| Form N-CSR Cover | 12 Months Ended |
| Aug. 31, 2024 | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSR |
| Amendment Flag | false |
| Registrant Name | First Trust Exchange-Traded Fund VIII |
| Entity Central Index Key | 0001667919 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | Aug. 31, 2024 |
| Shareholder Report | 12 Months Ended | |
| Aug. 31, 2024 USD ($) Holding | ||
| Shareholder Report [Line Items] | ||
| Document Type | N-CSR | |
| Amendment Flag | false | |
| Registrant Name | First Trust Exchange-Traded Fund VIII | |
| Entity Central Index Key | 0001667919 | |
| Entity Investment Company Type | N-1A | |
| Document Period End Date | Aug. 31, 2024 | |
| C000169822 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | First Trust Flexible MunicipalHigh Income ETF | |
| Class Name | First Trust Flexible MunicipalHigh Income ETF | |
| Trading Symbol | MFLX | |
| Security Exchange Name | NASDAQ | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the First Trust Flexible Municipal High Income ETF (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/MFLX info ftportfolios.com | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/MFLX | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage First Trust Flexible Municipal High Income ETF $ (1) 0.75 % (1) (1) Excludes any Acquired Fund Fees and Expenses of underlying investment companies in which the Fund invests. | |
| Expenses Paid, Amount | $ 79 | [1] |
| Expense Ratio, Percent | 0.75% | [1] |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 9.97% for the 12 months ended August 31, 2024. The Fund outperformed its benchmark, the Bloomberg Municipal Long Bond (22+) Index, which returned 8.34% for the same Period. The following key Fund factors impacted Fund performance relative to the benchmark during the Period: Credit Rating: Yield Curve Positioning/Duration: Interest Rate Hedge: Sector/Industry: U.S. Treasury Rate Trends: Industry Fund Flows: New Issue Supply: Municipal Credit Yields: Municipal Credit Spreads: During the Period, the Fund purchased odd lot positions which had a positive impact on performance of 0.058%. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (September 27, 2016 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year 5 Year Since First Trust Flexible Municipal High Income ETF 9.97 % 1.26 % 1.85 % Bloomberg Municipal Long Bond (22+) Index 8.34 % 0.53 % 1.98 % Blended Benchmark (1) 9.20 % 1.96 % 3.00 % Bloomberg Municipal Bond Index 6.09 % 1.02 % 1.94 % (1) The Blended Benchmark returns are a 50/50 split between the Bloomberg Municipal High Yield Bond Index and the Bloomberg Municipal Bond Index. | |
| Performance Inception Date | Sep. 27, 2016 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/MFLX | |
| Net Assets | $ 15,634,548 | |
| Holdings Count | Holding | 71 | |
| Advisory Fees Paid, Amount | $ 112,116 | |
| Investment Company Portfolio Turnover | 51% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 71 Total advisory fee paid $ Portfolio turnover rate 51 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The tables below show the investment makeup of the Fund, representing the percentage of net assets and percentage of total investments, respectively, of the Fund. Fund Allocation Municipal Bonds 90.5 % Closed-End Funds 8.1 % Net Other Assets and Liabilities 1.4 % Total 100.0 % Credit Quality (1) (1) This represents the municipal and closed-end fund holdings in the Fund. The ratings for the Municipal Bond portion of the Fund are by S&P Global Ratings, Moody’s Investors Service, Inc., Fitch Ratings, or a comparably rated NRSRO. For situations in which a security is rated by more than one NRSRO and the ratings are not equivalent, the highest ratings are used. The ratings for the CEF portion of the Fund are provided by Morningstar. A credit rating is an assessment provided by a nationally recognized statistical rating organization (NRSRO) of the creditworthiness of an issuer with respect to debt obligations except for those debt obligations that are only privately rated. Ratings are measured on a scale that generally ranges from AAA (highest) to D (lowest). Investment grade is defined as those issuers that have a long-term credit rating of BBB- or higher. “NR” Any amount shown as 0.0% represents less than 0.1%. | |
| Credit Quality Explanation [Text Block] | This represents the municipal and closed-end fund holdings in the Fund. The ratings for the Municipal Bond portion of the Fund are by S&P Global Ratings, Moody’s Investors Service, Inc., Fitch Ratings, or a comparably rated NRSRO. For situations in which a security is rated by more than one NRSRO and the ratings are not equivalent, the highest ratings are used. The ratings for the CEF portion of the Fund are provided by Morningstar. A credit rating is an assessment provided by a nationally recognized statistical rating organization (NRSRO) of the creditworthiness of an issuer with respect to debt obligations except for those debt obligations that are only privately rated. Ratings are measured on a scale that generally ranges from AAA (highest) to D (lowest). Investment grade is defined as those issuers that have a long-term credit rating of BBB- or higher. “NR” | |
| Credit Ratings Selection [Text Block] | This represents the municipal and closed-end fund holdings in the Fund. The ratings for the Municipal Bond portion of the Fund are by S&P Global Ratings, Moody’s Investors Service, Inc., Fitch Ratings, or a comparably rated NRSRO. | |
| C000205110 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | First Trust Low DurationStrategic Focus ETF | |
| Class Name | First Trust Low DurationStrategic Focus ETF | |
| Trading Symbol | LDSF | |
| Security Exchange Name | NASDAQ | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the First Trust Low Duration Strategic Focus ETF (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/LDSF info ftportfolios.com | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/LDSF | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage First Trust Low Duration Strategic Focus ETF $ (1) 0.20 % (1) (1) Excludes any Acquired Fund Fees and Expenses of underlying investment companies in which the Fund invests. | |
| Expenses Paid, Amount | $ 21 | [2] |
| Expense Ratio, Percent | 0.20% | [2] |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 7.46% for the 12 months ended August 31, 2024. The Fund outperformed its primary benchmark, the Bloomberg 1-5 Year Government/Credit Index, which returned 6.67% for the same Period. The Fund underperformed the secondary blended benchmark (80% Bloomberg 1-5 Year Government/Credit Index and 20% ICE BofA US High Yield Constrained Index), which returned 7.82% for the same Period. The outperformance relative to the primary benchmark and the underperformance relative to the secondary benchmark were driven by the Fund’s allocation to credit spread sensitive assets through investments such as investment grade corporate bonds, mortgage-backed securities (“MBS”), high-yield bonds and senior loans, as these assets outperformed. The primary benchmark has no allocation to high-yield bonds, in contrast to 20% in the secondary benchmark. Neither benchmark had an allocation to MBS during the Period. High yield corporate bond spreads narrowed from 387 to 318 basis points and the ICE BofA US High Yield Constrained Index returned 12.47%, as ‘risk’ assets benefitted from continued economic and corporate profit growth and market enthusiasm surrounding Artificial Intelligence-related growth companies provided a tailwind to returns. Meanwhile, the Federal Reserve (the “Fed”) made their last rate hike in July of 2023 and remained on hold throughout the Period before declining inflation and signs of labor market deterioration caused them to signal that rate cuts are expected in 2024, causing the market to price in lower yields and providing greater confidence the Fed would engineer a soft landing. The Fund’s largest allocations were to MBS and short-duration investment-grade corporate bonds through the First Trust Low Duration Opportunities ETF and the First Trust Limited Duration Investment Grade Corporate ETF. These ETFs individually represented between 35% and 40% of the Fund and contributed positively to performance relative to the primary benchmark but were modest drags on returns relative to the blended benchmark given the blended benchmark’s exposure to high yield bonds, as both funds returned 7.66% on a market price basis, over the Period. The best performing holding was the First Trust Tactical High Yield ETF which the Fund held at 10% over the entire Period and returned 11.20% on a market price basis, and which benefited from tightening credit spreads, declining interest rates and elevated levels of income. This allocation to high yield resulted in roughly a 10% overweight to the primary benchmark and a 10% underweight to the secondary blended benchmark. The top detractor from relative performance was the First Trust Enhanced Short Maturity ETF which returned 5.68% on a market price basis, in line with a modest spread over the target range of the Federal Funds target rate, which was between 5.25% and 5.50% for the entire Period, however it underperformed both benchmarks. The declining rate environment, in which the 2-Year U.S. Treasury fell from 4.86% to 3.91% and the 10-Year U.S. Treasury declined from 4.11% to 3.90%, provided a greater benefit to total returns of fixed income securities with longer duration. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (January 3, 2019 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year 5 Year Since First Trust Low Duration Strategic Focus ETF 7.46 % 1.57 % 2.19 % Bloomberg 1-5 Year Government/Credit Index 6.67 % 1.32 % 1.93 % Blended Benchmark (1) 7.82 % 1.96 % 2.72 % Bloomberg US Aggregate Bond Index 7.30 % -0.04 % 1.39 % (1) The Blended Benchmark consists of the following two indexes: 80% of the Bloomberg 1-5 Year Government/Credit Index which measures the performance of U.S. dollar-denominated U.S. Treasury bonds, government related bonds and investment grade U.S. corporate bonds that have a maturity between one and five years; and 20% of the ICE BofA US High Yield Constrained Index which tracks the performance of U.S. dollar denominated below investment grade corporate debt publicly issued in the U.S. domestic market but caps issuer exposure at 2%. | |
| Performance Inception Date | Jan. 03, 2019 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/LDSF | |
| Net Assets | $ 153,152,294 | |
| Holdings Count | Holding | 8 | |
| Advisory Fees Paid, Amount | $ 257,182 | |
| Investment Company Portfolio Turnover | 15% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 8 Total advisory fee paid $ Portfolio turnover rate 15 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Exchange-Traded Funds 100.0 % Money Market Funds 0.0 % Net Other Assets and Liabilities 0.0 % Total 100.0 % Any amount shown as 0.0% represents less than 0.1%. | |
| C000214901 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. Equity Buffer ETF - November | |
| Class Name | FT Vest U.S. Equity Buffer ETF - November | |
| Trading Symbol | FNOV | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Buffer ETF - November (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/FNOV info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/FNOV | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Buffer ETF - November $ 0.85 % | |
| Expenses Paid, Amount | $ 91 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 14.61% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 13.93 % Changes in other Variables 1.53 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (November 15, 2019 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Buffer ETF - November 14.61 % 9.31 % S&P 500 ® 27.14 % 15.01 % | |
| Performance Inception Date | Nov. 15, 2019 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/FNOV | |
| Net Assets | $ 701,158,434 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 4,876,908 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.5 % Purchased Options 108.2 % Written Options (8.6 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/FNOV info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/FNOV | |
| C000215123 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | First Trust Active Factor Mid Cap ETF | |
| Class Name | First Trust Active Factor Mid Cap ETF | |
| Trading Symbol | AFMC | |
| Security Exchange Name | NYSEArca | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the First Trust Active Factor Mid Cap ETF (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/AFMC info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/AFMC | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage First Trust Active Factor Mid Cap ETF $ 0.65 % | |
| Expenses Paid, Amount | $ 74 | |
| Expense Ratio, Percent | 0.65% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 26.81% for the 12 months ended August 31, 2024. The Fund outperformed its benchmark, the S&P MidCap 400 ® This outperformance was largely attributable to strong performance from the momentum and quality factors. The momentum factor benefited from the Artificial Intelligence trade. Additionally, quality stocks with better balance sheets and higher profitability outpaced peers as interest rates remained higher than expected. The strong performance was also aided by positive selection and industry effects. By contrast, the value factor subtracted from the Fund’s returns during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (December 3, 2019 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since First Trust Active Factor Mid Cap ETF 26.81 % 11.41 % S&P MidCap 400 ® 18.75 % 11.53 % Russell 3000 ® 26.14 % 14.60 % | |
| Performance Inception Date | Dec. 03, 2019 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/AFMC | |
| Net Assets | $ 14,228,486 | |
| Holdings Count | Holding | 247 | |
| Advisory Fees Paid, Amount | $ 62,842 | |
| Investment Company Portfolio Turnover | 60% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 247 Total advisory fee paid $ Portfolio turnover rate 60 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The tables below show the investment makeup of the Fund, representing the percentage of total investments of the Fund. Top Ten Holdings United Therapeutics Corp. 1.6 % Sprouts Farmers Market, Inc. 1.5 % Toll Brothers, Inc. 1.5 % Tenet Healthcare Corp. 1.3 % KB Home 1.2 % MGIC Investment Corp. 1.2 % Old Republic International Corp. 1.2 % GoDaddy, Inc., Class A 1.1 % EMCOR Group, Inc. 1.1 % Vistra Corp. 1.0 % Sector Allocation | |
| Largest Holdings [Text Block] | Top Ten Holdings United Therapeutics Corp. 1.6 % Sprouts Farmers Market, Inc. 1.5 % Toll Brothers, Inc. 1.5 % Tenet Healthcare Corp. 1.3 % KB Home 1.2 % MGIC Investment Corp. 1.2 % Old Republic International Corp. 1.2 % GoDaddy, Inc., Class A 1.1 % EMCOR Group, Inc. 1.1 % Vistra Corp. 1.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/AFMC info ftportfolios.com The Fund may have significant investments in various jurisdictions or investment sectors from time to time, making the Fund subject to the risks of such jurisdictions or investment sectors. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/AFMC | |
| C000169819 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | First Trust Income Opportunities ETF | |
| Class Name | First Trust Income Opportunities ETF | |
| Trading Symbol | FCEF | |
| Security Exchange Name | NASDAQ | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the First Trust Income Opportunities ETF (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/FCEF info ftportfolios.com | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/FCEF | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage First Trust Income Opportunities ETF $ (1) 0.85 % (1) (1) Excludes any Acquired Fund Fees and Expenses of underlying investment companies in which the Fund invests. | |
| Expenses Paid, Amount | $ 94 | [3] |
| Expense Ratio, Percent | 0.85% | [3] |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 21.94% for the 12 months ended August 31, 2024. The Fund outperformed its blended benchmark, which consists of the following two indexes: 60% of the First Trust Equity Closed-End Fund Total Return Index, and 40% of the First Trust Taxable Fixed Income Closed-End Fund Total Return Index. The blended benchmark returned 21.00% for the same Period. This outperformance was a result of several factors including the security selection within the portfolio, sector selection as well as the Fund’s ability to actively manage positions on a continuous basis. Strength across the board in closed-end funds allowed the Fund to move out of previously established defensive positions and into funds which had the best potential for growth in the current market environment. The Fund posted strong performance during the Period on anticipation that the Federal Reserve would begin to lower interest rates in an effort to encourage growth in a slowing economy. Strong general equity market performance also played a role in the Fund posting a double-digit total return for the Period. In the closed-end fund space, wide discounts and the proactive move by many Fund sponsors to raise distribution levels encouraged retail investors to revisit the closed-end fund space as an investment option within their portfolios. As investor sentiment turned, we witnessed buyers return to the space. In the past, the Fund witnessed fund sponsors raising distributions in the equity-based funds to coincide with total returns funds were generating, however, the use of a total return-like distribution policy has not been common within the fixed income funds. Driving fund sponsors to push distribution rates higher was an activist hedge fund. The hedge fund had been accumulating large share positions in a multitude of outstanding closed-end funds which it used to press sponsors to initiate policies which would work to reduce discounts. In some instances, this shareholder sought Board of Director seats, initiated proxy contests and worked to take over fund mandates. While these types of shareholders have existed in the closed-end fund space for a number of years, the engagement that we witnessed over the last year was unprecedented. During the fiscal year, the Fund continued to make a conscious effort to continue to pay an attractive distribution to shareholders, one that consists predominately of income from the underlying funds. The Fund will continue to utilize a total return approach to investing that has worked so well through the years. While big “yields” in the closed-end fund space can be enticing to investors, the ability of the Fund to deliver that yield through a portfolio that delivers a total return above and beyond the payout is where the Fund will focus. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (September 27, 2016 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year 5 Year Since First Trust Income Opportunities ETF 21.94 % 6.62 % 7.27 % Russell 3000 ® 26.14 % 15.19 % 14.25 % Blended Benchmark (1) 21.00 % 6.28 % 6.83 % (1) A blended benchmark (the “Blended Benchmark”) comprised 60% of the First Trust Equity Closed-End Fund Total Return Index, a cap-weighted index (based on NAV) designed to provide a broad representation of the equity based closed-end fund universe, and 40% of the First Trust Taxable Fixed Income Closed-End Fund Total Return Index, a cap-weighted index (based on NAV) designed to provide a broad representation of the taxable fixed income closed-end fund universe, has been selected as a secondary benchmark to provide a more direct correlation to the Fund's underlying portfolio. The Blended Benchmark returns are calculated by using the monthly return of the two indices during each period shown above. At the beginning of each month the two indices are rebalanced to a 60-40 ratio to account for divergence from that ratio that occurred during the course of each month. The monthly returns are then compounded for each period shown above, giving the performance for the Blended Benchmark for each period shown above. | |
| Performance Inception Date | Sep. 27, 2016 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/FCEF | |
| Net Assets | $ 38,496,587 | |
| Holdings Count | Holding | 54 | |
| Advisory Fees Paid, Amount | $ 259,088 | |
| Investment Company Portfolio Turnover | 14% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 54 Total advisory fee paid $ Portfolio turnover rate 14 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The tables below show the investment makeup of the Fund, representing the percentage of total investments and percentage of net assets, respectively, of the Fund. Top Ten Holdings Eaton Vance Tax-Advantaged Global Dividend Income Fund 4.0 % Morgan Stanley Institutional Liquidity Funds - Treasury Portfolio - Institutional Class 3.7 % abrdn Healthcare Opportunities Fund 3.5 % abrdn Healthcare Investors 3.5 % abrdn Global Infrastructure Income Fund 3.3 % Source Capital, Inc. 3.3 % Eaton Vance Tax-Advantaged Dividend Income Fund 3.3 % John Hancock Tax-Advantaged Dividend Income Fund 3.3 % Invesco Variable Rate Investment Grade ETF 3.2 % Eaton Vance Tax-Advantaged Global Dividend Opportunities Fund 3.1 % Fund Allocation | |
| Largest Holdings [Text Block] | Top Ten Holdings Eaton Vance Tax-Advantaged Global Dividend Income Fund 4.0 % Morgan Stanley Institutional Liquidity Funds - Treasury Portfolio - Institutional Class 3.7 % abrdn Healthcare Opportunities Fund 3.5 % abrdn Healthcare Investors 3.5 % abrdn Global Infrastructure Income Fund 3.3 % Source Capital, Inc. 3.3 % Eaton Vance Tax-Advantaged Dividend Income Fund 3.3 % John Hancock Tax-Advantaged Dividend Income Fund 3.3 % Invesco Variable Rate Investment Grade ETF 3.2 % Eaton Vance Tax-Advantaged Global Dividend Opportunities Fund 3.1 % | |
| C000200735 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | First Trust TCW Unconstrained Plus Bond ETF | |
| Class Name | First Trust TCW Unconstrained Plus Bond ETF | |
| Trading Symbol | UCON | |
| Security Exchange Name | NYSEArca | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the First Trust TCW Unconstrained Plus Bond ETF (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/UCON info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/UCON | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage First Trust TCW Unconstrained Plus Bond ETF $ 0.85 % | |
| Expenses Paid, Amount | $ 89 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 8.35% for the 12 months ended August 31, 2024. The Fund outperformed its benchmark, the ICE BofA 3-Month US Treasury Bill Index, which returned 5.48% for the same Period. This outperformance was largely driven by the positive duration (sensitivity to interest rate moves) position, which reached a cycle-long of approximately 3.6 years by the end of October 2023 but hovered near 3.0 years thereafter. While this positive duration position weighed on returns early in the Period as rates reached their cycle highs in October 2023, the precipitous decline in Treasury yields over the last two months as markets became increasingly confident in a September 2024 rate cut by the Federal Reserve more than offset the performance drag that had accumulated up to that point. Also significant to outperformance was the allocation to fixed income spread sectors given a broad-based reduction in yield premiums across sectors, spurred by the late 2023 rally and attendant investor optimism regarding the future state of the economy. Though this optimism moderated somewhat in the first half of 2024, valuations remain rich across a large swath of the fixed income market, especially corporates where yield premiums remain near post-Great Financial Crisis lows. As such, exposure to corporates benefitted relative returns, with the strong market tone providing opportunity to crystalize gains and trim holdings where investment theses materialized. This was most prominent across the banking sector, where UBS (formerly Credit Suisse) contributed from an issue selection standpoint as it stabilized from its early 2023 dislocations, while other large systemically important banks that had been a focus in the Fund’s holdings also rallied and compressed towards the rest of the investment grade corporate index. Away from corporates, securitized credit exposure was also additive. Non-agency holdings performed the best amid sustained demand and limited net issuance in the sector, with investor optimism helping drive a flattening of credit curves and outperformance among more subordinated tranches. Asset-backed securities were also additive, with collateralized loan obligations contributing as their floating rate nature mitigated the impact of rising rates while falling yield premiums helped propel the sector to strong returns. Among commercial mortgage-backed securities (“MBS”), positioning favored private label issues, focusing on single asset single borrower deals which benefitted from strong performing collateral. Finally, despite strong performance in recent months as yields have come down, agency MBS detracted for the Period given elevated levels of rate volatility throughout much of the Period. Derivatives positioning in the Fund was largely focused on futures positions to manage duration, interest rate swaps for hedging, and a small allocation to currency forwards, all of which had little impact on the Fund’s performance for the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (June 4, 2018 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year 5 Year Since First Trust TCW Unconstrained Plus Bond ETF 8.35 % 2.89 % 3.47 % ICE BofA 3-Month US Treasury Bill Index 5.48 % 2.27 % 2.27 % ICE BofA US Dollar 3-Month Deposit Offered Rate Average Index (1) 5.57 % 2.50 % 2.51 % Bloomberg U.S. Aggregate Bond Index 7.30 % -0.04 % 1.71 % (1) On May 31, 2023, the ICE BofA US Dollar 3-Month Deposit Offered Rate Average Index was replaced as a securities market index for the Fund with the ICE BofA 3‑Month US Treasury Bill Index in connection with the phase out of the London interbank offered rate. | |
| Performance Inception Date | Jun. 04, 2018 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Sep. 01, 2023 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/UCON | |
| Net Assets | $ 2,906,455,874 | |
| Holdings Count | Holding | 1,052 | |
| Advisory Fees Paid, Amount | $ 17,623,436 | |
| Investment Company Portfolio Turnover | 314% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 1,052 Total advisory fee paid $ Portfolio turnover rate 314 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The tables below show the investment makeup of the Fund, representing the percentage of total investments of the Fund. Top Ten Holdings Dreyfus Government Cash Management Fund, Institutional Shares, Class I, 5.19% 6.3 % Federal Home Loan Bank Discount Notes, 0.00%, 01/27/25 4.0 % U.S. Treasury Bill, 0.00%, 10/17/24 2.4 % U.S. Treasury Bill, 0.00%, 11/12/24 2.4 % Federal Home Loan Bank Discount Notes, 0.00%, 01/14/25 2.3 % U.S. Treasury Bill, 0.00%, 11/14/24 2.0 % U.S. Treasury Note, 3.75%, 08/15/27 1.9 % U.S. Treasury Bill, 0.00%, 10/29/24 1.7 % U.S. Treasury Bill, 0.00%, 11/21/24 1.5 % Government National Mortgage Association, Pool TBA, 5.00%, 10/15/54 1.2 % Credit Quality (1) (1) The credit quality and ratings information presented above reflect the ratings assigned by one or more nationally recognized statistical rating organizations (NRSROs), including S&P Global Ratings, Moody’s Investors Service, Inc., Fitch Ratings, or a comparably rated NRSRO. For situations in which a security is rated by more than one NRSRO and the ratings are not equivalent, the lowest ratings are used. Sub-investment grade ratings are those rated BB+/Ba1 or lower. Investment grade ratings are those rated BBB-/Baa3 or higher. The credit ratings shown relate to the creditworthiness of the issuers of the underlying securities in the Fund, and not to the Fund or its shares. U.S. Treasury, U.S. Agency and U.S. Agency mortgage-backed securities appear under “Government/Agency.” Credit ratings are subject to change. Any amount shown as 0.0% represents less than 0.1%. | |
| Credit Quality Explanation [Text Block] | The credit quality and ratings information presented above reflect the ratings assigned by one or more nationally recognized statistical rating organizations (NRSROs), including S&P Global Ratings, Moody’s Investors Service, Inc., Fitch Ratings, or a comparably rated NRSRO. For situations in which a security is rated by more than one NRSRO and the ratings are not equivalent, the lowest ratings are used. Sub-investment grade ratings are those rated BB+/Ba1 or lower. Investment grade ratings are those rated BBB-/Baa3 or higher. The credit ratings shown relate to the creditworthiness of the issuers of the underlying securities in the Fund, and not to the Fund or its shares. U.S. Treasury, U.S. Agency and U.S. Agency mortgage-backed securities appear under “Government/Agency.” Credit ratings are subject to change. | |
| Credit Ratings Selection [Text Block] | The credit quality and ratings information presented above reflect the ratings assigned by one or more nationally recognized statistical rating organizations (NRSROs), including S&P Global Ratings, Moody’s Investors Service, Inc., Fitch Ratings, or a comparably rated NRSRO. | |
| Largest Holdings [Text Block] | Top Ten Holdings Dreyfus Government Cash Management Fund, Institutional Shares, Class I, 5.19% 6.3 % Federal Home Loan Bank Discount Notes, 0.00%, 01/27/25 4.0 % U.S. Treasury Bill, 0.00%, 10/17/24 2.4 % U.S. Treasury Bill, 0.00%, 11/12/24 2.4 % Federal Home Loan Bank Discount Notes, 0.00%, 01/14/25 2.3 % U.S. Treasury Bill, 0.00%, 11/14/24 2.0 % U.S. Treasury Note, 3.75%, 08/15/27 1.9 % U.S. Treasury Bill, 0.00%, 10/29/24 1.7 % U.S. Treasury Bill, 0.00%, 11/21/24 1.5 % Government National Mortgage Association, Pool TBA, 5.00%, 10/15/54 1.2 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/UCON info ftportfolios.com Effective December 31, 2024, Stephen M. Kane will retire from the Fund’s investment sub-advisor and will no longer serve as a portfolio manager of the Fund. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/UCON | |
| C000211017 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. Equity Buffer ETF - August | |
| Class Name | FT Vest U.S. Equity Buffer ETF - August | |
| Trading Symbol | FAUG | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Buffer ETF - August (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/FAUG info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/FAUG | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Buffer ETF - August $ 0.85 % | |
| Expenses Paid, Amount | $ 92 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 16.80% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 12.41 % Changes in other Variables 5.24 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (November 6, 2019 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Buffer ETF - August 16.80 % 8.76 % S&P 500 ® 27.14 % 15.30 % | |
| Performance Inception Date | Nov. 06, 2019 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/FAUG | |
| Net Assets | $ 736,421,939 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 5,109,995 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 1.1 % Purchased Options 102.6 % Written Options (3.6 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/FAUG info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/FAUG | |
| C000214903 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. EquityDeep Buffer ETF - November | |
| Class Name | FT Vest U.S. EquityDeep Buffer ETF - November | |
| Trading Symbol | DNOV | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Deep Buffer ETF - November (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/DNOV info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/DNOV | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Deep Buffer ETF - November $ 0.85 % | |
| Expenses Paid, Amount | $ 91 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 13.86% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 12.12 % Changes in other Variables 2.59 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (November 15, 2019 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Deep Buffer ETF - November 13.86 % 6.90 % S&P 500 ® 27.14 % 15.01 % | |
| Performance Inception Date | Nov. 15, 2019 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/DNOV | |
| Net Assets | $ 246,031,226 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 2,196,223 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.4 % Purchased Options 110.2 % Written Options (10.5 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/DNOV info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/DNOV | |
| C000215124 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | First Trust Active Factor Small Cap ETF | |
| Class Name | First Trust Active Factor Small Cap ETF | |
| Trading Symbol | AFSM | |
| Security Exchange Name | NYSEArca | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the First Trust Active Factor Small Cap ETF (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/AFSM info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/AFSM | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage First Trust Active Factor Small Cap ETF $ 0.75 % | |
| Expenses Paid, Amount | $ 84 | |
| Expense Ratio, Percent | 0.75% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 22.72% for the 12 months ended August 31, 2024. The Fund outperformed its benchmark, the Russell 2000 ® This outperformance was largely attributable to strong performance from the momentum and quality factors. The momentum factor benefited from the Artificial Intelligence trade. Stocks with better balance sheets and higher profitability outpaced peers as interest rates remained higher than expected. In addition, selection effect added to performance. By contrast, the value factor and sector exposures, primarily from an underweight to the Technology and Financials sectors, subtracted from the Fund’s performance. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (December 3, 2019 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since First Trust Active Factor Small Cap ETF 22.72 % 10.29 % Russell 2000 ® 18.47 % 8.54 % Russell 3000 ® 26.14 % 14.60 % | |
| Performance Inception Date | Dec. 03, 2019 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/AFSM | |
| Net Assets | $ 15,282,901 | |
| Holdings Count | Holding | 307 | |
| Advisory Fees Paid, Amount | $ 53,780 | |
| Investment Company Portfolio Turnover | 79% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 307 Total advisory fee paid $ Portfolio turnover rate 79 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The tables below show the investment makeup of the Fund, representing the percentage of total investments of the Fund. Top Ten Holdings National HealthCare Corp. 1.3 % Mueller Industries, Inc. 1.1 % Alkermes PLC 1.0 % InterDigital, Inc. 0.9 % Abercrombie & Fitch Co., Class A 0.9 % SkyWest, Inc. 0.9 % Daktronics, Inc. 0.9 % Catalyst Pharmaceuticals, Inc. 0.9 % M/I Homes, Inc. 0.8 % Preferred Bank 0.8 % Sector Allocation | |
| Largest Holdings [Text Block] | Top Ten Holdings National HealthCare Corp. 1.3 % Mueller Industries, Inc. 1.1 % Alkermes PLC 1.0 % InterDigital, Inc. 0.9 % Abercrombie & Fitch Co., Class A 0.9 % SkyWest, Inc. 0.9 % Daktronics, Inc. 0.9 % Catalyst Pharmaceuticals, Inc. 0.9 % M/I Homes, Inc. 0.8 % Preferred Bank 0.8 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/AFSM info ftportfolios.com The Fund may have significant investments in various jurisdictions or investment sectors from time to time, making the Fund subject to the risks of such jurisdictions or investment sectors. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/AFSM | |
| C000217670 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. EquityDeep Buffer ETF - February | |
| Class Name | FT Vest U.S. EquityDeep Buffer ETF - February | |
| Trading Symbol | DFEB | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Deep Buffer ETF - February (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/DFEB info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/DFEB | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Deep Buffer ETF - February $ 0.85 % | |
| Expenses Paid, Amount | $ 91 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 15.24% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 12.01 % Changes in other Variables 4.08 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (February 21, 2020 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Deep Buffer ETF - February 15.24 % 6.82 % S&P 500 ® 27.14 % 14.13 % | |
| Performance Inception Date | Feb. 21, 2020 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/DFEB | |
| Net Assets | $ 262,627,031 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 2,080,212 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.7 % Purchased Options 103.4 % Written Options (4.0 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/DFEB info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/DFEB | |
| C000226051 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. EquityDeep Buffer ETF - March | |
| Class Name | FT Vest U.S. EquityDeep Buffer ETF - March | |
| Trading Symbol | DMAR | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Deep Buffer ETF - March (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/DMAR info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/DMAR | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Deep Buffer ETF - March $ 0.85 % | |
| Expenses Paid, Amount | $ 90 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 12.93% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 8.91 % Changes in other Variables 4.87 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (March 19, 2021 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Deep Buffer ETF - March 12.93 % 6.63 % S&P 500 ® 27.14 % 12.93 % | |
| Performance Inception Date | Mar. 19, 2021 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/DMAR | |
| Net Assets | $ 301,068,348 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 2,177,754 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.8 % Purchased Options 102.4 % Written Options (3.1 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/DMAR info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/DMAR | |
| C000224383 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest Laddered Deep Buffer ETF | |
| Class Name | FT Vest Laddered Deep Buffer ETF | |
| Trading Symbol | BUFD | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest Laddered Deep Buffer ETF (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/BUFD info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/BUFD | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest Laddered Deep Buffer ETF $ (1) 0.19 % (1) (1) Excludes any Acquired Fund Fees and Expenses of underlying investment companies in which the Fund invests. | |
| Expenses Paid, Amount | $ 20 | [4] |
| Expense Ratio, Percent | 0.19% | [4] |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 13.97% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 10.44 % Changes in other Variables 4.58 % Fees and Expenses** -1.05 % The Fund holds a portfolio that consists of a number of buffer funds, and thus is exposed to the combinations of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the underlying buffer funds’ Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. ** Includes any Acquired Fund Fees and Expenses of underlying investment companies in which the Fund invests. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (January 20, 2021 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest Laddered Deep Buffer ETF 13.97 % 6.04 % S&P 500 ® 27.14 % 12.91 % | |
| Performance Inception Date | Jan. 20, 2021 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | May 10, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/BUFD | |
| Net Assets | $ 978,328,172 | |
| Holdings Count | Holding | 13 | |
| Advisory Fees Paid, Amount | $ 1,509,179 | |
| Investment Company Portfolio Turnover | 1% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 13 Total advisory fee paid $ Portfolio turnover rate 1 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Exchange-Traded Funds 100.0 % Money Market Funds 0.0 % Net Other Assets and Liabilities (0.0 % ) Total 100.0 % Any amount shown as 0.0% represents less than 0.1%. | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/BUFD info ftportfolios.com Effective May 10, 2024, the name of the Fund changed from “FT Vest Fund of Deep Buffer ETFs” to “FT Vest Laddered Deep Buffer ETF.” During the fiscal year ended August 31, 2024, the Fund’s diversification status under the Investment Company Act of 1940 changed from non-diversified to diversified. The Fund’s principal investment strategies and principal risks were revised accordingly. Pursuant to a contractual agreement, effective August 1, 2024, the Fund’s investment advisor agreed to waive management fees of 0.10% of average daily net assets through December 31, 2025. | |
| Material Fund Change Name [Text Block] | Effective May 10, 2024, the name of the Fund changed from “FT Vest Fund of Deep Buffer ETFs” to “FT Vest Laddered Deep Buffer ETF.” | |
| Material Fund Change Expenses [Text Block] | Pursuant to a contractual agreement, effective August 1, 2024, the Fund’s investment advisor agreed to waive management fees of 0.10% of average daily net assets through December 31, 2025. | |
| Material Fund Change Strategies [Text Block] | During the fiscal year ended August 31, 2024, the Fund’s diversification status under the Investment Company Act of 1940 changed from non-diversified to diversified. The Fund’s principal investment strategies and principal risks were revised accordingly. | |
| Material Fund Change Risks Change [Text Block] | During the fiscal year ended August 31, 2024, the Fund’s diversification status under the Investment Company Act of 1940 changed from non-diversified to diversified. The Fund’s principal investment strategies and principal risks were revised accordingly. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/BUFD | |
| C000226050 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. Equity Buffer ETF - March | |
| Class Name | FT Vest U.S. Equity Buffer ETF - March | |
| Trading Symbol | FMAR | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Buffer ETF - March (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/FMAR info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/FMAR | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Buffer ETF - March $ 0.85 % | |
| Expenses Paid, Amount | $ 92 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 15.67% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 11.84 % Changes in other Variables 4.68 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (March 19, 2021 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Buffer ETF - March 15.67 % 10.45 % S&P 500 ® 27.14 % 12.93 % | |
| Performance Inception Date | Mar. 19, 2021 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/FMAR | |
| Net Assets | $ 860,250,150 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 4,672,327 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.7 % Purchased Options 102.2 % Written Options (2.8 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/FMAR info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/FMAR | |
| C000226055 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest International Equity ModerateBuffer ETF - March | |
| Class Name | FT Vest International Equity ModerateBuffer ETF - March | |
| Trading Symbol | YMAR | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest International Equity Moderate Buffer ETF - March (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/YMAR info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/YMAR | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest International Equity Moderate Buffer ETF - March $ 0.90 % | |
| Expenses Paid, Amount | $ 97 | |
| Expense Ratio, Percent | 0.90% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 14.98% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the MSCI EAFE Index, which returned 19.40% for the same Period. This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 11.77 % Changes in other Variables 4.11 % Fees and Expenses -0.90 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (March 19, 2021 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest International Equity Moderate Buffer ETF - March 14.98 % 5.42 % MSCI EAFE Index 19.40 % 5.63 % | |
| Performance Inception Date | Mar. 19, 2021 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Mar. 18, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/YMAR | |
| Net Assets | $ 99,693,605 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 691,292 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.8 % Purchased Options 101.2 % Written Options (1.9 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/YMAR info ftportfolios.com Effective March 18, 2024, the name of the Fund changed from “FT Vest International Equity Buffer ETF - March” to “FT Vest International Equity Moderate Buffer ETF - March”, the Fund’s buffer against Underlying ETF losses increased from 10% to 15%, and the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Material Fund Change Name [Text Block] | Effective March 18, 2024, the name of the Fund changed from “FT Vest International Equity Buffer ETF - March” to “FT Vest International Equity Moderate Buffer ETF - March”, the Fund’s buffer against Underlying ETF losses increased from 10% to 15%, and the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/YMAR | |
| C000227373 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | First Trust Innovation Leaders ETF | |
| Class Name | First Trust Innovation Leaders ETF | |
| Trading Symbol | ILDR | |
| Security Exchange Name | NYSEArca | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the First Trust Innovation Leaders ETF (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/ILDR info ftportfolios.com | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/ILDR | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage First Trust Innovation Leaders ETF $ 0.75 % | |
| Expenses Paid, Amount | $ 86 | |
| Expense Ratio, Percent | 0.75% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 29.64% for the 12 months ended August 31, 2024. The Fund underperformed its benchmark, the Russell 3000 ® This underperformance was driven by negative selection effect and mostly offset by favorable allocation. Key Drivers of Negative Selection Effect: Health Care stocks were the largest detriment to the Fund’s performance for the Period as stock selection within the Health Care sector drove 367 basis points (bps) of underperformance. The Fund did not have exposure to Eli Lilly and Company which had an average benchmark weight of 2.33% for the Period and returned 74.37% as its leading weight loss drugs gained approval from the Food and Drug Administration and went to market. High contribution to negative selection effect for the Period arose from Coherus Biosciences, Inc., down 65.85%, Replimune Group, Inc., down 50.20%, Fulgent Genetics, Inc., down 37.85% and Inmode Ltd., down 37.54%. NVIDIA Corp. contributed to negative performance despite the Fund having an average exposure of 6.03% to the stock for the Period. NVIDIA Corp. was up 141.93% on the strength of Artificial Intelligence-related demand for its Graphics Processing Units. However, the benchmark had an average weight of 7.04% to NVIDIA for the Period which generated relative underperformance for the Fund. Key Drivers of Positive Allocation Effect: Within the Consumer Discretionary sector holdings, the Fund held few stocks and, predominately, Amazon.com, Inc. This provided favorable allocation as the Fund’s average discretionary weight was only 5.68% for the Period compared with 14.71% in the benchmark. As consumers exhibited spending exhaustion driven by inflation ravaged incomes, the sector did not keep pace with the broader market for the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (May 25, 2021 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since First Trust Innovation Leaders ETF 29.64 % 5.16 % Russell 3000 ® 30.10 % 11.76 % Russell 3000 ® 26.14 % 9.73 % | |
| Performance Inception Date | May 25, 2021 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/ILDR | |
| Net Assets | $ 40,147,388 | |
| Holdings Count | Holding | 63 | |
| Advisory Fees Paid, Amount | $ 191,103 | |
| Investment Company Portfolio Turnover | 43% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 63 Total advisory fee paid $ Portfolio turnover rate 43 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The tables below show the investment makeup of the Fund, representing the percentage of total investments of the Fund. Top Ten Holdings NVIDIA Corp. 7.7 % Oracle Corp. 6.0 % Amazon.com, Inc. 5.3 % Microsoft Corp. 5.3 % Alphabet, Inc., Class C 3.9 % ServiceNow, Inc. 3.6 % Meta Platforms, Inc., Class A 3.5 % Uber Technologies, Inc. 3.3 % Broadcom, Inc. 3.0 % Siemens AG 2.3 % Sector Allocation | |
| Largest Holdings [Text Block] | Top Ten Holdings NVIDIA Corp. 7.7 % Oracle Corp. 6.0 % Amazon.com, Inc. 5.3 % Microsoft Corp. 5.3 % Alphabet, Inc., Class C 3.9 % ServiceNow, Inc. 3.6 % Meta Platforms, Inc., Class A 3.5 % Uber Technologies, Inc. 3.3 % Broadcom, Inc. 3.0 % Siemens AG 2.3 % | |
| C000241937 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. EquityModerate Buffer ETF - May | |
| Class Name | FT Vest U.S. EquityModerate Buffer ETF - May | |
| Trading Symbol | GMAY | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Moderate Buffer ETF - May (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/GMAY info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/GMAY | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Moderate Buffer ETF - May $ 0.85 % | |
| Expenses Paid, Amount | $ 91 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 13.37% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 9.37 % Changes in other Variables 4.85 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (May 19, 2023 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Moderate Buffer ETF - May 13.37 % 14.48 % S&P 500 ® 27.14 % 28.01 % | |
| Performance Inception Date | May 19, 2023 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/GMAY | |
| Net Assets | $ 275,190,760 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 1,264,254 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.9 % Purchased Options 102.7 % Written Options (3.5 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/GMAY info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/GMAY | |
| C000211018 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. EquityDeep Buffer ETF - August | |
| Class Name | FT Vest U.S. EquityDeep Buffer ETF - August | |
| Trading Symbol | DAUG | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Deep Buffer ETF - August (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/DAUG info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/DAUG | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Deep Buffer ETF - August $ 0.85 % | |
| Expenses Paid, Amount | $ 91 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 13.37% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 9.57 % Changes in other Variables 4.65 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (November 6, 2019 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Deep Buffer ETF - August 13.37 % 5.29 % S&P 500 ® 27.14 % 15.30 % | |
| Performance Inception Date | Nov. 06, 2019 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/DAUG | |
| Net Assets | $ 273,983,182 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 2,659,618 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 1.1 % Purchased Options 101.7 % Written Options (2.7 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/DAUG info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/DAUG | |
| C000223312 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest Nasdaq-100® Buffer ETF - December | |
| Class Name | FT Vest Nasdaq-100® Buffer ETF - December | |
| Trading Symbol | QDEC | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest Nasdaq-100 ® | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/QDEC info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/QDEC | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest Nasdaq-100 ® $ 0.90 % | |
| Expenses Paid, Amount | $ 97 | |
| Expense Ratio, Percent | 0.90% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 15.58% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the Nasdaq-100 Index ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 10.00 % Changes in other Variables 6.48 % Fees and Expenses -0.90 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (December 18, 2020 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest Nasdaq-100 ® 15.58 % 7.95 % Nasdaq-100 Index ® 27.30 % 13.21 % S&P 500 ® 27.14 % 13.76 % | |
| Performance Inception Date | Dec. 18, 2020 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/QDEC | |
| Net Assets | $ 355,470,601 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 2,809,339 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.5 % Purchased Options 104.5 % Written Options (4.9 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/QDEC info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/QDEC | |
| C000224232 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. EquityDeep Buffer ETF - January | |
| Class Name | FT Vest U.S. EquityDeep Buffer ETF - January | |
| Trading Symbol | DJAN | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Deep Buffer ETF - January (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/DJAN info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/DJAN | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Deep Buffer ETF - January $ 0.85 % | |
| Expenses Paid, Amount | $ 91 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 14.16% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 10.49 % Changes in other Variables 4.52 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (January 15, 2021 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Deep Buffer ETF - January 14.16 % 6.59 % S&P 500 ® 27.14 % 13.54 % | |
| Performance Inception Date | Jan. 15, 2021 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/DJAN | |
| Net Assets | $ 245,331,379 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 1,991,100 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.6 % Purchased Options 106.0 % Written Options (6.5 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/DJAN info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/DJAN | |
| C000224911 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. EquityEnhance & Moderate Buffer ETF - June | |
| Class Name | FT Vest U.S. EquityEnhance & Moderate Buffer ETF - June | |
| Trading Symbol | XJUN | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Enhance & Moderate Buffer ETF - June (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/XJUN info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/XJUN | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Enhance & Moderate Buffer ETF - June $ 0.85 % | |
| Expenses Paid, Amount | $ 90 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 11.71% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 7.63 % Changes in other Variables 4.93 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (July 12, 2021 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Enhance & Moderate Buffer ETF - June 11.71 % 7.87 % S&P 500 ® 27.14 % 10.10 % | |
| Performance Inception Date | Jul. 12, 2021 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/XJUN | |
| Net Assets | $ 186,547,120 | |
| Holdings Count | Holding | 6 | |
| Advisory Fees Paid, Amount | $ 2,038,257 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 6 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 1.0 % Purchased Options 111.7 % Written Options (12.6 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/XJUN info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/XJUN | |
| C000226054 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest Nasdaq-100® Buffer ETF - March | |
| Class Name | FT Vest Nasdaq-100® Buffer ETF - March | |
| Trading Symbol | QMAR | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest Nasdaq-100 ® | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/QMAR info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/QMAR | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest Nasdaq-100 ® $ 0.90 % | |
| Expenses Paid, Amount | $ 97 | |
| Expense Ratio, Percent | 0.90% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 15.18% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the Nasdaq-100 Index ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 9.37 % Changes in other Variables 6.71 % Fees and Expenses -0.90 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (March 19, 2021 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest Nasdaq-100 ® 15.18 % 10.34 % Nasdaq-100 Index ® 27.30 % 13.84 % S&P 500 ® 27.14 % 12.93 % | |
| Performance Inception Date | Mar. 19, 2021 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/QMAR | |
| Net Assets | $ 416,610,335 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 2,712,496 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.8 % Purchased Options 102.9 % Written Options (3.6 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/QMAR info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/QMAR | |
| C000240892 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. EquityModerate Buffer ETF - February | |
| Class Name | FT Vest U.S. EquityModerate Buffer ETF - February | |
| Trading Symbol | GFEB | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Moderate Buffer ETF - February (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/GFEB info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/GFEB | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Moderate Buffer ETF - February $ 0.85 % | |
| Expenses Paid, Amount | $ 91 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 14.58% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 11.17 % Changes in other Variables 4.26 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (February 17, 2023 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Moderate Buffer ETF - February 14.58 % 14.79 % S&P 500 ® 27.14 % 25.53 % | |
| Performance Inception Date | Feb. 17, 2023 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/GFEB | |
| Net Assets | $ 393,977,223 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 2,402,428 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.7 % Purchased Options 104.3 % Written Options (4.9 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/GFEB info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/GFEB | |
| C000242929 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. EquityModerate Buffer ETF - June | |
| Class Name | FT Vest U.S. EquityModerate Buffer ETF - June | |
| Trading Symbol | GJUN | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Moderate Buffer ETF - June (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/GJUN info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/GJUN | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Moderate Buffer ETF - June $ 0.85 % | |
| Expenses Paid, Amount | $ 91 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 14.51% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 11.13 % Changes in other Variables 4.23 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (June 16, 2023 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Moderate Buffer ETF - June 14.51 % 13.88 % S&P 500 ® 27.14 % 24.55 % | |
| Performance Inception Date | Jun. 16, 2023 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/GJUN | |
| Net Assets | $ 542,830,977 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 2,575,317 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 1.0 % Purchased Options 102.1 % Written Options (3.0 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/GJUN info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/GJUN | |
| C000242936 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. EquityModerate Buffer ETF - October | |
| Class Name | FT Vest U.S. EquityModerate Buffer ETF - October | |
| Trading Symbol | GOCT | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Moderate Buffer ETF - October (the “Fund”) for the period of October 20, 2023 (commencement of investment operations) to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/GOCT info ftportfolios.com | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/GOCT | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Moderate Buffer ETF - October $ (1) 0.85 % (2) (1) The Fund commenced investment operations on October 20, 2023. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher. (2) Annualized. | |
| Expenses Paid, Amount | $ 79 | [5] |
| Expense Ratio, Percent | 0.85% | [6] |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 13.78% for the period from the Fund’s inception date on October 20, 2023 through August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 8.37 % Changes in other Variables 6.14 % Fees and Expenses -0.73 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (October 20, 2023 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) Since FT Vest U.S. Equity Moderate Buffer ETF - October 13.78 % S&P 500 ® 35.42 % | |
| Performance Inception Date | Oct. 20, 2023 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/GOCT | |
| Net Assets | $ 95,773,283 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 925,283 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.4 % Purchased Options 116.5 % Written Options (16.8 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| C000243421 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. EquityEnhance & Moderate Buffer ETF - August | |
| Class Name | FT Vest U.S. EquityEnhance & Moderate Buffer ETF - August | |
| Trading Symbol | XAUG | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Enhance & Moderate Buffer ETF - August (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/XAUG info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/XAUG | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Enhance & Moderate Buffer ETF - August $ 0.85 % | |
| Expenses Paid, Amount | $ 90 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 10.82% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 6.40 % Changes in other Variables 5.27 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (August 18, 2023 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Enhance & Moderate Buffer ETF - August 10.82 % 12.01 % S&P 500 ® 27.14 % 30.01 % | |
| Performance Inception Date | Aug. 18, 2023 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/XAUG | |
| Net Assets | $ 27,550,932 | |
| Holdings Count | Holding | 6 | |
| Advisory Fees Paid, Amount | $ 215,388 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 6 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 1.0 % Purchased Options 112.0 % Written Options (13.0 % ) Net Other Assets and Liabilities (0.0 % ) Total 100.0 % Any amount shown as 0.0% represents less than 0.1%. | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/XAUG info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/XAUG | |
| C000226537 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. Equity Buffer ETF - April | |
| Class Name | FT Vest U.S. Equity Buffer ETF - April | |
| Trading Symbol | FAPR | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Buffer ETF - April (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/FAPR info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/FAPR | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Buffer ETF - April $ 0.85 % | |
| Expenses Paid, Amount | $ 94 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 20.33% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 12.40 % Changes in other Variables 8.78 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (April 16, 2021 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Buffer ETF - April 20.33 % 8.86 % S&P 500 ® 27.14 % 10.98 % | |
| Performance Inception Date | Apr. 16, 2021 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/FAPR | |
| Net Assets | $ 689,112,102 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 4,290,770 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.8 % Purchased Options 103.8 % Written Options (4.6 % ) Net Other Assets and Liabilities (0.0 % ) Total 100.0 % Any amount shown as 0.0% represents less than 0.1%. | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/FAPR info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/FAPR | |
| C000227615 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | First Trust Expanded Technology ETF | |
| Class Name | First Trust Expanded Technology ETF | |
| Trading Symbol | XPND | |
| Security Exchange Name | NYSEArca | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the First Trust Expanded Technology ETF (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/XPND info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/XPND | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage First Trust Expanded Technology ETF $ 0.65 % | |
| Expenses Paid, Amount | $ 74 | |
| Expense Ratio, Percent | 0.65% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 29.18% for the 12 months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was largely attributable to the Fund’s weighting methodology designed to minimize single stock risk and to the Fund’s exposure to industries outside of the benchmark. The Semiconductor stock NVIDIA Corp. (NVDA) represented over 15% of the benchmark and returned 141.93% over the Period, accounting for over 40% of the benchmark’s net contribution. The Fund caps the weight of individual names to a 4.50% max at the time of rebalance, which caused the Fund to be structurally underweight the technology market’s undisputed winner. The effect of the Fund’s underweight in NVDA accounted for a significant portion of the underperformance. The Financials sector and the Communication Services sector, which combined represented about 30% of the Fund, could not keep pace with the Information Technology sector. Of the five industries held by the Fund within these two sectors, only the Interactive Media & Services industry outperformed the benchmark. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (June 14, 2021 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since First Trust Expanded Technology ETF 29.18 % 11.04 % S&P 500 ® 38.73 % 19.19 % S&P 500 ® 27.14 % 10.91 % | |
| Performance Inception Date | Jun. 14, 2021 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/XPND | |
| Net Assets | $ 21,065,698 | |
| Holdings Count | Holding | 51 | |
| Advisory Fees Paid, Amount | $ 94,936 | |
| Investment Company Portfolio Turnover | 61% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 51 Total advisory fee paid $ Portfolio turnover rate 61 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The tables below show the investment makeup of the Fund, representing the percentage of total investments of the Fund. Top Ten Holdings Broadcom, Inc. 5.1 % Oracle Corp. 5.0 % Apple, Inc. 5.0 % T-Mobile US, Inc. 4.7 % Meta Platforms, Inc., Class A 4.7 % NVIDIA Corp. 4.6 % Mastercard, Inc., Class A 4.5 % Visa, Inc., Class A 4.2 % Microsoft Corp. 4.2 % International Business Machines Corp. 4.2 % Sector Allocation | |
| Largest Holdings [Text Block] | Top Ten Holdings Broadcom, Inc. 5.1 % Oracle Corp. 5.0 % Apple, Inc. 5.0 % T-Mobile US, Inc. 4.7 % Meta Platforms, Inc., Class A 4.7 % NVIDIA Corp. 4.6 % Mastercard, Inc., Class A 4.5 % Visa, Inc., Class A 4.2 % Microsoft Corp. 4.2 % International Business Machines Corp. 4.2 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/XPND info ftportfolios.com The Fund may have significant investments in various jurisdictions or investment sectors from time to time, making the Fund subject to the risks of such jurisdictions or investment sectors. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/XPND | |
| C000230294 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest Nasdaq-100® Buffer ETF - September | |
| Class Name | FT Vest Nasdaq-100® Buffer ETF - September | |
| Trading Symbol | QSPT | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest Nasdaq-100 ® | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/QSPT info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/QSPT | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest Nasdaq-100 ® $ 0.90 % | |
| Expenses Paid, Amount | $ 99 | |
| Expense Ratio, Percent | 0.90% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 20.25% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the Nasdaq-100 Index ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 11.21 % Changes in other Variables 9.94 % Fees and Expenses -0.90 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (September 17, 2021 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest Nasdaq-100 ® 20.25 % 9.53 % Nasdaq-100 Index ® 27.30 % 9.52 % S&P 500 ® 27.14 % 10.25 % | |
| Performance Inception Date | Sep. 17, 2021 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/QSPT | |
| Net Assets | $ 293,273,209 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 2,162,299 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.3 % Purchased Options 106.8 % Written Options (7.0 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/QSPT info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/QSPT | |
| C000242934 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. EquityModerate Buffer ETF - December | |
| Class Name | FT Vest U.S. EquityModerate Buffer ETF - December | |
| Trading Symbol | GDEC | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Moderate Buffer ETF - December (the “Fund”) for the period of December 15, 2023 (commencement of investment operations) to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/GDEC info ftportfolios.com | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/GDEC | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Moderate Buffer ETF - December $ (1) 0.85 % (2) (1) The Fund commenced investment operations on December 15, 2023. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher. (2) Annualized. | |
| Expenses Paid, Amount | $ 64 | [7] |
| Expense Ratio, Percent | 0.85% | [8] |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 9.79% for the period from the Fund’s inception date on December 15, 2023 through August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 7.05 % Changes in other Variables 3.34 % Fees and Expenses -0.60 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (December 15, 2023 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) Since FT Vest U.S. Equity Moderate Buffer ETF - December 9.79 % S&P 500 ® 20.86 % | |
| Performance Inception Date | Dec. 15, 2023 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/GDEC | |
| Net Assets | $ 126,965,952 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 985,390 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.4 % Purchased Options 108.5 % Written Options (8.8 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| C000242937 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. EquityModerate Buffer ETF - September | |
| Class Name | FT Vest U.S. EquityModerate Buffer ETF - September | |
| Trading Symbol | GSEP | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Moderate Buffer ETF - September (the “Fund”) for the period of September 15, 2023 (commencement of investment operations) to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/GSEP info ftportfolios.com | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/GSEP | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Moderate Buffer ETF - September $ (1) 0.85 % (2) (1) The Fund commenced investment operations on September 15, 2023. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher. (2) Annualized. | |
| Expenses Paid, Amount | $ 88 | [9] |
| Expense Ratio, Percent | 0.85% | [10] |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 13.60% for the period from the Fund’s inception date on September 15, 2023 through August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 9.82 % Changes in other Variables 4.59 % Fees and Expenses -0.81 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (September 15, 2023 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) Since FT Vest U.S. Equity Moderate Buffer ETF - September 13.60 % S&P 500 ® 28.68 % | |
| Performance Inception Date | Sep. 15, 2023 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/GSEP | |
| Net Assets | $ 128,444,282 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 980,170 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.3 % Purchased Options 110.8 % Written Options (11.0 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| C000243422 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. EquityEnhance & Moderate Buffer ETF - July | |
| Class Name | FT Vest U.S. EquityEnhance & Moderate Buffer ETF - July | |
| Trading Symbol | XJUL | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Enhance & Moderate Buffer ETF - July (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/XJUL info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/XJUL | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Enhance & Moderate Buffer ETF - July $ 0.85 % | |
| Expenses Paid, Amount | $ 90 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 12.14% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 8.19 % Changes in other Variables 4.80 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (July 21, 2023 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Enhance & Moderate Buffer ETF - July 12.14 % 11.25 % S&P 500 ® 27.14 % 23.61 % | |
| Performance Inception Date | Jul. 21, 2023 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/XJUL | |
| Net Assets | $ 51,944,949 | |
| Holdings Count | Holding | 6 | |
| Advisory Fees Paid, Amount | $ 406,735 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 6 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 1.0 % Purchased Options 111.7 % Written Options (12.6 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/XJUL info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/XJUL | |
| C000245572 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. Equity Enhance & Moderate Buffer ETF - April | |
| Class Name | FT Vest U.S. Equity Enhance & Moderate Buffer ETF - April | |
| Trading Symbol | XAPR | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Enhance & Moderate Buffer ETF - April (the “Fund”) for the period of April 19, 2024 (commencement of investment operations) to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/XAPR info ftportfolios.com | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/XAPR | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Enhance & Moderate Buffer ETF - April $ (1) 0.85 % (2) (1) The Fund commenced investment operations on April 19, 2024. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher. (2) Annualized. | |
| Expenses Paid, Amount | $ 32 | [11] |
| Expense Ratio, Percent | 0.85% | [12] |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 6.33% for the period from the Fund’s inception date on April 19, 2024 through August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 3.98 % Changes in other Variables 2.66 % Fees and Expenses -0.31 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (April 19, 2024 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) Since FT Vest U.S. Equity Enhance & Moderate Buffer ETF - April 6.33 % S&P 500 ® 14.29 % | |
| Performance Inception Date | Apr. 19, 2024 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/XAPR | |
| Net Assets | $ 14,217,464 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 39,472 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Purchased Options 123.6 % Written Options (24.3 % ) Net Other Assets and Liabilities 0.7 % Total 100.0 % | |
| C000241464 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. EquityModerate Buffer ETF - April | |
| Class Name | FT Vest U.S. EquityModerate Buffer ETF - April | |
| Trading Symbol | GAPR | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Moderate Buffer ETF - April (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/GAPR info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/GAPR | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Moderate Buffer ETF - April $ 0.85 % | |
| Expenses Paid, Amount | $ 92 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 15.93% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 9.00 % Changes in other Variables 7.78 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (April 21, 2023 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Moderate Buffer ETF - April 15.93 % 16.28 % S&P 500 ® 27.14 % 27.69 % | |
| Performance Inception Date | Apr. 21, 2023 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/GAPR | |
| Net Assets | $ 218,741,924 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 1,375,718 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.8 % Purchased Options 105.4 % Written Options (6.1 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/GAPR info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/GAPR | |
| C000242928 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. EquityModerate Buffer ETF - July | |
| Class Name | FT Vest U.S. EquityModerate Buffer ETF - July | |
| Trading Symbol | GJUL | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Moderate Buffer ETF - July (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/GJUL info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/GJUL | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Moderate Buffer ETF - July $ 0.85 % | |
| Expenses Paid, Amount | $ 92 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 15.50% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 11.50 % Changes in other Variables 4.85 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (July 21, 2023 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Moderate Buffer ETF - July 15.50 % 14.09 % S&P 500 ® 27.14 % 23.61 % | |
| Performance Inception Date | Jul. 21, 2023 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/GJUL | |
| Net Assets | $ 368,714,580 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 2,347,994 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 1.1 % Purchased Options 102.3 % Written Options (3.3 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/GJUL info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/GJUL | |
| C000242935 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. EquityModerate Buffer ETF - November | |
| Class Name | FT Vest U.S. EquityModerate Buffer ETF - November | |
| Trading Symbol | GNOV | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Moderate Buffer ETF - November (the “Fund”) for the period of November 17, 2023 (commencement of investment operations) to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/GNOV info ftportfolios.com | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/GNOV | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Moderate Buffer ETF - November $ (1) 0.85 % (2) (1) The Fund commenced investment operations on November 17, 2023. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher. (2) Annualized. | |
| Expenses Paid, Amount | $ 71 | [13] |
| Expense Ratio, Percent | 0.85% | [14] |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 11.78% for the period from the Fund’s inception date on November 17, 2023 through August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 8.05 % Changes in other Variables 4.39 % Fees and Expenses -0.66 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (November 17, 2023 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) Since FT Vest U.S. Equity Moderate Buffer ETF - November 11.78 % S&P 500 ® 26.53 % | |
| Performance Inception Date | Nov. 17, 2023 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/GNOV | |
| Net Assets | $ 158,473,141 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 1,059,751 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.4 % Purchased Options 111.0 % Written Options (11.3 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| C000250352 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. Equity Buffer & Premium Income ETF - June | |
| Class Name | FT Vest U.S. Equity Buffer & Premium Income ETF - June | |
| Trading Symbol | XIJN | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Buffer & Premium Income ETF - June (the “Fund”) for the period of June 21, 2024 (commencement of investment operations) to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/XIJN info ftportfolios.com | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/XIJN | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Buffer & Premium Income ETF - June $ (1) 0.85 % (2) (1) The Fund commenced investment operations on June 21, 2024. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher. (2) Annualized. | |
| Expenses Paid, Amount | $ 17 | [15] |
| Expense Ratio, Percent | 0.85% | [16] |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 1.86% for the period from the Fund’s inception date on June 21, 2024 through August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 0.61 % Changes in other Variables 1.41 % Fees and Expenses -0.16 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (June 21, 2024 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) Since FT Vest U.S. Equity Buffer & Premium Income ETF - June 1.86 % S&P 500 ® 3.61 % | |
| Performance Inception Date | Jun. 21, 2024 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/XIJN | |
| Net Assets | $ 4,634,133 | |
| Holdings Count | Holding | 15 | |
| Advisory Fees Paid, Amount | $ 5,185 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 15 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The tables below show the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation U.S. Treasury Bills 5.7 % Purchased Options 104.5 % Written Options (11.0 % ) Net Other Assets and Liabilities 0.8 % Total 100.0 % | |
| C000218639 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | First Trust TCW Securitized Plus ETF | |
| Class Name | First Trust TCW Securitized Plus ETF | |
| Trading Symbol | DEED | |
| Security Exchange Name | NYSEArca | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the First Trust TCW Securitized Plus ETF (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/DEED info ftportfolios.com | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/DEED | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage First Trust TCW Securitized Plus ETF $ 0.75 % | |
| Expenses Paid, Amount | $ 78 | |
| Expense Ratio, Percent | 0.75% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 8.83% for the 12 months ended August 31, 2024. The Fund outperformed its benchmark, the Bloomberg U.S. Mortgage-Backed Securities Index, which returned 7.46% for the same Period. This outperformance was driven by the Fund’s focus on structured credit given a continued tightening of yield spreads across collateral types and deal structures, with non-agency commercial mortgage-backed securities exposure providing the largest benefit. More specifically, the Fund’s emphasis on single asset single borrower deals with high-quality collateral and attractive yields provided a boost to relative returns, along with interest only commercial mortgage-backed securities bonds that benefitted from strong cash flows over the period. Issue selection in asset-backed securities was also notable, particularly collateralized loan obligations which benefitted from positive cash flows and strong market technicals as demand continued to outweigh supply. Finally, residential mortgage-backed securities exposure contributed, despite a drag from being underweight agency mortgage-backed securities in recent months as the sector has performed well amid declining rate volatility. Contributions came from non-agency holdings which benefitted from sustained demand and limited net issuance in the sector, with investor optimism helping drive a flattening of credit curves and outperformance among more subordinated tranches. Also significant to relative performance was the Fund’s longer-than-Index duration position. While this duration position weighed on returns early in the Period as rates reached their cycle highs in October 2023, the precipitous decline in Treasury yields over the last two months as markets became increasingly confident in a September 2024 rate cut by the Federal Reserve more than offset the performance drag that had accumulated up to that point. Yield curve positioning focused on front-end yields provided a further boost as the recent rally has been led by the policy sensitive 2-Year yield. Derivative positioning in the Fund is largely focused on futures positions used to manage duration, with a small allocation to currency forwards which had little impact on the Fund’s performance for the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (April 29, 2020 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since First Trust TCW Securitized Plus ETF 8.83 % -0.03 % Bloomberg U.S. Mortgage-Backed Securities Index 7.46 % -1.14 % Bloomberg U.S. Aggregate Bond Index 7.30 % -1.08 % | |
| Performance Inception Date | Apr. 29, 2020 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/DEED | |
| Net Assets | $ 72,819,140 | |
| Holdings Count | Holding | 271 | |
| Advisory Fees Paid, Amount | $ 506,297 | |
| Investment Company Portfolio Turnover | 408% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 271 Total advisory fee paid $ Portfolio turnover rate 408 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The tables below show the investment makeup of the Fund, representing the percentage of total investments of the Fund. Top Ten Holdings Dreyfus Government Cash Management Fund, Institutional Shares, Class I, 5.19% 7.0 % U.S. Treasury Note, 3.75%, 08/31/26 5.1 % Federal National Mortgage Association, Pool TBA, 2.50%, 09/15/54 2.0 % Government National Mortgage Association, Pool TBA, 5.00%, 10/15/54 2.0 % Federal National Mortgage Association, Pool TBA, 3.00%, 09/15/54 1.6 % Government National Mortgage Association, Pool TBA, 2.50%, 09/15/54 1.5 % Government National Mortgage Association, Pool TBA, 4.50%, 09/15/54 1.4 % Federal National Mortgage Association, Pool TBA, 5.50%, 09/15/54 1.3 % Federal National Mortgage Association, Pool TBA, 2.00%, 09/15/54 1.3 % Federal Home Loan Mortgage Corporation, Pool QD7088, 2.00%, 02/01/52 1.3 % Credit Quality (1) (1) The credit quality and ratings information presented above reflect the ratings assigned by one or more nationally recognized statistical rating organizations (NRSROs), including S&P Global Ratings, Moody’s Investors Service, Inc., Fitch Ratings, or a comparably rated NRSRO. For situations in which a security is rated by more than one NRSRO and the ratings are not equivalent, the lowest ratings are used. Sub-investment grade ratings are those rated BB+/Ba1 or lower. Investment grade ratings are those rated BBB-/Baa3 or higher. The credit ratings shown relate to the creditworthiness of the issuers of the underlying securities in the Fund, and not to the Fund or its shares. U.S.Treasury, U.S. Agency and U.S. Agency mortgage-backed securities appear under “Government/Agency.” Credit ratings are subject to change. Any amount shown as 0.0% represents less than 0.1%. | |
| Credit Quality Explanation [Text Block] | The credit quality and ratings information presented above reflect the ratings assigned by one or more nationally recognized statistical rating organizations (NRSROs), including S&P Global Ratings, Moody’s Investors Service, Inc., Fitch Ratings, or a comparably rated NRSRO. For situations in which a security is rated by more than one NRSRO and the ratings are not equivalent, the lowest ratings are used. Sub-investment grade ratings are those rated BB+/Ba1 or lower. Investment grade ratings are those rated BBB-/Baa3 or higher. The credit ratings shown relate to the creditworthiness of the issuers of the underlying securities in the Fund, and not to the Fund or its shares. U.S.Treasury, U.S. Agency and U.S. Agency mortgage-backed securities appear under “Government/Agency.” Credit ratings are subject to change. | |
| Credit Ratings Selection [Text Block] | The credit quality and ratings information presented above reflect the ratings assigned by one or more nationally recognized statistical rating organizations (NRSROs), including S&P Global Ratings, Moody’s Investors Service, Inc., Fitch Ratings, or a comparably rated NRSRO. | |
| Largest Holdings [Text Block] | Top Ten Holdings Dreyfus Government Cash Management Fund, Institutional Shares, Class I, 5.19% 7.0 % U.S. Treasury Note, 3.75%, 08/31/26 5.1 % Federal National Mortgage Association, Pool TBA, 2.50%, 09/15/54 2.0 % Government National Mortgage Association, Pool TBA, 5.00%, 10/15/54 2.0 % Federal National Mortgage Association, Pool TBA, 3.00%, 09/15/54 1.6 % Government National Mortgage Association, Pool TBA, 2.50%, 09/15/54 1.5 % Government National Mortgage Association, Pool TBA, 4.50%, 09/15/54 1.4 % Federal National Mortgage Association, Pool TBA, 5.50%, 09/15/54 1.3 % Federal National Mortgage Association, Pool TBA, 2.00%, 09/15/54 1.3 % Federal Home Loan Mortgage Corporation, Pool QD7088, 2.00%, 02/01/52 1.3 % | |
| C000219664 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. Equity Deep Buffer ETF - June | |
| Class Name | FT Vest U.S. Equity Deep Buffer ETF - June | |
| Trading Symbol | DJUN | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Deep Buffer ETF - June (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/DJUN info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/DJUN | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Deep Buffer ETF - June $ 0.85 % | |
| Expenses Paid, Amount | $ 92 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 15.39% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 11.82 % Changes in other Variables 4.42 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (June 19, 2020 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Deep Buffer ETF - June 15.39 % 8.11 % S&P 500 ® 27.14 % 17.17 % | |
| Performance Inception Date | Jun. 19, 2020 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/DJUN | |
| Net Assets | $ 248,708,743 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 1,642,585 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 1.0 % Purchased Options 101.1 % Written Options (2.0 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/DJUN info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/DJUN | |
| C000221308 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. Equity Buffer ETF - September | |
| Class Name | FT Vest U.S. Equity Buffer ETF - September | |
| Trading Symbol | FSEP | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Buffer ETF - September (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/FSEP info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/FSEP | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Buffer ETF - September $ 0.85 % | |
| Expenses Paid, Amount | $ 92 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 15.56% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 12.74 % Changes in other Variables 3.67 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (September 18, 2020 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Buffer ETF - September 15.56 % 10.71 % S&P 500 ® 27.14 % 16.18 % | |
| Performance Inception Date | Sep. 18, 2020 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/FSEP | |
| Net Assets | $ 598,276,499 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 4,059,771 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.3 % Purchased Options 107.5 % Written Options (7.7 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/FSEP info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/FSEP | |
| C000222137 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. EquityDeep Buffer ETF - October | |
| Class Name | FT Vest U.S. EquityDeep Buffer ETF - October | |
| Trading Symbol | DOCT | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Deep Buffer ETF - October (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/DOCT info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/DOCT | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Deep Buffer ETF - October $ 0.85 % | |
| Expenses Paid, Amount | $ 89 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 9.35% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 8.15 % Changes in other Variables 2.05 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (October 16, 2020 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Deep Buffer ETF - October 9.35 % 7.01 % S&P 500 ® 27.14 % 15.04 % | |
| Performance Inception Date | Oct. 16, 2020 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/DOCT | |
| Net Assets | $ 192,207,705 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 1,540,175 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.4 % Purchased Options 116.6 % Written Options (16.9 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/DOCT info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/DOCT | |
| C000230351 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | First Trust SkyBridgeCrypto Industry and Digital Economy ETF | |
| Class Name | First Trust SkyBridgeCrypto Industry and Digital Economy ETF | |
| Trading Symbol | CRPT | |
| Security Exchange Name | NYSEArca | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the First Trust SkyBridge Crypto Industry and Digital Economy ETF (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/CRPT info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/CRPT | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage First Trust SkyBridge Crypto Industry and Digital Economy ETF $ 0.85 % | |
| Expenses Paid, Amount | $ 127 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 98.79% for the 12 months ended August 31, 2024. The Fund outperformed its benchmark, the S&P 500 ® This outperformance was driven primarily by the Fund’s exposure to crypto industry equities that experienced a sharp increase in value driven by a crypto industry recovery and Bitcoin’s sharp increase in price over the Period, with several of the Fund’s top positions (for example, MicroStrategy, Inc. and Coinbase Global, Inc.) outperforming the return on spot Bitcoin over the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (September 20, 2021 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since First Trust SkyBridge Crypto Industry and Digital Economy ETF 98.79 % -15.27 % S&P 500 ® 27.14 % 10.92 % | |
| Performance Inception Date | Sep. 20, 2021 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/CRPT | |
| Net Assets | $ 51,050,606 | |
| Holdings Count | Holding | 31 | |
| Advisory Fees Paid, Amount | $ 346,621 | |
| Investment Company Portfolio Turnover | 215% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 31 Total advisory fee paid $ Portfolio turnover rate 215 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The tables below show the investment makeup of the Fund, representing the percentage of total investments of the Fund. Top Ten Holdings MicroStrategy, Inc., Class A 20.4 % Coinbase Global, Inc., Class A 18.1 % Galaxy Digital Holdings Ltd. 6.4 % Cleanspark, Inc. 4.5 % Riot Platforms, Inc. 4.5 % Marathon Digital Holdings, Inc. 4.5 % Cipher Mining, Inc. 4.5 % NVIDIA Corp. 4.4 % Terawulf, Inc. 4.3 % Iris Energy Ltd. 4.2 % Sector Allocation | |
| Largest Holdings [Text Block] | Top Ten Holdings MicroStrategy, Inc., Class A 20.4 % Coinbase Global, Inc., Class A 18.1 % Galaxy Digital Holdings Ltd. 6.4 % Cleanspark, Inc. 4.5 % Riot Platforms, Inc. 4.5 % Marathon Digital Holdings, Inc. 4.5 % Cipher Mining, Inc. 4.5 % NVIDIA Corp. 4.4 % Terawulf, Inc. 4.3 % Iris Energy Ltd. 4.2 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/CRPT info ftportfolios.com The Trust’s Board of Trustees approved a change to the Fund’s principal investment strategies to allow the Fund to invest in Bitcoin Exchange-Traded Products. These Bitcoin Exchange-Traded Products are expected to be held by the Fund indirectly via a wholly-owned subsidiary of the Fund organized under the laws of the Cayman Islands. The Fund generally intends to invest up to 25% of its net assets in Bitcoin Exchange-Traded Products; however, at certain times, the Fund may invest more than 25% of its net assets in Bitcoin Exchange-Traded Products. The Fund’s principal investment strategies and principal risks were revised accordingly. | |
| Material Fund Change Strategies [Text Block] | The Trust’s Board of Trustees approved a change to the Fund’s principal investment strategies to allow the Fund to invest in Bitcoin Exchange-Traded Products. These Bitcoin Exchange-Traded Products are expected to be held by the Fund indirectly via a wholly-owned subsidiary of the Fund organized under the laws of the Cayman Islands. The Fund generally intends to invest up to 25% of its net assets in Bitcoin Exchange-Traded Products; however, at certain times, the Fund may invest more than 25% of its net assets in Bitcoin Exchange-Traded Products. The Fund’s principal investment strategies and principal risks were revised accordingly. | |
| Material Fund Change Risks Change [Text Block] | The Trust’s Board of Trustees approved a change to the Fund’s principal investment strategies to allow the Fund to invest in Bitcoin Exchange-Traded Products. These Bitcoin Exchange-Traded Products are expected to be held by the Fund indirectly via a wholly-owned subsidiary of the Fund organized under the laws of the Cayman Islands. The Fund generally intends to invest up to 25% of its net assets in Bitcoin Exchange-Traded Products; however, at certain times, the Fund may invest more than 25% of its net assets in Bitcoin Exchange-Traded Products. The Fund’s principal investment strategies and principal risks were revised accordingly. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/CRPT | |
| C000231330 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest Buffered Allocation Defensive ETF | |
| Class Name | FT Vest Buffered Allocation Defensive ETF | |
| Trading Symbol | BUFT | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest Buffered Allocation Defensive ETF (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/BUFT info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/BUFT | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest Buffered Allocation Defensive ETF $ (1) 0.20 % (1) (1) Excludes any Acquired Fund Fees and Expenses of underlying investment companies in which the Fund invests. | |
| Expenses Paid, Amount | $ 21 | [17] |
| Expense Ratio, Percent | 0.20% | [17] |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 9.76% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 9.36 % Changes in other Variables 1.45 % Fees and Expenses** -1.05 % The Fund holds a portfolio that consists of a number of buffer funds, and thus is exposed to the combinations of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the underlying buffer funds’ Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. ** Includes any Acquired Fund Fees and Expenses of underlying investment companies in which the Fund invests. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (October 26, 2021 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest Buffered Allocation Defensive ETF 9.76 % 3.47 % S&P 500 ® 27.14 % 9.40 % | |
| Performance Inception Date | Oct. 26, 2021 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Mar. 13, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/BUFT | |
| Net Assets | $ 113,549,903 | |
| Holdings Count | Holding | 8 | |
| Advisory Fees Paid, Amount | $ 211,158 | |
| Investment Company Portfolio Turnover | 361% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 8 Total advisory fee paid $ Portfolio turnover rate 361 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Exchange-Traded Funds 99.7 % Money Market Funds 0.3 % Net Other Assets and Liabilities (0.0 % ) Total 100.0 % Any amount shown as 0.0% represents less than 0.1% | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/BUFT info ftportfolios.com Effective March 13, 2024, the Fund’s principal investment strategies were revised to permit the universe of Underlying ETFs to also include investments in the series of FT Vest U.S. Equity Moderate Buffer ETFs and for the Fund’s portfolio to be evaluated on a quarterly, instead of monthly, basis. | |
| Material Fund Change Strategies [Text Block] | Effective March 13, 2024, the Fund’s principal investment strategies were revised to permit the universe of Underlying ETFs to also include investments in the series of FT Vest U.S. Equity Moderate Buffer ETFs and for the Fund’s portfolio to be evaluated on a quarterly, instead of monthly, basis. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/BUFT | |
| C000178745 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | First Trust TCW Opportunistic Fixed Income ETF | |
| Class Name | First Trust TCW Opportunistic Fixed Income ETF | |
| Trading Symbol | FIXD | |
| Security Exchange Name | NASDAQ | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the First Trust TCW Opportunistic Fixed Income ETF (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/FIXD info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/FIXD | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage First Trust TCW Opportunistic Fixed Income ETF $ 0.64 % | |
| Expenses Paid, Amount | $ 66 | |
| Expense Ratio, Percent | 0.64% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 7.55% for the 12 months ended August 31, 2024. The Fund outperformed its benchmark, the Bloomberg U.S. Aggregate Bond Index, which returned 7.30% for the same Period. This outperformance was driven in part by favorable issue selection in the Fund. Corporate issue selection contributed to relative performance, led largely by outperforming bank issues, including UBS (formerly Credit Suisse) as prices and spreads continued to stabilize from the early 2023 dislocation, while other large systemically important banks that had been a focus in the Fund’s holdings also rallied and compressed towards the rest of the investment grade corporate index. Consistent with disciplined value investing, the outsized compression of corporate yield spreads throughout the Period led to a trimming of the Fund’s corporate exposure, realizing gains, and affording the Fund liquidity to redeploy upon future pricing and spread dislocations. Away from corporates, issue selection within securitized products was also notable, led by non-agency mortgage-backed securities (“MBS”) holdings, where the large allocation to legacy collateral and floating rate structures helped mitigate the impacts of rate volatility during the period while providing attractive coupon income. Similarly, collateralized loan obligations contributed within the asset-backed securities allocation, with compressing spreads an added benefit to relative returns. Commercial mortgage-backed securities holdings emphasized single asset single borrower (“SASBs”) deal structures with strong collateral and/or sponsors, which outperformed over the period while avoiding some of the broader credit concerns that affected conduit structures and idiosyncratic struggles faced by SASBs with weaker property collateral. Finally, the overweight to agency MBS contributed for the Period given strong performance in recent months as yields have come down. Also significant to relative performance was the Fund’s longer-than-Index duration position and yield curve positioning. While this duration position weighed on returns early in the Period as rates reached their cycle highs in October 2023, the precipitous decline in Treasury yields over the last two months as markets became increasingly confident in a September 2024 rate cut by the Federal Reserve more than offset the performance drag that had accumulated up to that point. In addition, yield curve positioning focused on front-end yields provided a further boost as the recent rally has been led by the policy sensitive 2-Year yield. Derivatives positioning in the Fund was largely focused on futures positions to manage duration, interest rate swaps for hedging, and a small allocation to currency forwards, all of which had little impact on the Fund’s performance for the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (February 14, 2017 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year 5 Year Since First Trust TCW Opportunistic Fixed Income ETF 7.55 % -0.12 % 1.59 % Bloomberg U.S. Aggregate Bond Index 7.30 % -0.04 % 1.58 % | |
| Performance Inception Date | Feb. 14, 2017 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/FIXD | |
| Net Assets | $ 5,279,538,093 | |
| Holdings Count | Holding | 900 | |
| Advisory Fees Paid, Amount | $ 31,248,891 | |
| Investment Company Portfolio Turnover | 511% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 900 Total advisory fee paid $ Portfolio turnover rate 511 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The tables below show the investment makeup of the Fund, representing the percentage of total investments of the Fund. Top Ten Holdings Dreyfus Government Cash Management Fund, Institutional Shares, Class I, 5.19% 11.7 % U.S. Treasury Note, 4.00%, 07/31/29 6.9 % U.S. Treasury Note, 3.63%, 08/31/29 6.6 % U.S. Treasury Note, 3.88%, 08/15/34 4.2 % U.S. Treasury Bond, 4.25%, 08/15/54 3.8 % U.S. Treasury Bond, 4.13%, 08/15/44 2.9 % U.S. Treasury Note, 3.75%, 08/31/26 2.6 % Federal National Mortgage Association, Pool TBA, 3.50%, 09/15/54 2.0 % U.S. Treasury Note, 3.75%, 08/15/27 1.9 % U.S. Treasury Bond, 4.63%, 05/15/44 1.5 % Credit Quality (1) (1) The credit quality and ratings information presented above reflect the ratings assigned by one or more nationally recognized statistical rating organizations (NRSROs), including S&P Global Ratings, Moody’s Investors Service, Inc., Fitch Ratings, or a comparably rated NRSRO. For situations in which a security is rated by more than one NRSRO and the ratings are not equivalent, the lowest ratings are used. Sub-investment grade ratings are those rated BB+/Ba1 or lower. Investment grade ratings are those rated BBB-/Baa3 or higher. The credit ratings shown relate to the creditworthiness of the issuers of the underlying securities in the Fund, and not to the Fund or its shares. U.S. Treasury, U.S. Agency and U.S. Agency mortgage-backed securities appear under “Government/Agency.” Credit ratings are subject to change. Any amount shown as 0.0% represents less than 0.1%. | |
| Credit Quality Explanation [Text Block] | The credit quality and ratings information presented above reflect the ratings assigned by one or more nationally recognized statistical rating organizations (NRSROs), including S&P Global Ratings, Moody’s Investors Service, Inc., Fitch Ratings, or a comparably rated NRSRO. For situations in which a security is rated by more than one NRSRO and the ratings are not equivalent, the lowest ratings are used. Sub-investment grade ratings are those rated BB+/Ba1 or lower. Investment grade ratings are those rated BBB-/Baa3 or higher. The credit ratings shown relate to the creditworthiness of the issuers of the underlying securities in the Fund, and not to the Fund or its shares. U.S. Treasury, U.S. Agency and U.S. Agency mortgage-backed securities appear under “Government/Agency.” Credit ratings are subject to change. | |
| Credit Ratings Selection [Text Block] | The credit quality and ratings information presented above reflect the ratings assigned by one or more nationally recognized statistical rating organizations (NRSROs), including S&P Global Ratings, Moody’s Investors Service, Inc., Fitch Ratings, or a comparably rated NRSRO. | |
| Largest Holdings [Text Block] | Top Ten Holdings Dreyfus Government Cash Management Fund, Institutional Shares, Class I, 5.19% 11.7 % U.S. Treasury Note, 4.00%, 07/31/29 6.9 % U.S. Treasury Note, 3.63%, 08/31/29 6.6 % U.S. Treasury Note, 3.88%, 08/15/34 4.2 % U.S. Treasury Bond, 4.25%, 08/15/54 3.8 % U.S. Treasury Bond, 4.13%, 08/15/44 2.9 % U.S. Treasury Note, 3.75%, 08/31/26 2.6 % Federal National Mortgage Association, Pool TBA, 3.50%, 09/15/54 2.0 % U.S. Treasury Note, 3.75%, 08/15/27 1.9 % U.S. Treasury Bond, 4.63%, 05/15/44 1.5 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/FIXD info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s principal investment strategies were revised to reflect that the Fund’s average portfolio duration varies within 1.5 years (previously 1 year) of the portfolio duration of the securities comprising the Bloomberg U.S. Aggregate Bond Index. Effective December 31, 2024, Stephen M. Kane will retire from the Fund’s investment sub-advisor and will no longer serve as a portfolio manager of the Fund. | |
| Material Fund Change Strategies [Text Block] | During the fiscal year ended August 31, 2024, the Fund’s principal investment strategies were revised to reflect that the Fund’s average portfolio duration varies within 1.5 years (previously 1 year) of the portfolio duration of the securities comprising the Bloomberg U.S. Aggregate Bond Index. Effective December 31, 2024, Stephen M. Kane will retire from the Fund’s investment sub-advisor and will no longer serve as a portfolio manager of the Fund. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/FIXD | |
| C000220038 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. Equity Deep Buffer ETF - July | |
| Class Name | FT Vest U.S. Equity Deep Buffer ETF - July | |
| Trading Symbol | DJUL | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Deep Buffer ETF - July (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/DJUL info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/DJUL | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Deep Buffer ETF - July $ 0.85 % | |
| Expenses Paid, Amount | $ 92 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 16.68% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 12.46 % Changes in other Variables 5.07 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (July 17, 2020 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Deep Buffer ETF - July 16.68 % 7.53 % S&P 500 ® 27.14 % 16.35 % | |
| Performance Inception Date | Jul. 17, 2020 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/DJUL | |
| Net Assets | $ 353,841,862 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 3,090,265 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 1.0 % Purchased Options 101.3 % Written Options (2.2 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/DJUL info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/DJUL | |
| C000221311 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. EquityDeep Buffer ETF - September | |
| Class Name | FT Vest U.S. EquityDeep Buffer ETF - September | |
| Trading Symbol | DSEP | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Deep Buffer ETF - September (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/DSEP info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/DSEP | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Deep Buffer ETF - September $ 0.85 % | |
| Expenses Paid, Amount | $ 91 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 13.57% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 10.09 % Changes in other Variables 4.33 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (September 18, 2020 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Deep Buffer ETF - September 13.57 % 7.55 % S&P 500 ® 27.14 % 16.18 % | |
| Performance Inception Date | Sep. 18, 2020 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/DSEP | |
| Net Assets | $ 179,523,180 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 1,549,018 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.3 % Purchased Options 110.2 % Written Options (10.4 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/DSEP info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/DSEP | |
| C000223224 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. Equity Buffer ETF - December | |
| Class Name | FT Vest U.S. Equity Buffer ETF - December | |
| Trading Symbol | FDEC | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Buffer ETF - December (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/FDEC info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/FDEC | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Buffer ETF - December $ 0.85 % | |
| Expenses Paid, Amount | $ 93 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 18.84% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 15.30 % Changes in other Variables 4.39 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (December 18, 2020 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Buffer ETF - December 18.84 % 10.26 % S&P 500 ® 27.14 % 13.76 % | |
| Performance Inception Date | Dec. 18, 2020 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/FDEC | |
| Net Assets | $ 723,659,054 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 5,371,114 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.5 % Purchased Options 105.8 % Written Options (6.2 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/FDEC info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/FDEC | |
| C000223318 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest International Equity ModerateBuffer ETF - December | |
| Class Name | FT Vest International Equity ModerateBuffer ETF - December | |
| Trading Symbol | YDEC | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest International Equity Moderate Buffer ETF - December (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/YDEC info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/YDEC | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest International Equity Moderate Buffer ETF - December $ 0.90 % | |
| Expenses Paid, Amount | $ 96 | |
| Expense Ratio, Percent | 0.90% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 13.37% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the MSCI EAFE Index, which returned 19.40% for the same Period. This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 11.23 % Changes in other Variables 3.04 % Fees and Expenses -0.90 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (December 18, 2020 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest International Equity Moderate Buffer ETF - December 13.37 % 5.75 % MSCI EAFE Index 19.40 % 6.67 % | |
| Performance Inception Date | Dec. 18, 2020 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Dec. 18, 2023 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/YDEC | |
| Net Assets | $ 70,311,374 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 651,681 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.6 % Purchased Options 100.6 % Written Options (1.1 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/YDEC info ftportfolios.com Effective December 18, 2023, the name of the Fund changed from “FT Vest International Equity Buffer ETF - December” to “FT Vest International Equity Moderate Buffer ETF - December”, the Fund’s buffer against Underlying ETF losses increased from 10% to 15%, and the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Material Fund Change Name [Text Block] | Effective December 18, 2023, the name of the Fund changed from “FT Vest International Equity Buffer ETF - December” to “FT Vest International Equity Moderate Buffer ETF - December”, the Fund’s buffer against Underlying ETF losses increased from 10% to 15%, and the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/YDEC | |
| C000230440 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | First Trust Multi-ManagerSmall Cap Opportunities ETF | |
| Class Name | First Trust Multi-ManagerSmall Cap Opportunities ETF | |
| Trading Symbol | MMSC | |
| Security Exchange Name | NYSEArca | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the First Trust Multi-Manager Small Cap Opportunities ETF (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/MMSC info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/MMSC | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage First Trust Multi-Manager Small Cap Opportunities ETF $ 0.95 % | |
| Expenses Paid, Amount | $ 106 | |
| Expense Ratio, Percent | 0.95% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 23.06% for the 12 months ended August 31, 2024. The Fund outperformed its benchmark, the Russell 2000 ® The outperformance was largely due to selection within the Industrials sector, followed by selection within the Consumer Discretionary and the Energy sectors. In the Industrials sector, an off-benchmark position in Axon Enterprise, Inc., up 71.4%, benefitted Fund performance as the company reported record sales, raised guidance, and saw excitement around its Artificial Intelligence product. An overweight to FTAI Aviation Ltd. was also beneficial as the stock was up 252.5% as the company continued to report strong numbers and see continued growth. In the Consumer Discretionary sector, an off-benchmark position in Wingstop, Inc. was additive with the restaurant up 141.0% in the Period. Selection in the Energy sector was also additive with the benchmark holdings in the sector down and the holdings in the Fund putting up positive performance. Detracting from relative performance was selection in the Information Technology sector as the Fund’s holdings underperformed the benchmark. An allocation to cash was a drag on returns versus the benchmark in an up market. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (October 13, 2021 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since First Trust Multi-Manager Small Cap Opportunities ETF 23.06 % -0.03 % Russell 2000 ® 17.67 % -1.20 % Russell 3000 ® 26.14 % 9.36 % | |
| Performance Inception Date | Oct. 13, 2021 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/MMSC | |
| Net Assets | $ 21,177,786 | |
| Holdings Count | Holding | 199 | |
| Advisory Fees Paid, Amount | $ 108,422 | |
| Investment Company Portfolio Turnover | 86% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 199 Total advisory fee paid $ Portfolio turnover rate 86 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The tables below show the investment makeup of the Fund, representing the percentage of total investments of the Fund. Top Ten Holdings Axon Enterprise, Inc. 2.0 % CyberArk Software Ltd. 1.8 % TransMedics Group, Inc. 1.4 % Leonardo DRS, Inc. 1.4 % BellRing Brands, Inc. 1.3 % Crinetics Pharmaceuticals, Inc. 1.3 % Varonis Systems, Inc. 1.3 % Onto Innovation, Inc. 1.2 % Palomar Holdings, Inc. 1.2 % Wingstop, Inc. 1.2 % Sector Allocation | |
| Largest Holdings [Text Block] | Top Ten Holdings Axon Enterprise, Inc. 2.0 % CyberArk Software Ltd. 1.8 % TransMedics Group, Inc. 1.4 % Leonardo DRS, Inc. 1.4 % BellRing Brands, Inc. 1.3 % Crinetics Pharmaceuticals, Inc. 1.3 % Varonis Systems, Inc. 1.3 % Onto Innovation, Inc. 1.2 % Palomar Holdings, Inc. 1.2 % Wingstop, Inc. 1.2 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/MMSC info ftportfolios.com The Fund may have significant investments in various jurisdictions or investment sectors from time to time, making the Fund subject to the risks of such jurisdictions or investment sectors. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/MMSC | |
| C000236305 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest Laddered Nasdaq Buffer ETF | |
| Class Name | FT Vest Laddered Nasdaq Buffer ETF | |
| Trading Symbol | BUFQ | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest Laddered Nasdaq Buffer ETF (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/BUFQ info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/BUFQ | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest Laddered Nasdaq Buffer ETF $ (1) 0.19 % (1) (1) Excludes any Acquired Fund Fees and Expenses of underlying investment companies in which the Fund invests. | |
| Expenses Paid, Amount | $ 21 | [18] |
| Expense Ratio, Percent | 0.19% | [18] |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 16.97% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the Nasdaq-100 Index ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 11.14 % Changes in other Variables 6.93 % Fees and Expenses** -1.10 % The Fund holds a portfolio that consists of a number of buffer funds, and thus is exposed to the combinations of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the underlying buffer funds’ Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. ** Includes any Acquired Fund Fees and Expenses of underlying investment companies in which the Fund invests. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (June 15, 2022 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest Laddered Nasdaq Buffer ETF 16.97 % 18.60 % Nasdaq-100 Index ® 27.30 % 27.81 % S&P 500 ® 27.14 % 21.69 % | |
| Performance Inception Date | Jun. 15, 2022 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | May 10, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/BUFQ | |
| Net Assets | $ 710,358,652 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 845,615 | |
| Investment Company Portfolio Turnover | 1% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 1 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Exchange-Traded Funds 100.0 % Money Market Funds 0.0 % Net Other Assets and Liabilities (0.0 % ) Total 100.0 % Any amount shown as 0.0% represents less than 0.1%. | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/BUFQ info ftportfolios.com Effective May 10, 2024, the name of the Fund changed from “FT Vest Fund of Nasdaq-100 ® | |
| Material Fund Change Name [Text Block] | Effective May 10, 2024, the name of the Fund changed from “FT Vest Fund of Nasdaq-100 ® | |
| Material Fund Change Expenses [Text Block] | Pursuant to a contractual agreement, effective August 1, 2024, the Fund’s investment advisor agreed to waive management fees of 0.10% of average daily net assets through December 31, 2025. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/BUFQ | |
| C000240186 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. EquityModerate Buffer ETF - January | |
| Class Name | FT Vest U.S. EquityModerate Buffer ETF - January | |
| Trading Symbol | GJAN | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Moderate Buffer ETF - January (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/GJAN info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/GJAN | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Moderate Buffer ETF - January $ 0.85 % | |
| Expenses Paid, Amount | $ 91 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 13.95% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 10.13 % Changes in other Variables 4.67 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (January 20, 2023 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Moderate Buffer ETF - January 13.95 % 14.78 % S&P 500 ® 27.14 % 26.36 % | |
| Performance Inception Date | Jan. 20, 2023 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/GJAN | |
| Net Assets | $ 253,631,076 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 1,808,424 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.6 % Purchased Options 106.9 % Written Options (7.4 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/GJAN info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/GJAN | |
| C000241255 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. EquityEnhance & Moderate Buffer ETF - March | |
| Class Name | FT Vest U.S. EquityEnhance & Moderate Buffer ETF - March | |
| Trading Symbol | XMAR | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Enhance & Moderate Buffer ETF - March (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/XMAR info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/XMAR | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Enhance & Moderate Buffer ETF - March $ 0.85 % | |
| Expenses Paid, Amount | $ 89 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 10.46% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 5.77 % Changes in other Variables 5.54 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (March 17, 2023 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Enhance & Moderate Buffer ETF - March 10.46 % 12.65 % S&P 500 ® 27.14 % 30.49 % | |
| Performance Inception Date | Mar. 17, 2023 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/XMAR | |
| Net Assets | $ 182,479,544 | |
| Holdings Count | Holding | 6 | |
| Advisory Fees Paid, Amount | $ 1,763,997 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 6 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.7 % Purchased Options 117.7 % Written Options (18.3 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/XMAR info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/XMAR | |
| C000215122 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | First Trust Active Factor Large Cap ETF | |
| Class Name | First Trust Active Factor Large Cap ETF | |
| Trading Symbol | AFLG | |
| Security Exchange Name | NYSEArca | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the First Trust Active Factor Large Cap ETF (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/AFLG info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/AFLG | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage First Trust Active Factor Large Cap ETF $ 0.55 % | |
| Expenses Paid, Amount | $ 64 | |
| Expense Ratio, Percent | 0.55% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 31.10% for the 12 months ended August 31, 2024. The Fund outperformed its benchmark, the S&P 500 ® This outperformance was largely attributable to strong performance from the momentum and quality factors. Both quality and momentum were overweight the Technology sector, which was the best performing sector. In addition, both selection and industry effects added to performance. By contrast, the value and small size factors subtracted from the Fund’s returns as the largest stocks in the benchmark continued to outpace the broader market during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (December 3, 2019 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since First Trust Active Factor Large Cap ETF 31.10 % 12.90 % S&P 500 ® 27.14 % 15.37 % | |
| Performance Inception Date | Dec. 03, 2019 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/AFLG | |
| Net Assets | $ 18,324,103 | |
| Holdings Count | Holding | 253 | |
| Advisory Fees Paid, Amount | $ 40,712 | |
| Investment Company Portfolio Turnover | 48% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 253 Total advisory fee paid $ Portfolio turnover rate 48 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The tables below show the investment makeup of the Fund, representing the percentage of total investments of the Fund. Top Ten Holdings Apple, Inc. 7.5 % Microsoft Corp. 4.9 % NVIDIA Corp. 4.7 % Alphabet, Inc., Class A 2.0 % Berkshire Hathaway, Inc., Class B 1.7 % Amazon.com, Inc. 1.7 % Meta Platforms, Inc., Class A 1.5 % Broadcom, Inc. 1.3 % Hartford Financial Services Group (The), Inc. 1.1 % Universal Health Services, Inc., Class B 1.1 % Sector Allocation | |
| Largest Holdings [Text Block] | Top Ten Holdings Apple, Inc. 7.5 % Microsoft Corp. 4.9 % NVIDIA Corp. 4.7 % Alphabet, Inc., Class A 2.0 % Berkshire Hathaway, Inc., Class B 1.7 % Amazon.com, Inc. 1.7 % Meta Platforms, Inc., Class A 1.5 % Broadcom, Inc. 1.3 % Hartford Financial Services Group (The), Inc. 1.1 % Universal Health Services, Inc., Class B 1.1 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/AFLG info ftportfolios.com The Fund may have significant investments in various jurisdictions or investment sectors from time to time, making the Fund subject to the risks of such jurisdictions or investment sectors. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/AFLG | |
| C000216581 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | First Trust Multi-ManagerLarge Growth ETF | |
| Class Name | First Trust Multi-ManagerLarge Growth ETF | |
| Trading Symbol | MMLG | |
| Security Exchange Name | NYSEArca | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the First Trust Multi-Manager Large Growth ETF (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/MMLG info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/MMLG | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage First Trust Multi-Manager Large Growth ETF $ 0.85 % | |
| Expenses Paid, Amount | $ 97 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 27.91% for the 12 months ended August 31, 2024. The Fund underperformed its benchmark, the Russell 1000 ® This underperformance was driven by the Fund’s positions in the Health Care sector where selection detracted from performance relative to the benchmark. An overweight to Dexcom, Inc., which works with devices for glucose monitoring for diabetes, returned -31.3% over the Period after reporting weak revenue and guidance. Additionally, the Fund was overweight to 10x Genomics, Inc., which was down 55.0% for the Period with an unfavorable ruling in a patent infringement case in Germany and a competitor gaining reach in the space. Selection in the Information Technology sector was also a detractor. An overweight to Snowflake, Inc., a software solutions company, detracted as the company traded down 27.2%. An overweight to Atlassian Corp. hurt performance as the name was down 18.9%. An overweight to Entegris, Inc. hurt Fund performance as the name was up but less than the benchmark. An off-benchmark position in ASML Holding N.V. returned -13.4% and also hurt Fund performance. Offsetting some losses was selection in the Consumer Discretionary sector which was up approximately 12.2% for the benchmark and the Fund outperformed. Additionally, the Fund’s selection within the Communication Services sector also aided returns as the Fund’s sector holdings outpaced the benchmark. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (July 21, 2020 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since First Trust Multi-Manager Large Growth ETF 27.91 % 8.63 % Russell 1000 ® 30.75 % 16.25 % Russell 1000 ® 26.60 % 15.58 % | |
| Performance Inception Date | Jul. 21, 2020 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/MMLG | |
| Net Assets | $ 69,550,338 | |
| Holdings Count | Holding | 77 | |
| Advisory Fees Paid, Amount | $ 501,843 | |
| Investment Company Portfolio Turnover | 41% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 77 Total advisory fee paid $ Portfolio turnover rate 41 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The tables below show the investment makeup of the Fund, representing the percentage of total investments of the Fund. Top Ten Holdings NVIDIA Corp. 9.3 % Microsoft Corp. 7.7 % Amazon.com, Inc. 6.5 % Apple, Inc. 4.7 % Meta Platforms, Inc., Class A 4.6 % ServiceNow, Inc. 4.1 % Alphabet, Inc., Class A 2.9 % Netflix, Inc. 2.4 % ASML Holding N.V. 2.2 % Eli Lilly & Co. 2.1 % Sector Allocation | |
| Largest Holdings [Text Block] | Top Ten Holdings NVIDIA Corp. 9.3 % Microsoft Corp. 7.7 % Amazon.com, Inc. 6.5 % Apple, Inc. 4.7 % Meta Platforms, Inc., Class A 4.6 % ServiceNow, Inc. 4.1 % Alphabet, Inc., Class A 2.9 % Netflix, Inc. 2.4 % ASML Holding N.V. 2.2 % Eli Lilly & Co. 2.1 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/MMLG info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s diversification status under the Investment Company Act of 1940 changed from non-diversified to diversified. The Fund’s principal investment strategies and principal risks were revised accordingly. | |
| Material Fund Change Strategies [Text Block] | During the fiscal year ended August 31, 2024, the Fund’s diversification status under the Investment Company Act of 1940 changed from non-diversified to diversified. The Fund’s principal investment strategies and principal risks were revised accordingly. | |
| Material Fund Change Risks Change [Text Block] | During the fiscal year ended August 31, 2024, the Fund’s diversification status under the Investment Company Act of 1940 changed from non-diversified to diversified. The Fund’s principal investment strategies and principal risks were revised accordingly. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/MMLG | |
| C000218407 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. Equity Buffer ETF - May | |
| Class Name | FT Vest U.S. Equity Buffer ETF - May | |
| Trading Symbol | FMAY | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Buffer ETF - May (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/FMAY info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/FMAY | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Buffer ETF - May $ 0.85 % | |
| Expenses Paid, Amount | $ 92 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 16.37% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 12.31 % Changes in other Variables 4.91 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (May 15, 2020 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Buffer ETF - May 16.37 % 10.09 % S&P 500 ® 27.14 % 18.97 % | |
| Performance Inception Date | May 15, 2020 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/FMAY | |
| Net Assets | $ 823,199,153 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 5,195,218 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.9 % Purchased Options 102.2 % Written Options (3.0 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/FMAY info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/FMAY | |
| C000219511 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest Laddered Buffer ETF | |
| Class Name | FT Vest Laddered Buffer ETF | |
| Trading Symbol | BUFR | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest Laddered Buffer ETF (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/BUFR info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/BUFR | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest Laddered Buffer ETF $ (1) 0.19 % (1) (1) Excludes any Acquired Fund Fees and Expenses of underlying investment companies in which the Fund invests. | |
| Expenses Paid, Amount | $ 21 | [19] |
| Expense Ratio, Percent | 0.19% | [19] |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 16.73% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 12.38 % Changes in other Variables 5.40 % Fees and Expenses** -1.05 % The Fund holds a portfolio that consists of a number of buffer funds, and thus is exposed to the combinations of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the underlying buffer funds’ Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. ** Includes any Acquired Fund Fees and Expenses of underlying investment companies in which the Fund invests. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (August 10, 2020 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest Laddered Buffer ETF 16.73 % 10.06 % S&P 500 ® 27.14 % 15.43 % | |
| Performance Inception Date | Aug. 10, 2020 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | May 10, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/BUFR | |
| Net Assets | $ 5,093,180,782 | |
| Holdings Count | Holding | 13 | |
| Advisory Fees Paid, Amount | $ 6,347,411 | |
| Investment Company Portfolio Turnover | 1% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 13 Total advisory fee paid $ Portfolio turnover rate 1 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Exchange-Traded Funds 100.0 % Money Market Funds 0.0 % Net Other Assets and Liabilities (0.0 % ) Total 100.0 % Any amount shown as 0.0% represents less than 0.1%. | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/BUFR info ftportfolios.com Effective May 10, 2024, the name of the Fund changed from “FT Vest Fund of Buffer ETFs” to “FT Vest Laddered Buffer ETF.” During the fiscal year ended August 31, 2024, the Fund’s diversification status under the Investment Company Act of 1940 changed from non-diversified to diversified. The Fund’s principal investment strategies and principal risks were revised accordingly. Pursuant to a contractual agreement, effective August 1, 2024, the Fund’s investment advisor agreed to waive management fees of 0.10% of average daily net assets through December 31, 2025. | |
| Material Fund Change Name [Text Block] | Effective May 10, 2024, the name of the Fund changed from “FT Vest Fund of Buffer ETFs” to “FT Vest Laddered Buffer ETF.” | |
| Material Fund Change Expenses [Text Block] | Pursuant to a contractual agreement, effective August 1, 2024, the Fund’s investment advisor agreed to waive management fees of 0.10% of average daily net assets through December 31, 2025. | |
| Material Fund Change Strategies [Text Block] | During the fiscal year ended August 31, 2024, the Fund’s diversification status under the Investment Company Act of 1940 changed from non-diversified to diversified. The Fund’s principal investment strategies and principal risks were revised accordingly. | |
| Material Fund Change Risks Change [Text Block] | During the fiscal year ended August 31, 2024, the Fund’s diversification status under the Investment Company Act of 1940 changed from non-diversified to diversified. The Fund’s principal investment strategies and principal risks were revised accordingly. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/BUFR | |
| C000217668 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. Equity Buffer ETF - February | |
| Class Name | FT Vest U.S. Equity Buffer ETF - February | |
| Trading Symbol | FFEB | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Buffer ETF - February (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/FFEB info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/FFEB | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Buffer ETF - February $ 0.85 % | |
| Expenses Paid, Amount | $ 93 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 19.11% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 15.37 % Changes in other Variables 4.59 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (February 21, 2020 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Buffer ETF - February 19.11 % 10.42 % S&P 500 ® 27.14 % 14.13 % | |
| Performance Inception Date | Feb. 21, 2020 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/FFEB | |
| Net Assets | $ 926,256,152 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 5,697,944 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.7 % Purchased Options 102.8 % Written Options (3.4 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/FFEB info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/FFEB | |
| C000218409 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. Equity Deep Buffer ETF - May | |
| Class Name | FT Vest U.S. Equity Deep Buffer ETF - May | |
| Trading Symbol | DMAY | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Deep Buffer ETF - May (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/DMAY info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/DMAY | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Deep Buffer ETF - May $ 0.85 % | |
| Expenses Paid, Amount | $ 91 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 13.67% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 9.61 % Changes in other Variables 4.91 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (May 15, 2020 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Deep Buffer ETF - May 13.67 % 6.32 % S&P 500 ® 27.14 % 18.97 % | |
| Performance Inception Date | May 15, 2020 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/DMAY | |
| Net Assets | $ 314,939,085 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 1,761,852 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.9 % Purchased Options 101.5 % Written Options (2.3 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/DMAY info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/DMAY | |
| C000219662 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. Equity Buffer ETF - June | |
| Class Name | FT Vest U.S. Equity Buffer ETF - June | |
| Trading Symbol | FJUN | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Buffer ETF - June (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/FJUN info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/FJUN | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Buffer ETF - June $ 0.85 % | |
| Expenses Paid, Amount | $ 93 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 18.04% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 14.90 % Changes in other Variables 3.99 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (June 19, 2020 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Buffer ETF - June 18.04 % 12.56 % S&P 500 ® 27.14 % 17.17 % | |
| Performance Inception Date | Jun. 19, 2020 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/FJUN | |
| Net Assets | $ 816,700,692 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 5,470,813 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 1.0 % Purchased Options 101.9 % Written Options (2.8 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/FJUN info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/FJUN | |
| C000220040 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. Equity Buffer ETF - July | |
| Class Name | FT Vest U.S. Equity Buffer ETF - July | |
| Trading Symbol | FJUL | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Buffer ETF - July (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/FJUL info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/FJUL | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Buffer ETF - July $ 0.85 % | |
| Expenses Paid, Amount | $ 93 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 19.51% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 14.94 % Changes in other Variables 5.42 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (July 17, 2020 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Buffer ETF - July 19.51 % 11.49 % S&P 500 ® 27.14 % 16.35 % | |
| Performance Inception Date | Jul. 17, 2020 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/FJUL | |
| Net Assets | $ 828,703,694 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 5,395,755 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 1.1 % Purchased Options 102.1 % Written Options (3.1 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/FJUL info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/FJUL | |
| C000227834 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest International Equity Moderate Buffer ETF - June | |
| Class Name | FT Vest International Equity Moderate Buffer ETF - June | |
| Trading Symbol | YJUN | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest International Equity Moderate Buffer ETF - June (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/YJUN info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/YJUN | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest International Equity Moderate Buffer ETF - June $ 0.90 % | |
| Expenses Paid, Amount | $ 95 | |
| Expense Ratio, Percent | 0.90% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 12.03% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the MSCI EAFE Index, which returned 19.40% for the same Period. This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 11.37 % Changes in other Variables 1.56 % Fees and Expenses -0.90 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (June 18, 2021 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest International Equity Moderate Buffer ETF - June 12.03 % 4.01 % MSCI EAFE Index 19.40 % 4.65 % | |
| Performance Inception Date | Jun. 18, 2021 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Jun. 24, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/YJUN | |
| Net Assets | $ 174,275,037 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 1,372,586 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 1.1 % Purchased Options 102.5 % Written Options (3.5 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/YJUN info ftportfolios.com Effective June 24, 2024, the name of the Fund changed from “FT Vest International Equity Buffer ETF - June” to “FT Vest International Equity Moderate Buffer ETF - June”, the Fund’s buffer against Underlying ETF losses increased from 10% to 15%, and the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Material Fund Change Name [Text Block] | Effective June 24, 2024, the name of the Fund changed from “FT Vest International Equity Buffer ETF - June” to “FT Vest International Equity Moderate Buffer ETF - June”, the Fund’s buffer against Underlying ETF losses increased from 10% to 15%, and the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/YJUN | |
| C000230301 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. EquityEnhance & Moderate Buffer ETF - December | |
| Class Name | FT Vest U.S. EquityEnhance & Moderate Buffer ETF - December | |
| Trading Symbol | XDEC | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Enhance & Moderate Buffer ETF - December (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/XDEC info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/XDEC | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Enhance & Moderate Buffer ETF - December $ 0.85 % | |
| Expenses Paid, Amount | $ 89 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 10.25% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 6.11 % Changes in other Variables 4.99 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (December 17, 2021 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Enhance & Moderate Buffer ETF - December 10.25 % 7.13 % S&P 500 ® 27.14 % 9.42 % | |
| Performance Inception Date | Dec. 17, 2021 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/XDEC | |
| Net Assets | $ 325,381,283 | |
| Holdings Count | Holding | 6 | |
| Advisory Fees Paid, Amount | $ 3,044,445 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 6 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.5 % Purchased Options 130.5 % Written Options (30.9 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/XDEC info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/XDEC | |
| C000231328 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest Buffered Allocation Growth ETF | |
| Class Name | FT Vest Buffered Allocation Growth ETF | |
| Trading Symbol | BUFG | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest Buffered Allocation Growth ETF (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/BUFG info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/BUFG | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest Buffered Allocation Growth ETF $ (1) 0.20 % (1) (1) Excludes any Acquired Fund Fees and Expenses of underlying investment companies in which the Fund invests. | |
| Expenses Paid, Amount | $ 22 | [20] |
| Expense Ratio, Percent | 0.20% | [20] |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 16.72% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 16.86 % Changes in other Variables 0.91 % Fees and Expenses** -1.05 % The Fund holds a portfolio that consists of a number of buffer funds, and thus is exposed to the combinations of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the underlying buffer funds’ Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. ** Includes any Acquired Fund Fees and Expenses of underlying investment companies in which the Fund invests. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (October 26, 2021 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest Buffered Allocation Growth ETF 16.72 % 6.28 % S&P 500 ® 27.14 % 9.40 % | |
| Performance Inception Date | Oct. 26, 2021 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Mar. 13, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/BUFG | |
| Net Assets | $ 237,980,706 | |
| Holdings Count | Holding | 8 | |
| Advisory Fees Paid, Amount | $ 394,572 | |
| Investment Company Portfolio Turnover | 347% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 8 Total advisory fee paid $ Portfolio turnover rate 347 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Exchange-Traded Funds 99.7 % Money Market Funds 0.3 % Net Other Assets and Liabilities (0.0 % ) Total 100.0 % Any amount shown as 0.0% represents less than 0.1% | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/BUFG info ftportfolios.com Effective March 13, 2024, the Fund’s principal investment strategies were revised to permit the universe of Underlying ETFs to also include investments in the series of FT Vest U.S. Equity Moderate Buffer ETFs and for the Fund’s portfolio to be evaluated on a quarterly, instead of monthly, basis. | |
| Material Fund Change Strategies [Text Block] | Effective March 13, 2024, the Fund’s principal investment strategies were revised to permit the universe of Underlying ETFs to also include investments in the series of FT Vest U.S. Equity Moderate Buffer ETFs and for the Fund’s portfolio to be evaluated on a quarterly, instead of monthly, basis. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/BUFG | |
| C000244790 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. EquityBuffer & Premium Income ETF - September | |
| Class Name | FT Vest U.S. EquityBuffer & Premium Income ETF - September | |
| Trading Symbol | XISE | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Buffer & Premium Income ETF - September (the “Fund”) for the period of September 15, 2023 (commencement of investment operations) to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/XISE info ftportfolios.com | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/XISE | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Buffer & Premium Income ETF - September $ (1) 0.85 % (2) (1) The Fund commenced investment operations on September 15, 2023. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher. (2) Annualized. | |
| Expenses Paid, Amount | $ 85 | [21] |
| Expense Ratio, Percent | 0.85% | [22] |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 7.31% for the period from the Fund’s inception date on September 15, 2023 through August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 9.78 % Changes in other Variables -1.66 % Fees and Expenses -0.81 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (September 15, 2023 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) Since FT Vest U.S. Equity Buffer & Premium Income ETF - September 7.31 % S&P 500 ® 28.68 % | |
| Performance Inception Date | Sep. 15, 2023 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/XISE | |
| Net Assets | $ 78,442,428 | |
| Holdings Count | Holding | 6 | |
| Advisory Fees Paid, Amount | $ 398,593 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 6 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation U.S. Treasury Bills 0.6 % Money Market Funds 0.8 % Purchased Options 125.5 % Written Options (26.8 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| C000245574 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. EquityEnhance & Moderate Buffer ETF - January | |
| Class Name | FT Vest U.S. EquityEnhance & Moderate Buffer ETF - January | |
| Trading Symbol | XJAN | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Enhance & Moderate Buffer ETF - January (the “Fund”) for the period of January 19, 2024 (commencement of investment operations) to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/XJAN info ftportfolios.com | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/XJAN | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Enhance & Moderate Buffer ETF - January $ (1) 0.85 % (2) (1) The Fund commenced investment operations on January 19, 2024. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher. (2) Annualized. | |
| Expenses Paid, Amount | $ 54 | [23] |
| Expense Ratio, Percent | 0.85% | [24] |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 6.84% for the period from the Fund’s inception date on January 19, 2024 through August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 4.43 % Changes in other Variables 2.93 % Fees and Expenses -0.52 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (January 19, 2024 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) Since FT Vest U.S. Equity Enhance & Moderate Buffer ETF - January 6.84 % S&P 500 ® 17.72 % | |
| Performance Inception Date | Jan. 19, 2024 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/XJAN | |
| Net Assets | $ 56,062,713 | |
| Holdings Count | Holding | 6 | |
| Advisory Fees Paid, Amount | $ 411,099 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 6 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.6 % Purchased Options 126.5 % Written Options (27.0 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| C000245577 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. EquityEnhance & Moderate Buffer ETF - October | |
| Class Name | FT Vest U.S. EquityEnhance & Moderate Buffer ETF - October | |
| Trading Symbol | XOCT | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Enhance & Moderate Buffer ETF - October (the “Fund”) for the period of October 20, 2023 (commencement of investment operations) to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/XOCT info ftportfolios.com | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/XOCT | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Enhance & Moderate Buffer ETF - October $ (1) 0.85 % (2) (1) The Fund commenced investment operations on October 20, 2023. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher. (2) Annualized. | |
| Expenses Paid, Amount | $ 78 | [25] |
| Expense Ratio, Percent | 0.85% | [26] |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 11.18% for the period from the Fund’s inception date on ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 5.73 % Changes in other Variables 6.18 % Fees and Expenses -0.73 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (October 20, 2023 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) Since FT Vest U.S. Equity Enhance & Moderate Buffer ETF - October 11.18 % S&P 500 ® 35.42 % | |
| Performance Inception Date | Oct. 20, 2023 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/XOCT | |
| Net Assets | $ 58,173,367 | |
| Holdings Count | Holding | 6 | |
| Advisory Fees Paid, Amount | $ 344,989 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 6 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.4 % Purchased Options 150.0 % Written Options (50.3 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| C000222135 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. Equity Buffer ETF - October | |
| Class Name | FT Vest U.S. Equity Buffer ETF - October | |
| Trading Symbol | FOCT | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Buffer ETF - October (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/FOCT info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/FOCT | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Buffer ETF - October $ 0.85 % | |
| Expenses Paid, Amount | $ 89 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 9.85% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 10.94 % Changes in other Variables -0.24 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (October 16, 2020 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Buffer ETF - October 9.85 % 9.23 % S&P 500 ® 27.14 % 15.04 % | |
| Performance Inception Date | Oct. 16, 2020 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/FOCT | |
| Net Assets | $ 602,383,963 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 4,100,312 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.4 % Purchased Options 113.2 % Written Options (13.5 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/FOCT info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/FOCT | |
| C000223226 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. EquityDeep Buffer ETF - December | |
| Class Name | FT Vest U.S. EquityDeep Buffer ETF - December | |
| Trading Symbol | DDEC | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Deep Buffer ETF - December (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/DDEC info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/DDEC | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Deep Buffer ETF - December $ 0.85 % | |
| Expenses Paid, Amount | $ 91 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 14.58% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 10.83 % Changes in other Variables 4.60 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (December 18, 2020 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Deep Buffer ETF - December 14.58 % 7.25 % S&P 500 ® 27.14 % 13.76 % | |
| Performance Inception Date | Dec. 18, 2020 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/DDEC | |
| Net Assets | $ 322,617,352 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 2,656,770 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.5 % Purchased Options 107.5 % Written Options (7.9 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/DDEC info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/DDEC | |
| C000224230 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. Equity Buffer ETF - January | |
| Class Name | FT Vest U.S. Equity Buffer ETF - January | |
| Trading Symbol | FJAN | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Buffer ETF - January (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/FJAN info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/FJAN | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Buffer ETF - January $ 0.85 % | |
| Expenses Paid, Amount | $ 93 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 17.84% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 13.90 % Changes in other Variables 4.79 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (January 15, 2021 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Buffer ETF - January 17.84 % 11.35 % S&P 500 ® 27.14 % 13.54 % | |
| Performance Inception Date | Jan. 15, 2021 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/FJAN | |
| Net Assets | $ 742,339,869 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 5,001,784 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.6 % Purchased Options 104.9 % Written Options (5.4 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/FJAN info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/FJAN | |
| C000224778 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | First Trust TCW Emerging Markets Debt ETF | |
| Class Name | First Trust TCW Emerging Markets Debt ETF | |
| Trading Symbol | EFIX | |
| Security Exchange Name | NYSEArca | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the First Trust TCW Emerging Markets Debt ETF (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/EFIX info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/EFIX | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage First Trust TCW Emerging Markets Debt ETF $ 0.95 % | |
| Expenses Paid, Amount | $ 102 | |
| Expense Ratio, Percent | 0.95% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 14.63% for the 12 months ended August 31, 2024. The Fund outperformed its benchmark, the JP Morgan Emerging Market Bond Index Global Diversified, which returned 13.42% for the same Period. This outperformance was driven by security selection decisions and an overweight to high yield relative to investment grade (high yield sovereigns returned approximately 18.6% versus 8.5% for investment grade sovereigns.) From a sector perspective, an off-index allocation to corporates also benefited relative performance. From a country perspective, the outperformance for the Period was driven by: Overweight positioning and security selection in Egypt based on our view of support from international partners, market reforms and monetary policy tightening Underweight positioning and security selection in China based on our view of valuations and growth outlook Security selection in Brazil and Colombia Overweight positioning in Pakistan, which benefited from International Monetary Fund support and reduced political uncertainty post elections Security selection in Kazakhstan, particularly select oil & gas quasi-sovereign exposure Overweight positioning and security selection in Chile, particularly select metals & mining quasi-sovereign exposure and other corporate exposure On the other hand, the following hurt relative performance during the Period: Overweight positioning and security selection in Venezuela given an unfavorable election outcome Off-index exposure to oil & gas corporates in Israel due to elevated geopolitical tensions in the region Security selection in the Dominican Republic Overweight positioning in Ghana during the fourth quarter of 2023 Derivative positioning in the Fund is largely focused on a small allocation to currency forwards and intermittent use of credit default swaps for hedging index exposure, both of which had little impact on performance. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (February 17, 2021 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since First Trust TCW Emerging Markets Debt ETF 14.63 % -0.10 % JP Morgan Emerging Market Bond Index Global Diversified 13.42 % -0.71 % | |
| Performance Inception Date | Feb. 17, 2021 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/EFIX | |
| Net Assets | $ 41,904,760 | |
| Holdings Count | Holding | 193 | |
| Advisory Fees Paid, Amount | $ 344,186 | |
| Investment Company Portfolio Turnover | 98% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 193 Total advisory fee paid $ Portfolio turnover rate 98 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The tables below show the investment makeup of the Fund, representing the percentage of total investments of the Fund. Top Ten Holdings Dreyfus Government Cash Management Fund, Institutional Shares, Class I, 5.19% 2.1 % Saudi Government International Bond, 5.75%, 01/16/54 1.7 % Oman Government International Bond, 6.25%, 01/25/31 1.5 % Bahrain Government International Bond, 6.75%, 09/20/29 1.5 % Peruvian Government International Bond, 2.78%, 01/23/31 1.3 % Colombia Government International Bond, 8.75%, 11/14/53 1.3 % Greensaif Pipelines Bidco Sarl, 6.13%, 02/23/38 1.2 % Egypt Government International Bond, 7.30%, 09/30/33 1.2 % Dominican Republic International Bond, 4.50%, 01/30/30 1.2 % Ukraine Government International Bond, 0.00%, 08/01/41 1.2 % Credit Quality (1) (1) The credit quality and ratings information presented above reflect the ratings assigned by one or more nationally recognized statistical rating organizations (NRSROs), including S&P Global Ratings, Moody’s Investors Service, Inc., Fitch Ratings, or a comparably rated NRSRO. For situations in which a security is rated by more than one NRSRO and the ratings are not equivalent, the lowest ratings are used. Sub-investment grade ratings are those rated BB+/Ba1 or lower. Investment grade ratings are those rated BBB-/Baa3 or higher. The credit ratings shown relate to the creditworthiness of the issuers of the underlying securities in the Fund, and not to the Fund or its shares. U.S.Treasury, U.S. Agency and U.S. Agency mortgage-backed securities appear under “Government/Agency.” Credit ratings are subject to change. | |
| Credit Quality Explanation [Text Block] | The credit quality and ratings information presented above reflect the ratings assigned by one or more nationally recognized statistical rating organizations (NRSROs), including S&P Global Ratings, Moody’s Investors Service, Inc., Fitch Ratings, or a comparably rated NRSRO. For situations in which a security is rated by more than one NRSRO and the ratings are not equivalent, the lowest ratings are used. Sub-investment grade ratings are those rated BB+/Ba1 or lower. Investment grade ratings are those rated BBB-/Baa3 or higher. The credit ratings shown relate to the creditworthiness of the issuers of the underlying securities in the Fund, and not to the Fund or its shares. U.S.Treasury, U.S. Agency and U.S. Agency mortgage-backed securities appear under “Government/Agency.” Credit ratings are subject to change. | |
| Credit Ratings Selection [Text Block] | The credit quality and ratings information presented above reflect the ratings assigned by one or more nationally recognized statistical rating organizations (NRSROs), including S&P Global Ratings, Moody’s Investors Service, Inc., Fitch Ratings, or a comparably rated NRSRO. | |
| Largest Holdings [Text Block] | Top Ten Holdings Dreyfus Government Cash Management Fund, Institutional Shares, Class I, 5.19% 2.1 % Saudi Government International Bond, 5.75%, 01/16/54 1.7 % Oman Government International Bond, 6.25%, 01/25/31 1.5 % Bahrain Government International Bond, 6.75%, 09/20/29 1.5 % Peruvian Government International Bond, 2.78%, 01/23/31 1.3 % Colombia Government International Bond, 8.75%, 11/14/53 1.3 % Greensaif Pipelines Bidco Sarl, 6.13%, 02/23/38 1.2 % Egypt Government International Bond, 7.30%, 09/30/33 1.2 % Dominican Republic International Bond, 4.50%, 01/30/30 1.2 % Ukraine Government International Bond, 0.00%, 08/01/41 1.2 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/EFIX info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s diversification status under the Investment Company Act of 1940 changed from non-diversified to diversified. The Fund’s principal investment strategies and principal risks were revised accordingly. | |
| Material Fund Change Strategies [Text Block] | During the fiscal year ended August 31, 2024, the Fund’s diversification status under the Investment Company Act of 1940 changed from non-diversified to diversified. The Fund’s principal investment strategies and principal risks were revised accordingly. | |
| Material Fund Change Risks Change [Text Block] | During the fiscal year ended August 31, 2024, the Fund’s diversification status under the Investment Company Act of 1940 changed from non-diversified to diversified. The Fund’s principal investment strategies and principal risks were revised accordingly. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/EFIX | |
| C000239915 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. Small CapModerate Buffer ETF - May | |
| Class Name | FT Vest U.S. Small CapModerate Buffer ETF - May | |
| Trading Symbol | SMAY | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Small Cap Moderate Buffer ETF - May (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/SMAY info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/SMAY | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Small Cap Moderate Buffer ETF - May $ 0.90 % | |
| Expenses Paid, Amount | $ 97 | |
| Expense Ratio, Percent | 0.90% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 15.95% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the Russell 2000 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 8.76 % Changes in other Variables 8.09 % Fees and Expenses -0.90 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (May 19, 2023 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Small Cap Moderate Buffer ETF - May 15.95 % 16.45 % Russell 2000 ® 18.47 % 20.78 % Russell 3000 ® 26.14 % 27.40 % | |
| Performance Inception Date | May 19, 2023 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/SMAY | |
| Net Assets | $ 76,924,893 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 319,093 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 1.0 % Purchased Options 103.7 % Written Options (4.6 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/SMAY info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/SMAY | |
| C000245575 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. Equity Enhance & Moderate Buffer ETF - May | |
| Class Name | FT Vest U.S. Equity Enhance & Moderate Buffer ETF - May | |
| Trading Symbol | XMAY | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Enhance & Moderate Buffer ETF - May (the “Fund”) for the period of May 17, 2024 (commencement of investment operations) to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/XMAY info ftportfolios.com | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/XMAY | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Enhance & Moderate Buffer ETF - May $ (1) 0.85 % (2) (1) The Fund commenced investment operations on May 17, 2024. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher. (2) Annualized. | |
| Expenses Paid, Amount | $ 25 | [27] |
| Expense Ratio, Percent | 0.85% | [28] |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 3.84% for the period from the Fund’s inception date on May 17, 2024 through August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 2.35 % Changes in other Variables 1.73 % Fees and Expenses -0.24 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (May 17, 2024 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) Since FT Vest U.S. Equity Enhance & Moderate Buffer ETF - May 3.84 % S&P 500 ® 6.91 % | |
| Performance Inception Date | May 17, 2024 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/XMAY | |
| Net Assets | $ 21,552,952 | |
| Holdings Count | Holding | 6 | |
| Advisory Fees Paid, Amount | $ 68,562 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 6 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.9 % Purchased Options 114.6 % Written Options (15.4 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| C000246128 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. Small CapModerate Buffer ETF - November | |
| Class Name | FT Vest U.S. Small CapModerate Buffer ETF - November | |
| Trading Symbol | SNOV | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Small Cap Moderate Buffer ETF - November (the “Fund”) for the period of November 17, 2023 (commencement of investment operations) to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/SNOV info ftportfolios.com | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/SNOV | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Small Cap Moderate Buffer ETF - November $ (1) 0.90 % (2) (1) The Fund commenced investment operations on November 17, 2023. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher. (2) Annualized. | |
| Expenses Paid, Amount | $ 76 | [29] |
| Expense Ratio, Percent | 0.90% | [30] |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 13.82% for the period from the Fund’s inception date on November 17, 2023 through August 31, 2024. The Fund underperformed its benchmark, the Russell 2000 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 9.12 % Changes in other Variables 5.40 % Fees and Expenses -0.70 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (November 17, 2023 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) Since FT Vest U.S. Small Cap Moderate Buffer ETF - November 13.82 % Russell 2000 ® 24.76 % Russell 3000 ® 26.16 % | |
| Performance Inception Date | Nov. 17, 2023 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/SNOV | |
| Net Assets | $ 22,733,685 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 168,302 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.5 % Purchased Options 107.6 % Written Options (8.0 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| C000248689 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. Equity Buffer & Premium Income ETF - March | |
| Class Name | FT Vest U.S. Equity Buffer & Premium Income ETF - March | |
| Trading Symbol | XIMR | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Buffer & Premium Income ETF - March (the “Fund”) for the period of March 18, 2024 (commencement of investment operations) to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/XIMR info ftportfolios.com | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/XIMR | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Buffer & Premium Income ETF - March $ (1) 0.85 % (2) (1) The Fund commenced investment operations on March 18, 2024. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher. (2) Annualized. | |
| Expenses Paid, Amount | $ 40 | [31] |
| Expense Ratio, Percent | 0.85% | [32] |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 3.72% for the period from the Fund’s inception date on March 18, 2024 through August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 1.29 % Changes in other Variables 2.81 % Fees and Expenses -0.38 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (March 18, 2024 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) Since FT Vest U.S. Equity Buffer & Premium Income ETF - March 3.72 % S&P 500 ® 10.36 % | |
| Performance Inception Date | Mar. 18, 2024 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/XIMR | |
| Net Assets | $ 21,066,550 | |
| Holdings Count | Holding | 11 | |
| Advisory Fees Paid, Amount | $ 60,173 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 11 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation U.S. Treasury Bills 3.8 % Money Market Funds 1.2 % Purchased Options 109.3 % Written Options (14.2 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| C000248806 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest Nasdaq-100® Conservative Buffer ETF - April | |
| Class Name | FT Vest Nasdaq-100® Conservative Buffer ETF - April | |
| Trading Symbol | QCAP | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest Nasdaq-100 ® | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/QCAP info ftportfolios.com | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/QCAP | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest Nasdaq-100 ® $ (1) 0.90 % (2) (1) The Fund commenced investment operations on April 19, 2024. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher. (2) Annualized. | |
| Expenses Paid, Amount | $ 34 | [33] |
| Expense Ratio, Percent | 0.90% | [34] |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 7.39% for the period from the Fund’s inception date on April 19, 2024 through August 31, 2024. The Fund underperformed its benchmark, the Nasdaq-100 Index ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 4.41 % Changes in other Variables 3.31 % Fees and Expenses -0.33 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (April 19, 2024 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) Since FT Vest Nasdaq-100 ® 7.39 % Nasdaq-100 Index ® 15.24 % S&P 500 ® 14.29 % | |
| Performance Inception Date | Apr. 19, 2024 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/QCAP | |
| Net Assets | $ 30,981,260 | |
| Holdings Count | Holding | 4 | |
| Advisory Fees Paid, Amount | $ 87,983 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 4 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Purchased Options 107.8 % Written Options (8.5 % ) Net Other Assets and Liabilities 0.7 % Total 100.0 % | |
| C000246681 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. EquityBuffer & Premium Income ETF - December | |
| Class Name | FT Vest U.S. EquityBuffer & Premium Income ETF - December | |
| Trading Symbol | XIDE | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Buffer & Premium Income ETF - December (the “Fund”) for the period of December 15, 2023 (commencement of investment operations) to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/XIDE info ftportfolios.com | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/XIDE | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Buffer & Premium Income ETF - December $ (1) 0.85 % (2) (1) The Fund commenced investment operations on December 15, 2023. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher. (2) Annualized. | |
| Expenses Paid, Amount | $ 62 | [35] |
| Expense Ratio, Percent | 0.85% | [36] |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 5.22% for the period from the Fund’s inception date on December 15, 2023 through August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 1.72 % Changes in other Variables 4.10 % Fees and Expenses -0.60 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (December 15, 2023 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) Since FT Vest U.S. Equity Buffer & Premium Income ETF - December 5.22 % S&P 500 ® 20.86 % | |
| Performance Inception Date | Dec. 15, 2023 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/XIDE | |
| Net Assets | $ 20,529,041 | |
| Holdings Count | Holding | 8 | |
| Advisory Fees Paid, Amount | $ 109,166 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 8 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation U.S. Treasury Bills 2.2 % Money Market Funds 1.0 % Purchased Options 118.5 % Written Options (21.6 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| C000248798 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest Nasdaq-100® Moderate Buffer ETF - August | |
| Class Name | FT Vest Nasdaq-100® Moderate Buffer ETF - August | |
| Trading Symbol | QMAG | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest Nasdaq-100 ® | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/QMAG info ftportfolios.com | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/QMAG | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest Nasdaq-100 ® $ (1) 0.90 % (2) (1) The Fund commenced investment operations on August 16, 2024. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher. (2) Annualized. | |
| Expenses Paid, Amount | $ 4 | [37] |
| Expense Ratio, Percent | 0.90% | [38] |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 0.40% for the period from the Fund’s inception date on August 16, 2024 through August 31, 2024. The Fund outperformed its benchmark, the Nasdaq-100 Index ® This outperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 0.12 % Changes in other Variables 0.31 % Fees and Expenses -0.03 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (August 16, 2024 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) Since FT Vest Nasdaq-100 ® 0.40 % Nasdaq-100 Index ® 0.35 % S&P 500 ® 1.75 % | |
| Performance Inception Date | Aug. 16, 2024 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/QMAG | |
| Net Assets | $ 72,090,340 | |
| Holdings Count | Holding | 4 | |
| Advisory Fees Paid, Amount | $ 10,200 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 4 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Purchased Options 104.4 % Written Options (5.5 % ) Net Other Assets and Liabilities 1.1 % Total 100.0 % | |
| C000248808 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest Nasdaq-100® Conservative Buffer ETF - July | |
| Class Name | FT Vest Nasdaq-100® Conservative Buffer ETF - July | |
| Trading Symbol | QCJL | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest Nasdaq-100 ® | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/QCJL info ftportfolios.com | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/QCJL | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest Nasdaq-100 ® $ (1) 0.90 % (2) (1) The Fund commenced investment operations on July 19, 2024. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher. (2) Annualized. | |
| Expenses Paid, Amount | $ 11 | [39] |
| Expense Ratio, Percent | 0.90% | [40] |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 1.00% for the period from the Fund’s inception date on July 19, 2024 ® This outperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 0.09 % Changes in other Variables 1.01 % Fees and Expenses -0.10 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (July 19, 2024 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) Since FT Vest Nasdaq-100 ® 1.00 % Nasdaq-100 Index ® 0.36 % S&P 500 ® 2.77 % | |
| Performance Inception Date | Jul. 19, 2024 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/QCJL | |
| Net Assets | $ 48,380,430 | |
| Holdings Count | Holding | 4 | |
| Advisory Fees Paid, Amount | $ 37,856 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 4 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Purchased Options 103.5 % Written Options (4.5 % ) Net Other Assets and Liabilities 1.0 % Total 100.0 % | |
| C000246916 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. Small CapModerate Buffer ETF - February | |
| Class Name | FT Vest U.S. Small CapModerate Buffer ETF - February | |
| Trading Symbol | SFEB | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Small Cap Moderate Buffer ETF - February (the “Fund”) for the period of February 16, 2024 (commencement of investment operations) to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/SFEB info ftportfolios.com | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/SFEB | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Small Cap Moderate Buffer ETF - February $ (1) 0.90 % (2) (1) The Fund commenced investment operations on February 16, 2024. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher. (2) Annualized. | |
| Expenses Paid, Amount | $ 50 | [41] |
| Expense Ratio, Percent | 0.90% | [42] |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 6.98% for the period from the Fund’s inception date on ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 4.75 % Changes in other Variables 2.71 % Fees and Expenses -0.48 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (February 16, 2024 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) Since FT Vest U.S. Small Cap Moderate Buffer ETF - February 6.98 % Russell 2000 ® 9.96 % Russell 3000 ® 12.85 % | |
| Performance Inception Date | Feb. 16, 2024 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/SFEB | |
| Net Assets | $ 66,584,615 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 271,851 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.7 % Purchased Options 102.7 % Written Options (3.3 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| C000226539 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. Equity DeepBuffer ETF - April | |
| Class Name | FT Vest U.S. Equity DeepBuffer ETF - April | |
| Trading Symbol | DAPR | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Deep Buffer ETF - April (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/DAPR info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/DAPR | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Deep Buffer ETF - April $ 0.85 % | |
| Expenses Paid, Amount | $ 92 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 16.20% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 9.23 % Changes in other Variables 7.82 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (April 16, 2021 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Deep Buffer ETF - April 16.20 % 5.65 % S&P 500 ® 27.14 % 10.98 % | |
| Performance Inception Date | Apr. 16, 2021 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/DAPR | |
| Net Assets | $ 238,687,735 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 1,851,204 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.8 % Purchased Options 104.6 % Written Options (5.3 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/DAPR info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/DAPR | |
| C000227832 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest Nasdaq-100® Buffer ETF - June | |
| Class Name | FT Vest Nasdaq-100® Buffer ETF - June | |
| Trading Symbol | QJUN | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest Nasdaq-100 ® | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/QJUN info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/QJUN | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest Nasdaq-100 ® $ 0.90 % | |
| Expenses Paid, Amount | $ 98 | |
| Expense Ratio, Percent | 0.90% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 17.51% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the Nasdaq-100 Index ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 13.97 % Changes in other Variables 4.44 % Fees and Expenses -0.90 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (June 18, 2021 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest Nasdaq-100 ® 17.51 % 9.50 % Nasdaq-100 Index ® 27.30 % 11.82 % S&P 500 ® 27.14 % 11.67 % | |
| Performance Inception Date | Jun. 18, 2021 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/QJUN | |
| Net Assets | $ 484,859,527 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 3,369,878 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 1.0 % Purchased Options 103.2 % Written Options (4.1 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/QJUN info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/QJUN | |
| C000230296 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest International Equity Buffer ETF - September (now known as FT Vest International Equity Moderate Buffer ETF - September) | |
| Class Name | FT Vest International Equity Buffer ETF - September (now known as FT Vest International Equity Moderate Buffer ETF - September) | |
| Trading Symbol | YSEP | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest International Equity Buffer ETF - September (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/YSEP info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during and after the reporting period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/YSEP | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest International Equity Buffer ETF - September $ 0.90 % | |
| Expenses Paid, Amount | $ 97 | |
| Expense Ratio, Percent | 0.90% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 15.24% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the MSCI EAFE Index, which returned 19.40% for the same Period. This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 11.98 % Changes in other Variables 4.16 % Fees and Expenses -0.90 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (September 17, 2021 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest International Equity Buffer ETF - September 15.24 % 4.67 % MSCI EAFE Index 19.40 % 4.28 % | |
| Performance Inception Date | Sep. 17, 2021 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Sep. 23, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/YSEP | |
| Net Assets | $ 34,253,525 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 296,994 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.4 % Purchased Options 99.8 % Written Options (0.1 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/YSEP info ftportfolios.com Effective September 23, 2024, the name of the Fund changed from “FT Vest International Equity Buffer ETF - September” to “FT Vest International Equity Moderate Buffer ETF - September”, the Fund’s buffer against Underlying ETF losses increased from 10% to 15%, and the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. Effective September 18, 2023, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Material Fund Change Name [Text Block] | Effective September 23, 2024, the name of the Fund changed from “FT Vest International Equity Buffer ETF - September” to “FT Vest International Equity Moderate Buffer ETF - September”, the Fund’s buffer against Underlying ETF losses increased from 10% to 15%, and the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/YSEP | |
| C000243241 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest Laddered Moderate Buffer ETF | |
| Class Name | FT Vest Laddered Moderate Buffer ETF | |
| Trading Symbol | BUFZ | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest Laddered Moderate Buffer ETF (the “Fund”) for the period of October 25, 2023 (commencement of investment operations) to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/BUFZ info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/BUFZ | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest Laddered Moderate Buffer ETF $ (1) (2) 0.17 % (1) (3) (1) Excludes any Acquired Fund Fees and Expenses of underlying investment companies in which the Fund invests. (2) The Fund commenced investment operations on October 25, 2023. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher. (3) Annualized. | |
| Expenses Paid, Amount | $ 16 | [43],[44] |
| Expense Ratio, Percent | 0.17% | [43],[45] |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 17.47% for the period from the Fund’s inception date on October 25, 2023 through August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 13.03 % Changes in other Variables 5.31 % Fees and Expenses** -0.87 % The Fund holds a portfolio that consists of a number of buffer funds, and thus is exposed to the combinations of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the underlying buffer funds’ Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. ** Includes any Acquired Fund Fees and Expenses of underlying investment companies in which the Fund invests. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (October 25, 2023 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) Since FT Vest Laddered Moderate Buffer ETF 17.47 % S&P 500 ® 36.62 % | |
| Performance Inception Date | Oct. 25, 2023 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 01, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/BUFZ | |
| Net Assets | $ 229,238,047 | |
| Holdings Count | Holding | 13 | |
| Advisory Fees Paid, Amount | $ 115,183 | |
| Investment Company Portfolio Turnover | 1% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 13 Total advisory fee paid $ Portfolio turnover rate 1 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Exchange-Traded Funds 100.0 % Money Market Funds 0.0 % Net Other Assets and Liabilities (0.0 % ) Total 100.0 % Any amount shown as 0.0% represents less than 0.1%. | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/BUFZ info ftportfolios.com Pursuant to a contractual agreement, effective August 1, 2024, the Fund’s investment advisor agreed to waive management fees of 0.10% of average daily net assets through December 31, 2025. | |
| Material Fund Change Expenses [Text Block] | Pursuant to a contractual agreement, effective August 1, 2024, the Fund’s investment advisor agreed to waive management fees of 0.10% of average daily net assets through December 31, 2025. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/BUFZ | |
| C000244041 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. Small CapModerate Buffer ETF - August | |
| Class Name | FT Vest U.S. Small CapModerate Buffer ETF - August | |
| Trading Symbol | SAUG | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Small Cap Moderate Buffer ETF - August (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/SAUG info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/SAUG | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Small Cap Moderate Buffer ETF - August $ 0.90 % | |
| Expenses Paid, Amount | $ 97 | |
| Expense Ratio, Percent | 0.90% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 14.76% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the Russell 2000 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 9.57 % Changes in other Variables 6.09 % Fees and Expenses -0.90 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (August 18, 2023 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Small Cap Moderate Buffer ETF - August 14.76 % 15.99 % Russell 2000 ® 18.47 % 20.31 % Russell 3000 ® 26.14 % 29.05 % | |
| Performance Inception Date | Aug. 18, 2023 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/SAUG | |
| Net Assets | $ 58,121,158 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 317,419 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 1.1 % Purchased Options 104.7 % Written Options (5.8 % ) Net Other Assets and Liabilities 0.0 % Total 100.0 % Any amount shown as 0.0% represents less than 0.1%. | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/SAUG info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/SAUG | |
| C000245573 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. EquityEnhance & Moderate Buffer ETF - February | |
| Class Name | FT Vest U.S. EquityEnhance & Moderate Buffer ETF - February | |
| Trading Symbol | XFEB | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Enhance & Moderate Buffer ETF - February (the “Fund”) for the period of February 16, 2024 (commencement of investment operations) to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/XFEB info ftportfolios.com | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/XFEB | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Enhance & Moderate Buffer ETF - February $ (1) 0.85 % (2) (1) The Fund commenced investment operations on February 16, 2024. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher. (2) Annualized. | |
| Expenses Paid, Amount | $ 47 | [46] |
| Expense Ratio, Percent | 0.85% | [47] |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 6.37% for the period from the Fund’s inception date on February 16, 2024 through August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 4.08 % Changes in other Variables 2.75 % Fees and Expenses -0.46 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (February 16, 2024 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) Since FT Vest U.S. Equity Enhance & Moderate Buffer ETF - February 6.37 % S&P 500 ® 13.67 % | |
| Performance Inception Date | Feb. 16, 2024 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/XFEB | |
| Net Assets | $ 25,501,057 | |
| Holdings Count | Holding | 6 | |
| Advisory Fees Paid, Amount | $ 133,526 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 6 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.7 % Purchased Options 120.9 % Written Options (21.5 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| C000237796 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. Equity Enhance& Moderate Buffer ETF - September | |
| Class Name | FT Vest U.S. Equity Enhance& Moderate Buffer ETF - September | |
| Trading Symbol | XSEP | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Enhance & Moderate Buffer ETF - September (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/XSEP info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/XSEP | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Enhance & Moderate Buffer ETF - September $ 0.85 % | |
| Expenses Paid, Amount | $ 90 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 11.00% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 6.10 % Changes in other Variables 5.75 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (September 21, 2022 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Enhance & Moderate Buffer ETF - September 11.00 % 12.79 % S&P 500 ® 27.14 % 24.75 % | |
| Performance Inception Date | Sep. 21, 2022 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/XSEP | |
| Net Assets | $ 149,680,732 | |
| Holdings Count | Holding | 6 | |
| Advisory Fees Paid, Amount | $ 1,123,821 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 6 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.3 % Purchased Options 138.2 % Written Options (38.4 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/XSEP info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/XSEP | |
| C000240568 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | First Trust Multi-Strategy Alternative ETF | |
| Class Name | First Trust Multi-Strategy Alternative ETF | |
| Trading Symbol | LALT | |
| Security Exchange Name | NYSEArca | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the First Trust Multi-Strategy Alternative ETF (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/LALT info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/LALT | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage First Trust Multi-Strategy Alternative ETF $ (1) 0.20 % (1) (1) Excludes any Acquired Fund Fees and Expenses of underlying investment companies in which the Fund invests. | |
| Expenses Paid, Amount | $ 21 | [48] |
| Expense Ratio, Percent | 0.20% | [48] |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 5.49% for the 12 months ended August 31, 2024. The Fund underperformed its benchmark, the Credit Suisse AllHedge Index, which returned 7.01% the same Period. The overall economic backdrop over the Period was one of solid economic growth and declining inflation. Broad based economic indicators highlighting these trends were: Average Quarterly Gross Domestic Product Growth in the prior four calendar quarters (Third Quarter 2023 – Second Quarter 2024) was 3.2%; Year-over-year Consumer Price Index continued to decline, falling from 3.7% as of August 31, 2023 to 2.5% as of August 31, 2024; Year-over-year increase in real wages, as measured by the U.S. Bureau of Labor Statistics, increased by 0.9%. U.S. equities, as measured by the S&P 500 ® In response to the macro-economic environment, the Fund increased its holdings of equity long-short exchange-traded funds (“ETFs”). As of August 31, 2024, the Fund held 21.66% in the First Trust Long/Short Equity ETF (“FTLS”), up 11.71% from August 31, 2023. This was beneficial to the Fund as FTLS had the second highest total return of the ETFs held during the Period and contributed more than any other ETF to the Fund’s total return. The top performing ETF held by the Fund, and the second largest contributor to Fund’s total return, was the iShares Gold Trust ETF (“IAU”), which rallied strongly during the second half of the Period as market participants began anticipating that the Fed would likely lower short-term borrowing rates in the second half of 2024. IAU was up 29.08%, 23.51% in the second half of the Period. IAU’s weight within the Fund’s portfolio was increased during the Period, rising from 4.95% to 8.53% as of August 31, 2024. Also increasing in weight during the Period was the Fund’s allocation to the First Trust TCW Unconstrained Plus Bond ETF which returned 8.35% over the Period. The Fund’s weight was increased to 12.50% (up 2.50%) as of the end of the first quarter of the calendar year. During the Period, the commodity allocation in the First Trust Global Tactical Commodity Strategy Fund (“FTGC”) and the merger arbitrage allocation in the First Trust Merger Arbitrage ETF (“MARB”) were reduced. FTGC’s allocation was reduced from 10.50% to 4.78% and MARB’s allocation was reduced from 11.96% to 5.10%. FTGC was the worst performing allocation during the Period, despite outperforming its benchmark by 1.82%. Commodities were down during the Period as declining inflation rates reduced the attractiveness of commodities to investors seeking inflation hedges. MARB’s total returns for the Period were positive but below the levels available from a risk-free cash allocation. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (January 31, 2023 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since First Trust Multi-Strategy Alternative ETF 5.49 % 4.40 % Credit Suisse AllHedge Index 7.01 % 5.69 % S&P 500 ® 27.14 % 24.85 % | |
| Performance Inception Date | Jan. 31, 2023 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/LALT | |
| Net Assets | $ 10,416,857 | |
| Holdings Count | Holding | 8 | |
| Advisory Fees Paid, Amount | $ 10,093 | |
| Investment Company Portfolio Turnover | 21% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 8 Total advisory fee paid $ Portfolio turnover rate 21 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The tables below show the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Exchange-Traded Funds 99.9 % Net Other Assets and Liabilities 0.1 % Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/LALT info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s principal investment strategies were revised to allow the Fund to invest in exchange-traded products with exposure to credit default swaps. The Fund’s principal investment strategies and principal risks were revised accordingly. | |
| Material Fund Change Strategies [Text Block] | During the fiscal year ended August 31, 2024, the Fund’s principal investment strategies were revised to allow the Fund to invest in exchange-traded products with exposure to credit default swaps. The Fund’s principal investment strategies and principal risks were revised accordingly. | |
| Material Fund Change Risks Change [Text Block] | During the fiscal year ended August 31, 2024, the Fund’s principal investment strategies were revised to allow the Fund to invest in exchange-traded products with exposure to credit default swaps. The Fund’s principal investment strategies and principal risks were revised accordingly. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/LALT | |
| C000241257 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. EquityModerate Buffer ETF - March | |
| Class Name | FT Vest U.S. EquityModerate Buffer ETF - March | |
| Trading Symbol | GMAR | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Moderate Buffer ETF - March (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/GMAR info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/GMAR | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Moderate Buffer ETF - March $ 0.85 % | |
| Expenses Paid, Amount | $ 90 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 12.69% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 8.60 % Changes in other Variables 4.94 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (March 17, 2023 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Moderate Buffer ETF - March 12.69 % 14.96 % S&P 500 ® 27.14 % 30.49 % | |
| Performance Inception Date | Mar. 17, 2023 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/GMAR | |
| Net Assets | $ 361,427,722 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 1,733,988 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.8 % Purchased Options 103.2 % Written Options (3.9 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/GMAR info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/GMAR | |
| C000242927 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. EquityModerate Buffer ETF - August | |
| Class Name | FT Vest U.S. EquityModerate Buffer ETF - August | |
| Trading Symbol | GAUG | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Moderate Buffer ETF - August (the “Fund”) for the year of September 1, 2023 to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/GAUG info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/GAUG | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Moderate Buffer ETF - August $ 0.85 % | |
| Expenses Paid, Amount | $ 91 | |
| Expense Ratio, Percent | 0.85% | |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 13.60% for the twelve months ended August 31, 2024. The Fund underperformed its benchmark, the S&P 500 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 9.29 % Changes in other Variables 5.16 % Fees and Expenses -0.85 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (August 18, 2023 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) 1 Year Since FT Vest U.S. Equity Moderate Buffer ETF - August 13.60 % 15.06 % S&P 500 ® 27.14 % 30.01 % | |
| Performance Inception Date | Aug. 18, 2023 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 31, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/GAUG | |
| Net Assets | $ 175,027,755 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 874,319 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 1.1 % Purchased Options 102.8 % Written Options (3.9 % ) Net Other Assets and Liabilities (0.0 % ) Total 100.0 % Any amount shown as 0.0% represents less than 0.1%. | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/GAUG info ftportfolios.com During the fiscal year ended August 31, 2024, the Fund’s predetermined upside cap on Underlying ETF returns was reset based upon prevailing market conditions at the start of the new Target Outcome Period. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/GAUG | |
| C000248800 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest Nasdaq-100® Moderate Buffer ETF - May | |
| Class Name | FT Vest Nasdaq-100® Moderate Buffer ETF - May | |
| Trading Symbol | QMMY | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest Nasdaq-100 ® | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/QMMY info ftportfolios.com | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/QMMY | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest Nasdaq-100 ® $ (1) 0.90 % (2) (1) The Fund commenced investment operations on May 17, 2024. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher. (2) Annualized. | |
| Expenses Paid, Amount | $ 27 | [49] |
| Expense Ratio, Percent | 0.90% | [50] |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 3.97% for the period from the Fund’s inception date on May 17, 2024 through August 31, 2024. The Fund underperformed its benchmark, the Nasdaq-100 Index ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 2.38 % Changes in other Variables 1.85 % Fees and Expenses -0.26 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (May 17, 2024 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) Since FT Vest Nasdaq-100 ® 3.97 % Nasdaq-100 Index ® 5.78 % S&P 500 ® 6.91 % | |
| Performance Inception Date | May 17, 2024 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/QMMY | |
| Net Assets | $ 55,795,965 | |
| Holdings Count | Holding | 4 | |
| Advisory Fees Paid, Amount | $ 251,368 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 4 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Purchased Options 103.9 % Written Options (4.7 % ) Net Other Assets and Liabilities 0.8 % Total 100.0 % | |
| C000249954 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest Laddered Small Cap Moderate Buffer ETF | |
| Class Name | FT Vest Laddered Small Cap Moderate Buffer ETF | |
| Trading Symbol | BUFS | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest Laddered Small Cap Moderate Buffer ETF (the “Fund”) for the period of May 29, 2024 (commencement of investment operations) to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/BUFS info ftportfolios.com | |
| Material Fund Change Notice [Text Block] | This report describes changes to the Fund that occurred during the Period. | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/BUFS | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest Laddered Small Cap Moderate Buffer ETF $ (1) (2) 0.15 % (1) (3) (1) Excludes any Acquired Fund Fees and Expenses of underlying investment companies in which the Fund invests. (2) The Fund commenced investment operations on May 29, 2024. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher. (3) Annualized. | |
| Expenses Paid, Amount | $ 4 | [51],[52] |
| Expense Ratio, Percent | 0.15% | [51],[53] |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 5.65% for the period from the Fund’s inception date on May 29, 2024 through August 31, 2024. The Fund underperformed its benchmark, the Russell 2000 ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 4.46 % Changes in other Variables 1.46 % Fees and Expenses** -0.27 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the underlying buffer funds’ Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. ** Includes any Acquired Fund Fees and Expenses of underlying investment companies in which the Fund invests. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (May 29, 2024 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) Since FT Vest Laddered Small Cap Moderate Buffer ETF 5.65 % Russell 2000 ® 9.33 % Russell 3000 ® 7.64 % | |
| Performance Inception Date | May 29, 2024 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Material Change Date | Aug. 01, 2024 | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/BUFS | |
| Net Assets | $ 10,480,703 | |
| Holdings Count | Holding | 5 | |
| Advisory Fees Paid, Amount | $ 2,386 | |
| Investment Company Portfolio Turnover | 1% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 5 Total advisory fee paid $ Portfolio turnover rate 1 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Exchange-Traded Funds 99.9 % Money Market Funds 0.1 % Net Other Assets and Liabilities (0.0 % ) Total 100.0 % Any amount shown as 0.0% represents less than 0.1%. | |
| Material Fund Change [Text Block] | HOW HAS THE FUND MATERIALLY CHANGED? This is a summary of certain changes to the Fund since September 1, 2023. For more complete information, you may review the Fund’s prospectus and any applicable supplements at www.ftportfolios.com/fund-documents/etf/BUFS info ftportfolios.com Pursuant to a contractual agreement, effective August 1, 2024, the Fund’s investment advisor agreed to waive management fees of 0.10% of average daily net assets through May 21, 2026. | |
| Material Fund Change Expenses [Text Block] | Pursuant to a contractual agreement, effective August 1, 2024, the Fund’s investment advisor agreed to waive management fees of 0.10% of average daily net assets through May 21, 2026. | |
| Updated Prospectus Phone Number | 1-800-621-1675 | |
| Updated Prospectus Email Address | info@ftportfolios.com | |
| Updated Prospectus Web Address | www.ftportfolios.com/fund-documents/etf/BUFS | |
| C000245576 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | FT Vest U.S. EquityEnhance & Moderate Buffer ETF - November | |
| Class Name | FT Vest U.S. EquityEnhance & Moderate Buffer ETF - November | |
| Trading Symbol | XNOV | |
| Security Exchange Name | CboeBZX | |
| Annual or Semi-Annual Statement [Text Block] | This annual shareholder report contains important information about the FT Vest U.S. Equity Enhance & Moderate Buffer ETF - November (the “Fund”) for the period of November 17, 2023 (commencement of investment operations) to August 31, 2024 (the “Period”). | |
| Shareholder Report Annual or Semi-Annual | annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.ftportfolios.com/fund-documents/etf/XNOV info ftportfolios.com | |
| Additional Information Phone Number | 1-800-621-1675 | |
| Additional Information Email | info@ftportfolios.com | |
| Additional Information Website | www.ftportfolios.com/fund-documents/etf/XNOV | |
| Expenses [Text Block] | WHAT WERE THE FUND COSTS FOR THE LAST YEAR? (Based on a hypothetical $10,000 investment) Fund Costs of a $10,000 investment Costs paid as a percentage FT Vest U.S. Equity Enhance & Moderate Buffer ETF - November $ (1) 0.85 % (2) (1) The Fund commenced investment operations on November 17, 2023. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher. (2) Annualized. | |
| Expenses Paid, Amount | $ 70 | [54] |
| Expense Ratio, Percent | 0.85% | [55] |
| Factors Affecting Performance [Text Block] | HOW DID THE FUND PERFORM LAST YEAR? WHAT AFFECTED THE FUND’S PERFORMANCE? The Fund returned 9.14% for the period from the Fund’s inception date on November 17, 2023 through ® This underperformance was due to the following: Fund NAV Performance Attributed to*: Changes in Reference Asset 5.39 % Changes in other Variables 4.42 % Fees and Expenses -0.67 % The Fund holds a combination of FLexible EXchange ® * The Fund’s performance is impacted by changes in the values of the FLEX Options to which it is exposed. We attribute (allocate) the impact on the Fund’s performance into three components. The first of the three components is the impact on the Fund’s performance due to changes in the Fund’s Reference Asset. The second component is the aggregate impact on the Fund’s performance due to changes in other variables that impact FLEX Options prices - these include changes in a) the Reference Asset’s dividends, b) interest rates, c) implied volatility, and d) time to option expiration. The third component is from the Fund’s fees and expenses incurred during the Period. | |
| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance is not a good predictor of the Fund’s future performance. | |
| Line Graph [Table Text Block] | FUND PERFORMANCE (November 17, 2023 to August 31, 2024) The performance line graph below shows the performance of a hypothetical $10,000 initial investment in the Fund over a ten-year period (or for the life of the Fund, if shorter). The subsequent account value as of the end of the Period is listed next to the name of the Fund or index, as applicable. The performance table below shows the average annual total returns of the Fund for the past one-, five-, and ten-year periods, as applicable (or for the life of the Fund, if shorter), as Investment Performance of $10,000 | |
| Average Annual Return [Table Text Block] | Average Annual Total Returns (as of August 31, 2024) Since FT Vest U.S. Equity Enhance & Moderate Buffer ETF - November 9.14 % S&P 500 ® 26.53 % | |
| Performance Inception Date | Nov. 17, 2023 | |
| No Deduction of Taxes [Text Block] | The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares. | |
| Updated Performance Information Location [Text Block] | Visit www.ftportfolios.com/etf/XNOV | |
| Net Assets | $ 35,962,841 | |
| Holdings Count | Holding | 6 | |
| Advisory Fees Paid, Amount | $ 169,319 | |
| Investment Company Portfolio Turnover | 0% | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (As of August 31, 2024) Fund net assets $ Total number of portfolio holdings 6 Total advisory fee paid $ Portfolio turnover rate 0 % | |
| Holdings [Text Block] | WHAT DID THE FUND INVEST IN? (As of August 31, 2024) The table below shows the investment makeup of the Fund, representing the percentage of net assets of the Fund. Fund Allocation Money Market Funds 0.5 % Purchased Options 137.6 % Written Options (38.0 % ) Net Other Assets and Liabilities (0.1 % ) Total 100.0 % | |
| [1]Excludes any Acquired Fund Fees and Expenses of underlying investment companies in which the Fund invests.[2]Excludes any Acquired Fund Fees and Expenses of underlying investment companies in which the Fund invests.[3]Excludes any Acquired Fund Fees and Expenses of underlying investment companies in which the Fund invests.[4]Excludes any Acquired Fund Fees and Expenses of underlying investment companies in which the Fund invests.[5]The Fund commenced investment operations on October 20, 2023. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher.[6]Annualized.[7]The Fund commenced investment operations on December 15, 2023. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher.[8]Annualized.[9]The Fund commenced investment operations on September 15, 2023. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher.[10]Annualized.[11]The Fund commenced investment operations on April 19, 2024. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher.[12]Annualized.[13]The Fund commenced investment operations on November 17, 2023. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher.[14]Annualized.[15]The Fund commenced investment operations on June 21, 2024. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher.[16]Annualized.[17]Excludes any Acquired Fund Fees and Expenses of underlying investment companies in which the Fund invests.[18]Excludes any Acquired Fund Fees and Expenses of underlying investment companies in which the Fund invests.[19]Excludes any Acquired Fund Fees and Expenses of underlying investment companies in which the Fund invests.[20]Excludes any Acquired Fund Fees and Expenses of underlying investment companies in which the Fund invests.[21]The Fund commenced investment operations on September 15, 2023. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher.[22]Annualized.[23]The Fund commenced investment operations on January 19, 2024. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher.[24]Annualized.[25]The Fund commenced investment operations on October 20, 2023. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher.[26]Annualized.[27]The Fund commenced investment operations on May 17, 2024. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher.[28]Annualized.[29]The Fund commenced investment operations on November 17, 2023. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher.[30]Annualized.[31]The Fund commenced investment operations on March 18, 2024. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher.[32]Annualized.[33]The Fund commenced investment operations on April 19, 2024. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher.[34]Annualized.[35]The Fund commenced investment operations on December 15, 2023. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher.[36]Annualized.[37]The Fund commenced investment operations on August 16, 2024. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher.[38]Annualized.[39]The Fund commenced investment operations on July 19, 2024. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher.[40]Annualized.[41]The Fund commenced investment operations on February 16, 2024. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher.[42]Annualized.[43]Excludes any Acquired Fund Fees and Expenses of underlying investment companies in which the Fund invests.[44]The Fund commenced investment operations on October 25, 2023. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher.[45]Annualized.[46]The Fund commenced investment operations on February 16, 2024. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher.[47]Annualized.[48]Excludes any Acquired Fund Fees and Expenses of underlying investment companies in which the Fund invests.[49]The Fund commenced investment operations on May 17, 2024. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher.[50]Annualized.[51]Excludes any Acquired Fund Fees and Expenses of underlying investment companies in which the Fund invests.[52]The Fund commenced investment operations on May 29, 2024. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher.[53]Annualized.[54]The Fund commenced investment operations on November 17, 2023. Had the Fund been in operation for a complete fiscal year, the cost of a $10,000 investment would have been higher.[55]Annualized. | ||
| Shareholder Report, Line Graph (Details) - USD ($) | 1 Months Ended | 2 Months Ended | 3 Months Ended | 4 Months Ended | 5 Months Ended | 7 Months Ended | 9 Months Ended | 10 Months Ended | 12 Months Ended | 13 Months Ended | 15 Months Ended | 16 Months Ended | 17 Months Ended | 18 Months Ended | 19 Months Ended | 23 Months Ended | 27 Months Ended | 32 Months Ended | 34 Months Ended | 35 Months Ended | 38 Months Ended | 39 Months Ended | 41 Months Ended | 42 Months Ended | 43 Months Ended | 44 Months Ended | 47 Months Ended | 49 Months Ended | 50 Months Ended | 52 Months Ended | 54 Months Ended | 57 Months Ended | 58 Months Ended | 60 Months Ended | 66 Months Ended | 68 Months Ended | 75 Months Ended | 91 Months Ended | 95 Months Ended | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2023 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 31, 2024 | Aug. 16, 2024 | Jul. 19, 2024 | Jun. 21, 2024 | May 29, 2024 | May 17, 2024 | Apr. 19, 2024 | Mar. 18, 2024 | Feb. 29, 2024 | Feb. 28, 2024 | Feb. 16, 2024 | Jan. 19, 2024 | Dec. 15, 2023 | Nov. 17, 2023 | Oct. 25, 2023 | Oct. 20, 2023 | Sep. 15, 2023 | Aug. 18, 2023 | Jul. 21, 2023 | Jun. 16, 2023 | May 19, 2023 | Apr. 21, 2023 | Mar. 17, 2023 | Feb. 28, 2023 | Feb. 17, 2023 | Jan. 31, 2023 | Jan. 20, 2023 | Sep. 21, 2022 | Aug. 31, 2022 | Jun. 15, 2022 | Feb. 28, 2022 | Dec. 17, 2021 | Oct. 26, 2021 | Oct. 13, 2021 | Sep. 20, 2021 | Sep. 17, 2021 | Aug. 31, 2021 | Jul. 12, 2021 | Jun. 18, 2021 | Jun. 14, 2021 | May 25, 2021 | Apr. 16, 2021 | Mar. 19, 2021 | Feb. 28, 2021 | Feb. 17, 2021 | Jan. 20, 2021 | Jan. 15, 2021 | Dec. 18, 2020 | Oct. 16, 2020 | Sep. 18, 2020 | Aug. 31, 2020 | Aug. 10, 2020 | Jul. 21, 2020 | Jul. 17, 2020 | Jun. 19, 2020 | May 15, 2020 | Apr. 29, 2020 | Feb. 29, 2020 | Feb. 28, 2020 | Feb. 21, 2020 | Dec. 03, 2019 | Nov. 15, 2019 | Nov. 06, 2019 | Aug. 31, 2019 | Feb. 28, 2019 | Jan. 03, 2019 | Aug. 31, 2018 | Jun. 04, 2018 | Feb. 28, 2018 | Aug. 31, 2017 | Feb. 28, 2017 | Feb. 14, 2017 | Sep. 27, 2016 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000169822 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | First Trust Flexible Municipal High Income ETF | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 10,513 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,561 | $ 11,101 | $ 10,304 | $ 10,360 | $ 11,446 | $ 12,775 | $ 11,637 | $ 10,978 | $ 11,087 | $ 10,859 | $ 9,889 | $ 9,613 | $ 9,415 | $ 9,919 | $ 9,433 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 9.97% | 1.26% | 1.85% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000205110 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | First Trust Low Duration Strategic Focus ETF | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | $ 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 10,517 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | 11,301 | $ 11,301 | 11,301 | $ 11,301 | 11,301 | 11,301 | $ 11,301 | 10,863 | 10,288 | 10,299 | 10,655 | 10,839 | 10,780 | 10,671 | 10,648 | 10,452 | 10,210 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 7.46% | 1.57% | 2.19% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000214901 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Buffer ETF - November | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | $ 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 13,367 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | 15,321 | $ 15,321 | $ 15,321 | 15,321 | $ 15,321 | 15,321 | 15,321 | 15,321 | 14,421 | 11,963 | 11,623 | 12,088 | 12,533 | 11,603 | 10,762 | $ 9,705 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 14.61% | 9.31% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000215123 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | First Trust Active Factor Mid Cap ETF | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | $ 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 13,168 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | $ 16,698 | 16,698 | $ 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 16,698 | 15,009 | 12,422 | 11,491 | 12,705 | 13,367 | 11,858 | 9,314 | 9,126 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 26.81% | 11.41% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000169819 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | First Trust Income Opportunities ETF | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | $ 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 14,303 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | $ 17,434 | 17,434 | 17,434 | $ 17,434 | 17,434 | 17,434 | 17,434 | 17,434 | $ 17,434 | 15,475 | 14,155 | 14,205 | 15,317 | 16,638 | 14,633 | 12,399 | 12,450 | 12,657 | 12,044 | 12,267 | 11,572 | 11,348 | 10,698 | 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 21.94% | 6.62% | 7.27% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000200735 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | First Trust TCW Unconstrained Plus Bond ETF | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | $ 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 11,417 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | 12,371 | $ 12,371 | 12,371 | 12,371 | $ 12,371 | 12,371 | $ 12,371 | 11,819 | 11,128 | 11,066 | 11,489 | 11,716 | 11,596 | 11,261 | 10,960 | 10,728 | 10,323 | 10,106 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 8.35% | 2.89% | 3.47% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000211017 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Buffer ETF - August | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | $ 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 12,831 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | 14,987 | $ 14,987 | 14,987 | $ 14,987 | 14,987 | 14,987 | $ 14,987 | 14,987 | 14,987 | 14,031 | 11,837 | 11,728 | 12,332 | 12,458 | 11,615 | 10,947 | 9,764 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 16.80% | 8.76% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000214903 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Deep Buffer ETF - November | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | $ 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 12,092 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | $ 13,768 | $ 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,768 | 13,080 | 10,953 | 10,736 | 11,155 | 11,453 | 10,949 | 10,504 | 9,705 | 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 13.86% | 6.90% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000215124 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | First Trust Active Factor Small Cap ETF | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | $ 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 12,972 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | $ 15,920 | 15,920 | $ 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 15,920 | 14,807 | 12,530 | 11,690 | 12,977 | 13,518 | 12,461 | 9,297 | 8,981 | 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 22.72% | 10.29% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000217670 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Deep Buffer ETF - February | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | $ 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 11,698 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | $ 13,481 | $ 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | 13,481 | $ 12,536 | 10,720 | 11,069 | 11,545 | 11,304 | 10,600 | 10,183 | 9,462 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 15.24% | 6.82% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000226051 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Deep Buffer ETF - March | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | $ 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 11,051 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | $ 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | $ 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 12,480 | 11,591 | 10,213 | 10,257 | 10,703 | 10,625 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 12.93% | 6.63% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000224383 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest Laddered Deep Buffer ETF | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | $ 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 10,841 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | $ 12,357 | 12,357 | $ 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 11,624 | 9,950 | 9,860 | 10,384 | 10,423 | 9,980 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 13.97% | 6.04% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000226050 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Buffer ETF - March | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | $ 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 12,182 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | $ 14,091 | 14,091 | $ 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 14,091 | 13,003 | 10,983 | 10,568 | 11,003 | 10,946 | 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 15.67% | 10.45% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000226055 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest International Equity Moderate Buffer ETF - March | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | $ 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 10,435 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | $ 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,998 | 11,269 | 9,825 | 8,976 | 9,900 | 10,559 | 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 14.98% | 5.42% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000227373 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | First Trust Innovation Leaders ETF | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | $ 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 9,092 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | $ 11,787 | 11,787 | 11,787 | $ 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 11,787 | 10,944 | 7,655 | 7,575 | 9,242 | 11,435 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 29.64% | 5.16% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000241937 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Moderate Buffer ETF - May | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | $ 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | $ 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 10,494 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | $ 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,898 | 11,208 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 13.37% | 14.48% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000211018 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Deep Buffer ETF - August | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | $ 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | $ 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 11,309 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | $ 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,821 | 12,159 | 10,462 | 10,495 | 11,409 | 11,548 | 11,056 | 10,681 | 9,804 | 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 13.37% | 5.29% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000223312 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest Nasdaq-100® Buffer ETF - December | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | $ 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 11,482 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | $ 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | $ 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 13,271 | 12,414 | 9,909 | 10,030 | 10,978 | 11,371 | 10,111 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 15.58% | 7.95% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000224232 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Deep Buffer ETF - January | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | $ 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 11,041 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | $ 12,605 | $ 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 12,605 | 11,826 | 10,136 | 10,226 | 10,719 | 10,625 | 10,033 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 14.16% | 6.59% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000224911 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Enhance & Moderate Buffer ETF - June | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | $ 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 11,353 | 12,682 | 12,682 | 12,682 | 12,682 | $ 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | $ 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,682 | 12,110 | 10,609 | 10,199 | 10,098 | 10,131 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 11.71% | 7.87% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000226054 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest Nasdaq-100® Buffer ETF - March | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | $ 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 12,196 | 14,047 | 14,047 | 14,047 | 14,047 | $ 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | $ 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 14,047 | 12,969 | 10,339 | 10,125 | 10,958 | 11,088 | 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 15.18% | 10.34% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000240892 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Moderate Buffer ETF - February | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | $ 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | $ 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 10,784 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | $ 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 12,357 | 11,544 | 9,850 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 14.58% | 14.79% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000242929 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Moderate Buffer ETF - June | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | $ 11,700 | 11,700 | 11,700 | 11,700 | $ 11,700 | 11,700 | 11,700 | 11,700 | $ 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 10,218 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,700 | 11,034 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 14.51% | 13.88% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000242936 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Moderate Buffer ETF - October | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | $ 11,378 | 11,378 | $ 11,378 | 11,378 | 11,378 | 11,378 | $ 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 11,378 | 10,933 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 13.78% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000243421 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Enhance & Moderate Buffer ETF - August | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | $ 11,250 | 11,250 | $ 11,250 | $ 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 10,152 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 11,250 | 10,802 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 10.82% | 12.01% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000226537 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Buffer ETF - April | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | $ 13,319 | $ 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 11,069 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | $ 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 13,319 | 12,031 | 10,057 | 9,787 | 10,459 | 10,556 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 20.33% | 8.86% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000227615 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | First Trust Expanded Technology ETF | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | $ 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 10,840 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | $ 14,003 | $ 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 14,003 | 13,077 | 8,559 | 8,433 | 9,765 | 10,837 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 29.18% | 11.04% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000230294 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest Nasdaq-100® Buffer ETF - September | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | $ 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 10,882 | 13,086 | 13,086 | 13,086 | $ 13,086 | 13,086 | 13,086 | 13,086 | $ 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 13,086 | 12,259 | 8,915 | 8,925 | 9,648 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 20.25% | 9.53% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000242934 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Moderate Buffer ETF - December | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | $ 10,979 | 10,979 | 10,979 | 10,979 | $ 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | $ 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,979 | 10,413 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 9.79% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000242937 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Moderate Buffer ETF - September | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | $ 11,360 | 11,360 | 11,360 | 11,360 | $ 11,360 | 11,360 | $ 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 11,360 | 10,829 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 13.60% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000243422 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Enhance & Moderate Buffer ETF - July | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | $ 11,262 | 11,262 | $ 11,262 | $ 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 10,042 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 11,262 | 10,719 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 12.14% | 11.25% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000245572 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Enhance & Moderate Buffer ETF - April | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | $ 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | $ 10,633 | 10,633 | 10,633 | $ 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | 10,633 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 6.33% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000241464 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Moderate Buffer ETF - April | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | $ 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | $ 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | $ 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 10,596 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 12,284 | 11,287 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 15.93% | 16.28% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000242928 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Moderate Buffer ETF - July | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | $ 11,584 | 11,584 | 11,584 | $ 11,584 | 11,584 | 11,584 | $ 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 10,029 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 11,584 | 10,859 | 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 15.50% | 14.09% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000242935 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Moderate Buffer ETF - November | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | $ 11,178 | 11,178 | 11,178 | $ 11,178 | 11,178 | 11,178 | $ 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 11,178 | 10,653 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 11.78% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000250352 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Buffer & Premium Income ETF - June | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 10,186 | 10,186 | $ 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | $ 10,186 | 10,186 | 10,186 | $ 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | 10,186 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 1.86% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000218639 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | First Trust TCW Securitized Plus ETF | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 9,989 | 9,989 | $ 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | $ 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,178 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | $ 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,989 | 9,349 | 9,121 | 9,523 | 10,390 | 10,684 | 10,492 | 10,380 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 8.83% | (0.03%) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000219664 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Deep Buffer ETF - June | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | $ 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 12,026 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | $ 13,878 | 13,878 | $ 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,878 | 13,064 | 10,975 | 10,723 | 11,190 | 11,253 | 10,751 | 10,453 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 15.39% | 8.11% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000221308 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Buffer ETF - September | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | $ 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 12,933 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | $ 14,946 | 14,946 | 14,946 | 14,946 | $ 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,946 | 14,056 | 11,552 | 11,213 | 11,566 | 11,576 | 10,887 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 15.56% | 10.71% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000222137 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Deep Buffer ETF - October | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | $ 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 11,888 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | $ 13,000 | $ 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 13,000 | 12,491 | 10,753 | 10,244 | 10,753 | 10,850 | 10,372 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 9.35% | 7.01% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000230351 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | First Trust SkyBridge Crypto Industry and Digital Economy ETF | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | $ 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 3,088 | 6,138 | $ 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | $ 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,138 | 6,267 | 2,440 | 3,354 | 7,431 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 98.79% | (15.27%) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000231330 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest Buffered Allocation Defensive ETF | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | $ 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 10,040 | $ 11,019 | $ 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 11,019 | 10,615 | 9,340 | 9,325 | 9,865 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 9.76% | 3.47% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000178745 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | First Trust TCW Opportunistic Fixed Income ETF | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | $ 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 10,469 | $ 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | 11,260 | $ 11,260 | 11,260 | 11,260 | 11,260 | $ 11,260 | 11,260 | 10,703 | 10,402 | 10,700 | 11,772 | 12,276 | 12,048 | 12,182 | 11,699 | 11,325 | 10,470 | 10,265 | 10,130 | 10,323 | 10,068 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 7.55% | (0.12%) | 1.59% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000220038 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Deep Buffer ETF - July | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | $ 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 11,561 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | $ 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | 13,489 | $ 13,489 | 13,489 | 13,489 | 13,489 | $ 13,489 | 13,489 | 12,603 | 10,433 | 10,291 | 10,860 | 10,969 | 10,546 | 10,238 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 16.68% | 7.53% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000221311 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Deep Buffer ETF - September | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | $ 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 11,737 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | $ 13,330 | 13,330 | $ 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 13,330 | 12,681 | 10,514 | 10,225 | 10,803 | 10,853 | 10,494 | 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 13.57% | 7.55% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000223224 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Buffer ETF - December | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | $ 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 12,081 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | $ 14,357 | 14,357 | 14,357 | $ 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 14,357 | 13,446 | 10,826 | 10,469 | 11,014 | 11,160 | 10,195 | 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 18.84% | 10.26% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000223318 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest International Equity Moderate Buffer ETF - December | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | $ 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 10,847 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | $ 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 12,298 | 11,491 | 10,374 | 9,287 | 10,134 | 10,892 | 10,184 | 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 13.37% | 5.75% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000230440 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | First Trust Multi-Manager Small Cap Opportunities ETF | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | $ 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 8,118 | 9,990 | 9,990 | $ 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | $ 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,990 | 9,425 | 7,568 | 7,513 | 8,653 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 23.06% | (0.03%) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000236305 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest Laddered Nasdaq Buffer ETF | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | $ 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | $ 14,582 | 14,582 | 12,468 | 14,582 | 14,582 | $ 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 14,582 | 13,664 | 10,548 | 10,484 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 16.97% | 18.60% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000240186 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Moderate Buffer ETF - January | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | $ 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | $ 12,486 | 12,486 | $ 12,486 | 12,486 | 10,957 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 12,486 | 11,801 | 10,033 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 13.95% | 14.78% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000241255 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Enhance & Moderate Buffer ETF - March | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | $ 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | $ 11,896 | 11,896 | 11,896 | $ 11,896 | 11,896 | 11,896 | 11,896 | 10,769 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,896 | 11,204 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 10.46% | 12.65% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000215122 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | First Trust Active Factor Large Cap ETF | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | $ 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | $ 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 13,567 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | $ 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 17,786 | 15,787 | 12,470 | 12,198 | 13,312 | 13,733 | 11,678 | 10,667 | 9,344 | 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 31.10% | 12.90% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000216581 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | First Trust Multi-Manager Large Growth ETF | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | $ 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 10,990 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | $ 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | $ 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 14,058 | 13,608 | 9,121 | 9,166 | 11,485 | 14,285 | 12,233 | 11,018 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 27.91% | 8.63% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000218407 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Buffer ETF - May | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | $ 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 12,989 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | $ 15,115 | 15,115 | 15,115 | 15,115 | $ 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 15,115 | 14,123 | 11,849 | 11,757 | 12,195 | 12,291 | 11,454 | 11,032 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 16.37% | 10.09% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000219511 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest Laddered Buffer ETF | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | $ 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 12,640 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | $ 14,753 | 14,753 | $ 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 14,753 | 13,736 | 11,393 | 11,078 | 11,552 | 11,621 | 10,773 | 10,180 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 16.73% | 10.06% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000217668 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Buffer ETF - February | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | $ 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 13,149 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | $ 15,662 | 15,662 | 15,662 | 15,662 | $ 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 15,662 | 14,495 | 11,858 | 11,555 | 12,190 | 12,210 | 10,825 | 10,261 | 9,214 | 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 19.11% | 10.42% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000218409 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Deep Buffer ETF - May | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | $ 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 11,445 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | $ 13,012 | 13,012 | $ 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 13,012 | 12,204 | 10,471 | 10,414 | 11,236 | 11,284 | 10,843 | 10,596 | 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 13.67% | 6.32% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000219662 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Buffer ETF - June | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | $ 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 13,923 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | $ 16,436 | $ 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 16,436 | 15,283 | 12,274 | 12,032 | 12,161 | 12,254 | 11,342 | 10,764 | 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 18.04% | 12.56% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000220040 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Buffer ETF - July | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | $ 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 13,102 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | $ 15,658 | 15,658 | $ 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 15,658 | 14,405 | 11,677 | 11,488 | 11,620 | 11,782 | 10,992 | 10,453 | 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 19.51% | 11.49% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000227834 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest International Equity Moderate Buffer ETF - June | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | $ 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 10,125 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | $ 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | $ 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 11,343 | 10,786 | 9,704 | 8,742 | 9,664 | 10,246 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 12.03% | 4.01% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000230301 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Enhance & Moderate Buffer ETF - December | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | $ 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | $ 12,046 | 10,926 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | $ 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 12,046 | 11,535 | 10,092 | 9,502 | 9,839 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 10.25% | 7.13% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000231328 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest Buffered Allocation Growth ETF | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | $ 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | $ 11,894 | 10,190 | $ 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,894 | 11,054 | 9,250 | 9,075 | 9,690 | 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 16.72% | 6.28% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000244790 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Buffer & Premium Income ETF - September | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | $ 10,731 | 10,731 | $ 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | $ 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,731 | 10,436 | 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 7.31% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000245574 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Enhance & Moderate Buffer ETF - January | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | $ 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | $ 10,684 | 10,684 | $ 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,684 | 10,221 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 6.84% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000245577 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Enhance & Moderate Buffer ETF - October | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | $ 11,118 | 11,118 | 11,118 | $ 11,118 | 11,118 | $ 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 11,118 | 10,755 | 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 11.18% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000222135 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Buffer ETF - October | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | $ 14,078 | 14,078 | $ 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 12,816 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | $ 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 14,078 | 13,428 | 11,416 | 11,011 | 11,453 | 11,517 | 10,639 | 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 9.85% | 9.23% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000223226 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Deep Buffer ETF - December | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | $ 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 11,308 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | $ 12,957 | 12,957 | $ 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,957 | 12,240 | 10,353 | 10,043 | 10,499 | 10,634 | 10,089 | 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 14.58% | 7.25% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000224230 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Buffer ETF - January | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | $ 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 12,532 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | $ 14,767 | $ 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | 14,767 | $ 13,752 | 11,311 | 10,762 | 11,364 | 11,101 | 10,053 | 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 17.84% | 11.35% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000224778 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | First Trust TCW Emerging Markets Debt ETF | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | $ 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 8,693 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | $ 9,965 | 9,965 | 9,965 | $ 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,965 | 9,331 | 8,452 | 8,305 | 9,204 | 10,193 | 9,825 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 14.63% | (0.10%) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000239915 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Small Cap Moderate Buffer ETF - May | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | $ 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | $ 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 10,488 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | $ 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 12,161 | 11,121 | 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 15.95% | 16.45% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000245575 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Enhance & Moderate Buffer ETF - May | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 10,384 | 10,384 | 10,384 | $ 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | $ 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | $ 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | 10,384 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 3.84% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000246128 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Small Cap Moderate Buffer ETF - November | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 11,382 | 11,382 | 11,382 | $ 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | $ 11,382 | 11,382 | 11,382 | $ 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 11,382 | 10,706 | 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 13.82% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000248689 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Buffer & Premium Income ETF - March | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | $ 10,372 | 10,372 | 10,372 | 10,372 | $ 10,372 | 10,372 | 10,372 | $ 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | 10,372 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 3.72% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000248806 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest Nasdaq-100® Conservative Buffer ETF - April | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | $ 10,739 | $ 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | $ 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,739 | 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 7.39% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000246681 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Buffer & Premium Income ETF - December | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | $ 10,522 | 10,522 | 10,522 | 10,522 | $ 10,522 | 10,522 | 10,522 | 10,522 | $ 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,522 | 10,206 | 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 5.22% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000248798 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest Nasdaq-100® Moderate Buffer ETF - August | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 10,040 | $ 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | $ 10,040 | 10,040 | 10,040 | 10,040 | $ 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | 10,040 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 0.40% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000248808 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest Nasdaq-100® Conservative Buffer ETF - July | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 10,100 | $ 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | $ 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | 10,100 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 1% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000246916 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Small Cap Moderate Buffer ETF - February | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | $ 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | $ 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,698 | 10,056 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 6.98% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000226539 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Deep Buffer ETF - April | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | $ 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | $ 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 10,360 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | $ 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 12,037 | 11,025 | 9,830 | 9,943 | 10,290 | 10,346 | 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 16.20% | 5.65% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000227832 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest Nasdaq-100® Buffer ETF - June | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | $ 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 11,379 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | $ 13,372 | 13,372 | 13,372 | $ 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 13,372 | 12,692 | 9,602 | 9,456 | 10,211 | 10,549 | 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 17.51% | 9.50% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000230296 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest International Equity Buffer ETF - September | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | $ 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 9,930 | 11,443 | 11,443 | 11,443 | $ 11,443 | 11,443 | $ 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 11,443 | 10,526 | 9,444 | 8,607 | 9,509 | 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 15.24% | 4.67% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000243241 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest Laddered Moderate Buffer ETF | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | $ 11,747 | $ 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | $ 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,747 | 11,085 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 17.47% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000244041 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Small Cap Moderate Buffer ETF - August | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | $ 11,660 | $ 11,660 | $ 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 10,160 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 11,660 | 10,746 | 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 14.76% | 15.99% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000245573 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Enhance & Moderate Buffer ETF - February | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | $ 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | $ 10,637 | $ 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,637 | 10,097 | 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 6.37% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000237796 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Enhance & Moderate Buffer ETF - September | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | $ 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | $ 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | $ 12,633 | 12,633 | 12,633 | 11,381 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,633 | 12,180 | 10,530 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 11% | 12.79% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000240568 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | First Trust Multi-Strategy Alternative ETF | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | $ 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | $ 10,704 | 10,704 | $ 10,704 | 10,704 | 10,704 | 10,147 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,704 | 10,394 | 9,890 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 5.49% | 4.40% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000241257 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Moderate Buffer ETF - March | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | $ 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | $ 12,254 | 12,254 | $ 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 10,874 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 12,254 | 11,424 | 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 12.69% | 14.96% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000242927 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Moderate Buffer ETF - August | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | $ 11,563 | $ 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | $ 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 10,179 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 11,563 | 10,974 | 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 13.60% | 15.06% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000248800 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest Nasdaq-100® Moderate Buffer ETF - May | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 10,397 | 10,397 | 10,397 | $ 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | $ 10,397 | $ 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,397 | 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 3.97% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000249954 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest Laddered Small Cap Moderate Buffer ETF | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 10,565 | 10,565 | 10,565 | $ 10,565 | $ 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | $ 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | 10,565 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 5.65% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C000245576 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | FT Vest U.S. Equity Enhance & Moderate Buffer ETF - November | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 10,914 | 10,914 | 10,914 | 10,914 | $ 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | $ 10,914 | 10,914 | 10,914 | $ 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,914 | 10,499 | 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 9.14% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bloomberg Municipal Bond Index [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | Bloomberg Municipal Bond Index | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | $ 11,644 | 11,644 | 11,644 | $ 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 10,975 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | $ 11,644 | 11,644 | 11,644 | 11,644 | 11,644 | $ 11,644 | 11,451 | 10,862 | 10,791 | 11,446 | 11,813 | 11,523 | 11,425 | 11,402 | 11,066 | 10,416 | 10,178 | 10,003 | 10,128 | 9,758 | 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 6.09% | 1.02% | 1.94% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bloomberg US Aggregate Bond Index [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | Bloomberg US Aggregate Bond Index | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | $ 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,079 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | $ 10,814 | 10,814 | 10,814 | 10,814 | 10,814 | $ 10,814 | 10,814 | $ 10,814 | $ 10,814 | $ 10,814 | $ 10,814 | 10,316 | 9,984 | 10,201 | 11,059 | 11,528 | 11,359 | 11,538 | 10,000 | 11,204 | 10,836 | 10,032 | 10,000 | 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 7.30% | (1.08%) | (0.04%) | 1.39% | 1.71% | 1.58% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Standard & Poor's 500 Index [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | S&P 500® Index | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | $ 15,498 | $ 19,703 | $ 19,703 | 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | 19,703 | $ 19,703 | $ 19,703 | $ 19,703 | 19,703 | 10,000 | 10,000 | $ 10,000 | 10,000 | 10,000 | $ 10,000 | 17,656 | 10,000 | $ 10,000 | $ 10,000 | 10,000 | $ 10,000 | $ 10,000 | $ 10,000 | 10,000 | $ 10,000 | $ 10,000 | 10,000 | $ 10,000 | $ 10,000 | 13,533 | $ 10,000 | 10,000 | $ 10,000 | $ 10,000 | 13,367 | 10,000 | 14,663 | $ 10,000 | $ 10,000 | $ 10,000 | 10,000 | 15,058 | $ 10,000 | 10,000 | 10,000 | $ 10,000 | 10,000 | 12,597 | $ 10,000 | $ 10,000 | 10,000 | $ 10,000 | $ 10,000 | 11,479 | $ 10,000 | $ 10,000 | $ 10,000 | $ 10,000 | 9,595 | 10,000 | $ 10,000 | 10,000 | $ 10,000 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 2.77% | 1.75% | 3.61% | 6.91% | 14.29% | 10.36% | 13.67% | 17.72% | 20.86% | 26.53% | 35.42% | 36.62% | 27.14% | 30.01% | 28.68% | 23.61% | 24.55% | 28.01% | 27.69% | 30.49% | 25.53% | 24.85% | 26.36% | 24.75% | 21.69% | 9.42% | 13.54% | 9.40% | 10.92% | 10.25% | 10.10% | 11.67% | 10.91% | 10.98% | 12.93% | 12.91% | 13.76% | 13.54% | 15.04% | 16.18% | 16.35% | 15.43% | 17.17% | 18.97% | 14.13% | 15.37% | 15.30% | 15.01% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Russell 3000 Index [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | Russell 3000® Index | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 22,794 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | $ 28,753 | 28,753 | 28,753 | 28,753 | 28,753 | $ 28,753 | 10,000 | 25,930 | 10,000 | 10,000 | 10,000 | 10,000 | 20,162 | 19,862 | 21,932 | 10,000 | 22,903 | 10,000 | 19,531 | 17,215 | 14,433 | 10,000 | 14,176 | 13,502 | 13,993 | 12,853 | 11,637 | 11,058 | 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 7.64% | 12.85% | 26.16% | 26.14% | 29.05% | 27.40% | 9.36% | 9.73% | 14.60% | 15.19% | 14.25% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| MSCI EAFE Index [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | MSCI EAFE Index | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 12,081 | 12,081 | 12,081 | 12,081 | $ 12,081 | 12,081 | 12,081 | $ 12,081 | 12,081 | 12,081 | $ 12,081 | 12,081 | 12,081 | $ 12,081 | $ 12,081 | 12,081 | 12,081 | 12,081 | $ 12,081 | 12,081 | 12,081 | 12,081 | 12,081 | 12,081 | 12,081 | 12,081 | 12,081 | 10,118 | 12,081 | 12,081 | $ 12,081 | $ 12,081 | 12,081 | $ 12,081 | $ 12,081 | 12,081 | 12,081 | $ 12,081 | 12,081 | 12,081 | $ 12,081 | 12,081 | 12,081 | 12,081 | 12,081 | 12,081 | 12,081 | 12,081 | 12,081 | 12,081 | 12,081 | $ 12,081 | 12,081 | 12,081 | $ 12,081 | 12,081 | 12,081 | 12,081 | 12,081 | $ 12,081 | 11,052 | 9,660 | 8,580 | 9,973 | 10,000 | 10,699 | 10,000 | 10,000 | 10,195 | 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 19.40% | 4.28% | 4.65% | 5.63% | 6.67% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| JP Morgan Emerging Market Bond Index Global Diversified [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | JP Morgan Emerging Market Bond Index Global Diversified | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | $ 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 8,597 | 9,750 | 9,750 | 9,750 | $ 9,750 | 9,750 | $ 9,750 | 9,750 | 9,750 | 9,750 | $ 9,750 | $ 9,750 | 9,750 | $ 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,750 | 9,135 | 8,301 | 8,128 | 9,086 | 10,264 | 9,822 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 13.42% | (0.71%) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Russell 1000 Index [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | Russell 1000® Index | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | $ 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | 14,327 | 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | $ 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | $ 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | $ 18,137 | 18,137 | 18,137 | 18,137 | 18,137 | $ 18,137 | 16,337 | 12,585 | 12,415 | 13,711 | 14,264 | 12,056 | 10,785 | 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 26.60% | 15.58% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Blended Benchmark C000169822 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | [1] | 9.20% | 1.96% | 3% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bloomberg Municipal Long Bond 22 Index [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | Bloomberg Municipal Long Bond (22+) Index | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | $ 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 10,783 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | $ 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | $ 11,682 | 11,682 | 11,682 | 11,682 | 11,682 | $ 11,682 | 11,401 | 10,632 | 10,629 | 11,939 | 12,372 | 11,884 | 11,722 | 11,875 | 11,375 | 10,235 | 10,235 | 10,027 | 10,105 | 9,614 | 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 8.34% | 0.53% | 1.98% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bloomberg 1 5 Year Government Credit Index [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | Bloomberg 1-5 Year Government/Credit Index | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | $ 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 10,443 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | 11,140 | $ 11,140 | $ 11,140 | 11,140 | 11,140 | 11,140 | $ 11,140 | 10,722 | 10,256 | 10,321 | 10,683 | 10,962 | 10,924 | 10,926 | 10,675 | 10,433 | 10,037 | 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 6.67% | 1.32% | 1.93% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Blended Benchmark C000205110 [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | [2] | 7.82% | 1.96% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Blended Benchmark [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | Blended Benchmark | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | $ 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 13,956 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | $ 16,887 | [3] | $ 16,887 | [3] | $ 16,887 | [3] | 16,887 | [3] | 16,887 | [3] | $ 16,887 | [3] | 15,125 | [3] | 13,705 | [3] | 13,645 | [3] | 14,733 | [3] | 15,935 | [3] | 14,085 | [3] | 12,258 | [3] | 12,117 | [3] | 12,452 | [3] | 11,851 | [3] | $ 10,000 | [2] | 12,131 | [3] | $ 11,502 | [3] | $ 11,239 | [3] | $ 10,667 | [3] | $ 10,000 | [3] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 21% | [3] | 6.28% | [3] | 2.72% | [2] | 6.83% | [3] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| S And P MidCap 400 Index [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | S&P MidCap 400® Index | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | $ 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 14,132 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | 16,781 | $ 16,781 | 16,781 | 16,781 | $ 16,781 | 16,781 | $ 16,781 | 16,781 | 16,781 | $ 16,781 | 15,568 | 13,771 | 12,764 | 13,857 | 14,242 | 12,834 | 9,838 | 9,181 | 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 18.75% | 11.53% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| ICE BofA 3 Month US Treasury Bill Index [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | ICE BofA 3-Month US Treasury Bill Index | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | $ 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 10,908 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | 11,506 | $ 11,506 | 11,506 | 11,506 | $ 11,506 | 11,506 | 11,506 | $ 11,506 | 11,506 | 11,506 | 11,201 | 10,645 | 10,463 | 10,427 | 10,424 | 10,423 | 10,416 | 10,381 | 10,286 | 10,159 | 10,049 | 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 5.48% | 2.27% | 2.27% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| ICE BofA US Dollar 3 Month Deposit Offered Rate Average Index [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | ICE BofA US Dollar 3-Month Deposit Offered Rate Average Index | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | $ 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,060 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | 11,676 | $ 11,676 | 11,676 | 11,676 | $ 11,676 | 11,676 | 11,676 | 11,364 | 10,781 | 10,572 | 10,505 | 10,497 | 10,487 | 10,475 | $ 10,425 | $ 10,318 | $ 10,185 | $ 10,057 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | [4] | 5.57% | 2.50% | 2.51% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Russell 2000 Index [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | Russell 2000® Index | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 14,752 | 14,752 | 14,752 | 14,752 | $ 14,752 | 14,752 | 14,752 | $ 14,752 | 14,752 | 14,752 | $ 14,752 | 14,752 | 14,752 | $ 14,752 | $ 14,752 | 14,752 | 14,752 | 14,752 | $ 14,752 | 14,752 | 14,752 | 14,752 | 14,752 | 14,752 | 14,752 | 14,752 | 14,752 | 12,452 | 14,752 | 14,752 | 14,752 | 14,752 | 14,752 | 14,752 | 14,752 | 14,752 | 14,752 | 14,752 | 14,752 | 14,752 | 14,752 | 14,752 | 14,752 | 14,752 | 14,752 | 14,752 | 14,752 | 14,752 | 14,752 | 14,752 | 14,752 | $ 14,752 | 14,752 | 14,752 | $ 14,752 | 14,752 | 14,752 | $ 14,752 | 14,752 | 14,752 | $ 10,000 | 13,569 | $ 10,000 | $ 10,000 | $ 10,000 | $ 10,000 | 12,330 | 11,898 | 13,118 | 14,489 | 13,958 | 9,851 | $ 9,244 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 9.33% | 9.96% | 24.76% | 18.47% | 20.31% | 20.78% | 8.54% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Russell 3000 Growth Index [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | Russell 3000® Growth Index | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 14,380 | 14,380 | 14,380 | 14,380 | $ 14,380 | 14,380 | 14,380 | $ 14,380 | 14,380 | 14,380 | $ 14,380 | 14,380 | 14,380 | $ 14,380 | $ 14,380 | 14,380 | 14,380 | 14,380 | $ 14,380 | 14,380 | 14,380 | 14,380 | 14,380 | 14,380 | 14,380 | 14,380 | 14,380 | 11,053 | 14,380 | 14,380 | 14,380 | 14,380 | 14,380 | 14,380 | $ 14,380 | 14,380 | 14,380 | 14,380 | 14,380 | 14,380 | 14,380 | 14,380 | 14,380 | 14,380 | 14,380 | 14,380 | 14,380 | 14,380 | 14,380 | 14,380 | 14,380 | $ 14,380 | 14,380 | 14,380 | 14,380 | 14,380 | 14,380 | 14,380 | 14,380 | 14,380 | 13,020 | 9,044 | 9,133 | 10,396 | 11,337 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 30.10% | 11.76% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nasdaq 100 Index [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | Nasdaq-100 Index® | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 15,642 | $ 15,642 | 15,642 | $ 15,642 | 15,642 | $ 15,642 | 15,642 | 15,642 | 15,642 | 15,642 | 15,642 | 15,642 | 15,642 | $ 15,642 | 15,642 | 15,642 | 15,642 | 15,642 | 15,642 | 15,642 | 15,642 | 15,642 | 15,642 | 15,642 | 15,642 | $ 15,642 | 15,642 | 12,047 | 15,642 | 15,642 | 15,642 | $ 15,642 | 15,642 | $ 15,642 | $ 15,642 | 15,642 | 15,642 | $ 15,642 | 15,642 | 15,642 | $ 15,642 | 15,642 | 15,642 | 15,642 | 15,642 | 15,642 | 15,642 | 15,642 | 15,642 | 15,642 | 15,642 | 15,642 | 15,642 | 15,642 | 15,642 | 15,642 | 15,642 | 15,642 | 15,642 | 15,642 | $ 10,000 | $ 10,000 | $ 10,000 | $ 10,000 | 14,363 | 9,359 | 9,538 | $ 10,000 | 11,065 | $ 10,000 | 12,110 | $ 10,000 | $ 10,000 | 10,147 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 0.36% | 0.35% | 5.78% | 15.24% | 27.30% | 27.81% | 9.52% | 11.82% | 13.84% | 13.21% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| S And P 500 Information Technology Index [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | S&P 500® Information Technology Index | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 17,581 | $ 17,581 | 17,581 | $ 17,581 | 17,581 | $ 17,581 | 17,581 | 17,581 | 17,581 | 17,581 | 17,581 | 17,581 | 17,581 | $ 17,581 | 17,581 | 17,581 | 17,581 | 17,581 | 17,581 | 17,581 | 17,581 | 17,581 | 17,581 | 17,581 | 17,581 | $ 17,581 | 17,581 | 12,673 | 17,581 | 17,581 | 17,581 | $ 17,581 | 17,581 | $ 17,581 | 17,581 | $ 17,581 | 17,581 | $ 17,581 | 17,581 | 17,581 | $ 17,581 | 17,581 | 17,581 | 17,581 | 17,581 | 17,581 | 17,581 | 17,581 | 17,581 | 17,581 | 17,581 | 17,581 | 17,581 | 17,581 | 17,581 | 17,581 | 17,581 | 17,581 | 17,581 | 17,581 | 15,280 | 9,620 | 9,505 | 10,803 | 11,097 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 38.73% | 19.19% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bloomberg U S Mortgage Backed Securities Index [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | Bloomberg U.S. Mortgage-Backed Securities Index | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | $ 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 8,854 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | $ 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | $ 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,515 | 9,021 | 8,820 | 9,043 | 9,703 | 10,018 | 9,990 | 10,036 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 7.46% | (1.14%) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Russell 2000 Growth Index [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | Russell 2000® Growth Index | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | $ 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 8,209 | 9,659 | 9,659 | $ 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | $ 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,659 | 9,047 | 7,923 | 7,688 | 8,604 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 17.67% | (1.20%) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Russell 1000 Growth Index [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | Russell 1000® Growth Index | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | $ 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 14,205 | 18,573 | 18,573 | $ 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | $ 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 18,573 | 16,790 | 11,505 | $ 11,649 | $ 13,277 | $ 14,392 | $ 11,796 | $ 11,198 | $ 10,000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 30.75% | 16.25% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Credit Suisse AllHedge Index [Member] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value [Line Items] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Line Graph and Table Measure Name | Credit Suisse AllHedge Index | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Account Value | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,199 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,914 | $ 10,813 | $ 9,958 | $ 10,000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Average Annual Return, Percent | 7.01% | 5.69% | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| [1]The Blended Benchmark returns are a 50/50 split between the Bloomberg Municipal High Yield Bond Index and the Bloomberg Municipal Bond Index.[2]The Blended Benchmark consists of the following two indexes: 80% of the Bloomberg 1-5 Year Government/Credit Index which measures the performance of U.S. dollar-denominated U.S. Treasury bonds, government related bonds and investment grade U.S. corporate bonds that have a maturity between one and five years; and 20% of the ICE BofA US High Yield Constrained Index which tracks the performance of U.S. dollar denominated below investment grade corporate debt publicly issued in the U.S. domestic market but caps issuer exposure at 2%. [3]A blended benchmark (the “Blended Benchmark”) comprised 60% of the First Trust Equity Closed-End Fund Total Return Index, a cap-weighted index (based on NAV) designed to provide a broad representation of the equity based closed-end fund universe, and 40% of the First Trust Taxable Fixed Income Closed-End Fund Total Return Index, a cap-weighted index (based on NAV) designed to provide a broad representation of the taxable fixed income closed-end fund universe, has been selected as a secondary benchmark to provide a more direct correlation to the Fund's underlying portfolio. The Blended Benchmark returns are calculated by using the monthly return of the two indices during each period shown above. At the beginning of each month the two indices are rebalanced to a 60-40 ratio to account for divergence from that ratio that occurred during the course of each month. The monthly returns are then compounded for each period shown above, giving the performance for the Blended Benchmark for each period shown above.[4]On May 31, 2023, the ICE BofA US Dollar 3-Month Deposit Offered Rate Average Index was replaced as a securities market index for the Fund with the ICE BofA 3‑Month US Treasury Bill Index in connection with the phase out of the London interbank offered rate. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Shareholder Report, Holdings (Details) | Aug. 31, 2024 | |
| C000169822 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000169822 [Member] | CCC D [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0% | [1] |
| C000169822 [Member] | NR [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 25.90% | [1] |
| C000169822 [Member] | Standard & Poor's, AAA Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2.60% | [1] |
| C000169822 [Member] | Standard & Poor's, AA Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 19.40% | [1] |
| C000169822 [Member] | Standard & Poor's, A Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 21.50% | [1] |
| C000169822 [Member] | Standard & Poor's, BBB Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 19.90% | [1] |
| C000169822 [Member] | Standard & Poor's, BB Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 9% | [1] |
| C000169822 [Member] | Standard & Poor's, B Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.70% | [1] |
| C000169822 [Member] | Municipal Bonds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 90.50% | |
| C000169822 [Member] | Closed End Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 8.10% | |
| C000169822 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1.40% | |
| C000205110 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000205110 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0% | |
| C000205110 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0% | |
| C000205110 [Member] | Exchange Traded Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000214901 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000214901 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000214901 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.50% | |
| C000214901 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 108.20% | |
| C000214901 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (8.60%) | |
| C000215123 [Member] | United Therapeutics Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.60% | |
| C000215123 [Member] | Sprouts Farmers Market Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.50% | |
| C000215123 [Member] | Toll Brothers Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.50% | |
| C000215123 [Member] | Tenet Healthcare Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.30% | |
| C000215123 [Member] | KB Home [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.20% | |
| C000215123 [Member] | MGIC Investment Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.20% | |
| C000215123 [Member] | Old Republic International Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.20% | |
| C000215123 [Member] | GoDaddy Inc Class A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.10% | |
| C000215123 [Member] | EMCOR Group Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.10% | |
| C000215123 [Member] | Vistra Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1% | |
| C000215123 [Member] | Consumer Staples Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 5.10% | |
| C000215123 [Member] | Industrial Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 20.60% | |
| C000215123 [Member] | Information Technology Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 12% | |
| C000215123 [Member] | Materials Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 5.50% | |
| C000215123 [Member] | Unclassified Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.70% | |
| C000215123 [Member] | Energy Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3.10% | |
| C000215123 [Member] | Financial Services Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 15.30% | |
| C000215123 [Member] | Healthcare Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 10.50% | |
| C000215123 [Member] | Consumer Discretionary Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 15.30% | |
| C000215123 [Member] | Real Estate Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 7.90% | |
| C000169819 [Member] | Eaton Vance Tax Advantaged Global Dividend Income Fund [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4% | |
| C000169819 [Member] | Morgan Stanley Institutional Liquidity Funds Treasury Portfolio Institutional Class [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3.70% | |
| C000169819 [Member] | abrdn Healthcare Opportunities Fund [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3.50% | |
| C000169819 [Member] | abrdn Healthcare Investors [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3.50% | |
| C000169819 [Member] | abrdn Global Infrastructure Income Fund [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3.30% | |
| C000169819 [Member] | Source Capital Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3.30% | |
| C000169819 [Member] | Eaton Vance Tax Advantaged Dividend Income Fund [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3.30% | |
| C000169819 [Member] | John Hancock Tax Advantaged Dividend Income Fund [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3.30% | |
| C000169819 [Member] | Invesco Variable Rate Investment Grade ETF [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3.20% | |
| C000169819 [Member] | Eaton Vance Tax Advantaged Global Dividend Opportunities Fund [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3.10% | |
| C000169819 [Member] | Closed End Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 93.10% | |
| C000169819 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.10% | |
| C000169819 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.70% | |
| C000169819 [Member] | Exchange Traded Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.10% | |
| C000200735 [Member] | Federal Home Loan Bank Discount Notes 0 00 01 27 25 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4% | |
| C000200735 [Member] | Dreyfus Government Cash Management Fund Institutional Shares Class I 5 19 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 6.30% | |
| C000200735 [Member] | U S Treasury Bill 0 00 10 17 24 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2.40% | |
| C000200735 [Member] | U S Treasury Bill 0 00 11 12 24 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2.40% | |
| C000200735 [Member] | Federal Home Loan Bank Discount Notes 0 00 01 14 25 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2.30% | |
| C000200735 [Member] | U S Treasury Bill 0 00 11 14 24 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2% | |
| C000200735 [Member] | U S Treasury Note 3 75 08 15 27 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.90% | |
| C000200735 [Member] | U S Treasury Bill 0 00 10 29 24 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.70% | |
| C000200735 [Member] | U S Treasury Bill 0 00 11 21 24 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.50% | |
| C000200735 [Member] | Government National Mortgage Association Pool TBA 5 00 10 15 54 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.20% | |
| C000200735 [Member] | Standard & Poor's, AAA Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 6.30% | [2] |
| C000200735 [Member] | Standard & Poor's, AA Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 5.90% | [2] |
| C000200735 [Member] | Standard & Poor's, A Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 6.60% | [2] |
| C000200735 [Member] | Standard & Poor's, BBB Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 12.70% | [2] |
| C000200735 [Member] | Standard & Poor's, BB Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 8.30% | [2] |
| C000200735 [Member] | Standard & Poor's, B Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.60% | [2] |
| C000200735 [Member] | Standard & Poor's, CCC Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.50% | [2] |
| C000200735 [Member] | Standard & Poor's, CC Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3.40% | [2] |
| C000200735 [Member] | Standard & Poor's, C Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.60% | [2] |
| C000200735 [Member] | Standard & Poor's, D Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.70% | [2] |
| C000200735 [Member] | Not Rated [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0% | [2] |
| C000200735 [Member] | Money Market Funds Quality [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 6.30% | [2] |
| C000200735 [Member] | Government Agency [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 40.10% | [2] |
| C000211017 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000211017 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000211017 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1.10% | |
| C000211017 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 102.60% | |
| C000211017 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (3.60%) | |
| C000214903 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000214903 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000214903 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.40% | |
| C000214903 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 110.20% | |
| C000214903 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (10.50%) | |
| C000215124 [Member] | National HealthCare Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.30% | |
| C000215124 [Member] | Mueller Industries Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.10% | |
| C000215124 [Member] | Alkermes PLC [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1% | |
| C000215124 [Member] | InterDigital Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.90% | |
| C000215124 [Member] | Abercrombie And Fitch Co Class A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.90% | |
| C000215124 [Member] | SkyWest Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.90% | |
| C000215124 [Member] | Daktronics Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.90% | |
| C000215124 [Member] | Catalyst Pharmaceuticals Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.90% | |
| C000215124 [Member] | M I Homes Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.80% | |
| C000215124 [Member] | Preferred Bank [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.80% | |
| C000215124 [Member] | Consumer Staples Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.70% | |
| C000215124 [Member] | Industrial Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 18% | |
| C000215124 [Member] | Information Technology Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 14.90% | |
| C000215124 [Member] | Materials Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4% | |
| C000215124 [Member] | Unclassified Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2.60% | |
| C000215124 [Member] | Energy Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 5.50% | |
| C000215124 [Member] | Financial Services Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 15.80% | |
| C000215124 [Member] | Healthcare Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 17.90% | |
| C000215124 [Member] | Consumer Discretionary Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 12.10% | |
| C000215124 [Member] | Real Estate Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.50% | |
| C000217670 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000217670 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000217670 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.70% | |
| C000217670 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 103.40% | |
| C000217670 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (4.00%) | |
| C000226051 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000226051 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000226051 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.80% | |
| C000226051 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 102.40% | |
| C000226051 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (3.10%) | |
| C000224383 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000224383 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.00%) | |
| C000224383 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0% | |
| C000224383 [Member] | Exchange Traded Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000226050 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000226050 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000226050 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.70% | |
| C000226050 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 102.20% | |
| C000226050 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (2.80%) | |
| C000226055 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000226055 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000226055 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.80% | |
| C000226055 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 101.20% | |
| C000226055 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (1.90%) | |
| C000227373 [Member] | NVIDIA Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 7.70% | |
| C000227373 [Member] | Oracle Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 6% | |
| C000227373 [Member] | Amazon com Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 5.30% | |
| C000227373 [Member] | Microsoft Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 5.30% | |
| C000227373 [Member] | Alphabet Inc Class C [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3.90% | |
| C000227373 [Member] | ServiceNow Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3.60% | |
| C000227373 [Member] | Meta Platforms Inc Class A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3.50% | |
| C000227373 [Member] | Uber Technologies Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3.30% | |
| C000227373 [Member] | Broadcom Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3% | |
| C000227373 [Member] | Siemens AG [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2.30% | |
| C000227373 [Member] | Industrial Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 11.80% | |
| C000227373 [Member] | Information Technology Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 48.10% | |
| C000227373 [Member] | Financial Services Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 6% | |
| C000227373 [Member] | Healthcare Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 17.30% | |
| C000227373 [Member] | Consumer Discretionary Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 6.20% | |
| C000227373 [Member] | Communications Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 9.70% | |
| C000227373 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.90% | |
| C000241937 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000241937 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000241937 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.90% | |
| C000241937 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 102.70% | |
| C000241937 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (3.50%) | |
| C000211018 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000211018 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000211018 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1.10% | |
| C000211018 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 101.70% | |
| C000211018 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (2.70%) | |
| C000223312 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000223312 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000223312 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.50% | |
| C000223312 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 104.50% | |
| C000223312 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (4.90%) | |
| C000224232 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000224232 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000224232 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.60% | |
| C000224232 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 106% | |
| C000224232 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (6.50%) | |
| C000224911 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000224911 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000224911 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1% | |
| C000224911 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 111.70% | |
| C000224911 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (12.60%) | |
| C000226054 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000226054 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000226054 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.80% | |
| C000226054 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 102.90% | |
| C000226054 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (3.60%) | |
| C000240892 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000240892 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000240892 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.70% | |
| C000240892 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 104.30% | |
| C000240892 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (4.90%) | |
| C000242929 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000242929 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000242929 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1% | |
| C000242929 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 102.10% | |
| C000242929 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (3.00%) | |
| C000242936 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000242936 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000242936 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.40% | |
| C000242936 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 116.50% | |
| C000242936 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (16.80%) | |
| C000243421 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000243421 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.00%) | |
| C000243421 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1% | |
| C000243421 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 112% | |
| C000243421 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (13.00%) | |
| C000226537 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000226537 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.00%) | |
| C000226537 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.80% | |
| C000226537 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 103.80% | |
| C000226537 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (4.60%) | |
| C000227615 [Member] | NVIDIA Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.60% | |
| C000227615 [Member] | Oracle Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 5% | |
| C000227615 [Member] | Microsoft Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.20% | |
| C000227615 [Member] | Meta Platforms Inc Class A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.70% | |
| C000227615 [Member] | Broadcom Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 5.10% | |
| C000227615 [Member] | Apple Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 5% | |
| C000227615 [Member] | T Mobile US Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.70% | |
| C000227615 [Member] | Mastercard Inc Class A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.50% | |
| C000227615 [Member] | Visa Inc Class A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.20% | |
| C000227615 [Member] | International Business Machines Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.20% | |
| C000227615 [Member] | Information Technology Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 69% | |
| C000227615 [Member] | Financial Services Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 13% | |
| C000227615 [Member] | Communications Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 17.70% | |
| C000227615 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.30% | |
| C000230294 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000230294 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000230294 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | |
| C000230294 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 106.80% | |
| C000230294 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (7.00%) | |
| C000242934 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000242934 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000242934 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.40% | |
| C000242934 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 108.50% | |
| C000242934 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (8.80%) | |
| C000242937 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000242937 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000242937 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | |
| C000242937 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 110.80% | |
| C000242937 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (11.00%) | |
| C000243422 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000243422 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000243422 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1% | |
| C000243422 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 111.70% | |
| C000243422 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (12.60%) | |
| C000245572 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000245572 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.70% | |
| C000245572 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 123.60% | |
| C000245572 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (24.30%) | |
| C000241464 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000241464 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000241464 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.80% | |
| C000241464 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 105.40% | |
| C000241464 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (6.10%) | |
| C000242928 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000242928 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000242928 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1.10% | |
| C000242928 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 102.30% | |
| C000242928 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (3.30%) | |
| C000242935 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000242935 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000242935 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.40% | |
| C000242935 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 111% | |
| C000242935 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (11.30%) | |
| C000250352 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000250352 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.80% | |
| C000250352 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 104.50% | |
| C000250352 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (11.00%) | |
| C000250352 [Member] | U S Treasury Bills [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 5.70% | |
| C000218639 [Member] | Dreyfus Government Cash Management Fund Institutional Shares Class I 5 19 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 7% | |
| C000218639 [Member] | Government National Mortgage Association Pool TBA 5 00 10 15 54 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2% | |
| C000218639 [Member] | U S Treasury Note 3 75 08 31 26 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 5.10% | |
| C000218639 [Member] | Federal National Mortgage Association Pool TBA 2 50 09 15 54 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2% | |
| C000218639 [Member] | Federal National Mortgage Association Pool TBA 3 00 09 15 54 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.60% | |
| C000218639 [Member] | Government National Mortgage Association Pool TBA 2 50 09 15 54 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.50% | |
| C000218639 [Member] | Government National Mortgage Association Pool TBA 4 50 09 15 54 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.40% | |
| C000218639 [Member] | Federal National Mortgage Association Pool TBA 5 50 09 15 54 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.30% | |
| C000218639 [Member] | Federal National Mortgage Association Pool TBA 2 00 09 15 54 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.30% | |
| C000218639 [Member] | Federal Home Loan Mortgage Corporation Pool QD7088 2 00 02 01 52 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.30% | |
| C000218639 [Member] | Standard & Poor's, AAA Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2.50% | [3] |
| C000218639 [Member] | Standard & Poor's, AA Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 6.90% | [3] |
| C000218639 [Member] | Standard & Poor's, A Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3.40% | [3] |
| C000218639 [Member] | Standard & Poor's, BBB Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.70% | [3] |
| C000218639 [Member] | Standard & Poor's, BB Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2% | [3] |
| C000218639 [Member] | Standard & Poor's, B Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3.30% | [3] |
| C000218639 [Member] | Standard & Poor's, CCC Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.70% | [3] |
| C000218639 [Member] | Standard & Poor's, CC Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.10% | [3] |
| C000218639 [Member] | Standard & Poor's, C Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.30% | [3] |
| C000218639 [Member] | Standard & Poor's, D Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.70% | [3] |
| C000218639 [Member] | Not Rated [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0% | [3] |
| C000218639 [Member] | Money Market Funds Quality [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 7% | [3] |
| C000218639 [Member] | Government Agency [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 61.40% | [3] |
| C000219664 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000219664 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000219664 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1% | |
| C000219664 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 101.10% | |
| C000219664 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (2.00%) | |
| C000221308 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000221308 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000221308 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | |
| C000221308 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 107.50% | |
| C000221308 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (7.70%) | |
| C000222137 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000222137 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000222137 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.40% | |
| C000222137 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 116.60% | |
| C000222137 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (16.90%) | |
| C000230351 [Member] | NVIDIA Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.40% | |
| C000230351 [Member] | MicroStrategy Inc Class A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 20.40% | |
| C000230351 [Member] | Coinbase Global Inc Class A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 18.10% | |
| C000230351 [Member] | Galaxy Digital Holdings Ltd [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 6.40% | |
| C000230351 [Member] | Cleanspark Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.50% | |
| C000230351 [Member] | Riot Platforms Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.50% | |
| C000230351 [Member] | Marathon Digital Holdings Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.50% | |
| C000230351 [Member] | Cipher Mining Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.50% | |
| C000230351 [Member] | Terawulf Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.30% | |
| C000230351 [Member] | Iris Energy Ltd [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.20% | |
| C000230351 [Member] | Information Technology Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 66.60% | |
| C000230351 [Member] | Financial Services Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 27.20% | |
| C000230351 [Member] | Consumer Discretionary Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.10% | |
| C000230351 [Member] | Communications Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 5.80% | |
| C000230351 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.30% | |
| C000231330 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000231330 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.00%) | |
| C000231330 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | |
| C000231330 [Member] | Exchange Traded Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 99.70% | |
| C000178745 [Member] | Dreyfus Government Cash Management Fund Institutional Shares Class I 5 19 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 11.70% | |
| C000178745 [Member] | U S Treasury Note 3 75 08 15 27 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.90% | |
| C000178745 [Member] | U S Treasury Note 3 75 08 31 26 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2.60% | |
| C000178745 [Member] | U S Treasury Bond 4 63 05 15 44 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.50% | |
| C000178745 [Member] | U S Treasury Note 4 00 07 31 29 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 6.90% | |
| C000178745 [Member] | U S Treasury Note 3 63 08 31 29 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 6.60% | |
| C000178745 [Member] | U S Treasury Note 3 88 08 15 34 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.20% | |
| C000178745 [Member] | U S Treasury Bond 4 25 08 15 54 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3.80% | |
| C000178745 [Member] | U S Treasury Bond 4 13 08 15 44 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2.90% | |
| C000178745 [Member] | Federal National Mortgage Association Pool TBA 3 50 09 15 54 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2% | |
| C000178745 [Member] | Standard & Poor's, AAA Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3.20% | [4] |
| C000178745 [Member] | Standard & Poor's, AA Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2.40% | [4] |
| C000178745 [Member] | Standard & Poor's, A Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.10% | [4] |
| C000178745 [Member] | Standard & Poor's, BBB Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 8.80% | [4] |
| C000178745 [Member] | Standard & Poor's, BB Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3.50% | [4] |
| C000178745 [Member] | Standard & Poor's, B Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.60% | [4] |
| C000178745 [Member] | Standard & Poor's, CCC Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.80% | [4] |
| C000178745 [Member] | Standard & Poor's, CC Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.80% | [4] |
| C000178745 [Member] | Standard & Poor's, C Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.10% | [4] |
| C000178745 [Member] | Standard & Poor's, D Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.20% | [4] |
| C000178745 [Member] | Not Rated [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0% | [4] |
| C000178745 [Member] | Money Market Funds Quality [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 11.70% | [4] |
| C000178745 [Member] | Government Agency [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 60.80% | [4] |
| C000220038 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000220038 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000220038 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1% | |
| C000220038 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 101.30% | |
| C000220038 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (2.20%) | |
| C000221311 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000221311 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000221311 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | |
| C000221311 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 110.20% | |
| C000221311 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (10.40%) | |
| C000223224 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000223224 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000223224 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.50% | |
| C000223224 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 105.80% | |
| C000223224 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (6.20%) | |
| C000223318 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000223318 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000223318 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.60% | |
| C000223318 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100.60% | |
| C000223318 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (1.10%) | |
| C000230440 [Member] | BellRing Brands Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.30% | |
| C000230440 [Member] | Crinetics Pharmaceuticals Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.30% | |
| C000230440 [Member] | Varonis Systems Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.30% | |
| C000230440 [Member] | Onto Innovation Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.20% | |
| C000230440 [Member] | Palomar Holdings Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.20% | |
| C000230440 [Member] | Wingstop Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.20% | |
| C000230440 [Member] | Leonardo DRS Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.40% | |
| C000230440 [Member] | Axon Enterprise Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2% | |
| C000230440 [Member] | CyberArk Software Ltd [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.80% | |
| C000230440 [Member] | TransMedics Group Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.40% | |
| C000230440 [Member] | Consumer Staples Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3.60% | |
| C000230440 [Member] | Industrial Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 24.20% | |
| C000230440 [Member] | Information Technology Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 21.60% | |
| C000230440 [Member] | Materials Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3.40% | |
| C000230440 [Member] | Energy Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 5.30% | |
| C000230440 [Member] | Financial Services Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 10% | |
| C000230440 [Member] | Healthcare Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 20.60% | |
| C000230440 [Member] | Consumer Discretionary Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 10.30% | |
| C000230440 [Member] | Communications Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.60% | |
| C000230440 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.40% | |
| C000236305 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000236305 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.00%) | |
| C000236305 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0% | |
| C000236305 [Member] | Exchange Traded Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000240186 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000240186 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000240186 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.60% | |
| C000240186 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 106.90% | |
| C000240186 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (7.40%) | |
| C000241255 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000241255 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000241255 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.70% | |
| C000241255 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 117.70% | |
| C000241255 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (18.30%) | |
| C000215122 [Member] | NVIDIA Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.70% | |
| C000215122 [Member] | Amazon com Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.70% | |
| C000215122 [Member] | Microsoft Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.90% | |
| C000215122 [Member] | Meta Platforms Inc Class A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.50% | |
| C000215122 [Member] | Broadcom Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.30% | |
| C000215122 [Member] | Apple Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 7.50% | |
| C000215122 [Member] | Alphabet Inc Class A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2% | |
| C000215122 [Member] | Berkshire Hathaway Inc Class B [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.70% | |
| C000215122 [Member] | Hartford Financial Services Group The Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.10% | |
| C000215122 [Member] | Universal Health Services Inc Class B [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.10% | |
| C000215122 [Member] | Consumer Staples Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 5.70% | |
| C000215122 [Member] | Industrial Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 10.20% | |
| C000215122 [Member] | Information Technology Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 29.10% | |
| C000215122 [Member] | Materials Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3.90% | |
| C000215122 [Member] | Unclassified Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 6.60% | |
| C000215122 [Member] | Financial Services Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 12.30% | |
| C000215122 [Member] | Healthcare Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 11.50% | |
| C000215122 [Member] | Consumer Discretionary Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 9.30% | |
| C000215122 [Member] | Communications Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 7.10% | |
| C000215122 [Member] | Utilities Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.30% | |
| C000216581 [Member] | NVIDIA Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 9.30% | |
| C000216581 [Member] | Amazon com Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 6.50% | |
| C000216581 [Member] | Microsoft Corp [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 7.70% | |
| C000216581 [Member] | ServiceNow Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.10% | |
| C000216581 [Member] | Meta Platforms Inc Class A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.60% | |
| C000216581 [Member] | Apple Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 4.70% | |
| C000216581 [Member] | Alphabet Inc Class A [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2.90% | |
| C000216581 [Member] | Netflix Inc [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2.40% | |
| C000216581 [Member] | ASML Holding N V [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2.20% | |
| C000216581 [Member] | Eli Lilly And Co [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2.10% | |
| C000216581 [Member] | Consumer Staples Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.50% | |
| C000216581 [Member] | Industrial Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 3.30% | |
| C000216581 [Member] | Information Technology Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 48.60% | |
| C000216581 [Member] | Materials Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.60% | |
| C000216581 [Member] | Unclassified Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.20% | |
| C000216581 [Member] | Financial Services Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 7.70% | |
| C000216581 [Member] | Healthcare Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 9.70% | |
| C000216581 [Member] | Consumer Discretionary Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 12.10% | |
| C000216581 [Member] | Communications Sector [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 13.60% | |
| C000216581 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.70% | |
| C000218407 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000218407 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000218407 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.90% | |
| C000218407 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 102.20% | |
| C000218407 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (3.00%) | |
| C000219511 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000219511 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.00%) | |
| C000219511 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0% | |
| C000219511 [Member] | Exchange Traded Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000217668 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000217668 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000217668 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.70% | |
| C000217668 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 102.80% | |
| C000217668 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (3.40%) | |
| C000218409 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000218409 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000218409 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.90% | |
| C000218409 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 101.50% | |
| C000218409 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (2.30%) | |
| C000219662 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000219662 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000219662 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1% | |
| C000219662 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 101.90% | |
| C000219662 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (2.80%) | |
| C000220040 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000220040 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000220040 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1.10% | |
| C000220040 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 102.10% | |
| C000220040 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (3.10%) | |
| C000227834 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000227834 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000227834 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1.10% | |
| C000227834 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 102.50% | |
| C000227834 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (3.50%) | |
| C000230301 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000230301 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000230301 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.50% | |
| C000230301 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 130.50% | |
| C000230301 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (30.90%) | |
| C000231328 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000231328 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.00%) | |
| C000231328 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | |
| C000231328 [Member] | Exchange Traded Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 99.70% | |
| C000244790 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000244790 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000244790 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.80% | |
| C000244790 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 125.50% | |
| C000244790 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (26.80%) | |
| C000244790 [Member] | US Treasury Bill Securities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.60% | |
| C000245574 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000245574 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000245574 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.60% | |
| C000245574 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 126.50% | |
| C000245574 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (27.00%) | |
| C000245577 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000245577 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000245577 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.40% | |
| C000245577 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 150% | |
| C000245577 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (50.30%) | |
| C000222135 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000222135 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000222135 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.40% | |
| C000222135 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 113.20% | |
| C000222135 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (13.50%) | |
| C000223226 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000223226 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000223226 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.50% | |
| C000223226 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 107.50% | |
| C000223226 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (7.90%) | |
| C000224230 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000224230 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000224230 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.60% | |
| C000224230 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 104.90% | |
| C000224230 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (5.40%) | |
| C000224778 [Member] | Dreyfus Government Cash Management Fund Institutional Shares Class I 5 19 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2.10% | |
| C000224778 [Member] | Saudi Government International Bond 5 75 01 16 54 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.70% | |
| C000224778 [Member] | Oman Government International Bond 6 25 01 25 31 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.50% | |
| C000224778 [Member] | Bahrain Government International Bond 6 75 09 20 29 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.50% | |
| C000224778 [Member] | Peruvian Government International Bond 2 78 01 23 31 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.30% | |
| C000224778 [Member] | Colombia Government International Bond 8 75 11 14 53 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.30% | |
| C000224778 [Member] | Greensaif Pipelines Bidco Sarl 6 13 02 23 38 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.20% | |
| C000224778 [Member] | Egypt Government International Bond 7 30 09 30 33 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.20% | |
| C000224778 [Member] | Dominican Republic International Bond 4 50 01 30 30 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.20% | |
| C000224778 [Member] | Ukraine Government International Bond 0 00 08 01 41 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.20% | |
| C000224778 [Member] | Standard & Poor's, AA Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.40% | [5] |
| C000224778 [Member] | Standard & Poor's, A Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 9.90% | [5] |
| C000224778 [Member] | Standard & Poor's, BBB Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 16.50% | [5] |
| C000224778 [Member] | Standard & Poor's, BB Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 29% | [5] |
| C000224778 [Member] | Standard & Poor's, B Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 16.10% | [5] |
| C000224778 [Member] | Standard & Poor's, CCC Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 10.50% | [5] |
| C000224778 [Member] | Standard & Poor's, CC Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2.70% | [5] |
| C000224778 [Member] | Standard & Poor's, C Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 0.60% | [5] |
| C000224778 [Member] | Standard & Poor's, D Rating [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 1.10% | [5] |
| C000224778 [Member] | Not Rated [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 10.10% | [5] |
| C000224778 [Member] | Money Market Funds Quality [Member] | ||
| Holdings [Line Items] | ||
| Percent of Total Investments | 2.10% | [5] |
| C000239915 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000239915 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000239915 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1% | |
| C000239915 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 103.70% | |
| C000239915 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (4.60%) | |
| C000245575 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000245575 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000245575 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.90% | |
| C000245575 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 114.60% | |
| C000245575 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (15.40%) | |
| C000246128 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000246128 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000246128 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.50% | |
| C000246128 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 107.60% | |
| C000246128 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (8.00%) | |
| C000248689 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000248689 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000248689 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1.20% | |
| C000248689 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 109.30% | |
| C000248689 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (14.20%) | |
| C000248689 [Member] | US Treasury Bill Securities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 3.80% | |
| C000248806 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000248806 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.70% | |
| C000248806 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 107.80% | |
| C000248806 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (8.50%) | |
| C000246681 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000246681 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000246681 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1% | |
| C000246681 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 118.50% | |
| C000246681 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (21.60%) | |
| C000246681 [Member] | U S Treasury Bills [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 2.20% | |
| C000248798 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000248798 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1.10% | |
| C000248798 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 104.40% | |
| C000248798 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (5.50%) | |
| C000248808 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000248808 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1% | |
| C000248808 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 103.50% | |
| C000248808 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (4.50%) | |
| C000246916 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000246916 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000246916 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.70% | |
| C000246916 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 102.70% | |
| C000246916 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (3.30%) | |
| C000226539 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000226539 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000226539 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.80% | |
| C000226539 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 104.60% | |
| C000226539 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (5.30%) | |
| C000227832 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000227832 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000227832 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1% | |
| C000227832 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 103.20% | |
| C000227832 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (4.10%) | |
| C000230296 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000230296 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000230296 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.40% | |
| C000230296 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 99.80% | |
| C000230296 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000243241 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000243241 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.00%) | |
| C000243241 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0% | |
| C000243241 [Member] | Exchange Traded Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000244041 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000244041 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0% | |
| C000244041 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1.10% | |
| C000244041 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 104.70% | |
| C000244041 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (5.80%) | |
| C000245573 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000245573 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000245573 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.70% | |
| C000245573 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 120.90% | |
| C000245573 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (21.50%) | |
| C000237796 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000237796 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000237796 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.30% | |
| C000237796 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 138.20% | |
| C000237796 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (38.40%) | |
| C000240568 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000240568 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.10% | |
| C000240568 [Member] | Exchange Traded Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 99.90% | |
| C000241257 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000241257 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000241257 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.80% | |
| C000241257 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 103.20% | |
| C000241257 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (3.90%) | |
| C000242927 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000242927 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.00%) | |
| C000242927 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 1.10% | |
| C000242927 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 102.80% | |
| C000242927 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (3.90%) | |
| C000248800 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000248800 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.80% | |
| C000248800 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 103.90% | |
| C000248800 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (4.70%) | |
| C000249954 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000249954 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.00%) | |
| C000249954 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.10% | |
| C000249954 [Member] | Exchange Traded Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 99.90% | |
| C000245576 [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 100% | |
| C000245576 [Member] | Net Other Assets and Liabilities [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (0.10%) | |
| C000245576 [Member] | Money Market Funds [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 0.50% | |
| C000245576 [Member] | Purchased Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | 137.60% | |
| C000245576 [Member] | Written Options [Member] | ||
| Holdings [Line Items] | ||
| Percent of Net Asset Value | (38.00%) | |
| [1]This represents the municipal and closed-end fund holdings in the Fund. The ratings for the Municipal Bond portion of the Fund are by S&P Global Ratings, Moody’s Investors Service, Inc., Fitch Ratings, or a comparably rated NRSRO. For situations in which a security is rated by more than one NRSRO and the ratings are not equivalent, the highest ratings are used. The ratings for the CEF portion of the Fund are provided by Morningstar. A credit rating is an assessment provided by a nationally recognized statistical rating organization (NRSRO) of the creditworthiness of an issuer with respect to debt obligations except for those debt obligations that are only privately rated. Ratings are measured on a scale that generally ranges from AAA (highest) to D (lowest). Investment grade is defined as those issuers that have a long-term credit rating of BBB- or higher. “NR” | ||
