v3.26.1
First Trust S-Network E-Commerce ETF Average Annual Total Returns
 12 Months Ended 59 Months Ended 60 Months Ended 111 Months Ended
Mar. 31, 2026
Dec. 31, 2026
Dec. 31, 2025
Dec. 31, 2026
Dec. 31, 2025
Dec. 31, 2025
S-Network Global E-Commerce Index(TM) (reflects no deduction for fees, expenses or taxes)[Member]            
Prospectus [Line Items]            
Average Annual Return, Percent [1],[2]     12.51%  
MSCI ACWI Index (reflects no deduction for fees, expenses or taxes)[Member]            
Prospectus [Line Items]            
Average Annual Return, Percent   22.34% 22.34% 11.70% 11.19% 12.08%
First Trust S-Network E-Commerce ETF            
Prospectus [Line Items]            
Average Annual Return, Percent     11.94%   7.89% 8.80%
Performance Inception Date Sep. 20, 2016          
First Trust S-Network E-Commerce ETF | After Taxes on Distributions            
Prospectus [Line Items]            
Average Annual Return, Percent     11.35%   7.42% 8.30%
First Trust S-Network E-Commerce ETF | After Taxes on Distributions and Sales            
Prospectus [Line Items]            
Average Annual Return, Percent     7.07%   5.97% 6.89%
[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.