Transamerica Multi-Asset Income Investment Strategy - Retail Class [Member] - Transamerica Multi-Asset Income	Oct. 31, 2025
Prospectus [Line Items]
Strategy [Heading]	<span style="color:#000000;font-family:Times New Roman;font-size:10pt;font-weight:bold;margin-left:0%;">Principal Investment Strategies:</span>
Strategy Narrative [Text Block]	The fund’s sub-adviser, Thompson, Siegel & Walmsley LLC (the “sub-adviser”), deploys an active strategy that normally seeks to invest in a range of securities, including primarily U.S. stocks with market capitalizations at the time of purchase in excess of $3 billion, preferred stocks, and income producing fixed-income securities. Under normal market conditions, the fund invests in a diversified portfolio of credit and equity securities and may shift its investments from one asset class to another in seeking to achieve the fund’s income objective. The sub-adviser employs a strategic approach to asset allocation and uses a “bottom-up” fundamental investment approach to security selection. The sub-adviser expects to generally invest the fund’s portfolio in a mix of common stock, preferred stock and fixed-income securities. Depending on market factors, allocations may range from approximately 20% to 60% for common stock, 0% to 40% for preferred stock and 20% to 60% for fixed-income securities.The equity securities in which the fund invests typically consist primarily of common stocks. Debt securities in which the fund invests normally include primarily high yield bonds (also known as “junk bonds”), although the fund may hold other fixed-income securities including various fixed, floating and variable rate instruments, secured and unsecured bonds, bonds convertible into common stock, senior floating rate and term loans, debentures, shorter term instruments and closed-end funds. The fund may invest all of its fixed-income allocation in securities that are rated below investment grade. The fund may invest in fixed-income securities of any maturity and does not have a target average duration. The fund maintains the flexibility to invest in securities of companies from a variety of sectors, but from time to time, based on economic conditions, the fund may have significant investments in one or more particular sectors. The fund may also invest up to 25% of its assets in foreign securities, either directly or through depositary receipts. The fund may also invest in exchange-traded funds (“ETFs”). The fund may invest in privately issued securities, including those that are normally purchased pursuant to Rule 144A or Regulation S promulgated under the Securities Act of 1933, as amended.

Transamerica Multi-Asset Income Investment Strategy - Retail Class [Member] - Transamerica Multi-Asset Income

Oct. 31, 2025

<span style="color:#000000;font-family:Times New Roman;font-size:10pt;font-weight:bold;margin-left:0%;">Principal Investment Strategies:</span>

Strategy Narrative [Text Block]

The fund’s sub-adviser, Thompson, Siegel & Walmsley LLC (the “sub-adviser”), deploys an active strategy that normally seeks to invest in a range of securities, including primarily U.S. stocks with market capitalizations at the time of purchase in excess of $3 billion, preferred stocks, and income producing fixed-income securities. Under normal market conditions, the fund invests in a diversified portfolio of credit and equity securities and may shift its investments from one asset class to another in seeking to achieve the fund’s income objective. The sub-adviser employs a strategic approach to asset allocation and uses a “bottom-up” fundamental investment approach to security selection. The sub-adviser expects to generally invest the fund’s portfolio in a mix of common stock, preferred stock and fixed-income securities. Depending on market factors, allocations may range from approximately 20% to 60% for common stock, 0% to 40% for preferred stock and 20% to 60% for fixed-income securities.The equity securities in which the fund invests typically consist primarily of common stocks. Debt securities in which the fund invests normally include primarily high yield bonds (also known as “junk bonds”), although the fund may hold other fixed-income securities including various fixed, floating and variable rate instruments, secured and unsecured bonds, bonds convertible into common stock, senior floating rate and term loans, debentures, shorter term instruments and closed-end funds. The fund may invest all of its fixed-income allocation in securities that are rated below investment grade. The fund may invest in fixed-income securities of any maturity and does not have a target average duration. The fund maintains the flexibility to invest in securities of companies from a variety of sectors, but from time to time, based on economic conditions, the fund may have significant investments in one or more particular sectors. The fund may also invest up to 25% of its assets in foreign securities, either directly or through depositary receipts. The fund may also invest in exchange-traded funds (“ETFs”). The fund may invest in privately issued securities, including those that are normally purchased pursuant to Rule 144A or Regulation S promulgated under the Securities Act of 1933, as amended.