Performance Management - First Trust Flexible Income ETF |
May 31, 2025 |
|---|---|
| Prospectus [Line Items] | |
| Bar Chart and Performance Table [Heading] | <span style="color:#000000;font-family:Arial;font-size:9.90pt;font-weight:bold;">Annual Total Return</span> |
| Performance Narrative [Text Block] | The shareholders of First Trust Senior Floating Rate Income Fund II, a Massachusetts business trust that operated as a closed-end management investment company (the “Predecessor Fund”), approved an Agreement and Plan of Reorganization (the “Plan”) by and between the Predecessor Fund and the Trust, on behalf of the Fund, pursuant to which the Predecessor Fund would: (i) transfer all of its assets to the Fund in exchange solely for newly issued shares of the Fund and the Fund’s assumption of all of the liabilities of the Predecessor Fund; and (ii) immediately distribute such newly issued shares of the Fund to shareholders of the Predecessor Fund (the “Reorganization”).As a result of the consummation of the Reorganization on August 10, 2026, the Fund has assumed the performance history of the Predecessor Fund. Prior to the date of the Reorganization, the Fund had not commenced operations. As the Predecessor Fund and Fund have a number of differences, including significant differences in investment strategy and that the Predecessor Fund was a closed-end fund which utilized leverage while the Fund is an exchange-traded fund which does not utilize leverage, the Predecessor Fund’s past performance is not indicative of how the Fund will, or is expected to, perform in the future. Accordingly, any Fund performance and historical returns shown below that incorporates Predecessor Fund performance through August 10, 2026 is not indicative of the performance that the Fund would have generated.The bar chart and table below illustrate the annual calendar year returns of the Fund (having assumed the performance of the Predecessor Fund) based on net asset value and provide an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year-to-year and by showing how the Fund’s average annual total returns based on net asset value for 1, 5, 10 (as applicable) and since inception periods compared to those of a broad-based market index and a market index. The Fund’s updated performance information is accessible on the Fund’s website at http://www.ftportfolios.com. |
| Performance Past Does Not Indicate Future [Text] | <span style="color:#000000;font-family:Arial;font-size:9.00pt;">The Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.</span> |
| Performance Information Illustrates Variability of Returns [Text] | <span style="color:#000000;font-family:Arial;font-size:9.00pt;margin-left:0%;">The bar chart and table below illustrate the annual calendar year returns of the Fund (having assumed the performance of the Predecessor Fund) based on net asset value and provide an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year-to-year and by showing how the Fund’s average annual total returns based on net asset value for 1, 5, 10 (as applicable) and since inception periods compared to those of a broad-based market index and a market index. </span> |
| Bar Chart [Heading] | <span style="color:#000000;font-family:Arial;font-size:9.90pt;font-weight:bold;">First Trust Flexible Income ETF</span> <br/><span style="color:#000000;font-family:Arial;font-size:9.90pt;font-weight:bold;">Calendar Year Total Returns as of 12/31 </span><span style="color:#000000;font-family:Arial;font-size:7pt;font-weight:bold;position:relative;top:-3.25pt;">(1)</span> |
| Bar Chart Footnotes [Text Block] | (1)The Fund's calendar year-to-date total return based on net asset value for the period 12/31/25 to 06/30/26 was ____%. |
| Bar Chart Closing [Text Block] | During the periods shown in the chart above:ReturnPeriod EndedBest Quarter9.58%June 30, 2020Worst Quarter-14.76%March 31, 2020Year-to-DateJune 30, 2026 |
| Performance Table Heading | <span style="color:#000000;font-family:Arial;font-size:9.90pt;font-weight:bold;">Average Annual Total Returns for the Periods Ended December 31, 2025</span> |
| Performance Table Uses Highest Federal Rate | <span style="color:#000000;font-family:Arial;font-size:9.00pt;margin-left:0%;">All after-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of any state or local tax.</span> |
| Performance Table Not Relevant to Tax Deferred | <span style="color:#000000;font-family:Arial;font-size:9.00pt;margin-left:0%;">Your own actual after-tax returns will depend on your specific tax situation and may differ from what is shown here. After-tax returns are not relevant to investors who hold Fund shares in tax-deferred accounts such as individual retirement accounts </span><span style="color:#000000;font-family:Arial;font-size:9.00pt;">(</span><span style="color:#000000;font-family:Arial;font-size:9.00pt;font-style:italic;">IRAs</span><span style="color:#000000;font-family:Arial;font-size:9.00pt;">) or employee-sponsored retirement plans.</span> |
| Performance Table Explanation after Tax Higher | <span style="color:#000000;font-family:Arial;font-size:9.00pt;">Returns after taxes on distributions reflect the taxed return on the payment of dividends </span><span style="color:#000000;font-family:Arial;font-size:9.00pt;margin-left:0%;">and capital gains. Returns after taxes on distributions and sale of shares assume you sold your shares at period end, and, therefore, are also adjusted for any capital gains or losses incurred. Returns for an index do not include expenses, which are </span><span style="color:#000000;font-family:Arial;font-size:9.00pt;">deducted from Fund returns, or taxes.</span> |
| Performance Availability Website Address [Text] | <span style="color:#000000;font-family:Arial;font-size:9.00pt;">http://www.ftportfolios.com</span> |
| First Trust Flexible Income ETF | |
| Prospectus [Line Items] | |
| Year to Date Return, Label [Optional Text] | <span style="color:#000000;font-family:Arial;font-size:9.00pt;margin-left:0.0pt;">Year-to-Date</span> |
| Bar Chart, Year to Date Return | |
| Bar Chart, Year to Date Return, Date | Jun. 30, 2026 |
| Highest Quarterly Return, Label [Optional Text] | <span style="color:#000000;font-family:Arial;font-size:9.00pt;margin-left:0.0pt;">Best Quarter</span> |
| Highest Quarterly Return | 9.58% |
| Highest Quarterly Return, Date | Jun. 30, 2020 |
| Lowest Quarterly Return, Label [Optional Text] | <span style="color:#000000;font-family:Arial;font-size:9.00pt;margin-left:0.0pt;">Worst Quarter</span> |
| Lowest Quarterly Return | (14.76%) |
| Lowest Quarterly Return, Date | Mar. 31, 2020 |