S000025873 [Member] Performance Management - TAX-ADVANTAGED ULTRA-SHORT FIXED INCOME FUND |
Mar. 31, 2026 |
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| Prospectus [Line Items] | |
| Bar Chart and Performance Table [Heading] | FUND PERFORMANCE |
| Performance Narrative [Text Block] | The bar chart and table that follow provide an indication of the risks of investing in the Fund by showing (A) changes in the performance of the Fund from year to year, and (B) how the average annual total returns of the Fund compare to those of a broad-based securities market index, two style-specific indices (reflecting the market segments in which the Fund invests) and a custom blended benchmark that reflects the investment instruments in which the Fund invests, in that order. The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future. Updated performance information for the Fund is available and may be obtained on the Fund’s website at northerntrust.com/funds or by calling 800‑595‑9111.
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| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future. |
| Performance Information Illustrates Variability of Returns [Text] | The bar chart and table that follow provide an indication of the risks of investing in the Fund by showing (A) changes in the performance of the Fund from year to year, and (B) how the average annual total returns of the Fund compare to those of a broad-based securities market index, two style-specific indices (reflecting the market segments in which the Fund invests) and a custom blended benchmark that reflects the investment instruments in which the Fund invests, in that order. |
| Bar Chart [Heading] | CALENDAR YEAR TOTAL RETURN* |
| Bar Chart Closing [Text Block] | * Year to date total return for the six months ended June 30, 2026 was 1.35%. For the periods shown in the bar chart above, the highest quarterly return was 1.80% in the fourth quarter of 2023, and the lowest quarterly return was (1.46)% in the first quarter of 2022.
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| Performance Table Heading | AVERAGE ANNUAL TOTAL RETURN (For the periods ended December 31, 2025) |
| Performance Table Narrative | After‑tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after‑tax returns depend on an investor’s tax situation and may differ from those shown. After‑tax returns shown are not relevant to investors who hold their shares through tax‑advantaged arrangements, such as 401(k) plans or individual retirement accounts. In calculating the federal income taxes due on redemptions, capital gains taxes resulting from redemptions are subtracted from the redemption proceeds and the tax benefits from capital losses resulting from the redemptions are added to the redemption proceeds. Under certain circumstances, the addition of the tax benefits from capital losses resulting from redemptions may cause the Returns after taxes on distributions and sale of Fund shares to be greater than the Returns after taxes on distributions or even the Returns before taxes.
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| Performance Table Uses Highest Federal Rate | After‑tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. |
| Performance Table Not Relevant to Tax Deferred | Actual after‑tax returns depend on an investor’s tax situation and may differ from those shown. After‑tax returns shown are not relevant to investors who hold their shares through tax‑advantaged arrangements, such as 401(k) plans or individual retirement accounts. |
| Performance Table Explanation after Tax Higher | In calculating the federal income taxes due on redemptions, capital gains taxes resulting from redemptions are subtracted from the redemption proceeds and the tax benefits from capital losses resulting from the redemptions are added to the redemption proceeds. Under certain circumstances, the addition of the tax benefits from capital losses resulting from redemptions may cause the Returns after taxes on distributions and sale of Fund shares to be greater than the Returns after taxes on distributions or even the Returns before taxes. |
| Performance Availability Website Address [Text] | northerntrust.com/funds |
| Performance Availability Phone [Text] | 800‑595‑9111 |
| TAX-ADVANTAGED ULTRA-SHORT FIXED INCOME FUND | |
| Prospectus [Line Items] | |
| Year to Date Return, Label [Optional Text] | Year to date total return |
| Bar Chart, Year to Date Return | 1.35% |
| Bar Chart, Year to Date Return, Date | Jun. 30, 2026 |
| Highest Quarterly Return, Label [Optional Text] | highest quarterly return |
| Highest Quarterly Return | 1.80% |
| Highest Quarterly Return, Date | Dec. 31, 2023 |
| Lowest Quarterly Return, Label [Optional Text] | lowest quarterly return |
| Lowest Quarterly Return | (1.46%) |
| Lowest Quarterly Return, Date | Mar. 31, 2022 |