Label	Element	Value
Risk Return Abstract	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	EQ ADVISORS TRUST
Prospectus Date	rr_ProspectusDate	May 01, 2025
EQ Morgan Stanley Small Cap Growth Portfolio
Risk Return Abstract	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	<span style="color:#000000;font-family:Arial;font-size:11pt;font-weight:bold;">EQ/Morgan Stanley Small Cap Growth Portfolio</span><span style="color:#000000;font-family:Arial;font-size:11pt;font-weight:bold;line-height:13pt;">  </span><span style="color:#000000;font-family:Arial;font-size:11pt;font-weight:bold;">— Class IB and Class K Shares</span>
Objective [Heading]	rr_ObjectiveHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Investment Objective:</span>
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	Seeks to achieve long-term growth of capital.
Expense [Heading]	rr_ExpenseHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;text-transform:uppercase;">Fees and Expenses of the Portfolio</span>
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	The following table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Portfolio. The table below does not reflect any fees and expenses associated with variable life insurance contracts and variable annuity certificates and contracts (“Contracts”), which would increase overall fees and expenses. See the Contract prospectus for a description of those fees and expenses.
Shareholder Fees Caption [Text]	rr_ShareholderFeesCaption	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Shareholder Fees</span> <br/><span style="color:#000000;font-family:Arial;font-size:10pt;">(fees paid directly from your investment)</span>
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Annual Portfolio Operating Expenses</span><span style="color:#000000;font-family:Arial;font-size:10pt;">(expenses that you pay each year as a percentage of the value of your investment)</span>
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	<span style="font-family:Arial;font-size:8pt;">April 30, 2026</span>
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;text-transform:uppercase;">Portfolio Turnover</span>
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The Portfolio 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. These costs, which are not reflected in annual fund operating expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’s portfolio turnover rate was 75% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	75.00%
Expense Example [Heading]	rr_ExpenseExampleHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Example</span>
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This Example is intended to help you compare the cost of investing in the Portfolio with the cost of investing in other portfolios. The Example assumes that you invest $10,000 in the Portfolio for the periods indicated, that your investment has a 5% return each year, that the Portfolio’s operating expenses remain the same, and that the Expense Limitation Arrangement is not renewed. This Example does not reflect any Contract-related fees and expenses including redemption fees (if any) at the Contract level. If such fees and expenses were reflected, the total expenses would be higher. Although your actual costs may be higher or lower, based on these assumptions, whether you redeem or hold your shares, your costs would be:
Strategy [Heading]	rr_StrategyHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;text-transform:uppercase;">Investments, Risks, and Performance</span><span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Principal Investment Strategy</span>
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	Under normal circumstances, the Portfolio invests at least 80% of its net assets, plus borrowings for investment purposes, in securities of companies with small market capitalizations (or other financial instruments that derive their value from the securities of such companies). For purposes of this Portfolio, small market capitalization companies are those companies that have market capitalizations within the range of companies in the Russell 2000® Index (“Russell 2000”). A company’s market capitalization is based on its current market capitalization or its market capitalization at the time of the Portfolio’s investment. The market capitalization range of the companies in the Russell 2000 was between $9.12 million and $13.19 billion as of December 31, 2024. The size of companies in the Russell 2000 changes with market conditions, which can result in changes to the market capitalization range of companies in the index. The Portfolio intends to invest primarily in equity securities, but it may also invest in other securities that a Sub-Adviser believes provide opportunities for capital growth. The Portfolio may invest up to 15% of its assets in foreign securities, including securities of companies based in developing countries and depositary receipts of foreign-based companies. The Portfolio’s assets normally are allocated among two or more investment managers, each of which manages its portion of the Portfolio using a different but complementary investment strategy. One portion of the Portfolio is actively managed (“Active Allocated Portion”), and one portion of the Portfolio seeks to track the performance of a particular index (“Index Allocated Portion”). Under normal circumstances, the Active Allocated Portion consists of approximately 50% of the Portfolio’s net assets, and the Index Allocated Portion consists of approximately 50% of the Portfolio’s net assets. These percentages are targets established by the Adviser; actual allocations may deviate from these targets. The Sub-Adviser emphasizes a bottom-up stock selection process, seeking attractive investments on an individual company basis. In selecting securities for investment, the Sub-Adviser typically invests in unique companies it believes have sustainable competitive advantages with above average business visibility, the ability to deploy capital at high rates of return, strong balance sheets and an attractive risk/reward. The Sub-Adviser generally considers selling an investment when it determines the company no longer satisfies its investment criteria. The Active Allocated Portion’s equity investments may include common and preferred stocks, convertible securities and equity-linked securities, rights and warrants to purchase common stocks, depositary receipts, exchange-traded funds (“ETFs”), limited partnership interests, limited liability company interests and other specialty securities having equity features. The Active Allocated Portion may invest in privately placed and restricted securities. The Active Allocated Portion may utilize foreign currency forward exchange contracts, which are derivatives, in connection with its investments in foreign securities. The Index Allocated Portion seeks to track the performance (before fees and expenses) of the Russell 2000® Growth Index with minimal tracking error. This strategy is commonly referred to as an indexing strategy. The Index Allocated Portion may use a full replication technique or a sampling approach in pursuing its indexing strategy.
Risk [Heading]	rr_RiskHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Principal Risks</span>
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Risk/Return Bar Chart and Table</span>
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The bar chart and table below provide some indication of the risks of investing in the Portfolio by showing changes in the Portfolio’s performance from year to year and by showing how the Portfolio’s average annual total returns for the past one, five and ten years through December 31, 2024, compared to the returns of a broad-based securities market index.The additional securities market index shows how the Portfolio's performance compared with the returns of another index that has characteristics relevant to the Portfolio's investment strategies. Past performance is not an indication of future performance.Class IB shares were not operational for the period from April 14, 2015 through April 30, 2015. The returns of Class IB were calculated assuming the shares were in operation for the entire period.The performance results do not reflect any Contract-related fees and expenses, which would reduce the performance results.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	<span style="font-family:Arial;font-size:10pt;margin-left:0%;">The bar chart and table below provide some indication of the risks of investing in the Portfolio by showing changes in the Portfolio’s performance from year to year and by showing how the Portfolio’s average annual total returns for the past one</span><span style="font-family:Arial;font-size:10pt;">, five and ten years </span><span style="font-family:Arial;font-size:10pt;margin-left:0%;">through December 31, </span><span style="font-family:Arial;font-size:10pt;">2024, compared to the returns of a broad-based securities market index.</span>
Performance Additional Market Index [Text]	rr_PerformanceAdditionalMarketIndex	<span style="font-family:Arial;font-size:10pt;">The additional securities market </span><span style="font-family:Arial;font-size:10pt;margin-left:0%;">index shows how the Portfolio's performance compared with the returns of another index that has characteristics relevant to the </span><span style="font-family:Arial;font-size:10pt;">Portfolio's investment strategies. </span>
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	<span style="font-family:Arial;font-size:10pt;">Past performance is not an indication of future performance.</span>
Bar Chart [Heading]	rr_BarChartHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Calendar Year Annual Total Returns — Class IB</span>
Bar Chart Does Not Reflect Sales Loads [Text]	rr_BarChartDoesNotReflectSalesLoads	<span style="color:#000000;font-family:Arial;font-size:10pt;">The performance results do not reflect any Contract-related fees and expenses, which would reduce the performance results.</span>
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Best quarter (% and time period)54.29%2020 2nd QuarterWorst quarter (% and time period)-27.33%2022 2nd Quarter
Performance Table Heading	rr_PerformanceTableHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Average Annual Total Returns</span>
EQ Morgan Stanley Small Cap Growth Portfolio | Risk Lose Money [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	The value of your investment may fall, sometimes sharply, and you could lose money by investing in the Portfolio.
EQ Morgan Stanley Small Cap Growth Portfolio | Risk Not Insured Depository Institution [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	An investment in the Portfolio is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
EQ Morgan Stanley Small Cap Growth Portfolio | Market Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Market Risk —  The Portfolio is subject to the risk that the securities markets will move down, sometimes rapidly and unpredictably, based on overall economic conditions and other factors, which may negatively affect Portfolio performance. Securities markets also may experience long periods of decline in value. The value of a security can be more volatile than the market as a whole and can perform differently from the market as a whole. Any issuer of securities may perform poorly, causing the value of its securities to decline. Poor performance may be caused by a variety of factors, such as poor management decisions; reduced demand for the issuer’s goods or services; competitive pressures; negative perception in the marketplace; loss of major customers; strategic initiatives such as mergers or acquisitions and the market response to any such initiatives; and the historical and prospective earnings of the issuer. The value of a security also may decline due to general market conditions, such as real or perceived adverse economic or political conditions, inflation rates and/or investor expectations concerning such rates, changes in interest rates, recessions, or adverse investor sentiment generally. During a general downturn in the securities markets, multiple asset classes may decline in value simultaneously. Even when securities markets perform well, there can be no assurance that the investments held by the Portfolio will increase in value along with the broader market. Changes in the financial condition of (or other event affecting) a single issuer can impact an individual sector or industry, or the securities markets as a whole. The value of a security also may decline due to factors that affect a particular sector or industry, such as tariffs, labor shortages, or increased production costs and competitive conditions within the sector or industry. Geopolitical events, including acts of terrorism, tensions, war or other open conflicts between nations, or political or economic dysfunction within nations that are global economic powers or major oil or other commodities producers, may lead to overall instability in world economies and markets generally and have led, and may in the future lead, to increased market volatility and may have adverse long-term effects. World markets, or those in a particular region, may all react in similar fashion to economic, political or other developments. Events such as environmental and natural disasters or other catastrophes, public health crises (such as epidemics and pandemics), social unrest, and cybersecurity incidents, and governments’ reactions (or failure to react) to such events, could cause uncertainty in the markets and may adversely affect the performance of the global economy. Impacts from climate change may include significant risks to global financial assets and economic growth. The extent and duration of such events and resulting market disruptions could be substantial and could magnify the impact of other risks to the Portfolio. The value and liquidity of the Portfolio’s investments may be negatively affected by developments in other countries and regions, whether or not the Portfolio invests in securities of issuers located in or with significant exposure to the countries or regions directly affected. Changes in government or central bank policies, changes in existing laws and regulations, and political, diplomatic and other events within the United States and abroad could cause uncertainty in the markets, may affect investor and consumer confidence, and may adversely impact financial markets and the broader economy, perhaps suddenly and to a significant degree. High public debt and deficits in the United States and other countries create ongoing systemic and market risks and policymaking uncertainty and may negatively affect economic conditions and the values of markets, sectors and companies in which the Portfolio invests. In addition, markets and market participants are increasingly reliant on information data systems. Inaccurate data, software or other technology malfunctions, programming inaccuracies, unauthorized use or access, and similar circumstances may impair the performance of these systems and may have an adverse impact upon a single issuer, a group of issuers, or the market at large. Furthermore, impacts from the rapidly growing use of artificial intelligence technologies, including by market participants, may include significant risks to global financial markets.
EQ Morgan Stanley Small Cap Growth Portfolio | Equity Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Equity Risk —  In general, the values of stocks and other equity securities fluctuate, and sometimes widely fluctuate, in response to changes in a company’s financial condition as well as general market, economic and political conditions and other factors. Stock markets tend to run in cycles, with periods when stock prices generally go up and periods when stock prices generally go down. However, stock markets also can move up and down rapidly and unpredictably. In addition, common stock prices may be particularly sensitive to rising interest rates, which increase borrowing costs and the costs of capital. The Portfolio may experience a significant or complete loss on its investment in an equity security.
EQ Morgan Stanley Small Cap Growth Portfolio | Small-Cap Company Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Small-Cap Company Risk —  Small-cap companies carry additional risks because the operating histories of these companies tend to be more limited, their earnings and revenues less predictable (and some companies may be experiencing significant losses), and their share prices more volatile than those of larger, more established companies. The shares of smaller companies tend to trade less frequently than those of larger, more established companies, which can adversely affect the pricing of these securities and the Portfolio’s ability to purchase or sell these securities.
EQ Morgan Stanley Small Cap Growth Portfolio | Investment Style Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Investment Style Risk —  The Portfolio may use a particular style or set of styles — in this case, a “growth” style — to select investments. A particular style may be out of favor or may not produce the best results over short or longer time periods. Growth stocks may be more sensitive to changes in current or expected earnings than the prices of other stocks. Growth investing also is subject to the risk that the stock price of one or more companies will fall or will fail to appreciate as anticipated by the Portfolio, regardless of movements in the securities market. Growth stocks also tend to be more volatile than value stocks, so in a declining market their prices may decrease more than value stocks in general. Growth stocks also may increase the volatility of the Portfolio’s share price.
EQ Morgan Stanley Small Cap Growth Portfolio | Index Strategy Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Index Strategy Risk —  The Portfolio employs an index strategy for a portion of the Portfolio and generally will not modify its index strategy to respond to changes in market trends or the economy, which means that the Portfolio may be particularly susceptible to a general decline in the market segment relating to the relevant index. In addition, although the index strategy attempts to closely track the relevant index, the Portfolio may not invest in all of the securities in the index. Therefore, there can be no assurance that the performance of the index strategy will match that of the relevant index. To the extent that the Portfolio utilizes a representative sampling approach, it may experience greater tracking error than it would if the Portfolio sought to replicate the index.
EQ Morgan Stanley Small Cap Growth Portfolio | Sector Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Sector Risk —  From time to time, based on market or economic conditions, the Portfolio may have significant positions in one or more sectors of the market. To the extent the Portfolio invests more heavily in particular sectors, its performance will be especially sensitive to developments that significantly affect those sectors. Individual sectors may be more volatile, and may perform differently, than the broader market. The industries that constitute a sector may all react in the same way to economic, political, regulatory or other events.
EQ Morgan Stanley Small Cap Growth Portfolio | Information Technology Sector Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Information Technology Sector Risk —  Investment risks associated with investing in the information technology sector include, in addition to other risks, the intense competition to which information technology companies may be subject; the dramatic and often unpredictable changes in growth rates and competition for qualified personnel among information technology companies; effects on profitability from being heavily dependent on patent and intellectual property rights and the loss or impairment of those rights; rapid product obsolescence due to technological developments and frequent new product introduction; general economic conditions; and legislative or regulatory changes. Any of these factors could result in a material adverse impact on the Portfolio’s holdings and the performance of the Portfolio.
EQ Morgan Stanley Small Cap Growth Portfolio | Portfolio Management Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Portfolio Management Risk —  The Portfolio is subject to the risk that strategies used by an investment manager and its securities selections fail to produce the intended results. An investment manager’s judgments or decisions about the quality, relative yield or value of, or market trends affecting, a particular security or issuer, industry, sector, region or market segment, or about the economy or interest rates, may be incorrect or otherwise may not produce the intended results, which may result in losses to the Portfolio. In addition, many processes used in Portfolio management, including security selection, rely, in whole or in part, on the use of various technologies. The Portfolio may suffer losses if there are imperfections, errors or limitations in the quantitative, analytic or other tools, resources, information and data used, or the analyses employed or relied on, by an investment manager, or if such tools, resources, information or data are used incorrectly, fail to produce the desired results, or otherwise do not work as intended. There can be no assurance that the use of these technologies will result in effective investment decisions for the Portfolio. In addition, the Portfolio could experience losses if an investment manager’s judgments about the risks associated with the Portfolio’s investment program prove to be incorrect.
EQ Morgan Stanley Small Cap Growth Portfolio | Derivatives Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Derivatives Risk —  The Portfolio’s investments in derivatives may rise or fall in value more rapidly than other investments and may reduce the Portfolio’s returns and increase the volatility of the Portfolio’s net asset value. Investing in derivatives involves investment techniques and risk analyses different from, and risks in some respects greater than, those associated with investing in more traditional investments, such as stocks and bonds. Derivatives may be leveraged such that a small investment can have a significant impact on the Portfolio’s exposure to stock market values, interest rates, or other investments. As a result, a relatively small price movement in a derivatives contract may cause an immediate and substantial loss, and the Portfolio could lose more than the amount it invested. Some derivatives can have the potential for unlimited losses. In addition, it may be difficult or impossible for the Portfolio to purchase or sell certain derivatives in sufficient amounts to achieve the desired level of exposure, or to terminate or offset existing arrangements, which may result in a loss or may be costly to the Portfolio. Some derivatives are more sensitive to market price fluctuations and to interest rate changes than other investments. Derivatives may not behave as anticipated by the Portfolio, and derivatives strategies that are successful under certain market conditions may be less successful or unsuccessful under other market conditions. The Portfolio also may be exposed to losses if the counterparty in the transaction is unable or unwilling to fulfill its contractual obligation. In certain cases, the Portfolio may be hindered or delayed in exercising remedies against or closing out derivatives with a counterparty, resulting in additional losses. Derivatives also may be subject to the risk of mispricing or improper valuation, and valuation may be more difficult in times of market turmoil. Changes to the regulation of derivatives markets and mutual funds’ use of derivatives may impact the Portfolio’s ability to maintain its investments in derivatives, make derivatives more costly, limit their availability, adversely affect their value or performance, or otherwise disrupt markets.
EQ Morgan Stanley Small Cap Growth Portfolio | ETFs Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	ETFs Risk —  When the Portfolio invests in an ETF, it will indirectly bear its proportionate share of the fees and expenses incurred by the ETF. These fees and expenses are in addition to the advisory fees and other expenses that the Portfolio and its shareholders bear directly in connection with the Portfolio’s own operations. As a result, the Portfolio’s shareholders will be subject to two layers of fees and expenses with respect to investments in the Portfolio. The cost of investing in the Portfolio, therefore, may be higher than the cost of investing in a mutual fund that invests directly in individual stocks and bonds. In addition, the Portfolio’s net asset value will be subject to fluctuations in the market values of the ETFs in which it invests. The Portfolio is also subject to the risks associated with the securities or other investments in which the ETFs invest, and the ability of the Portfolio to meet its investment objective will directly depend on the ability of the ETFs to meet their investment objectives. A passively managed (or index-based) ETF’s performance may not match that of the index it seeks to track. An actively managed ETF’s performance will reflect its manager’s ability to make investment decisions that are suited to achieving the ETF’s investment objective. Furthermore, it is possible that an active trading market for an ETF may not develop or be maintained, in which case the liquidity and value of the Portfolio’s investment in the ETF could be substantially and adversely affected. The extent to which the investment performance and risks associated with the Portfolio correlate to those of a particular ETF will depend upon the extent to which the Portfolio’s assets are allocated from time to time for investment in the ETF, which will vary.
EQ Morgan Stanley Small Cap Growth Portfolio | Foreign Securities Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Foreign Securities Risk —  Investments in foreign securities, including depositary receipts, involve risks in addition to those associated with investments in U.S. securities. Foreign markets may be less liquid, more volatile and subject to less government supervision and regulation than U.S. markets, and it may take more time to clear and settle trades involving foreign securities, which could negatively impact the Portfolio’s investments and cause it to lose money. Security values also may be negatively affected by changes in the exchange rates between the U.S. dollar and foreign currencies. Differences between U.S. and foreign legal, political and economic systems, regulatory regimes and market practices, as well as changes in international trading patterns, trade barriers and other protectionist trade policies (including those of the United States), tariffs, governmental instability, acts of terrorism, war or other open conflicts, or other political, diplomatic or economic actions, also may adversely impact security values. Foreign securities are also subject to the risks associated with the potential imposition of economic or other sanctions against a particular foreign country, its nationals, businesses or industries. World markets, or those in a particular region, may all react in similar fashion to economic, political or other developments. Events and evolving conditions in certain economies or markets may alter the risks associated with investments tied to countries or regions that historically were perceived as comparatively stable and make such investments riskier and more volatile. Regardless of where a company is organized or its stock is traded, its performance may be significantly affected by events in regions from which it derives its profits or in which it conducts significant operations.
EQ Morgan Stanley Small Cap Growth Portfolio | Currency Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Currency Risk —  Investments that are denominated in or that provide exposure to foreign currencies are subject to the risk that those currencies will decline in value relative to the U.S. dollar. Any such decline may erode or reverse any potential gains from an investment in securities denominated in foreign currency or may widen existing loss. In the case of hedging positions, there is the risk that the U.S. dollar will decline in value relative to the currency being hedged. Currency rates may fluctuate significantly over short periods of time.
EQ Morgan Stanley Small Cap Growth Portfolio | Large Transaction Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Large Transaction Risk —  A significant percentage of the Portfolio’s shares may be owned or controlled by the Adviser and its affiliates, other Portfolios advised by the Adviser (including funds of funds), or other large shareholders, including primarily insurance company separate accounts. Accordingly, the Portfolio is subject to the potential for large-scale, relative to its asset size, inflows and outflows as a result of purchases and redemptions of its shares by such shareholders. These inflows and outflows could negatively affect the Portfolio’s net asset value and performance.
EQ Morgan Stanley Small Cap Growth Portfolio | Class IB
Risk Return Abstract	rr_RiskReturnAbstract
Shareholder Fees (fees paid directly from your investment)	rr_ShareholderFeeOther
Management Fee	rr_ManagementFeesOverAssets	0.80%
Distribution and/or Service Fees (12b-1 fees)	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other Expenses	rr_OtherExpensesOverAssets	0.19%
Total Annual Portfolio Operating Expenses	rr_ExpensesOverAssets	1.24%
Fee Waiver and/or Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.09%)	[1]
Total Annual Portfolio Operating Expenses After Fee Waiver and/or Expense Reimbursement	rr_NetExpensesOverAssets	1.15%
1 Year	rr_ExpenseExampleYear01	$ 117
3 Years	rr_ExpenseExampleYear03	385
5 Years	rr_ExpenseExampleYear05	672
10 Years	rr_ExpenseExampleYear10	$ 1,492
2015	rr_AnnualReturn2015	(5.90%)
2016	rr_AnnualReturn2016	8.77%
2017	rr_AnnualReturn2017	24.14%
2018	rr_AnnualReturn2018	(4.77%)
2019	rr_AnnualReturn2019	34.35%
2020	rr_AnnualReturn2020	95.74%
2021	rr_AnnualReturn2021	2.78%
2022	rr_AnnualReturn2022	(44.23%)
2023	rr_AnnualReturn2023	34.45%
2024	rr_AnnualReturn2024	20.79%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	<span style="color:#000000;font-family:Arial;font-size:8pt;margin-left:0.0pt;">Best quarter (% and time period)</span>
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Jun. 30, 2020
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	54.29%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	<span style="color:#000000;font-family:Arial;font-size:8pt;margin-left:0.0pt;">Worst quarter (% and time period)</span>
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Jun. 30, 2022
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(27.33%)
OneYear	rr_AverageAnnualReturnYear01	20.79%
FiveYears	rr_AverageAnnualReturnYear05	12.75%
TenYears	rr_AverageAnnualReturnYear10	11.47%
EQ Morgan Stanley Small Cap Growth Portfolio | Class K
Risk Return Abstract	rr_RiskReturnAbstract
Shareholder Fees (fees paid directly from your investment)	rr_ShareholderFeeOther
Management Fee	rr_ManagementFeesOverAssets	0.80%
Distribution and/or Service Fees (12b-1 fees)	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	0.19%
Total Annual Portfolio Operating Expenses	rr_ExpensesOverAssets	0.99%
Fee Waiver and/or Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.09%)	[1]
Total Annual Portfolio Operating Expenses After Fee Waiver and/or Expense Reimbursement	rr_NetExpensesOverAssets	0.90%
1 Year	rr_ExpenseExampleYear01	$ 92
3 Years	rr_ExpenseExampleYear03	306
5 Years	rr_ExpenseExampleYear05	538
10 Years	rr_ExpenseExampleYear10	$ 1,205
OneYear	rr_AverageAnnualReturnYear01	21.02%
FiveYears	rr_AverageAnnualReturnYear05	13.02%
TenYears	rr_AverageAnnualReturnYear10	11.72%
EQ Morgan Stanley Small Cap Growth Portfolio | Russell 3000® Index (reflects no deduction for fees, expenses, or taxes)
Risk Return Abstract	rr_RiskReturnAbstract
OneYear	rr_AverageAnnualReturnYear01	23.81%
FiveYears	rr_AverageAnnualReturnYear05	13.86%
TenYears	rr_AverageAnnualReturnYear10	12.55%
EQ Morgan Stanley Small Cap Growth Portfolio | Russell 2000® Growth Index (reflects no deduction for fees, expenses, or taxes)
Risk Return Abstract	rr_RiskReturnAbstract
OneYear	rr_AverageAnnualReturnYear01	15.15%
FiveYears	rr_AverageAnnualReturnYear05	6.86%
TenYears	rr_AverageAnnualReturnYear10	8.09%

[1] Pursuant to a contract, Equitable Investment Management Group, LLC (the “Adviser”) has agreed to waive its and its affiliates’ management, administrative and other fees and, if necessary, make payments to the Portfolio to limit the expenses of the Portfolio through April 30, 2026 (unless the Board of Trustees consents to an earlier revision or termination of this arrangement) (“Expense Limitation Arrangement”) so that the annual operating expenses of the Portfolio (exclusive of taxes, interest, brokerage commissions, dividend and interest expenses on securities sold short, capitalized expenses, acquired fund fees and expenses, and extraordinary expenses not incurred in the ordinary course of the Portfolio’s business) do not exceed an annual rate of average daily net assets of 1.15% for Class IB shares and 0.90% for Class K shares of the Portfolio. The Expense Limitation Arrangement may be terminated by the Adviser at any time after April 30, 2026. The Adviser may be reimbursed the amount of any such waivers or payments in the future provided that the waivers or payments are reimbursed within three years of the waivers or payments being recorded and the Portfolio’s expense ratio, after the reimbursement is taken into account, does not exceed the Portfolio’s expense cap at the time of the waiver or the Portfolio’s expense cap at the time of the reimbursement, whichever is lower.