Label	Element	Value
Risk Return Abstract	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	TRANSAMERICA FUNDS
Prospectus Date	rr_ProspectusDate	Mar. 01, 2022
Retail Class | Transamerica Mid Cap Growth
Risk Return Abstract	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	<span style="color:#000000;font-family:Times New Roman;font-size:11pt;font-weight:bold;">Transamerica Mid Cap Growth</span>
Objective [Heading]	rr_ObjectiveHeading	<span style="color:#000000;font-family:Times New Roman;font-size:10pt;font-weight:bold;">Investment Objective:</span>
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	Seeks long term capital appreciation.
Expense [Heading]	rr_ExpenseHeading	<span style="color:#000000;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.You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in Transamerica Funds. More information about these and other discounts is available from your financial professional, in the “Waivers and Reductions of Sales Charges” section of the fund’s prospectus, in the Appendix – “Waivers and Discounts Available from Intermediaries,” and in the fund’s statement of additional information (SAI) under the heading “Purchase of Shares.”
Shareholder Fees Caption [Text]	rr_ShareholderFeesCaption	<span style="color:#000000;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="color:#000000;font-family:Times New Roman;font-size:9pt;font-weight:bold;margin-left:0%;">Annual Fund Operating Expenses (expenses that you pay each </span><span style="color:#000000;font-family:Times New Roman;font-size:9pt;font-weight:bold;">year as a percentage of the value of your investment)</span>
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	<span style="color:#000000;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 99% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	99.00%
Expenses Deferred Charges [Text Block]	rr_ExpensesDeferredChargesTextBlock	Purchases of Class A shares in amounts of $1 million or more that are not subject to an initial sales charge may be subject to a 1.00% contingent deferred sales charge if those shares are redeemed within 24 months of their purchase. A deferred sales charge on Class A and C shares may apply to certain redemptions of shares purchased by exchange from another Transamerica Fund.
Expense Breakpoint Discounts [Text]	rr_ExpenseBreakpointDiscounts	<span style="color:#000000;font-family:Times New Roman;font-size:10pt;margin-left:7.00%;">You may qualify for sales charge discounts if you and your </span><span style="color:#000000;font-family:Times New Roman;font-size:10pt;">family invest, or agree to invest in the future, at least </span><span style="color:#000000;font-family:Times New Roman;font-size:10pt;">$50,000</span><span style="color:#000000;font-family:Times New Roman;font-size:10pt;"> in Transamerica Funds.</span>
Expense Breakpoint, Minimum Investment Required [Amount]	rr_ExpenseBreakpointMinimumInvestmentRequiredAmount	$ 50,000
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>
Expenses Restated to Reflect Current [Text]	rr_ExpensesRestatedToReflectCurrent	<span style="font-family:Times New Roman;font-size:8pt;">Other expenses have been revised to reflect current transfer agency fees with respect to Class I.</span>
Expense Example [Heading]	rr_ExpenseExampleHeading	<span style="color:#000000;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 (unless otherwise indicated). 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:
Expense Example by, Year, Caption [Text]	rr_ExpenseExampleByYearCaption	<span style="color:#000000;font-family:Times New Roman;font-size:9pt;font-weight:bold;">If the shares are redeemed at the end of each period:</span>
Expense Example, No Redemption, By Year, Caption [Text]	rr_ExpenseExampleNoRedemptionByYearCaption	<span style="color:#000000;font-family:Times New Roman;font-size:9pt;font-weight:bold;">If the shares are not redeemed:</span>
Strategy [Heading]	rr_StrategyHeading	<span style="font-family:Times New Roman;font-size:10pt;font-weight:bold;margin-left:0%;">Principal Investment Strategies:</span>
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The fund normally invests primarily in stocks of medium sized companies which the fund’s sub-adviser, Wellington Management Company LLP (the “sub-adviser”), believes will earn high returns on invested capital, benefit from long term secular growth trends, and meet the sub-adviser’s long term valuation criteria. Under normal circumstances, the sub-adviser invests at least 80% of the fund’s net assets (plus the amount of borrowings, if any, for investment purposes) in securities of medium sized (or mid-cap) companies and other investments with similar economic characteristics. The sub-adviser considers mid-cap companies to be companies with market capitalizations that, at the time of initial purchase, are within the range of capitalization of the companies that are included in the Russell Midcap®Growth Index1.  As of December 31, 2021, the market capitalizations of companies in the Russell Midcap® Growth Index ranged from approximately $1.22 billion to $58.76 billion. Over time, the capitalizations of the companies in the Russell Midcap® Growth Index will change. As they do, the size of the companies in which the fund invests may change.The fund’s equity securities may include common stocks and preferred stocks listed on the New York Stock Exchange and on other national securities exchanges and, generally to a lesser extent, stocks that are traded over-the-counter. The fund normally emphasizes common stocks. The fund may also invest in foreign securities. 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.The fund may also invest its assets in cash, cash equivalent securities or short-term debt securities, repurchase agreements and money market instruments. Generally, 5% or less of the fund’s assets will be invested in cash and cash equivalents.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="color:#000000;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 impactedby 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.Medium Capitalization Companies – The fund will be exposed to additional risks as a result of its investments in the securities of medium capitalization companies. Investing in medium capitalization companies involves greater risk than is customarily associated with more established companies. The prices of securities of medium capitalization companies generally are more volatile and are more likely to be adversely affected by changes in earnings results and investor expectations or poor economic or market conditions. Securities of medium capitalization companies may underperform larger capitalization companies, may be harder to sell at times and at prices the portfolio managers believe appropriate and may offer greater potential for losses.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.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.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.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 Shareholder – A significant portion of the fund’s shares may be owned by other funds sponsored by Transamerica. Transactions by these funds may be disruptive to the management of the fund. For example, the fund may experience large redemptions and could be required to sell securities at a time when it may not otherwise desire to do so. Such transactions may increase the fund’s brokerage and/or other transaction costs. These transactions may also accelerate the realization of taxable income to shareholders if such sales of investments resulted in gains. In addition, sizeable redemptions could cause the fund’s total expenses to increase.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.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.Repurchase Agreements – In a repurchase agreement, the fund purchases securities from a broker-dealer or a bank, called the counterparty, upon the agreement of the counterparty to repurchase the securities from the fund at a later date, and at a specified price. The securities purchased serve as the fund's collateral for the obligation of the counterparty to repurchase the securities. If the counterparty does not repurchase the securities, the fund is entitled to sell the securities, but the fund may not be able to sell them for the price at which they were purchased, thus causing a loss. If the counterparty becomes insolvent, there is some risk that the fund will not have a right to the securities, or the immediate right to sell the securities.
Risk Lose Money [Text]	rr_RiskLoseMoney	<span style="color:#000000;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="color:#000000;font-family:Times New Roman;font-size:10pt;">An investment in the fund is </span><span style="color:#000000;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="color:#000000;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.Performance information for Class R6 shares will be included after the share class has been in operation for one complete calendar year.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 December 1, 2018, the fund had a different sub-adviser and used different investment strategies. The performance set forth prior to that date is attributable to that sub-adviser.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	<span style="color:#000000;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</span><span style="font-family:Times New Roman;font-size:10pt;">-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 A</span>
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Quarter EndedReturnBest Quarter:6/30/202032.60%Worst Quarter:3/31/2020-21.21%
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, </span><span style="font-family:Times New Roman;font-size:8.5pt;font-weight:bold;line-height:11pt;"> </span><span style="font-family:Times New Roman;font-size:8.5pt;font-weight:bold;">2021)</span>
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	<span style="color:#000000;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="color:#000000;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="color:#000000;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 One Class of after Tax Shown [Text]	rr_PerformanceTableOneClassOfAfterTaxShown	<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 Table Narrative	rr_PerformanceTableNarrativeTextBlock	Class A, Class C and Class I shares commenced operations on October 31, 2013. Performance information is shown for one year and from the date of the reorganization of certain funds into the fund (March 10, 2017). The applicable predecessor fund, whose accounting and performance history were adopted in the reorganizations, did not offer Class A, Class C and Class I shares.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.After-tax returns are presented for only one class, and returns for other classes are presented before taxes only and will vary.
Retail Class | Transamerica Mid Cap Growth | A
Risk Return Abstract	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	5.50%
Maximum deferred sales charge (load) (as a percentage of purchase price or redemption proceeds, whichever is lower)	rr_MaximumDeferredSalesChargeOverOther	none	[1]
Management fees	rr_ManagementFeesOverAssets	0.69%
Distribution and service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other expenses	rr_OtherExpensesOverAssets	0.23%
Total annual fund operating expenses	rr_ExpensesOverAssets	1.17%
1 year	rr_ExpenseExampleYear01	$ 663
3 years	rr_ExpenseExampleYear03	901
5 years	rr_ExpenseExampleYear05	1,158
10 years	rr_ExpenseExampleYear10	1,892
1 year	rr_ExpenseExampleNoRedemptionYear01	663
3 years	rr_ExpenseExampleNoRedemptionYear03	901
5 years	rr_ExpenseExampleNoRedemptionYear05	1,158
10 years	rr_ExpenseExampleNoRedemptionYear10	$ 1,892
2018	rr_AnnualReturn2018	(19.29%)
2019	rr_AnnualReturn2019	42.95%
2020	rr_AnnualReturn2020	29.99%
2021	rr_AnnualReturn2021	6.54%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	<span style="color:#000000;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	32.60%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	<span style="color:#000000;font-family:Times New Roman;font-size:9pt;margin-left:0.0pt;">Worst Quarter:</span>
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Mar. 31, 2020
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(21.21%)
1 Year	rr_AverageAnnualReturnYear01	0.43%
Since Inception	rr_AverageAnnualReturnSinceInception	11.86%
Inception Date	rr_AverageAnnualReturnInceptionDate	Mar. 10, 2017
Retail Class | Transamerica Mid Cap Growth | C
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	1.00%	[1]
Management fees	rr_ManagementFeesOverAssets	0.69%
Distribution and service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	1.00%
Other expenses	rr_OtherExpensesOverAssets	0.21%
Total annual fund operating expenses	rr_ExpensesOverAssets	1.90%
1 year	rr_ExpenseExampleYear01	$ 293
3 years	rr_ExpenseExampleYear03	597
5 years	rr_ExpenseExampleYear05	1,026
10 years	rr_ExpenseExampleYear10	2,222
1 year	rr_ExpenseExampleNoRedemptionYear01	193
3 years	rr_ExpenseExampleNoRedemptionYear03	597
5 years	rr_ExpenseExampleNoRedemptionYear05	1,026
10 years	rr_ExpenseExampleNoRedemptionYear10	$ 2,222
1 Year	rr_AverageAnnualReturnYear01	4.78%
Since Inception	rr_AverageAnnualReturnSinceInception	12.35%
Inception Date	rr_AverageAnnualReturnInceptionDate	Mar. 10, 2017
Retail Class | Transamerica Mid Cap Growth | I
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	0.69%
Distribution and service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	none
Other expenses	rr_OtherExpensesOverAssets	0.16%	[2]
Total annual fund operating expenses	rr_ExpensesOverAssets	0.85%
1 year	rr_ExpenseExampleYear01	$ 87
3 years	rr_ExpenseExampleYear03	271
5 years	rr_ExpenseExampleYear05	471
10 years	rr_ExpenseExampleYear10	1,049
1 year	rr_ExpenseExampleNoRedemptionYear01	87
3 years	rr_ExpenseExampleNoRedemptionYear03	271
5 years	rr_ExpenseExampleNoRedemptionYear05	471
10 years	rr_ExpenseExampleNoRedemptionYear10	$ 1,049
1 Year	rr_AverageAnnualReturnYear01	6.59%
Since Inception	rr_AverageAnnualReturnSinceInception	13.51%
Inception Date	rr_AverageAnnualReturnInceptionDate	Mar. 10, 2017
Retail Class | Transamerica Mid Cap 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	0.69%
Distribution and service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	none
Other expenses	rr_OtherExpensesOverAssets
Total annual fund operating expenses	rr_ExpensesOverAssets	0.76%
1 year	rr_ExpenseExampleYear01	$ 78
3 years	rr_ExpenseExampleYear03	243
5 years	rr_ExpenseExampleYear05	422
10 years	rr_ExpenseExampleYear10	942
1 year	rr_ExpenseExampleNoRedemptionYear01	78
3 years	rr_ExpenseExampleNoRedemptionYear03	243
5 years	rr_ExpenseExampleNoRedemptionYear05	422
10 years	rr_ExpenseExampleNoRedemptionYear10	$ 942
Retail Class | Transamerica Mid Cap Growth | Return After Taxes on Distributions | A
Risk Return Abstract	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	(8.96%)
Since Inception	rr_AverageAnnualReturnSinceInception	7.01%
Retail Class | Transamerica Mid Cap Growth | Return After Taxes on Distributions and Sale of Fund Shares | A
Risk Return Abstract	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	3.56%
Since Inception	rr_AverageAnnualReturnSinceInception	7.94%
Retail Class | Transamerica Mid Cap Growth | Russell Midcap® Growth Index (reflects no deduction for fees, expenses or taxes)
Risk Return Abstract	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	12.73%	[3]
Since Inception	rr_AverageAnnualReturnSinceInception	19.29%	[3]

[1] Purchases of Class A shares in amounts of $1 million or more that are not subject to an initial sales charge may be subject to a 1.00% contingent deferred sales charge if those shares are redeemed within 24 months of their purchase. A deferred sales charge on Class A and C shares may apply to certain redemptions of shares purchased by exchange from another Transamerica Fund.

[2] Other expenses have been revised to reflect current transfer agency fees with respect to Class I.

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