Transamerica Large Cap Value Investment Strategy - Retail Class [Member] - Transamerica Large Cap Value	Oct. 31, 2025
Prospectus [Line Items]
Strategy [Heading]	<span style="font-family:Times New Roman;font-size:10pt;font-weight:bold;margin-left:0%;">Principal Investment Strategies:</span>
Strategy Narrative [Text Block]	Under normal circumstances, the fund will invest at least 80% of its net assets (plus the amount of borrowings, if any, for investment purposes) in equity securities of large cap companies. The fund considers large cap companies to be companies with capitalizations at the time of investment within the range of companies included in the Russell 1000® Index1. As of December 31, 2025, the market capitalization range of the Russell 1000® Index was between approximately $1.3 billion and $4.5 trillion. The fund’s sub-adviser, Great Lakes Advisors, LLC (the “sub-adviser”), normally focuses primarily on companies with market capitalizations greater than $5 billion. The fund typically holds between 35 and 50 positions. The Russell 3000® Index is the fund’s primary benchmark and the Russell 1000® Value Index is a secondary benchmark of the fund. The sub-adviser will employ a relative value approach, combining a quantitative screening tool to identify attractive candidate securities with a bottom-up, fundamental research process to select and weight individual securities. The sub-adviser’s proprietary quantitative screening tool is used to narrow the universe of potential investments by comparing stocks to their peers using a combination of factors, including relative valuation, potential for improving business prospects, earnings quality, and short-term price reversal. Valuation is assessed by the sub-adviser on both a relative and absolute basis. Relative valuation compares a stock to comparable assets in order to gauge its value and attractiveness, whereas absolute valuation evaluates a stock’s worth in absolute terms with no consideration regarding the value of other comparable assets. The sub-adviser generally invests in securities it believes to be attractively valued with the potential to exceed investor expectations and may sell securities that no longer meet the fund’s investment criteria. Value stocks as a group may be out of favor and underperform the overall equity market for a long period of time, for example, while the market favors “growth” stocks. The fund will generally invest in companies across a variety of industries and sectors. The fund will normally invest primarily in common stock and depositary receipts. The fund may invest up to 20% of its net assets in non-U.S. securities. The sub-adviser considers non-U.S. securities to include issuers organized or located outside the U.S. and/or that trade primarily in a market located outside the U.S. The fund may invest up to 20% of its net assets in medium capitalization companies.1 “Russell®” and other service marks and trademarks related to the Russell indexes are trademarks of the London Stock Exchange Group companies.

Transamerica Large Cap Value Investment Strategy - Retail Class [Member] - Transamerica Large Cap Value

Oct. 31, 2025

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

Strategy Narrative [Text Block]

Under normal circumstances, the fund will invest at least 80% of its net assets (plus the amount of borrowings, if any, for investment purposes) in equity securities of large cap companies. The fund considers large cap companies to be companies with capitalizations at the time of investment within the range of companies included in the Russell 1000® Index1. As of December 31, 2025, the market capitalization range of the Russell 1000® Index was between approximately $1.3 billion and $4.5 trillion. The fund’s sub-adviser, Great Lakes Advisors, LLC (the “sub-adviser”), normally focuses primarily on companies with market capitalizations greater than $5 billion. The fund typically holds between 35 and 50 positions. The Russell 3000® Index is the fund’s primary benchmark and the Russell 1000® Value Index is a secondary benchmark of the fund. The sub-adviser will employ a relative value approach, combining a quantitative screening tool to identify attractive candidate securities with a bottom-up, fundamental research process to select and weight individual securities. The sub-adviser’s proprietary quantitative screening tool is used to narrow the universe of potential investments by comparing stocks to their peers using a combination of factors, including relative valuation, potential for improving business prospects, earnings quality, and short-term price reversal. Valuation is assessed by the sub-adviser on both a relative and absolute basis. Relative valuation compares a stock to comparable assets in order to gauge its value and attractiveness, whereas absolute valuation evaluates a stock’s worth in absolute terms with no consideration regarding the value of other comparable assets. The sub-adviser generally invests in securities it believes to be attractively valued with the potential to exceed investor expectations and may sell securities that no longer meet the fund’s investment criteria. Value stocks as a group may be out of favor and underperform the overall equity market for a long period of time, for example, while the market favors “growth” stocks. The fund will generally invest in companies across a variety of industries and sectors. The fund will normally invest primarily in common stock and depositary receipts. The fund may invest up to 20% of its net assets in non-U.S. securities. The sub-adviser considers non-U.S. securities to include issuers organized or located outside the U.S. and/or that trade primarily in a market located outside the U.S. The fund may invest up to 20% of its net assets in medium capitalization companies.1 “Russell®” and other service marks and trademarks related to the Russell indexes are trademarks of the London Stock Exchange Group companies.