Label	Element	Value
Risk Return Abstract	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	TRANSAMERICA FUNDS
Prospectus Date	rr_ProspectusDate	Mar. 01, 2022
Retail Class | Transamerica Large Growth
Risk Return Abstract	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	<span style="font-family:Times New Roman;font-size:11pt;font-weight:bold;">Transamerica Large Growth</span>
Objective [Heading]	rr_ObjectiveHeading	<span style="font-family:Times New Roman;font-size:10pt;font-weight:bold;">Investment Objective:</span>
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	Seek to maximize long-term growth.
Expense [Heading]	rr_ExpenseHeading	<span style="font-family:Times New Roman;font-size:10pt;font-weight:bold;margin-left:0%;">Fees and Expenses:</span>
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	This table describes the fees and expenses that you may pay if you buy, hold and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.
Shareholder Fees Caption [Text]	rr_ShareholderFeesCaption	<span style="font-family:Times New Roman;font-size:9pt;font-weight:bold;margin-left:0%;">Shareholder Fees (fees paid directly from your investment)</span>
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	<span style="font-family:Times New Roman;font-size:9pt;font-weight:bold;">Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)</span>
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	<span style="font-family:Times New Roman;font-size:10pt;font-weight:bold;margin-left:0%;">Portfolio Turnover:</span>
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the Example, affect the fund’s performance.During the most recent fiscal year, the portfolio turnover rate for the fund was 48% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	48.00%
Other Expenses, New Fund, Based on Estimates [Text]	rr_OtherExpensesNewFundBasedOnEstimates	<span style="font-family:Times New Roman;font-size:8pt;">Other expenses are based on estimates for the current fiscal year.</span>
Expense Example [Heading]	rr_ExpenseExampleHeading	<span style="font-family:Times New Roman;font-size:10pt;font-weight:bold;margin-left:0%;">Example:</span>
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This Example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds.The Example assumes that you invest $10,000 in the fund for the time periods indicated and then redeem all shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading]	rr_StrategyHeading	<span style="font-family:Times New Roman;font-size:10pt;font-weight:bold;">Principal Investment Strategies:</span>
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The fund normally invests primarily in common stocks of companies that its sub-advisers, Morgan Stanley Investment Management Inc. (“MSIM”) and Wellington Management Company LLP (“Wellington Management”), believe have the potential for above average growth in earnings. Under normal circumstances, the fund invests at least 80% of its net assets (plus the amount of borrowings, if any, for investment purposes) in equity securities of large cap companies and other investments with similar economic characteristics. The fund considers large cap companies to be companies with market capitalizations that, at the time of initial purchase, exceed the market capitalization of the smallest company included in the Russell 1000® Growth Index1. As of December 31, 2021, the market capitalization of the smallest company in the Russell 1000® Growth Index was $1.22 billion. The fund generally emphasizes common and preferred stocks listed on the New York Stock Exchange and other U.S. securities exchanges and, to a lesser extent, equity securities that are listed on foreign securities exchanges and those traded over-the-counter. The fund’s investment manager, Transamerica Asset Management, Inc., determines the allocation of the fund’s assets between MSIM and Wellington Management and rebalances the allocation periodically to normally maintain approximately a 50% allocation of the fund’s assets to each sub-adviser.The fund may invest up to 25% of its net assets in securities of foreign issuers, including issuers located in emerging market or developing countries and securities classified as American Depositary Receipts (“ADRs”), Global Depositary Receipts (“GDRs”), American Depositary Shares (“ADSs”) or Global Depositary Shares (“GDSs”), foreign U.S. dollar denominated securities that are traded on a U.S. exchange or local shares of non-U.S. issuers. The fund may utilize foreign currency forward exchange contracts, which are derivatives, in connection with its investment in foreign securities for hedging purposes. The fund may also invest in warrants and rights.MSIM emphasizes a “bottom-up” stock selection process, seeking attractive investments on an individual company basis. MSIM integrates environmental, social and governance (“ESG”) factors into its investment process by using ESG factors as a lens for additional fundamental research, which can contribute to investment decision-making. This analysis of ESG factors is subjective and not determinative in the MSIM's investment process. MSIM may conclude that other attributes of an investment outweigh ESG factors when making investment decisions.Wellington Management uses fundamental research designed to identify issuers with improving quality metrics, business momentum and attractive relative valuations. Wellington Management’s investment process is aided by a proprietary quantitative screening process that narrows the sub-adviser’s investment universe to companies that are consistent with its investment philosophy.The fund uses multiple sub-advisers in an effort to control the volatility often associated with growth funds, but there can be no assurance that this strategy will succeed. Growth 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 “value” stocks.1 “Russell®” and other service marks and trademarks related to the Russell indexes are trademarks of the London Stock Exchange Group companies.
Risk [Heading]	rr_RiskHeading	<span style="font-family:Times New Roman;font-size:10pt;font-weight:bold;margin-left:0%;">Principal Risks:</span>
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	Risk is inherent in all investing. Many factors and risks affect the fund's performance, including those described below. The value of your investment in the fund, as well as the amount of return you receive on your investment, may fluctuate significantly day to day and over time. You may lose part or all of your investment in the fund or your investment may not perform as well as other similar investments. The following is a summary description of principal risks (in alphabetical order after certain key risks) of investing in the fund. An investment in the fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.You may lose money if you invest in this fund.Market – The market prices of the fund’s securities or other assets may go up or down, sometimes rapidly or unpredictably, due to general market conditions, overall economic trends or events, inflation, changes in interest rates, governmental actions or interventions, actions taken by the U.S. Federal Reserve or foreign central banks, market disruptions caused by tariffs, trade disputes or other factors, political developments, investor sentiment, the global and domestic effects of a pandemic, and other factors that may or may not be related to the issuer of the security or other asset. If the market prices of the fund’s securities and assets fall, the value of your investment will go down.Economies and financial markets throughout the world are increasingly interconnected. Economic, financial or political events, trading and tariff arrangements, public health events (such as the spread of infectious disease), wars, terrorism, cybersecurity events, technology and data interruptions, natural disasters, and other circumstances in one or more countries or regions could be highly disruptive to, and have profound impacts on, global economies or markets. As a result, whether or not the fund invests in securities of issuers located in or with significant exposure to the countries directly affected, the value and liquidity of the fund’s investments may go down.The pandemic of the novel coronavirus respiratory disease designated COVID-19 has resulted in extreme volatility in the financial markets, a domestic and global economic downturn, severe losses, particularly to some sectors of the economy and individual issuers, and reduced liquidity of many instruments. There also have been significant disruptions to business operations, including business closures; strained healthcare systems; disruptions to supply chains and employee availability; large fluctuations in consumer demand; and widespread uncertainty regarding the duration and long-term effects of the pandemic. The domestic and global economic downturn may be prolonged. The pandemic may result in domestic and foreign political and social instability, damage to diplomatic and international trade relations, and continued volatility and/or decreased liquidity in the securities markets. Developing or emerging market countries may be more impacted by the pandemic.The U.S. government and the Federal Reserve, as well as certain foreign governments and central banks, have taken extraordinary actions to support local and global economies and the financial markets in response to the COVID-19 pandemic, including by pushing interest rates to very low levels. This and other government intervention into the economy and financial markets to address the pandemic may not work as intended, particularly if the efforts are perceived by investors as being unlikely to achieve the desired results. Government actions to mitigate the economic impact of the pandemic have resulted in large expansion of government deficits and debt, the long-term consequences of which are not known. Rates of inflation have recently risen, which could adversely affect economies and markets.The COVID-19 pandemic could continue to adversely affect the value and liquidity of the fund’s investments, impair the fund’s ability to satisfy redemption requests, and negatively impact the fund’s performance. In addition, the pandemic, and measures taken to mitigate its effects, could result in disruptions to the services provided to the fund by its service providers.Growth Stocks – Returns on growth stocks may not move in tandem with returns on other categories of stocks or the market as a whole. Growth stocks typically are particularly sensitive to market movements and may involve larger price swings because their market prices tend to reflect future expectations. When it appears those expectations may not be met, the prices of growth securities typically fall. Growth 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 “value” stocks.Equity Securities – Equity securities generally have greater risk of loss than debt securities. Stock markets are volatile and the value of equity securities may go up or down, sometimes rapidly and unpredictably. The value of equity securities fluctuates based on real or perceived changes in a company’s financial condition, factors affecting a particular industry or industries, and overall market, economic and political conditions. If the market prices of the equity securities owned by the fund fall, the value of your investment in the fund will decline. The fund may lose its entire investment in the equity securities of an issuer. A change in financial condition or other event affecting a single issuer may adversely impact securities markets as a whole.Small and Medium Capitalization Companies – The fund will be exposed to additional risks as a result of its investments in the securities of small or medium capitalization companies. Small or medium capitalization companies may be more at risk than large capitalization companies because, among other things, they may have limited product lines, operating history, market or financial resources, or because they may depend on a limited management group. Securities of small and medium capitalization companies may be more volatile than and may underperform large capitalization companies, may be harder to sell at times and at prices the portfolio managers believe appropriate and may offer greater potential for losses.Foreign Investments – Investing in securities of foreign issuers or issuers with significant exposure to foreign markets involves additional risks. Foreign markets can be less liquid, less regulated, less transparent and more volatile than U.S. markets. The value of the fund’s foreign investments may decline, sometimes rapidly or unpredictably, because of factors affecting the particular issuer as well as foreign markets and issuers generally, such as unfavorable or unsuccessful government actions, reduction of government or central bank support, tariffs and trade disruptions, sanctions, political or financial instability, social unrest or other adverse economic or political developments. Foreign investments may also be subject to different accounting practices and different regulatory, legal, auditing, financial reporting and recordkeeping standards and practices, and may be more difficult to value than investments in U.S. issuers.Large Capitalization Companies – The fund’s investments in larger, more established companies may underperform other segments of the market because they may be less responsive to competitive challenges and opportunities and unable to attain high growth rates during periods of economic expansion.Management – The value of your investment may go down if the investment manager’s or sub-adviser's judgments and decisions are incorrect or otherwise do not produce the desired results, or if the investment strategy does not work as intended. You may also suffer losses if there are imperfections, errors or limitations in the quantitative, analytic or other tools, resources, information and data used, investment techniques applied, or the analyses employed or relied on, by the investment manager or sub-adviser, if such tools, resources, information or data are used incorrectly or otherwise do not work as intended, or if the investment manager’s or sub-adviser's investment style is out of favor or otherwise fails to produce the desired results. Any of these things could cause the fund to lose value or its results to lag relevant benchmarks or other funds with similar objectives.Active Trading – The fund may purchase and sell securities without regard to the length of time held. Active trading may be more pronounced during periods of market volatility, may have a negative impact on performance and may generate greater amounts of short-term capital gains.Convertible Securities – Convertible securities are subject to risks associated with both fixed-income and equity securities. For example, if market interest rates rise, the value of a convertible security typically falls. In addition, a convertible security is subject to the risk that the issuer will not be able to pay interest or dividends when due, and the market value of the security may change based on the issuer’s actual or perceived creditworthiness. Since the convertible security derives a portion of its value from the underlying common stock, the security is also subject to the same types of market and issuer-specific risks that apply to the underlying common stock. Convertible securities generally offer lower interest or dividend yields than non-convertible securities of similar quality.Counterparty – The fund could lose money if the counterparties to derivatives, repurchase agreements and other financial contracts entered into for the fund do not fulfill their contractual obligations. In addition, the fund may incur costs and may be hindered or delayed in enforcing its rights against a counterparty.Credit – If an issuer or other obligor (such as a party providing insurance or other credit enhancement) of a security held by the fund or a counterparty to a financial contract with the fund is unable or unwilling to meet its financial obligations, or is downgraded or perceived to be less creditworthy (whether by market participants or otherwise), or if the value of any underlying assets declines, the value of your investment will typically decline. A decline may be significant, particularly in certain market environments. In addition, the fund may incur costs and may be hindered or delayed in enforcing its rights against an issuer, obligor or counterparty.Currency – The value of a fund’s investments in securities denominated in foreign currencies increases or decreases as the rates of exchange between those currencies and the U.S. dollar change. U.S. dollar-denominated securities of foreign issuers may also be affected by currency risk. Currency exchange rates can be volatile and may fluctuate significantly over short periods of time. Currency conversion costs and currency fluctuations could reduce or eliminate investment gains or add to investment losses. A fund may be unable or may choose not to hedge its foreign currency exposure.Currency Hedging – The fund may hedge its currency risk using currency futures, forwards or options. However, hedging strategies and/or these instruments may not always work as intended, and a fund may be worse off than if it had not used a hedging strategy or instrument. Certain countries may also impose restrictions on the exchange or export of currency or adverse currency exchange rates and may be characterized by a lack of available currency hedging instruments.Depositary Receipts – Depositary receipts are generally subject to the same risks as are the foreign securities that they evidence or into which they may be converted, and they may be less liquid than the underlying shares in their primary trading market. Holders of depositary receipts may have limited voting rights, and investment restrictions in certain countries may adversely impact the value of depositary receipts because such restrictions may limit the ability to convert equity shares into depositary receipts and vice versa.Derivatives – The use of derivatives involves a variety of risks, which may be different from, or greater than, the risks associated with investing in traditional securities, such as stocks and bonds. Risks of derivatives include leverage risk, liquidity risk, valuation risk, market risk, counterparty risk, credit risk, operational risk and legal risk. Use of derivatives can increase fund losses, increase costs, reduce opportunities for gains, increase fund volatility, and not produce the result intended. Certain derivatives have the potential for unlimited loss, regardless of the size of the initial investment. Even a small investment in derivatives can have a disproportionate impact on the fund. Derivatives may be difficult or impossible to sell, unwind or value, and the counterparty (including, if applicable, the fund’s clearing broker, the derivatives exchange or the clearinghouse) may default on its obligations to the fund. In certain cases, the fund may incur costs and may be hindered or delayed in enforcing its rights against or closing out derivatives instruments with a counterparty, which may result in additional losses. Derivatives are also generally subject to the risks applicable to the assets, rates, indices or other indicators underlying the derivative, including market risk, credit risk, liquidity risk, management and valuation risk. Also, suitable derivative transactions may not be available in all circumstances or at reasonable prices. The value of a derivative may fluctuate more or less than, or otherwise not correlate well with, the underlying assets, rates, indices or other indicators to which it relates. The fund may, under the current asset segregation and coverage regulatory framework, be required to segregate or earmark liquid assets or otherwise cover its obligations under derivatives transactions and may have to liquidate positions before it is desirable in order to meet these segregation and coverage requirements. The SEC has adopted new Rule 18f-4 under the 1940 Act, which provides a comprehensive regulatory framework for the use of derivatives by registered investment companies and set limits on a fund’s investments in derivatives. Compliance with Rule 18f-4 is not required until August 2022, but the rule may impact the fund’s use of derivatives before that date. Rule 18f-4 could have an adverse impact on the fund’s performance and its ability to implement its investment strategies as it has historically.Emerging Markets – Investments in securities of issuers located or doing business in emerging markets are subject to heightened foreign investments risks and may experience rapid and extreme changes in value. Emerging market countries tend to have less developed and less stable economic, political and legal systems and regulatory and accounting standards, may have policies that restrict investment by foreigners or that prevent foreign investors such as the fund from withdrawing their money at will, and are more likely to experience nationalization, expropriation and confiscatory taxation. In addition, emerging market securities may have low trading volumes and may be or become illiquid.Focused Investing – To the extent the fund invests in a limited number of countries, regions, sectors, industries or market segments, in a limited number of issuers, or in issuers in related businesses or that are subject to related operating risks, the fund will be more susceptible to negative events affecting those countries, regions, sectors, industries, segments or issuers, and the value of its shares may be more volatile than if it invested more widely.Leveraging – To the extent that the fund borrows or uses derivatives or other investments, such as ETFs, that have embedded leverage, your investment may be subject to heightened volatility, risk of loss and costs. Other risks also will be compounded because leverage generally magnifies the effect of a change in the value of an asset and creates a risk of loss of value on a larger pool of assets than the fund would otherwise have. Use of leverage may result in the loss of a substantial amount, and possibly all, of the fund’s assets. The fund also may have to sell assets at inopportune times to satisfy its obligations or meet segregation, coverage or margin requirements.Liquidity – The fund may make investments that are illiquid or that become illiquid after purchase. Illiquid investments can be difficult to value, may trade at a discount from comparable, more liquid investments, and may be subject to wide fluctuations in value. If the fund is forced to sell an illiquid investment to meet redemption requests or other cash needs, the fund may be forced to sell at a substantial loss or may not be able to sell at all. Liquidity of particular investments, or even entire asset classes, including U.S. Treasury securities, can deteriorate rapidly, particularly during times of market turmoil, and those investments may be difficult or impossible for the fund to sell. This may prevent the fund from limiting losses.Preferred Stock – Preferred stock’s right to dividends and liquidation proceeds is junior to the rights of a company’s debt securities. The value of preferred stock may be subject to factors that affect fixed-income and equity securities. The value of preferred stock tends to vary more with fluctuations in the underlying common stock and less with fluctuations in interest rates and tends to exhibit greater volatility.Sustainability and Environmental, Social and Governance (“ESG”) Considerations – Applying sustainability and/or ESG factors as part of the fund’s security selection process may impact the sub-adviser’s investment decisions. Sustainability and ESG factors are not uniformly defined and applying such factors involves subjective assessments. Sustainability and ESG ratings and assessments of issuers can vary across investment advisers (including sub-advisers) and third party data providers and may change over time. Sustainability and ESG factors can be difficult to apply consistently across issuers, regions, countries, industries or sectors. The application of these factors could negatively impact the fund’s performance. Sustainability and ESG information from issuers and from third party data providers may be incomplete, inaccurate or unavailable, which could lead to an incorrect assessment of a company’s sustainability or ESG characteristics.Warrants and Rights – Warrants and rights may be considered more speculative than certain other types of investments because they do not entitle a holder to the dividends or voting rights for the securities that may be purchased, and they do not represent any rights in the assets of the issuing company. If the warrant is not exercised before the expiration date, it generally expires without any value and the fund will lose any amount it paid for the warrant.
Risk Lose Money [Text]	rr_RiskLoseMoney	<span style="font-family:Times New Roman;font-size:10pt;font-weight:bold;">You may lose money if you invest in this fund.</span>
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	<span style="font-family:Times New Roman;font-size:10pt;">An investment in the fund is </span><span style="font-family:Times New Roman;font-size:10pt;">not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.</span>
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	<span style="font-family:Times New Roman;font-size:10pt;font-weight:bold;margin-left:0%;">Performance:</span>
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	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 table shows how the fund’s average annual total returns for different periods compare to the returns of a broad measure of market performance.The past performance information shown below is for Class R4 shares, which are offered in a separate prospectus. Although Class R6 shares would have similar annual returns to Class R4 shares because the classes are invested in the same portfolio of securities, the returns for Class R6 shares will vary from Class R4 shares because Class R4 shares have higher expenses. Performance information for Class R6 shares will be included after the share class has been in operation for one complete calendar year. 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.The fund acquired the assets and assumed the liabilities of three Transamerica Partners funds, including Transamerica Partners Institutional Large Growth (the “predecessor fund”), on March 10, 2017, and the predecessor fund was the accounting and performance survivor of the reorganizations. This means that the predecessor fund's financial and performance history became the financial and performance history of the fund. In the reorganization of the predecessor fund, shareholders of the predecessor fund received Class R4 shares of the fund. The performance of Class R4 shares includes the performance of the predecessor fund prior to the reorganization, and has not been restated to reflect the annual operating expenses of Class R4 shares.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.Prior to October 18, 2019, the fund had a different co-sub-adviser, a different investment objective and used different investment strategies. Certain performance set forth prior to that date is attributable to that previous co-sub-adviser.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	<span style="font-family:Times New Roman;font-size:10pt;"> 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 table shows how the fund’s average annual total returns for different periods compare to the returns of a broad measure of market performance.</span>
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	<span style="font-family:Times New Roman;font-size:10pt;">1-888-233-4339</span>
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	<span style="font-family:Times New Roman;font-size:10pt;">www.transamerica.com/investments-fund-center</span>
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	<span style="font-family:Times New Roman;font-size:10pt;margin-left:0%;">As with all mutual funds, past performance (before and after taxes) </span><span style="font-family:Times New Roman;font-size:10pt;">is not a prediction of future results.</span>
Bar Chart [Heading]	rr_BarChartHeading	<span style="font-family:Times New Roman;font-size:8.5pt;font-weight:bold;margin-left:0%;">Annual Total Returns (calendar years ended December 31) - Class R4</span>
Bar Chart Does Not Reflect Sales Loads [Text]	rr_BarChartDoesNotReflectSalesLoads	<span style="font-family:Times New Roman;font-size:10pt;">The bar chart </span><span style="font-family:Times New Roman;font-size:10pt;">does not reflect the impact of sales charges, which, if reflected, would lower the returns.</span>
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Quarter EndedReturnBest Quarter:6/30/202043.50%Worst Quarter:12/31/2018-16.37%
Bar Chart, Returns for Class Not Offered in Prospectus [Text]	rr_BarChartReturnsForClassNotOfferedInProspectus	<span style="font-family:Times New Roman;font-size:10pt;margin-left:0%;">The past performance information shown below is for Class R4 </span><span style="font-family:Times New Roman;font-size:10pt;">shares, which are offered in a separate prospectus. Although Class R6 shares would have similar annual returns to Class R4 shares because the classes are invested in the same portfolio of securities, the returns for Class R6 shares will vary from Class R4 shares because Class R4 shares have higher expenses.</span>
Performance Table Heading	rr_PerformanceTableHeading	<span style="font-family:Times New Roman;font-size:8.5pt;font-weight:bold;margin-left:0%;">Average Annual Total Returns (periods ended December 31, 2021)</span>
Performance Table Does Reflect Sales Loads	rr_PerformanceTableDoesReflectSalesLoads	<span style="font-family:Times New Roman;font-size:10pt;"> The table includes deduction of applicable sales charges.</span>
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	<span style="font-family:Times New Roman;font-size:10pt;margin-left:0%;">The after-tax returns are calculated using the historic highest individual</span><span style="font-family:Times New Roman;font-size:10pt;"> federal marginal income tax rates and do not reflect the impact of state and local taxes.</span>
Performance Table Not Relevant to Tax Deferred	rr_PerformanceTableNotRelevantToTaxDeferred	<span style="font-family:Times New Roman;font-size:10pt;"> 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.</span>
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	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.
Retail Class | Transamerica Large Growth | R4
Risk Return Abstract	rr_RiskReturnAbstract
2012	rr_AnnualReturn2012	14.76%
2013	rr_AnnualReturn2013	35.00%
2014	rr_AnnualReturn2014	10.46%
2015	rr_AnnualReturn2015	8.89%
2016	rr_AnnualReturn2016	0.75%
2017	rr_AnnualReturn2017	32.49%
2018	rr_AnnualReturn2018	(0.47%)
2019	rr_AnnualReturn2019	34.27%
2020	rr_AnnualReturn2020	72.99%
2021	rr_AnnualReturn2021	9.74%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	<span style="font-family:Times New Roman;font-size:9pt;margin-left:0.0pt;">Best Quarter:</span>
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Jun. 30, 2020
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	43.50%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	<span style="font-family:Times New Roman;font-size:9pt;margin-left:0.0pt;">Worst Quarter:</span>
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2018
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(16.37%)
1 Year	rr_AverageAnnualReturnYear01	9.74%
5 Years	rr_AverageAnnualReturnYear05	27.44%
10 Years	rr_AverageAnnualReturnYear10	20.23%
Inception Date	rr_AverageAnnualReturnInceptionDate	Sep. 11, 2000
Retail Class | Transamerica Large Growth | R6
Risk Return Abstract	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum deferred sales charge (load) (as a percentage of purchase price or redemption proceeds, whichever is lower)	rr_MaximumDeferredSalesChargeOverOther	none
Management fees	rr_ManagementFeesOverAssets	0.65%
Distribution and service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	none
Other expenses	rr_OtherExpensesOverAssets	0.04%	[1]
Total annual fund operating expenses	rr_ExpensesOverAssets	0.69%
1 year	rr_ExpenseExampleYear01	$ 70
3 years	rr_ExpenseExampleYear03	221
5 years	rr_ExpenseExampleYear05	384
10 years	rr_ExpenseExampleYear10	$ 859
Retail Class | Transamerica Large Growth | Return After Taxes on Distributions | R4
Risk Return Abstract	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	4.25%
5 Years	rr_AverageAnnualReturnYear05	23.17%
10 Years	rr_AverageAnnualReturnYear10	18.14%
Retail Class | Transamerica Large Growth | Return After Taxes on Distributions and Sale of Fund Shares | R4
Risk Return Abstract	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	9.24%
5 Years	rr_AverageAnnualReturnYear05	21.57%
10 Years	rr_AverageAnnualReturnYear10	16.87%
Retail Class | Transamerica Large Growth | Russell 1000® Growth Index (reflects no deduction for fees, expenses or taxes)
Risk Return Abstract	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	27.60%	[2]
5 Years	rr_AverageAnnualReturnYear05	25.32%	[2]
10 Years	rr_AverageAnnualReturnYear10	19.79%	[2]

[1] Other expenses are based on estimates for the current fiscal year.

[2] “Russell®” and other service marks and trademarks related to the Russell indexes are trademarks of the London Stock Exchange Group companies.