Transamerica High Yield Muni Performance Management - Retail Class [Member] - Transamerica High Yield Muni |
Oct. 31, 2025 |
|---|---|
| Prospectus [Line Items] | |
| Bar Chart and Performance Table [Heading] | <span style="font-family:Times New Roman;font-size:10pt;font-weight:bold;margin-left:0%;">Performance:</span> |
| Performance Narrative [Text Block] | The bar chart and the table below provide some indication of the risks of investing in the fund. The bar chart shows how the fund’s performance has varied from year to year. The first index in the table shows how the fund’s average annual total returns for different periods compare to the returns of a broad measure of market performance. One or more secondary indices that the manager believes more closely reflect the market sectors and/or types of investments in which the fund invests also are used to measure the fund’s performance.The bar chart does not reflect the impact of sales charges, which, if reflected, would lower the returns.The table includes deduction of applicable sales charges.Absent any applicable fee waivers and/or expense limitations, performance would be lower.As with all mutual funds, past performance (before and after taxes) is not a prediction of future results. Updated performance information is available on our website at www.transamerica.com/investments-fund-center or by calling 1-888-233-4339. |
| Performance Past Does Not Indicate Future [Text] | <span style="color:#000000;font-family:Times New Roman;font-size:10pt;margin-left:0%;">As with all mutual funds, past performance (before and after taxes) is not a prediction of future results.</span> |
| Performance Information Illustrates Variability of Returns [Text] | <span style="font-family:Times New Roman;font-size:10pt;">The bar chart and the table below provide some </span><span style="font-family:Times New Roman;font-size:10pt;margin-left:0%;">indication of the risks of investing in the fund. The bar chart shows how the fund’s performance has varied from year to year. The </span><span style="font-family:Times New Roman;font-size:10pt;">first </span><span style="font-family:Times New Roman;font-size:10pt;margin-left:0%;">index in the </span><span style="font-family:Times New Roman;font-size:10pt;">table shows how the fund’s average annual total returns </span><span style="font-family:Times New Roman;font-size:10pt;margin-left:0%;">for different periods compare to the returns of a broad measure of market performance</span><span style="font-family:Times New Roman;font-size:10pt;">.</span> |
| Performance Additional Market Index [Text] | <span style="font-family:Times New Roman;font-size:10pt;"> One or more secondary indices that the </span><span style="font-family:Times New Roman;font-size:10pt;margin-left:0%;">manager believes more closely reflect the market sectors and/or types of investments in which the fund invests also are used to </span><span style="font-family:Times New Roman;font-size:10pt;">measure the fund’s performance.</span> |
| Bar Chart Does Not Reflect Sales Loads [Text] | <span style="color:#000000;font-family:Times New Roman;font-size:10pt;margin-left:0%;">The bar chart does not reflect the impact of sales charges, which, if reflected, would lower the returns.</span> |
| Bar Chart [Heading] | <span style="font-family:Times New Roman;font-size:8.5pt;font-weight:bold;">Annual Total Returns (calendar years ended December 31) - Class A</span> |
| Bar Chart Closing [Text Block] | Quarter EndedReturnBest Quarter:12/31/20238.16%Worst Quarter:6/30/2022-9.30% |
| Performance Table Heading | <span style="font-family:Times New Roman;font-size:8.5pt;font-weight:bold;">Average Annual Total Returns (periods ended December 31, 2025)</span> |
| Performance Table Narrative | The after-tax returns are calculated using the historic highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns may depend on the investor’s individual tax situation and may differ from those shown. After-tax returns may not be relevant if the investment is made through a tax-exempt or tax-deferred account, such as a 401(k) plan.In certain cases, returns after taxes on distributions and/or returns after taxes on distributions and sale of fund shares are higher than returns before taxes for the period shown because they reflect certain tax benefits.After-tax returns are presented for only one class, and returns for other classes are presented before taxes only and will vary. |
| Performance Table Does Reflect Sales Loads | <span style="color:#000000;font-family:Times New Roman;font-size:10pt;">The table includes deduction of applicable sales charges.</span> |
| Performance Table Uses Highest Federal Rate | <span style="font-family:Times New Roman;font-size:10pt;">The after-tax returns are calculated using the historic highest individual</span><span style="font-family:Times New Roman;font-size:10pt;margin-left:0%;"> federal marginal income tax rates and do not reflect the impact of state and local taxes. </span> |
| Performance Table Not Relevant to Tax Deferred | <span style="font-family:Times New Roman;font-size:10pt;">Actual after-tax returns may depend </span><span style="font-family:Times New Roman;font-size:10pt;margin-left:0%;">on the investor’s individual tax situation and may differ from those shown. After-tax returns may not be relevant if the investment is made through a tax-exempt or tax-deferred account, such as a 401(k) plan.</span> |
| Performance Table Explanation after Tax Higher | <span style="font-family:Times New Roman;font-size:10pt;">In certain cases, returns after taxes on distributions </span><span style="font-family:Times New Roman;font-size:10pt;margin-left:0%;">and/or returns after taxes on distributions and sale of fund shares are higher than returns before taxes for the period shown because </span><span style="font-family:Times New Roman;font-size:10pt;">they reflect certain tax benefits.</span> |
| Performance Table One Class of after Tax Shown [Text] | <span style="color:#000000;font-family:Times New Roman;font-size:10pt;font-weight:bold;margin-left:0%;">After-tax returns are presented for only one class, and returns </span><span style="color:#000000;font-family:Times New Roman;font-size:10pt;font-weight:bold;">for other classes are presented before taxes only and will vary.</span> |
| Performance Availability Website Address [Text] | <span style="color:#000000;font-family:Times New Roman;font-size:10pt;">www.transamerica.com/investments-fund-center</span> |
| Performance Availability Phone [Text] | <span style="color:#000000;font-family:Times New Roman;font-size:10pt;">1-888-233-4339</span> |
| A | |
| Prospectus [Line Items] | |
| Highest Quarterly Return, Label [Optional Text] | <span style="color:#000000;font-family:Times New Roman;font-size:9pt;margin-left:0.0pt;">Best Quarter:</span> |
| Highest Quarterly Return | 8.16% |
| Highest Quarterly Return, Date | Dec. 31, 2023 |
| Lowest Quarterly Return, Label [Optional Text] | <span style="color:#000000;font-family:Times New Roman;font-size:9pt;margin-left:0.0pt;">Worst Quarter:</span> |
| Lowest Quarterly Return | (9.30%) |
| Lowest Quarterly Return, Date | Jun. 30, 2022 |