v3.26.1
Shareholder Report, Average Annual Return (Details)
 10 Months Ended 12 Months Ended 18 Months Ended 23 Months Ended 50 Months Ended 57 Months Ended 60 Months Ended 105 Months Ended 114 Months Ended
Mar. 31, 2026
Mar. 31, 2026
Mar. 31, 2026
Mar. 31, 2026
Mar. 31, 2026
Mar. 31, 2026
Mar. 31, 2026
Mar. 31, 2026
Mar. 31, 2026
C000169744 [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   First Trust Nasdaq Bank ETF              
Average Annual Return, Percent   21.39%         5.68%   9.08%
C000169745 [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   First Trust Nasdaq Food & Beverage ETF              
Average Annual Return, Percent   (3.64%)         (0.36%)   3.15%
C000169746 [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   First Trust Nasdaq Oil & Gas ETF              
Average Annual Return, Percent   31.05%         23.07%   9.65%
C000169747 [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   First Trust Nasdaq Pharmaceuticals ETF              
Average Annual Return, Percent   26.44%         7.59%   7.13%
C000169748 [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   First Trust S-Network E-Commerce ETF              
Average Annual Return, Percent   (7.01%)         2.20%   6.70%
C000169749 [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   First Trust Nasdaq Semiconductor ETF              
Average Annual Return, Percent   95.77%         18.57%   24.14%
C000169750 [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   First Trust Nasdaq Transportation ETF              
Average Annual Return, Percent   30.11%         4.78%   8.57%
C000190378 [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   Emerging Markets Equity Select ETF              
Average Annual Return, Percent   7.96%         4.80% 3.92%  
C000190379 [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   First Trust Bloomberg Shareholder Yield ETF              
Average Annual Return, Percent   9.15%         9.24% 11.10%  
C000190380 [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   First Trust SMID Capital Strength ETF              
Average Annual Return, Percent   2.92%         6.26% 8.30%  
C000190381 [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   First Trust SMID Growth Strength ETF              
Average Annual Return, Percent   6.68%         2.46% 6.38%  
C000190382 [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   First Trust S&P 500 Diversified Dividend Aristocrats ETF              
Average Annual Return, Percent   15.20%         7.95% 10.04%  
C000227379 [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   First Trust S-Network Streaming & Gaming ETF              
Average Annual Return, Percent   4.69%     5.91%        
C000227613 [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   First Trust Indxx Medical Devices ETF              
Average Annual Return, Percent   (5.46%)       (5.66%)      
C000248907 [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   First Trust Bloomberg R&D Leaders ETF              
Average Annual Return, Percent   21.52%   19.03%          
C000251153 [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   First Trust New Constructs Core Earnings Leaders ETF              
Average Annual Return, Percent   19.82% 12.94%            
C000259078 [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   First Trust Balanced Income ETF              
Average Annual Return, Percent 11.34%                
Nasdaq US BenchmarkTM Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   Nasdaq US BenchmarkTM Index              
Average Annual Return, Percent   18.44%         10.97%   13.91%
MSCI ACWI Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   MSCI ACWI Index              
Average Annual Return, Percent   20.01%     10.11%   9.49%   11.36%
MSCI Emerging Markets Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   MSCI Emerging Markets Index              
Average Annual Return, Percent   29.55%         3.69% 6.30%  
Standard & Poor's 500 Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   S&P 500® Index              
Average Annual Return, Percent 12.03% 17.80% 10.80% 16.01%     12.06% 13.74%  
Russell 3000 Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   Russell 3000® Index              
Average Annual Return, Percent   18.09%         10.87% 13.17%  
MSCI World Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   MSCI World Index              
Average Annual Return, Percent   18.90%       9.20%      
Bloomberg US Aggregate Bond Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   Bloomberg US Aggregate Bond Index              
Average Annual Return, Percent 5.25%                
Nasdaq US Benchmark BanksTM Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   Nasdaq US Benchmark BanksTM Index              
Average Annual Return, Percent   22.70%         10.17%   12.71%
Nasdaq US Smart BanksTM Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   Nasdaq US Smart BanksTM Index              
Average Annual Return, Percent   22.10%         6.33%   9.79%
Nasdaq US Smart Food And BeverageTM Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   Nasdaq US Smart Food & BeverageTM Index              
Average Annual Return, Percent   (3.12%)         0.22%   3.78%
Nasdaq US Benchmark Food Beverage and TobaccoTM Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   Nasdaq US Benchmark Food, Beverage and TobaccoTM Index              
Average Annual Return, Percent   4.24%         6.19%   7.28%
Nasdaq US Benchmark EnergyTM Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   Nasdaq US Benchmark EnergyTM Index              
Average Annual Return, Percent   36.72%         23.33%   10.54%
Nasdaq US Smart Oil And GasTM Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   Nasdaq US Smart Oil & GasTM Index              
Average Annual Return, Percent   31.91%         23.87%   10.35%
Nasdaq US Smart PharmaceuticalsTM Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   Nasdaq US Smart PharmaceuticalsTM Index              
Average Annual Return, Percent   27.32%         8.31%   7.83%
Nasdaq US Benchmark PharmaceuticalsTM Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   Nasdaq US Benchmark PharmaceuticalsTM Index              
Average Annual Return, Percent   20.04%         14.72%   13.06%
S Network Global E Commerce IndexTM [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   S-Network Global E-Commerce IndexTM              
Average Annual Return, Percent [1],[2]   (6.95%)          
Nasdaq US Smart SemiconductorTM Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   Nasdaq US Smart SemiconductorTM Index              
Average Annual Return, Percent   97.10%         19.32%   24.94%
Nasdaq US Benchmark SemiconductorsTM Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   Nasdaq US Benchmark SemiconductorsTM Index              
Average Annual Return, Percent   67.20%         35.12%   32.20%
Nasdaq US Benchmark Industrial TransportationTM Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   Nasdaq US Benchmark Industrial TransportationTM Index              
Average Annual Return, Percent   22.98%         6.48%   13.13%
Nasdaq US Smart TransportationTM Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   Nasdaq US Smart TransportationTM Index              
Average Annual Return, Percent   30.96%         5.23%   9.12%
Nasdaq Riskalyze Emerging MarketsTM Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   Nasdaq Riskalyze Emerging MarketsTM Index              
Average Annual Return, Percent   8.94%         6.80% 5.89%  
Nasdaq Emerging Large Mid CapTM Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   Nasdaq Emerging Large Mid CapTM Index              
Average Annual Return, Percent   20.88%         5.01% 6.92%  
Nasdaq Riskalyze US Large CapTM Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   Nasdaq Riskalyze US Large CapTM Index              
Average Annual Return, Percent   27.90%         11.57% 12.75%  
Bloomberg Shareholder Yield Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   Bloomberg Shareholder Yield Index              
Average Annual Return, Percent [3],[4]   9.84%          
The SMID Capital Strength Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   The SMID Capital Strength Index              
Average Annual Return, Percent [5],[6]   3.56%          
Nasdaq Riskalyze US Mid CapTM Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   Nasdaq Riskalyze US Mid CapTM Index              
Average Annual Return, Percent   11.81%         6.57% 8.75%  
Russell 2500TM Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   Russell 2500TM Index              
Average Annual Return, Percent   23.45%         5.48% 9.50%  
S And P 1000 Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   S&P 1000® Index              
Average Annual Return, Percent   18.35%         6.19% 9.23%  
Nasdaq Riskalyze US Small Cap TM Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   Nasdaq Riskalyze US Small CapTM Index              
Average Annual Return, Percent   16.75%         4.57% 7.94%  
The SMID Growth Strength Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   The SMID Growth Strength Index              
Average Annual Return, Percent [7],[8]   7.37%          
Nasdaq Riskalyze US Large Cap Select DividendTM Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   Nasdaq Riskalyze US Large Cap Select DividendTM Index              
Average Annual Return, Percent   18.80%         9.61% 11.27%  
Nasdaq US 500 Large CapTM Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   Nasdaq US 500 Large CapTM Index              
Average Annual Return, Percent   17.17%         11.58% 13.68%  
S And P 500 Sector Neutral Dividend Aristocrats Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   S&P 500® Sector-Neutral Dividend Aristocrats Index              
Average Annual Return, Percent [9],[10]   15.84%          
S Network Streaming And Gaming Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   S-Network Streaming & Gaming Index              
Average Annual Return, Percent   4.42%     6.55%        
Indxx Medical Devices Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   Indxx Medical Devices Index              
Average Annual Return, Percent   (5.35%)       (5.23%)      
MSCI World Health Care Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   MSCI World Health Care Index              
Average Annual Return, Percent   4.23%       3.73%      
Bloomberg R And D Leaders Select Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   Bloomberg R&D Leaders Select Index              
Average Annual Return, Percent   22.27%   19.78%          
Bloomberg New Constructs Core Earnings Leaders Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   Bloomberg New Constructs Core Earnings Leaders Index              
Average Annual Return, Percent   20.71% 13.70%            
Bloomberg Moderate Allocation Income Focus Index [Member]                  
Average Annual Return [Line Items]                  
Line Graph and Table Measure Name   Bloomberg Moderate Allocation Income Focus Index              
Average Annual Return, Percent 11.64%                
[1] On January 26, 2022, the Fund’s underlying index changed from the Nasdaq US Smart RetailTM Index to the S-Network Global E-Commerce IndexTM. Therefore, performance and historical returns shown for the periods prior to January 26, 2022, are not necessarily indicative of the performance that the Fund, based on its current index, would have generated.
[2] Performance data is not available for all the periods shown in the table for the index because performance data does not exist for some of the entire periods.
[3] On March 4, 2024, the Fund’s underlying index changed from the Nasdaq Riskalyze US Large CapTM Index to the Bloomberg Shareholder Yield Index. Therefore, any Fund performance and historical returns shown above that incorporate Fund performance prior to March 4, 2024, reflect performance of the Fund based on the Nasdaq Riskalyze US Large CapTM Index and are not necessarily indicative of the performance that the Fund, based on the Bloomberg Shareholder Yield Index, would have generated.
[4] Performance data is not available for all the periods shown in the table for the index because performance data does not exist for some of the entire periods.
[5] On June 7, 2024, the Fund’s underlying index changed from the Nasdaq Riskalyze US Mid CapTM Index to The SMID Capital Strength Index. Therefore, the Fund’s performance and historical returns shown for the periods prior to this date are not necessarily indicative of the performance that the Fund, based on its current index, would have generated.
[6] Performance data is not available for all the periods shown in the table for the index because performance data does not exist for some of the entire periods.
[7] On December 3, 2024, the Fund’s underlying index changed from the Nasdaq Riskalyze US Small CapTM Index to The SMID Growth Strength Index. Therefore, the Fund’s performance and historical returns shown for the periods prior to this date are not necessarily indicative of the performance that the Fund, based on its current index, would have generated.
[8] Performance data is not available for all the periods shown in the table for the index because performance data does not exist for some of the entire periods.
[9]
On October 3, 2023, the Fund’s underlying index changed from the Nasdaq Riskalyze US Large Cap Select DividendTM Index to the S&P 500® Sector-Neutral Dividend Aristocrats Index. Therefore, the Fund’s performance and historical returns shown for the periods prior to this date are not necessarily indicative of the performance that the Fund, based on its current index, would have generated.
[10]
Performance data is not available for all the periods shown in the table for the index because performance data does not exist for some of the entire periods.