Transamerica Asset Allocation - Growth Portfolio Investment Strategy - Retail Class [Member] - Transamerica Asset Allocation - Growth Portfolio	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 is a fund of funds that seeks to achieve its investment objective by investing its assets primarily in a broad mix of Transamerica Funds (“underlying funds”). The fund’s sub-adviser, Goldman Sachs Asset Management, L.P. (the “sub-adviser”), follows an investment process that involves longer-term portfolio positioning through strategic asset allocation and dynamic asset allocation to pursue shorter-term opportunities based on the sub-adviser’s views of current market conditions. •Under normal circumstances, the fund expects to invest primarily in underlying funds that invest in U.S. and foreign (including emerging markets) equities, commodity-related securities, and alternative investments. •The underlying funds may invest in a variety of U.S. and foreign equity securities and alternative investments. The underlying funds may also invest in fixed-income (including high-yield) securities, real estate investment trusts (“REITs”) and derivatives. The sub-adviser develops and implements a strategic asset allocation for the fund. The sub-adviser seeks to budget the fund’s long term investment risk exposure across various risk factors to establish a diversified strategic asset allocation. An important component of the sub-adviser’s process is allocating risk across asset classes and strategies to increase diversification and, potentially, reduce volatility. The sub-adviser may dynamically adjust the fund’s asset allocation as part of its investment process in response to certain changes in the markets, the economic cycle and the macroeconomic environment. This dynamic asset allocation may change the fund’s portfolio positioning based on the sub-adviser’s short- to medium-term market views on dislocations and attractive investment opportunities. These views may impact the relative weights across asset classes, and the allocation to geographies, sectors and industries, as well as the fund’s duration and sensitivity to inflation. Allocation of assets among the underlying funds is based on factors such as diversification, general market views and outlooks, volatility in the equity markets, historical performance, current valuations, and other global economic factors. The fund may invest directly in U.S. government securities and/or short-term commercial paper. The fund’s investment manager, among other things, oversees and monitors the sub-adviser and is solely responsible for selecting the underlying funds among which the sub-adviser may allocate the fund’s assets. After the underlying funds have been selected, the sub-adviser determines which underlying funds it wishes to utilize to allocate the fund’s assets. The sub-adviser is not required to utilize all of the underlying funds selected by the manager in seeking to fulfill the fund’s target asset allocation.The sub-adviser may invest up to 10% of the fund’s net assets in underlying Transamerica-sponsored and third-party exchange-traded funds (“underlying ETFs”) that the sub-adviser selects as part of the sub-adviser’s asset allocation for the fund. The fund may, but is not required to, invest directly in futures contracts as part of the sub-adviser’s dynamic asset allocation. The use of futures would generally be limited to exchange-traded developed market equity index and U.S. Treasury futures. The fund may also have exposure to derivatives instruments, such as options, futures or forward contracts and swaps through its investments in the underlying funds and underlying ETFs. It is not possible to predict the extent to which the fund will be invested in a particular underlying fund at any time. The fund may be a significant shareholder in certain underlying funds. Each underlying fund and underlying ETF has its own investment objective, principal investment strategies and investment risks. The sub-adviser for each underlying fund and adviser or sub-adviser for each underlying ETF decides which securities to purchase and sell for that underlying fund or underlying ETF. The fund’s ability to achieve its investment objective depends largely on the performance of the underlying funds and underlying ETFs. The “Underlying Funds” section of the prospectus lists the underlying Transamerica Funds currently available for investment by the fund, provides a summary of their respective investment objectives and principal investment strategies, and identifies certain risks of those funds. The manager may change the underlying Transamerica Funds, and the sub-adviser may change the fund’s asset allocation, at any time without notice to shareholders and without shareholder approval.

Transamerica Asset Allocation - Growth Portfolio Investment Strategy - Retail Class [Member] - Transamerica Asset Allocation - Growth Portfolio

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 is a fund of funds that seeks to achieve its investment objective by investing its assets primarily in a broad mix of Transamerica Funds (“underlying funds”). The fund’s sub-adviser, Goldman Sachs Asset Management, L.P. (the “sub-adviser”), follows an investment process that involves longer-term portfolio positioning through strategic asset allocation and dynamic asset allocation to pursue shorter-term opportunities based on the sub-adviser’s views of current market conditions. •Under normal circumstances, the fund expects to invest primarily in underlying funds that invest in U.S. and foreign (including emerging markets) equities, commodity-related securities, and alternative investments. •The underlying funds may invest in a variety of U.S. and foreign equity securities and alternative investments. The underlying funds may also invest in fixed-income (including high-yield) securities, real estate investment trusts (“REITs”) and derivatives. The sub-adviser develops and implements a strategic asset allocation for the fund. The sub-adviser seeks to budget the fund’s long term investment risk exposure across various risk factors to establish a diversified strategic asset allocation. An important component of the sub-adviser’s process is allocating risk across asset classes and strategies to increase diversification and, potentially, reduce volatility. The sub-adviser may dynamically adjust the fund’s asset allocation as part of its investment process in response to certain changes in the markets, the economic cycle and the macroeconomic environment. This dynamic asset allocation may change the fund’s portfolio positioning based on the sub-adviser’s short- to medium-term market views on dislocations and attractive investment opportunities. These views may impact the relative weights across asset classes, and the allocation to geographies, sectors and industries, as well as the fund’s duration and sensitivity to inflation. Allocation of assets among the underlying funds is based on factors such as diversification, general market views and outlooks, volatility in the equity markets, historical performance, current valuations, and other global economic factors. The fund may invest directly in U.S. government securities and/or short-term commercial paper. The fund’s investment manager, among other things, oversees and monitors the sub-adviser and is solely responsible for selecting the underlying funds among which the sub-adviser may allocate the fund’s assets. After the underlying funds have been selected, the sub-adviser determines which underlying funds it wishes to utilize to allocate the fund’s assets. The sub-adviser is not required to utilize all of the underlying funds selected by the manager in seeking to fulfill the fund’s target asset allocation.The sub-adviser may invest up to 10% of the fund’s net assets in underlying Transamerica-sponsored and third-party exchange-traded funds (“underlying ETFs”) that the sub-adviser selects as part of the sub-adviser’s asset allocation for the fund. The fund may, but is not required to, invest directly in futures contracts as part of the sub-adviser’s dynamic asset allocation. The use of futures would generally be limited to exchange-traded developed market equity index and U.S. Treasury futures. The fund may also have exposure to derivatives instruments, such as options, futures or forward contracts and swaps through its investments in the underlying funds and underlying ETFs. It is not possible to predict the extent to which the fund will be invested in a particular underlying fund at any time. The fund may be a significant shareholder in certain underlying funds. Each underlying fund and underlying ETF has its own investment objective, principal investment strategies and investment risks. The sub-adviser for each underlying fund and adviser or sub-adviser for each underlying ETF decides which securities to purchase and sell for that underlying fund or underlying ETF. The fund’s ability to achieve its investment objective depends largely on the performance of the underlying funds and underlying ETFs. The “Underlying Funds” section of the prospectus lists the underlying Transamerica Funds currently available for investment by the fund, provides a summary of their respective investment objectives and principal investment strategies, and identifies certain risks of those funds. The manager may change the underlying Transamerica Funds, and the sub-adviser may change the fund’s asset allocation, at any time without notice to shareholders and without shareholder approval.