfolio for income purposes, although the investment manager may sell a security at any time if it believes it could help the Fund meet its goal. With a focus on income, individual securities are considered for purchase or sale based on various factors and considerations, including credit profile, risk,

structure, pricing, portfolio impact, duration management, restructuring, opportunistic trading and tax loss harvesting opportunities.

Strategy Portfolio Concentration [Text] oef_StrategyPortfolioConcentration Under normal market conditions, the Fund invests at least 80% of its net assets in municipal securities whose interest is free from federal income taxes, including the federal alternative minimum tax.
Bar Chart and Performance Table [Heading] oef_BarChartAndPerformanceTableHeading Performance
Performance Narrative [Text Block] oef_PerformanceNarrativeTextBlock

The following bar chart and table provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund's performance from year to year. The table shows how the Fund's average annual returns for 1 year, 5 years, 10 years or since inception, as applicable, compared with those of a broad measure of market performance and an additional index with characteristics relevant to the Fund. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. You can obtain updated performance information at www.franklintempleton.com or by calling (800) DIAL BEN/342-5236.

Performance Availability Phone [Text] oef_PerformanceAvailabilityPhone (800) DIAL BEN/342-5236
Performance Availability Website Address [Text] oef_PerformanceAvailabilityWebSiteAddress franklintempleton.com
Performance Past Does Not Indicate Future [Text] oef_PerformancePastDoesNotIndicateFuture The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.
Bar Chart [Heading] oef_BarChartHeading Annual Total Returns
Bar Chart Closing [Text Block] oef_BarChartClosingTextBlock
   

Best Quarter:

2023, Q4

6.93%

Worst Quarter:

2022, Q1

-6.98%

 

As of June 30, 2025, the Fund’s year-to-date return was 0.86%.

Performance Table Heading oef_PerformanceTableHeading Average Annual Total Returns For periods ended December 31, 2024
Index No Deduction for Fees, Expenses, or Taxes [Text] oef_IndexNoDeductionForFeesExpensesTaxes (index reflects no deduction for fees, expenses or taxes)
Franklin Dynamic Municipal Bond ETF | Principal Risks  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

Principal Risks

You could lose money by investing in the Fund. ETF shares are not deposits or obligations of, or guaranteed or endorsed by, any bank, and are not insured by the Federal Deposit Insurance Corporation, the Federal Reserve Board, or any other agency of the U.S. government. The Fund is subject to the principal risks noted below, any of which may adversely affect the Fund’s net asset value (NAV), trading price, yield, total return and ability to meet its investment goal. Unlike many ETFs, the Fund is not an index-based ETF.

Franklin Dynamic Municipal Bond ETF | Risk Lose Money [Member]  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock You could lose money by investing in the Fund.
Franklin Dynamic Municipal Bond ETF | Interest Rate  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

Interest Rate: When interest rates rise, debt security prices generally fall. The opposite is also generally true: debt security prices rise when interest rates fall. Interest rate changes are influenced by a number of factors, including government policy, monetary policy, inflation expectations, perceptions of risk, and supply of and demand for bonds. In general, securities with longer maturities or durations are more sensitive to interest rate changes.

Variable rate securities generally will not increase in market value if interest rates decline. Conversely, the market value may not decline when prevailing interest rates rise. Fixed rate debt securities generally are more sensitive to interest rate changes than variable rate securities.

Franklin Dynamic Municipal Bond ETF | Credit  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

Credit: An issuer of debt securities may fail to make interest payments or repay principal when due, in whole or in part. Changes in an issuer's financial strength or in a security's or government's credit rating may affect a security's value. A change in the credit rating of a municipal bond insurer that insures securities in the Fund’s portfolio may affect the value of the securities it insures, the Fund’s share price and Fund performance. The Fund might also be adversely impacted by the inability of an insurer to meet its insurance obligations.

Franklin Dynamic Municipal Bond ETF | Liquidity  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

Liquidity: The trading market for a particular security or type of security or other investments in which the Fund invests may become less liquid or even illiquid. Reduced liquidity will have an adverse impact on the Fund’s ability to sell such securities or other investments when necessary to meet the Fund’s liquidity needs, which may arise or increase in response to a specific economic event or because the investment manager wishes to purchase particular investments or believes that a higher level of liquidity would be advantageous. Reduced liquidity will also generally lower the value of such securities or other investments. Market prices for such securities or other investments may be relatively volatile.

Franklin Dynamic Municipal Bond ETF | Tax Legislative and Political Changes  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

Tax Legislative and Political Changes: The municipal securities market could be significantly affected by adverse political and legislative changes or litigation at the federal or state level. The value of municipal bonds is closely tied to the benefits of

tax-exempt income to investors. Significant revisions of federal income tax laws or regulations revising income tax rates or the tax-exempt character of municipal bonds, or even proposed changes and deliberations on this topic by the federal government, could cause municipal bond prices to fall. For example, lower federal income tax rates would reduce certain relative advantages of owning municipal bonds, and lower state income tax rates could have similar effects. In addition, the application of corporate minimum tax rates to financial statement income may have the effect of reducing demand for municipal bonds among corporate investors, which may in turn impact municipal bond prices.

Franklin Dynamic Municipal Bond ETF | Tax-Exempt Securities  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

Tax-Exempt Securities: Failure of a municipal security issuer to comply with applicable tax requirements may make income paid thereon taxable, resulting in a decline in the security’s value. In addition, there could be changes in applicable tax laws or tax treatments that reduce or eliminate the current federal income tax exemption on municipal securities or otherwise adversely affect the current federal or state tax status of municipal securities.

Franklin Dynamic Municipal Bond ETF | Market  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

Market: The market values of securities or other investments owned by the Fund will go up or down, sometimes rapidly or unpredictably. The market value of a security or other investment may be reduced by market activity or other results of supply and demand unrelated to the issuer. This is a basic risk associated with all investments. When there are more sellers than buyers, prices tend to fall. Likewise, when there are more buyers than sellers, prices tend to rise. In addition, the value of the Fund’s investments may go up or down due to general market or other conditions that are not specifically related to a particular issuer, such as: real or perceived adverse economic changes, including widespread liquidity issues and defaults in one or more industries; changes in interest, inflation or exchange rates; unexpected natural and man-made world events, such as diseases or disasters; financial, political or social disruptions, including terrorism and war; and U.S. trade disputes or other disputes with specific countries that could result in additional tariffs, trade barriers and/or investment restrictions in certain securities in those countries. Any of these conditions can adversely affect the economic prospects of many companies, sectors, nations, regions and the market in general, in ways that cannot necessarily be foreseen.

Franklin Dynamic Municipal Bond ETF | High-Yield Debt Instruments  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

High-Yield Debt Instruments: Issuers of lower-rated or “high-yield” debt instruments (also known as “junk bonds”) are not as strong financially as those issuing higher credit quality debt instruments. High-yield debt instruments are generally considered predominantly speculative by the applicable rating agencies as their issuers are more likely to encounter financial difficulties because they may be more highly leveraged, or because of other considerations. In addition, high yield debt instruments generally are more vulnerable to changes in the relevant economy, such as a recession or a sustained period of rising interest rates, that could affect their ability to make interest and principal payments when due. The

prices of high-yield debt instruments generally fluctuate more than those of higher credit quality. High-yield debt instruments are generally more illiquid (harder to sell) and harder to value.

Franklin Dynamic Municipal Bond ETF | States  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

States: The Fund’s portfolio is generally widely diversified among issuers of municipal securities. However, to the extent that the Fund has exposure from time to time to the municipal securities of a particular state, events in that state may affect the Fund’s investments and performance. These events may include economic or political policy changes, tax base erosion, unfunded pension and healthcare liabilities, constitutional limits on tax increases, budget deficits and other financial difficulties, and changes in the credit ratings assigned to municipal issuers of the state.

Franklin Dynamic Municipal Bond ETF | Municipal Project Focus  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

Municipal Project Focus:  The Fund may invest more than 25% of its assets in municipal securities that finance similar types of projects, such as utilities, hospitals, higher education and transportation. A change that affects one project, such as proposed legislation on the financing of the project, a shortage of the materials needed for the project, or a declining need for the project, would likely affect all similar projects, thereby increasing market risk.

Franklin Dynamic Municipal Bond ETF | Income  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

Income: The Fund's distributions to shareholders may decline when prevailing interest rates fall, when the Fund experiences defaults on debt securities it holds or when the Fund realizes a loss upon the sale of a debt security.

Franklin Dynamic Municipal Bond ETF | Prepayment  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

Prepayment: Prepayment risk occurs when a debt security can be repaid in whole or in part prior to the security's maturity and the Fund must reinvest the proceeds it receives, during periods of declining interest rates, in securities that pay a lower rate of interest. Also, if a security has been purchased at a premium, the value of the premium would be lost in the event of prepayment. Prepayments generally increase when interest rates fall.

Franklin Dynamic Municipal Bond ETF | Inflation  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

Inflation: The market price of debt securities generally falls as inflation increases because the purchasing power of the future income and repaid principal is expected to be worth less when received by the Fund. Debt securities that pay a fixed rather than variable interest rate are especially vulnerable to inflation risk because variable-rate debt securities may be able to participate, over the long term, in rising interest rates which have historically corresponded with long-term inflationary trends.

Franklin Dynamic Municipal Bond ETF | Zero Coupon and Deferred Interest Securities  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

Zero Coupon and Deferred Interest Securities: These bonds tend to react more sharply to changes in interest rates than traditional bonds. The discount on these securities typically increases as interest rates rise, the market becomes less liquid or the creditworthiness of the issuer deteriorates. Because investors receive no cash prior to the maturity or cash payment date, an investment in debt securities issued at a discount generally has a greater potential for complete loss of principal

and/or return than an investment in debt securities that make periodic interest payments.

Franklin Dynamic Municipal Bond ETF | Bond Insurers  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

Bond Insurers: Market conditions or changes to ratings criteria could adversely impact the ratings of municipal bond insurance companies. Downgrades and withdrawal of ratings from municipal bond insurers have substantially limited the availability of insurance sought by municipal bond issuers thereby reducing the supply of insured municipal securities.

Because of the consolidation among municipal bond insurers the Fund is subject to additional risks including the risk that credit risk may be concentrated among fewer insurers and the risk that events involving one or more municipal bond insurers could have a significant adverse effect on the value of the securities insured by an insurer and on the municipal markets as a whole.

Franklin Dynamic Municipal Bond ETF | Unrated Debt Securities  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

Unrated Debt Securities: Unrated debt securities determined by the investment manager to be of comparable credit quality to rated securities which the Fund may purchase may pay a higher interest rate than such rated debt securities and be subject to a greater risk of illiquidity or price changes. Less public information and independent credit analysis are typically available about unrated securities or issuers, and therefore they may be subject to greater risk of default.

Franklin Dynamic Municipal Bond ETF | Municipal Lease Obligations  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

Municipal Lease Obligations: Municipal lease obligations differ from other municipal securities because the relevant legislative body must appropriate the money each year to make the lease payments. If the money is not appropriated, the lease may be cancelled without penalty and investors who own the lease obligations may not be paid.

Franklin Dynamic Municipal Bond ETF | Management  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

Management: The Fund is subject to management risk because it is an actively managed ETF. The Fund's investment manager applies investment techniques and risk analyses in making investment decisions for the Fund, but there can be no guarantee that these decisions will produce the desired results.

Franklin Dynamic Municipal Bond ETF | Cybersecurity  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

Cybersecurity: Cybersecurity incidents, both intentional and unintentional, may allow an unauthorized party to gain access to Fund assets, Fund or customer data (including private shareholder information), or proprietary information, cause the Fund, the investment manager, authorized participants, or index providers (as applicable) and listing exchanges, and/or their service providers (including, but not limited to, Fund accountants, custodians, sub-custodians, transfer agents and financial intermediaries) to suffer data breaches, data corruption or loss of operational functionality or prevent Fund investors from purchasing, redeeming shares or receiving distributions. The investment manager has limited ability to prevent or mitigate cybersecurity incidents affecting third party service providers, and such third party service providers may have limited indemnification obligations to the Fund or the investment manager. Cybersecurity incidents may result in financial losses to the Fund and its shareholders, and substantial costs may be

incurred in an effort to prevent or mitigate future cybersecurity incidents. Issuers of securities in which the Fund invests are also subject to cybersecurity risks, and the value of these securities could decline if the issuers experience cybersecurity incidents.

Because technology is frequently changing, new ways to carry out cyber attacks are always developing. Therefore, there is a chance that some risks have not been identified or prepared for, or that an attack may not be detected, which puts limitations on the Fund's ability to plan for or respond to a cyber attack. Like other funds and business enterprises, the Fund, the investment manager, and their service providers are subject to the risk of cyber incidents occurring from time to time.

Franklin Dynamic Municipal Bond ETF | Market Trading  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

Market Trading: 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/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 investment manager cannot predict whether shares will trade above (premium), below (discount) or at NAV.

Franklin Dynamic Municipal Bond ETF | Authorized Participant Concentration  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

Authorized Participant Concentration: Only an Authorized Participant may engage in creation or redemption transactions directly with the Fund. "Authorized Participants" are broker-dealers that are permitted to create and redeem shares directly with the Fund and who have entered into agreements with the Fund’s distributor. The Fund has 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 create or redeem Creation Units (as defined below), Fund shares may trade at a discount to 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.

Franklin Dynamic Municipal Bond ETF | Cash Transactions  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

Cash Transactions: To the extent that the Fund effects redemptions partly or entirely for cash, rather than for in-kind securities, 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.

Franklin Dynamic Municipal Bond ETF | Large Shareholder  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

Large Shareholder: Certain large shareholders, including other funds or accounts advised by the investment manager or an affiliate of the investment manager, may from time to time own a substantial amount of the Fund’s shares. In addition, a

third-party investor, the investment manager or an affiliate of the investment manager, an authorized participant, a lead 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 listing exchange and may, therefore, have a material upward or downward effect on the market price of the shares.

 
Franklin Dynamic Municipal Bond ETF | Bloomberg Municipal Bond Index  
Risk/Return: oef_RiskReturnAbstract  
Average Annual Return, Label [Optional Text] oef_AverageAnnualReturnLabel Bloomberg Municipal Bond Index
Average Annual Return, Percent oef_AvgAnnlRtrPct 1.05%
Average Annual Return, Percent oef_AvgAnnlRtrPct 0.99%
Average Annual Return, Percent oef_AvgAnnlRtrPct 1.89% [1]
Performance Inception Date oef_PerfInceptionDate Aug. 31, 2017
Franklin Dynamic Municipal Bond ETF | Bloomberg Municipal 1-15 Year Index  
Risk/Return: oef_RiskReturnAbstract  
Average Annual Return, Label [Optional Text] oef_AverageAnnualReturnLabel Bloomberg Municipal 1-15 Year Index
Average Annual Return, Percent oef_AvgAnnlRtrPct 0.88%
Average Annual Return, Percent oef_AvgAnnlRtrPct 1.08%
Average Annual Return, Percent oef_AvgAnnlRtrPct 1.77% [1]
Performance Inception Date oef_PerfInceptionDate Aug. 31, 2017
Franklin Dynamic Municipal Bond ETF | Franklin Dynamic Municipal Bond ETF  
Risk/Return: oef_RiskReturnAbstract  
Management Fees (as a percentage of Assets) oef_ManagementFeesOverAssets 0.30%
Distribution and Service (12b-1) Fees oef_DistributionAndService12b1FeesOverAssets 0.00%
Other Expenses (as a percentage of Assets): oef_OtherExpensesOverAssets 0.00%
Expenses (as a percentage of Assets) oef_ExpensesOverAssets 0.30%
Expense Example, with Redemption, 1 Year oef_ExpenseExampleYear01 $ 31
Expense Example, with Redemption, 3 Years oef_ExpenseExampleYear03 97
Expense Example, with Redemption, 5 Years oef_ExpenseExampleYear05 169
Expense Example, with Redemption, 10 Years oef_ExpenseExampleYear10 $ 381
Year to Date Return, Label [Optional Text] oef_YearToDateReturnLabel As of June 30, 2025, the Fund’s year-to-date return was 0.86%.
Bar Chart, Year to Date Return, Date oef_BarChartYearToDateReturnDate Jun. 30, 2025
Bar Chart, Year to Date Return oef_BarChartYearToDateReturn 0.86%
Highest Quarterly Return, Label [Optional Text] oef_HighestQuarterlyReturnLabel Best Quarter
Highest Quarterly Return, Date oef_BarChartHighestQuarterlyReturnDate Dec. 31, 2023
Highest Quarterly Return oef_BarChartHighestQuarterlyReturn 6.93%
Lowest Quarterly Return, Label [Optional Text] oef_LowestQuarterlyReturnLabel Worst Quarter
Lowest Quarterly Return, Date oef_BarChartLowestQuarterlyReturnDate Mar. 31, 2022
Lowest Quarterly Return oef_BarChartLowestQuarterlyReturn (6.98%)
Average Annual Return, Label [Optional Text] oef_AverageAnnualReturnLabel Return before taxes
Average Annual Return, Percent oef_AvgAnnlRtrPct 5.15%
Average Annual Return, Percent oef_AvgAnnlRtrPct 2.35%
Average Annual Return, Percent oef_AvgAnnlRtrPct 2.55% [1]
Annual Return [Percent] oef_AnnlRtrPct 0.39%
Annual Return [Percent] oef_AnnlRtrPct 6.80%
Annual Return [Percent] oef_AnnlRtrPct 6.25%
Annual Return [Percent] oef_AnnlRtrPct 4.00%
Annual Return [Percent] oef_AnnlRtrPct (10.22%)
Annual Return [Percent] oef_AnnlRtrPct 7.67%
Annual Return [Percent] oef_AnnlRtrPct 5.15%
Performance Inception Date oef_PerfInceptionDate Aug. 31, 2017
Franklin Dynamic Municipal Bond ETF | Franklin Dynamic Municipal Bond ETF | After Taxes on Distributions  
Risk/Return: oef_RiskReturnAbstract  
Average Annual Return, Label [Optional Text] oef_AverageAnnualReturnLabel Return after taxes on distributions
Average Annual Return, Percent oef_AvgAnnlRtrPct 5.08%
Average Annual Return, Percent oef_AvgAnnlRtrPct 2.33%
Average Annual Return, Percent oef_AvgAnnlRtrPct 2.54% [1]
Performance Inception Date oef_PerfInceptionDate Aug. 31, 2017
Franklin Dynamic Municipal Bond ETF | Franklin Dynamic Municipal Bond ETF | After Taxes on Distributions and Sales  
Risk/Return: oef_RiskReturnAbstract  
Average Annual Return, Label [Optional Text] oef_AverageAnnualReturnLabel Return after taxes on distributions and sale of Fund shares
Average Annual Return, Percent oef_AvgAnnlRtrPct 4.70%
Average Annual Return, Percent oef_AvgAnnlRtrPct 2.49%
Average Annual Return, Percent oef_AvgAnnlRtrPct 2.61% [1]
Performance Inception Date oef_PerfInceptionDate Aug. 31, 2017
[1]

Since inception August 31, 2017.