Label	Element	Value
Risk Return Abstract	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	EQ ADVISORS TRUST
Prospectus Date	rr_ProspectusDate	May 01, 2025
EQ Fidelity Institutional AM Large Cap 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/Fidelity Institutional AM</span><span style="color:#000000;font-family:Arial;font-size:7pt;font-weight:bold;position:relative;top:-4.75pt;">®</span><span style="color:#000000;font-family:Arial;font-size:11pt;font-weight:bold;"> Large Cap 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 capital appreciation.
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 54% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	54.00%
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 any borrowings for investment purposes, in securities of large-cap companies (or other financial instruments that derive their value from the securities of such companies). For purposes of this Portfolio, large-cap companies are those companies with public stock market capitalizations within the range of companies constituting the Standard & Poor’s 500® Composite Stock Index (“S&P 500® Index”) at the time of investment. As of December 31, 2024, the market capitalizations of the companies in the S&P 500® Index ranged from approximately $6.06 billion to $3.81 trillion. The size of companies in the index changes with market conditions, which can result in changes to the market capitalization range of companies in the index. The Sub-Adviser invests the Portfolio’s assets in securities of companies whose value it believes is not fully recognized by the public. The types of companies in which the Portfolio may invest include companies experiencing positive fundamental change, such as a new management team or product launch, a significant cost-cutting initiative, a merger or acquisition, or a reduction in industry capacity that should lead to improved pricing; companies whose earnings potential has increased or is expected to increase more than generally perceived; companies that have enjoyed recent market popularity but which appear to have fallen temporarily out of favor for reasons that are considered non-recurring or short-term; and companies that are undervalued in relation to securities of other companies in the same industry. The Sub-Adviser normally invests the Portfolio’s assets primarily in common stocks. The Sub-Adviser may invest the Portfolio’s assets in securities of foreign issuers in addition to securities of domestic issuers. The Sub-Adviser allocates the Portfolio’s assets across different market sectors, using different portfolio managers to handle investments within each sector. At present, these sectors include consumer discretionary, consumer staples, energy, financials, health care, industrials, information technology, materials, real estate, communication services, and utilities. The Sub-Adviser expects the Portfolio’s sector allocations will approximate the sector weightings of the S&P 500® Index, a broadly diversified measure of the performance of 500 common stocks chosen for market size, liquidity, and industry group representation to represent U.S. equity performance. While the Sub-Adviser may overweight or underweight one or more sectors from time to time, the Sub-Adviser expects the Portfolio’s returns to be driven primarily by the security selections of the portfolio managers of each sector. The Sub-Adviser is not constrained by any particular investment style. At any given time, the Sub-Adviser may tend to buy “growth” stocks or “value” stocks, or a combination of both types. In buying and selling securities for the Portfolio, the Sub-Adviser relies on fundamental analysis, which involves a bottom-up assessment of a company’s potential for success in light of factors including its financial condition, earnings outlook, strategy, management, and industry position, and economic and market conditions. The Sub-Adviser may also use various techniques, such as buying and selling futures contracts and exchange traded funds, to increase or decrease the Portfolio’s exposure to changing security prices or other factors that affect security values.
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-year, five-year and since inception periods through December 31, 2024, compared to the returns of a broad-based securities market index.Past performance is not an indication of future performance.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-year, five-year and since inception periods 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 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)23.04%2020 2nd QuarterWorst quarter (% and time period)-19.76%2020 1st 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 Fidelity Institutional AM Large Cap 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 Fidelity Institutional AM Large Cap 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 Fidelity Institutional AM Large Cap 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 Fidelity Institutional AM Large Cap 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 Fidelity Institutional AM Large Cap Portfolio | Large-Cap Company Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Large-Cap Company Risk —  Larger more established companies may be unable to respond quickly to new competitive challenges such as changes in technology and consumer tastes, which may lead to a decline in their market price. Many larger companies also may not be able to attain the high growth rate of successful smaller companies, especially during extended periods of economic expansion.
EQ Fidelity Institutional AM Large Cap 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 Fidelity Institutional AM Large Cap 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 Fidelity Institutional AM Large Cap 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 Fidelity Institutional AM Large Cap 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 Fidelity Institutional AM Large Cap 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 Fidelity Institutional AM Large Cap Portfolio | Foreign Securities Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Foreign Securities Risk —  Investments in foreign securities 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 Fidelity Institutional AM Large Cap 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 Fidelity Institutional AM Large Cap Portfolio | European Economic Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	European Economic Risk —  The economies of European Union (“EU”) member countries and their trading partners, as well as the broader global economy, may be adversely affected by changes in the euro’s exchange rate, changes in EU or governmental regulations on trade, geopolitical and other events, including acts of terrorism, tensions, war or other open conflicts, and the threat of default or an actual default by an EU member country on its sovereign debt, which could negatively impact the Portfolio’s investments and cause it to lose money. Events in Europe may continue to impact the economies of every European country and their economic partners. The ongoing Russia-Ukraine conflict, the resulting responses by the United States and other countries, and the potential for wider conflict have had, and could continue to have, severe adverse effects on regional and global economies and could further increase volatility and uncertainty in the financial markets. In addition, uncertainties regarding the viability of the EU have impacted and may continue to impact regional and global markets. There are ongoing concerns regarding the economies of certain European countries and/or their sovereign debt following the United Kingdom’s withdrawal from the EU, commonly referred to as “Brexit”. Any further withdrawals from the EU could cause significant regional and global market disruption, which may negatively impact the Portfolio’s investments and cause it to lose money. Furthermore, the national politics of European countries have been unpredictable; unanticipated or sudden political or social developments may result in sudden and significant investment losses.
EQ Fidelity Institutional AM Large Cap Portfolio | Geographic Focus Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Geographic Focus Risk —  To the extent the Portfolio invests a significant portion of its assets in securities of companies domiciled, or exercising the predominant part of their economic activity, in one country or geographic region, it assumes the risk that economic, political, social and environmental conditions in that particular country or region will have a significant impact on the Portfolio’s investment performance and that the Portfolio’s performance will be more volatile than the performance of more geographically diversified funds.
EQ Fidelity Institutional AM Large Cap 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, both “growth” and “value” styles — to select investments. Those styles 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. Value stocks are subject to the risks that, notwithstanding that a stock is selling at a discount to its perceived true worth, the stock’s full value may never be fully recognized or realized by the market, or its price may go down. In addition, there is the risk that a stock judged to be undervalued may actually have been appropriately priced at the time of investment.
EQ Fidelity Institutional AM Large Cap Portfolio | Class IB
Risk Return Abstract	rr_RiskReturnAbstract
Shareholder Fees (fees paid directly from your investment)	rr_ShareholderFeeOther
Management Fee	rr_ManagementFeesOverAssets	0.52%
Distribution and/or Service Fees (12b-1 fees)	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other Expenses	rr_OtherExpensesOverAssets	0.13%
Total Annual Portfolio Operating Expenses	rr_ExpensesOverAssets	0.90%
Fee Waiver and/or Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.03%)	[1]
Total Annual Portfolio Operating Expenses After Fee Waiver and/or Expense Reimbursement	rr_NetExpensesOverAssets	0.87%
1 Year	rr_ExpenseExampleYear01	$ 89
3 Years	rr_ExpenseExampleYear03	284
5 Years	rr_ExpenseExampleYear05	496
10 Years	rr_ExpenseExampleYear10	$ 1,105
2019	rr_AnnualReturn2019	31.09%
2020	rr_AnnualReturn2020	26.32%
2021	rr_AnnualReturn2021	25.22%
2022	rr_AnnualReturn2022	(21.06%)
2023	rr_AnnualReturn2023	31.38%
2024	rr_AnnualReturn2024	24.51%
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	23.04%
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	Mar. 31, 2020
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(19.76%)
OneYear	rr_AverageAnnualReturnYear01	24.51%
FiveYears	rr_AverageAnnualReturnYear05	15.35%
SinceInception	rr_AverageAnnualReturnSinceInception	14.98%
InceptionDate	rr_AverageAnnualReturnInceptionDate	Oct. 22, 2018
EQ Fidelity Institutional AM Large Cap Portfolio | Class K
Risk Return Abstract	rr_RiskReturnAbstract
Shareholder Fees (fees paid directly from your investment)	rr_ShareholderFeeOther
Management Fee	rr_ManagementFeesOverAssets	0.52%
Distribution and/or Service Fees (12b-1 fees)	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	0.13%
Total Annual Portfolio Operating Expenses	rr_ExpensesOverAssets	0.65%
Fee Waiver and/or Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.03%)	[1]
Total Annual Portfolio Operating Expenses After Fee Waiver and/or Expense Reimbursement	rr_NetExpensesOverAssets	0.62%
1 Year	rr_ExpenseExampleYear01	$ 63
3 Years	rr_ExpenseExampleYear03	205
5 Years	rr_ExpenseExampleYear05	359
10 Years	rr_ExpenseExampleYear10	$ 808
OneYear	rr_AverageAnnualReturnYear01	24.84%
FiveYears	rr_AverageAnnualReturnYear05	15.64%
SinceInception	rr_AverageAnnualReturnSinceInception	15.27%
InceptionDate	rr_AverageAnnualReturnInceptionDate	Oct. 22, 2018
EQ Fidelity Institutional AM Large Cap Portfolio | S&P 500® Index (reflects no deduction for fees, expenses, or taxes)
Risk Return Abstract	rr_RiskReturnAbstract
OneYear	rr_AverageAnnualReturnYear01	25.02%
FiveYears	rr_AverageAnnualReturnYear05	14.53%
SinceInception	rr_AverageAnnualReturnSinceInception	14.84%

[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 (including Acquired Fund Fees and Expenses) of the Portfolio (exclusive of taxes, interest, brokerage commissions, dividend and interest expenses on securities sold short, capitalized 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 0.87% for Class IB shares and 0.62% 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.