The fund seeks to track the investment results of the Franklin Low Volatility High Dividend Index (the “Underlying Index”). The Underlying Index seeks to provide more stable income through investments in stocks of profitable U.S. companies with relatively high dividend yields and lower price and earnings volatility. The Underlying Index is based on a proprietary methodology created and sponsored by Franklin Advisers, Inc. (“Franklin Advisers”), the fund’s subadviser. Franklin Advisers is affiliated with both FTFA and the fund. The Underlying Index is composed of stocks of U.S. companies across a wide range of market capitalizations, including the largest 3,000 U.S. stocks as determined by the Solactive US Broad Market Index. Stocks in the Underlying Index must have demonstrated profitability over the last four fiscal quarters as a whole. Stocks whose yields are not supported by earnings are excluded from the Underlying Index. The methodology calculates a composite “stable yield” score, with the yield of stocks with relatively higher price volatility and earnings volatility adjusted downward and the yield of stocks with relatively lower price volatility and earnings volatility adjusted upward. Franklin Advisers anticipates that the number of component securities in the Underlying Index will range from 50 to 100. At the time of each reconstitution, no individual component of the Underlying Index will exceed 2.5% of the Underlying Index, no individual sector will exceed 25% of the Underlying Index, and real estate investment trust (“REIT”) components as a whole will not exceed 15% of the Underlying Index. The Underlying Index’s components are reconstituted annually and rebalanced quarterly. The composition of the Underlying Index and the fund after reconstitution and rebalancing may fluctuate and exceed the above Underlying Index limitations due to market movements. The Underlying Index may include large-, mid- or small-capitalization companies.

The fund may invest up to 20% of its net assets in certain index futures, options, options on index futures, swap contracts or other derivatives (“Financial Instruments”) related to its Underlying Index and its component securities; cash and cash equivalents; other investment companies, including exchange-traded funds; and in securities and other instruments not included in its Underlying Index but which Franklin Advisers believes will help the fund track its Underlying Index. The fund may invest in exchange-traded equity index futures to manage sector exposure and for cash management purposes.

S000051686 [Member] Investment Strategy - Franklin U.S. Low Volatility High Dividend Index ETF	Mar. 31, 2026
Prospectus [Line Items]
Strategy [Heading]	Principal investment strategies
Strategy Narrative [Text Block]	The fund seeks to track the investment results of the Franklin Low Volatility High Dividend Index (the “Underlying Index”). The Underlying Index seeks to provide more stable income through investments in stocks of profitable U.S. companies with relatively high dividend yields and lower price and earnings volatility. The Underlying Index is based on a proprietary methodology created and sponsored by Franklin Advisers, Inc. (“Franklin Advisers”), the fund’s subadviser. Franklin Advisers is affiliated with both FTFA and the fund. The Underlying Index is composed of stocks of U.S. companies across a wide range of market capitalizations, including the largest 3,000 U.S. stocks as determined by the Solactive US Broad Market Index. Stocks in the Underlying Index must have demonstrated profitability over the last four fiscal quarters as a whole. Stocks whose yields are not supported by earnings are excluded from the Underlying Index. The methodology calculates a composite “stable yield” score, with the yield of stocks with relatively higher price volatility and earnings volatility adjusted downward and the yield of stocks with relatively lower price volatility and earnings volatility adjusted upward. Franklin Advisers anticipates that the number of component securities in the Underlying Index will range from 50 to 100. At the time of each reconstitution, no individual component of the Underlying Index will exceed 2.5% of the Underlying Index, no individual sector will exceed 25% of the Underlying Index, and real estate investment trust (“REIT”) components as a whole will not exceed 15% of the Underlying Index. The Underlying Index’s components are reconstituted annually and rebalanced quarterly. The composition of the Underlying Index and the fund after reconstitution and rebalancing may fluctuate and exceed the above Underlying Index limitations due to market movements. The Underlying Index may include large-, mid- or small-capitalization companies. The fund’s portfolio is rebalanced when the Underlying Index is rebalanced or reconstituted. The fund may trade at times other than when the Underlying Index is rebalanced or reconstituted for a variety of reasons, including when adjustments may be made to its representative sampling process from time to time or when investing cash. The fund will invest at least 80% of its net assets, plus borrowings for investment purposes, if any, in securities that compose the Underlying Index. The fund’s investments in derivative instruments and other investments that provide investment exposure similar to the component securities of the Underlying Index are included in the fund’s 80% basket. The fund may invest up to 20% of its net assets in certain index futures, options, options on index futures, swap contracts or other derivatives (“Financial Instruments”) related to its Underlying Index and its component securities; cash and cash equivalents; other investment companies, including exchange-traded funds; and in securities and other instruments not included in its Underlying Index but which Franklin Advisers believes will help the fund track its Underlying Index. The fund may invest in exchange-traded equity index futures to manage sector exposure and for cash management purposes. Index investing. The fund uses a “passive” or indexing investment approach to achieve its investment objective. Unlike many investment companies, the fund does not try to outperform its Underlying Index and does not seek temporary defensive positions when markets decline or appear overvalued. Indexing may eliminate the chance that the fund will substantially outperform the Underlying Index and also may reduce some of the risks of active management, such as poor security selection. Indexing seeks to achieve lower costs and better after-tax performance by keeping portfolio turnover low in comparison to actively managed investment companies. The subadviser may use a representative sampling indexing strategy to manage the fund. “Representative sampling” is an indexing strategy that involves investing in a representative sample of securities that collectively has an investment profile similar to that of the Underlying Index. When representative sampling is used, the securities selected are expected to have, in the aggregate, investment characteristics (based on factors such as return variability, risk, market capitalization, country/region exposures and sector exposures) and fundamental characteristics (such as portfolio yield, price/earnings ratios and price/book ratios) similar to those of the Underlying Index. The fund may or may not hold all of the securities in the Underlying Index. Industry concentration policy. The fund will concentrate its investments (i.e., hold 25% or more of its total assets) in a particular industry to approximately the same extent that the Underlying Index is concentrated in the securities of such particular industry. For purposes of this limitation, securities of the U.S. government (including its agencies and instrumentalities) and repurchase agreements collateralized by U.S. government securities are not considered to be issued by members of any industry. As of March 31, 2026, the top sector represented by the fund’s Underlying Index was the utilities sector. This sector may change over time.
Strategy Portfolio Concentration [Text]	Industry concentration policy. The fund will concentrate its investments (i.e., hold 25% or more of its total assets) in a particular industry to approximately the same extent that the Underlying Index is concentrated in the securities of such particular industry. For purposes of this limitation, securities of the U.S. government (including its agencies and instrumentalities) and repurchase agreements collateralized by U.S. government securities are not considered to be issued by members of any industry.

Index investing. The fund uses a “passive” or indexing investment approach to achieve its investment objective. Unlike many investment companies, the fund does not try to outperform its Underlying Index and does not seek temporary defensive positions when markets decline or appear overvalued. Indexing may eliminate the chance that the fund will substantially outperform the Underlying Index and also may reduce some of the risks of active management, such as poor security selection. Indexing seeks to achieve lower costs and better after-tax performance by keeping portfolio turnover low in comparison to actively managed investment companies.

The subadviser may use a representative sampling indexing strategy to manage the fund. “Representative sampling” is an indexing strategy that involves investing in a representative sample of securities that collectively has an investment profile similar to that of the Underlying Index. When representative sampling is used, the securities selected are expected to have, in the aggregate, investment characteristics (based on factors such as return variability, risk, market capitalization, country/region exposures and sector exposures) and fundamental characteristics (such as portfolio yield, price/earnings ratios and price/book ratios) similar to those of the Underlying Index. The fund may or may not hold all of the securities in the Underlying Index.

Industry concentration policy. The fund will concentrate its investments (i.e., hold 25% or more of its total assets) in a particular industry to approximately the same extent that the Underlying Index is concentrated in the securities of such particular industry. For purposes of this limitation, securities of the U.S. government (including its agencies and instrumentalities) and repurchase agreements collateralized by U.S. government securities are not considered to be issued by members of any industry.