First Trust Municipal High Income ETF Average Annual Total Returns |
12 Months Ended | 44 Months Ended | 60 Months Ended | 74 Months Ended | 86 Months Ended | 90 Months Ended | |||
|---|---|---|---|---|---|---|---|---|---|
Jul. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2024 |
Dec. 31, 2024 |
Dec. 31, 2024 |
Dec. 31, 2024 |
Dec. 31, 2024 |
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| Bloomberg Municipal Bond Index (reflects no deduction for fees, expenses or taxes)[Member] | |||||||||
| Prospectus [Line Items] | |||||||||
| Average Annual Return, Percent | 1.05% | (0.18%) | 0.99% | 2.39% | 1.97% | 1.97% | |||
| Blended Benchmark (reflects no deduction for fees, expenses or taxes)[Member] | |||||||||
| Prospectus [Line Items] | |||||||||
| Average Annual Return, Percent | [1] | 2.26% | 1.77% | 2.94% | |||||
| First Trust Municipal High Income ETF | |||||||||
| Prospectus [Line Items] | |||||||||
| Average Annual Return, Percent | 5.58% | 1.58% | 3.03% | ||||||
| Performance Inception Date | Nov. 01, 2017 | ||||||||
| First Trust Municipal High Income ETF | After Taxes on Distributions | |||||||||
| Prospectus [Line Items] | |||||||||
| Average Annual Return, Percent | 3.88% | 0.14% | 1.59% | ||||||
| First Trust Municipal High Income ETF | After Taxes on Distributions and Sales | |||||||||
| Prospectus [Line Items] | |||||||||
| Average Annual Return, Percent | 3.29% | 0.59% | 1.70% | ||||||
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