Label	Element	Value
Risk Return Abstract	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	EQ ADVISORS TRUST
Prospectus Date	rr_ProspectusDate	May 01, 2025
EQ Aggressive Allocation Portfolio
Risk Return Abstract	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	<span style="font-family:Arial;font-size:11pt;font-weight:bold;">EQ/Aggressive Allocation Portfolio</span><span style="font-family:Arial;font-size:11pt;font-weight:bold;line-height:13pt;">  </span><span style="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>
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 will not incur transaction costs, such as commissions, when it buys and sells shares of the Underlying Portfolios (or “turns over” its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the Portfolio were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs. Such costs, if incurred, would not be reflected in annual fund operating expenses or in the example, and would affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’s portfolio turnover rate was 15% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	15.00%
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, and that the Portfolio’s operating expenses remain the same. 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	The Portfolio is managed by Equitable Investment Management Group, LLC (“EIM” or “Adviser”). The Portfolio pursues its investment objective by investing in other mutual funds (“Underlying Portfolios”) managed by the Adviser or Equitable Investment Management, LLC, an affiliate of the Adviser, and sub-advised by one or more investment sub-advisers. The Portfolio invests approximately 90% of its assets in the equity asset class and approximately 10% of its assets in the fixed income asset class through investments in Underlying Portfolios. Subject to this asset allocation target, the Portfolio generally invests its assets in a combination of Underlying Portfolios that would result in the Portfolio being invested in the following asset categories in the approximate target investment percentages shown in the chart below.Foreign Equity Securities25%Large Cap Equity Securities40%Small/Mid Cap Equity Securities25%Investment Grade Bonds9%High Yield (“Junk”) Bonds1%The target allocations to the investment grade and high yield bond asset categories may include securities of both U.S. and foreign issuers. The Portfolio is not limited with respect to the maturity or duration of the fixed income securities in which it invests. The high yield bond asset category generally includes fixed income securities rated at least CC by Standard & Poor’s Global Ratings or Fitch, Inc. or at least Ca by Moody’s Investors Service, Inc. or, if unrated, deemed to be of comparable quality by the Underlying Portfolio’s Adviser or sub-adviser. Actual allocations between asset classes and among asset categories can deviate from the amounts shown above by up to 15% of the Portfolio’s assets. The Underlying Portfolios in which the Portfolio may invest have been selected to represent what the Adviser believes is a reasonable spectrum of investment options for the Portfolio. In addition, the Portfolio may invest in Underlying Portfolios that tactically manage equity exposure. When market volatility is increasing above specific thresholds, such Underlying Portfolios may reduce their equity exposure. During such times, the Portfolio’s exposure to equity securities may be significantly less than if it invested in a traditional equity portfolio and the Portfolio may deviate significantly from its asset allocation targets. Although the Portfolio’s investment in Underlying Portfolios that tactically manage equity exposure is intended to reduce the Portfolio’s overall risk, it could result in periods of underperformance, even during periods when the market is rising. Volatility management techniques could reduce potential losses and/or mitigate financial risks to insurance companies that provide certain benefits and guarantees available under the Contracts and offer the Portfolio as an investment option in their products. Accordingly, volatility management techniques could also benefit the insurance companies by reducing the risk that the insurance companies will be required to pay amounts to meet the benefits and guarantees from their own resources. The Portfolio may invest in Underlying Portfolios that employ derivatives (including futures contracts) for a variety of purposes, including to reduce risk, to seek enhanced returns from certain asset classes, and to leverage exposure to certain asset classes. The Adviser has based the asset allocation target and target investment percentages for the Portfolio on a variety of factors, including the degree to which it believes the Underlying Portfolios, in combination, are appropriate for the Portfolio’s investment objective. The Adviser may change the asset allocation targets, the target investment percentages and the particular Underlying Portfolios in which the Portfolio invests without notice or shareholder approval. The Adviser may sell the Portfolio’s holdings for a variety of reasons, including to invest in an Underlying Portfolio that the Adviser believes offers superior investment opportunities.
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 and the composite index show how the Portfolio’s performance compared with the returns of other asset classes in which the Portfolio may invest.Past performance is not an indication of future performance.For periods prior to November 13, 2023, the performance shown below is that of the Portfolio's predecessor, which was managed by the Adviser and had a substantially identical investment objective, policies and strategies as the Portfolio.  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, five and ten years 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 and the composite index show how the Portfolio’s performance compared with the returns of other asset classes in which the </span><span style="font-family:Arial;font-size:10pt;">Portfolio may invest.</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)15.71%2020 4th QuarterWorst quarter (% and time period)-18.00%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 Aggressive Allocation 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 Aggressive Allocation 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 Aggressive Allocation 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 Aggressive Allocation Portfolio | Asset Allocation Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Asset Allocation Risk —  The Portfolio’s investment performance depends upon how its assets are allocated across various asset classes and how its assets are invested within those asset classes. Some asset classes and investments may perform below expectations, or below the securities markets generally, over short and extended periods. The allocation strategies used and the allocation and investment decisions made could cause the Portfolio to lose value and may not produce the desired results.
EQ Aggressive Allocation 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 Aggressive Allocation Portfolio | Interest Rate Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Interest Rate Risk —  Changes in interest rates may affect the yield, liquidity and value of investments in debt securities or other income-producing securities. Changes in interest rates also may affect the value of other securities. When interest rates rise, the value of the Portfolio’s debt securities generally declines. Conversely, when interest rates decline, the value of the Portfolio’s debt securities generally rises. Typically, the longer the maturity (i.e., the term of a debt security) or duration (i.e., a measure of the sensitivity of a debt security to changes in market interest rates, based on the entire cash flow associated with the security) of a debt security, the greater the effect a change in interest rates could have on the security’s price. Thus, the sensitivity of the Portfolio’s debt securities to interest rate risk will increase the greater the duration of those securities. Changes in government or central bank monetary policy may have a substantial and immediate impact on interest rates, which could result in losses to the Portfolio.
EQ Aggressive Allocation Portfolio | Credit Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Credit Risk —  The Portfolio is subject to the risk that the issuer or guarantor of a fixed income security, or the counterparty to a transaction, is unable or unwilling, or is perceived as unable or unwilling, to make timely interest or principal payments or otherwise honor its obligations, or defaults completely, which may cause the Portfolio’s holdings to lose value. The downgrade of a security’s credit rating may decrease its value. Lower credit quality also may lead to greater volatility in the price of a security and may negatively affect a security’s liquidity. The credit quality of a security can deteriorate suddenly and rapidly. The Portfolio may experience a significant or complete loss on a fixed income security or a transaction.
EQ Aggressive Allocation 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 Aggressive Allocation Portfolio | Volatility Management Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Volatility Management Risk —  The Portfolio may invest from time to time in Underlying Portfolios managed by the Adviser that may employ various volatility management techniques or make strategic adjustments to their asset mix (such as by using futures and options to manage equity exposure). Although these actions are intended to reduce the overall risk of investing in an Underlying Portfolio, they may not work as intended and may result in losses by an Underlying Portfolio, and in turn, the Portfolio, or periods of underperformance, particularly during periods when market values are increasing but market volatility is high or when an Underlying Portfolio has reduced its equity exposure but market changes do not impact equity returns adversely to the extent predicted by the Adviser. The result of any volatility management strategy will be subject to the Adviser’s ability to correctly assess the degree of correlation between the performance of the relevant market index and the metrics used by the Adviser to measure market volatility. Since the characteristics of many securities change as markets change or time passes, the result of any volatility management strategy also will be subject to the Adviser’s ability to continually recalculate, readjust, and execute volatility management techniques in an efficient manner. In addition, market conditions change, sometimes rapidly and unpredictably, and the Adviser may be unable to execute the volatility management strategy in a timely manner or at all. The Adviser to the Underlying Portfolios uses proprietary modeling tools to implement the volatility management strategy. If the proprietary modeling tools prove to be flawed or for other reasons do not produce the desired results, any decisions based on the modeling tools may expose an Underlying Portfolio, and in turn, the Portfolio, to additional risks and losses. The use of modeling tools has inherent risks, and the success of using a modeling tool depends, among other things, on the accuracy and completeness of the tool’s development, implementation and maintenance; on the tool’s assumptions and methodologies; and on the accuracy and reliability of the inputs and output of the tool. The Adviser from time to time may make changes to its proprietary modeling tools that do not require shareholder notice. Moreover, volatility management strategies may expose an Underlying Portfolio, and in turn, the Portfolio, to costs, such as increased portfolio transaction costs, which could cause or increase losses or reduce gains. In addition, it is not possible to manage volatility fully or perfectly. Futures contracts and other instruments used in connection with the volatility management strategy are not necessarily held by an Underlying Portfolio to hedge the value of the Underlying Portfolio’s other investments and, as a result, these futures contracts and other instruments may decline in value at the same time as the Underlying Portfolio’s other investments. Any one or more of these factors could prevent an Underlying Portfolio from achieving the intended volatility management or could cause an Underlying Portfolio, and in turn, the Portfolio, to underperform or experience losses (some of which may be sudden or substantial) or volatility for any particular period that may be higher or lower. In addition, the use of volatility management techniques may not protect against market declines and may limit an Underlying Portfolio’s, and thus the Portfolio’s, participation in market gains, even during periods when the market is rising. Volatility management techniques, when implemented effectively to reduce the overall risk of investing in an Underlying Portfolio, may result in underperformance by an Underlying Portfolio. For example, if an Underlying Portfolio has reduced its overall exposure to equities to avoid losses in certain market environments, the Underlying Portfolio may forgo some of the returns that can be associated with periods of rising equity values. An Underlying Portfolio’s performance, and therefore the Portfolio’s performance, may be lower than similar funds where volatility management techniques are not used.
EQ Aggressive Allocation Portfolio | Risks Related to Investments in Underlying Portfolios [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Risks Related to Investments in Underlying Portfolios —  When the Portfolio invests in an Underlying Portfolio, it will indirectly bear its proportionate share of the fees and expenses incurred by the Underlying Portfolio. 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. The Portfolio’s performance depends upon a favorable allocation by the Adviser among the Underlying Portfolios, as well as the ability of the Underlying Portfolios to generate favorable performance. The Underlying Portfolios’ investment programs may not be complementary, which could adversely affect the Portfolio’s performance. The Portfolio’s net asset value is subject to fluctuations in the net asset values of the Underlying Portfolios in which it invests. The Portfolio is also subject to the risks associated with the securities or other investments in which the Underlying Portfolios invest, and the ability of the Portfolio to meet its investment objective will directly depend on the ability of the Underlying Portfolios to meet their respective investment objectives. The Portfolio and the Underlying Portfolios are subject to certain general investment risks, including market risk, asset class risk, issuer-specific risk, investment style risk, portfolio management risk, and regulatory risk. In addition, to the extent the Portfolio invests in Underlying Portfolios that invest in equity securities, fixed income securities, and/or foreign securities, the Portfolio is subject to the risks associated with investing in such securities. The extent to which the investment performance and risks associated with the Portfolio correlate to those of a particular Underlying Portfolio will depend upon the extent to which the Portfolio’s assets are allocated from time to time for investment in the Underlying Portfolio, which will vary.
EQ Aggressive Allocation Portfolio | Affiliated Portfolio Risk [Member]
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Risk [Text Block]	rr_RiskTextBlock	Affiliated Portfolio Risk —  The Adviser is subject to conflicts of interest in selecting, and allocating the Portfolio’s assets among, the various Underlying Portfolios because the revenue and/or profits the Adviser and its affiliates receive from some of the Underlying Portfolios is higher than the revenue and/or profits received from other Underlying Portfolios for the services the Adviser and its affiliates provide. The Portfolio invests in affiliated Underlying Portfolios; unaffiliated Underlying Portfolios generally are not considered for investment.
EQ Aggressive Allocation 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 Aggressive Allocation Portfolio | Futures Contract Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Futures Contract Risk —  The primary risks associated with the use of futures contracts are (a) the imperfect correlation between the change in market value of the instruments held by the Portfolio and the price of the futures contract; (b) liquidity risks, including the possible absence of a liquid secondary market for a futures contract and the resulting inability to close a futures contract when desired; (c) losses (potentially unlimited) caused by unanticipated market movements; (d) an investment manager’s inability to predict correctly the direction of securities prices, interest rates, currency exchange rates and other economic factors; (e) the possibility that a counterparty, clearing member or clearinghouse will default in the performance of its obligations; (f) if the Portfolio has insufficient cash, it may have to sell securities from its portfolio to meet daily variation margin requirements, and the Portfolio may have to sell securities at a time when it may be disadvantageous to do so; and (g) transaction costs associated with investments in futures contracts may be significant, which could cause or increase losses or reduce gains. Futures contracts are also subject to the same risks as the underlying investments to which they provide exposure. In addition, futures contracts may subject the Portfolio to leveraging risk.
EQ Aggressive Allocation Portfolio | Investment Grade Securities Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Investment Grade Securities Risk —  Securities rated in the lower investment grade rating categories (e.g., BBB or Baa) are considered investment grade securities, but may have more risk than higher rated obligations because they are regarded as having only an adequate capacity to pay principal and interest, are considered to lack outstanding investment characteristics, and may possess certain speculative characteristics.
EQ Aggressive Allocation 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 Aggressive Allocation Portfolio | Leveraging Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Leveraging Risk —  When the Portfolio leverages its holdings, the value of an investment in the Portfolio will be more volatile and all other risks will tend to be compounded. Investments that create leverage can result in losses to the Portfolio that exceed the amount originally invested and may accelerate the rate of losses (some of which may be sudden or substantial). For certain investments that create leverage, relatively small market fluctuations can result in large changes in the value of such investments. There can be no assurance that the Portfolio’s use of any leverage will be successful.
EQ Aggressive Allocation Portfolio | Mid-Cap and Small-Cap Company Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Mid-Cap and Small-Cap Company Risk —  Mid-cap and 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, all of which can negatively affect their value. In general, these risks are greater for small-cap companies than for mid-cap companies.
EQ Aggressive Allocation Portfolio | Non-Investment Grade Securities Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Non-Investment Grade Securities Risk —  Bonds rated below BBB by Standard & Poor’s Global Ratings or Fitch Ratings, Ltd., or below Baa by Moody’s Investors Service, Inc. (or, if unrated, determined by the investment manager to be of comparable quality) are speculative in nature and are subject to additional risk factors such as increased possibility of default, illiquidity of the security, and changes in value based on changes in interest rates. Non-investment grade bonds, sometimes referred to as “junk bonds,” are usually issued by companies without long track records of sales and earnings, or by those companies with questionable credit strength. The creditworthiness of issuers of non-investment grade debt securities may be more complex to analyze than that of issuers of investment grade debt securities, and reliance on credit ratings may present additional risks.
EQ Aggressive Allocation 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 Aggressive Allocation Portfolio | Class IB
Risk Return Abstract	rr_RiskReturnAbstract
Shareholder Fees (fees paid directly from your investment)	rr_ShareholderFeeOther
Management Fee	rr_ManagementFeesOverAssets	0.09%
Distribution and/or Service Fees (12b-1 fees)	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other Expenses	rr_OtherExpensesOverAssets	0.15%
Acquired Fund Fees and Expenses	rr_AcquiredFundFeesAndExpensesOverAssets	0.67%
Total Annual Portfolio Operating Expenses	rr_ExpensesOverAssets	1.16%
1 Year	rr_ExpenseExampleYear01	$ 118
3 Years	rr_ExpenseExampleYear03	368
5 Years	rr_ExpenseExampleYear05	638
10 Years	rr_ExpenseExampleYear10	$ 1,409
2015	rr_AnnualReturn2015	(1.76%)
2016	rr_AnnualReturn2016	8.70%
2017	rr_AnnualReturn2017	19.17%
2018	rr_AnnualReturn2018	(8.72%)
2019	rr_AnnualReturn2019	24.46%
2020	rr_AnnualReturn2020	15.41%
2021	rr_AnnualReturn2021	17.14%
2022	rr_AnnualReturn2022	(18.31%)
2023	rr_AnnualReturn2023	18.37%
2024	rr_AnnualReturn2024	13.73%
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	Dec. 31, 2020
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	15.71%
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	(18.00%)
OneYear	rr_AverageAnnualReturnYear01	13.73%
FiveYears	rr_AverageAnnualReturnYear05	8.26%
TenYears	rr_AverageAnnualReturnYear10	7.95%
EQ Aggressive Allocation Portfolio | Class K
Risk Return Abstract	rr_RiskReturnAbstract
Shareholder Fees (fees paid directly from your investment)	rr_ShareholderFeeOther
Management Fee	rr_ManagementFeesOverAssets	0.09%
Distribution and/or Service Fees (12b-1 fees)	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	0.15%
Acquired Fund Fees and Expenses	rr_AcquiredFundFeesAndExpensesOverAssets	0.67%
Total Annual Portfolio Operating Expenses	rr_ExpensesOverAssets	0.91%
1 Year	rr_ExpenseExampleYear01	$ 93
3 Years	rr_ExpenseExampleYear03	290
5 Years	rr_ExpenseExampleYear05	504
10 Years	rr_ExpenseExampleYear10	$ 1,120
OneYear	rr_AverageAnnualReturnYear01	14.09%
FiveYears	rr_AverageAnnualReturnYear05	8.55%
TenYears	rr_AverageAnnualReturnYear10	8.24%
EQ Aggressive Allocation 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%
TenYears	rr_AverageAnnualReturnYear10	13.10%
EQ Aggressive Allocation Portfolio | Bloomberg U.S. Intermediate Government Bond Index (reflects no deduction for fees, expenses, or taxes)
Risk Return Abstract	rr_RiskReturnAbstract
OneYear	rr_AverageAnnualReturnYear01	2.44%
FiveYears	rr_AverageAnnualReturnYear05	0.49%
TenYears	rr_AverageAnnualReturnYear10	1.24%
EQ Aggressive Allocation Portfolio | EQ/Aggressive Allocation Index (reflects no deduction for fees, expenses, or taxes)
Risk Return Abstract	rr_RiskReturnAbstract
OneYear	rr_AverageAnnualReturnYear01	14.07%	[1]
FiveYears	rr_AverageAnnualReturnYear05	9.34%	[1]
TenYears	rr_AverageAnnualReturnYear10	8.94%	[1]

[1] The composite index is a hypothetical combination of unmanaged indexes composed of the Bloomberg U.S. Intermediate Government Bond Index, MSCI EAFE® Index, S&P MidCap 400® Index, S&P 500® Index, Russell 2000® Index, ICE BofA 3-Month U.S. Treasury Bill Index, and Bloomberg U.S. Long Government/Credit Bond Index at weightings of 6.5%, 25%, 14%, 39%, 12%, 1%, and 2.5%, respectively.