S000003467 [Member] Annual Total Returns |
12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2024 |
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Sit Tax-Free Income Fund | Sit Tax-Free Income Fund - Class S | ||||||||||
| Prospectus [Line Items] | ||||||||||
| Annual Return [Percent] | 5.30% | 5.01% | (12.84%) | 3.25% | 4.01% | 7.08% | 0.70% | 7.68% | 0.64% | 3.91% |