Label	Element	Value
Risk Return Abstract	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	EQ ADVISORS TRUST
Prospectus Date	rr_ProspectusDate	May 01, 2025
EQ MFS Technology 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/MFS Technology 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 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 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 51% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	51.00%
Other Expenses, New Fund, Based on Estimates [Text]	rr_OtherExpensesNewFundBasedOnEstimates	<span style="color:#000000;font-family:Arial;font-size:8pt;">Based on estimated amounts for the current fiscal year.</span>
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	Under normal circumstances, the Portfolio invests at least 80% of its net assets, plus any borrowings for investment purposes, in securities of issuers principally engaged in offering, using or developing products, processes, or services that will provide or will benefit significantly from technological advances and improvements. The Sub-Adviser considers an issuer to be principally engaged in offering, using or developing products, processes, or services that will provide or will benefit significantly from technological advances and improvements if at least 50% of any issuer’s assets, income, sales, or profits are committed to, or derived from, such activities, or a third party has given the issuer an industry or sector classification consistent with such activities. These issuers are in such fields as computer systems and software, networking and telecommunications, internet, business services, and electronics. The Portfolio may invest in securities of companies of any size and may invest in foreign securities, including emerging market securities. The Portfolio normally invests primarily in equity securities. Equity securities include common stocks and other securities that represent an ownership interest (or the right to acquire an ownership interest) in a company or other issuer, such as rights, warrants and depositary receipts. The Portfolio is non-diversified, which means that it may invest a greater portion of its assets in the securities of one or more issuers and invests overall in a smaller number of issuers than a diversified portfolio. In selecting investments for the Portfolio, the Sub-Adviser is not constrained to any particular investment style. The Sub-Adviser may invest the Portfolio’s assets in the stocks of companies that the Sub-Adviser believes to have above average earnings growth potential compared to other companies (growth companies) or the stocks of companies it believes are undervalued compared to their perceived worth (value companies) or in a combination of growth and value companies. However, companies that benefit from technological advancements and improvements often are growth companies. The stocks of growth companies tend to have prices that are high relative to their earnings, dividends, book value, or other financial measures. The Sub-Adviser uses an active bottom-up investment approach to buying and selling investments for the Portfolio. Investments are selected primarily based on fundamental analysis of individual issuers and their potential in light of their financial condition, and market, economic, political, and regulatory conditions. Factors considered may include analysis of an issuer’s earnings, cash flows, competitive position, and management ability. The Sub-Adviser may also consider environmental, social, and governance (ESG) factors in its fundamental investment analysis where the Sub-Adviser believes such factors could materially impact the economic value of an issuer. ESG factors considered may include, but are not limited to, climate change, resource depletion, an issuer’s governance structure and practices, data protection and privacy issues, and diversity and labor practices. Quantitative screening tools that systematically evaluate an issuer’s valuation, price and earnings momentum, earnings quality, and other factors, may also be considered. The Sub-Adviser may sell a security for a variety of reasons, such as to secure gains, limit losses, or redeploy assets into opportunities the Sub-Adviser believes to be more promising, among others. The Portfolio will concentrate its investments in the securities of issuers in the industries in the technology sector.
Strategy Portfolio Concentration [Text]	rr_StrategyPortfolioConcentration	<span style="color:#000000;font-family:Arial;font-size:10pt;margin-left:0%;">Under normal circumstances, the Portfolio invests at least 80% of its net assets, plus any borrowings for investment purposes, in securities of issuers principally engaged in offering, using or developing products, processes, or services that will provide or will benefit significantly from technological advances and improvements.</span>
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.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 K shares have not commenced operations as of the date of this Prospectus.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 One Year or Less [Text]	rr_PerformanceOneYearOrLess	<span style="color:#000000;font-family:Arial;font-size:10pt;">Class K shares have not commenced operations as of the date of this Prospectus.</span>
Performance Additional Market Index [Text]	rr_PerformanceAdditionalMarketIndex	<span style="font-family:Arial;font-size:10pt;">The additional </span><span style="font-family:Arial;font-size:10pt;margin-left:0%;">securities market index shows how the Portfolio's performance compared with the returns of another index that has characteristics </span><span style="font-family:Arial;font-size:10pt;">relevant to the 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)30.61%2020 2nd QuarterWorst quarter (% and time period)-21.69%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 MFS Technology Portfolio | Risk Nondiversified Status [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Non-Diversified Portfolio Risk —  The Portfolio may invest a relatively high percentage of its assets in a single issuer or a limited number of issuers. As a result, the Portfolio’s performance will be more vulnerable to changes in market value of a single issuer or group of issuers and more susceptible to risks associated with a single adverse economic, political, regulatory or other occurrence affecting one or more of these issuers.
EQ MFS Technology 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 MFS Technology 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 MFS Technology 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 MFS Technology 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 MFS Technology Portfolio | Technology Sector Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Technology Sector Risk —  The value of the shares of a Portfolio that invests primarily in technology companies is particularly vulnerable to factors affecting the technology sector, such as dependency on consumer and business acceptance as new technologies evolve, large and rapid price movements resulting from competition, rapid obsolescence of products and services and short product cycles. Many technology companies are small and at an earlier stage of development and, therefore, may be subject to risks such as those arising out of limited product lines, markets and financial and managerial resources. Any of these factors could result in a material adverse impact on the Portfolio’s holdings and the performance of the Portfolio.
EQ MFS Technology Portfolio | Sector Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Sector Risk —  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 MFS Technology Portfolio | Liquidity Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Liquidity Risk —  From time to time, there may be little or no active trading market for a particular investment in which the Portfolio may invest or is invested. In such a market, the value of such an investment and the Portfolio’s share price may fall dramatically. Illiquid investments may be difficult or impossible to sell or purchase at an advantageous time or price or in sufficient amounts to achieve the Portfolio’s desired level of exposure. To meet redemption requests during periods of illiquidity, the Portfolio may be forced to dispose of investments at unfavorable times or prices and/or under unfavorable conditions, which may result in losses or may be costly to the Portfolio. Investments that are illiquid or that trade in lower volumes may be more difficult to value. The Portfolio also may not receive its proceeds from the sale of certain investments for an extended period of time. Certain investments that were liquid when purchased may later become illiquid, sometimes abruptly, particularly in times of overall economic distress or adverse investor perception. An inability to sell a portfolio position can adversely affect the Portfolio’s value or prevent the Portfolio from being able to take advantage of other investment opportunities. During periods of market stress, an investment or even an entire market segment may become illiquid, sometimes abruptly, which can adversely affect the Portfolio’s ability to limit losses. In addition, a reduction in the ability or willingness of dealers and other institutional investors to make a market in certain securities may result in decreased liquidity in certain markets.
EQ MFS Technology 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 MFS Technology Portfolio | Cash Management Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Cash Management Risk —  The Portfolio may maintain cash and cash equivalent positions as part of the Portfolio’s strategy in order to take advantage of investment opportunities as they arise, to manage the Portfolio’s market exposure, and for other portfolio management purposes. As such, the Portfolio may maintain cash balances, which may be significant, with counterparties such as the Trust’s custodian or its affiliates. Maintaining larger cash and cash equivalent positions could negatively affect the Portfolio’s performance due to missed investment opportunities and may also subject the Portfolio to additional risks, such as increased credit risk with respect to the custodian bank holding the assets and the risk that a counterparty may be unable or unwilling, or perceived as unable or unwilling, to honor its obligations.
EQ MFS Technology 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 MFS Technology 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 MFS Technology Portfolio | Emerging Markets Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Emerging Markets Risk —  The risks associated with investments in emerging market countries often are significant and vary from jurisdiction to jurisdiction and company to company. Investments in emerging market countries are more susceptible to loss than investments in more developed foreign countries and may present market, credit, currency, liquidity, legal, political, technical and other risks different from, or greater than, the risks of investing in more developed foreign countries. Emerging market countries may be more likely to experience rapid and significant adverse developments in their political or economic structures, intervene in financial markets, restrict foreign investments, impose high withholding or other taxes on foreign investments, impose restrictive exchange control regulations, or nationalize or expropriate the assets of private companies, which may have negative impacts on transaction costs, market price, investment returns, and the legal rights and remedies available to the Portfolio. In addition, the securities markets of emerging market countries generally are smaller, less liquid and more volatile than those of more developed foreign countries, and emerging market countries often have less uniformity in regulatory, accounting, auditing and financial reporting requirements or standards, which may impact the availability and quality of information about issuers, and less reliable clearance and settlement, registration and custodial procedures. Emerging market countries also may be subject to high inflation and rapid currency devaluations, and currency-hedging techniques may be unavailable in certain emerging market countries. In addition, some emerging market countries may be heavily dependent on international trade, which can materially affect their securities markets. Securities of issuers traded on foreign exchanges may be suspended. The likelihood of such suspensions may be higher for securities of issuers in emerging market countries than in countries with more developed markets.
EQ MFS Technology 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 MFS Technology 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. In addition, the risks associated with investing in a narrowly defined geographic area are generally more pronounced with respect to investments in emerging market countries.
EQ MFS Technology 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 MFS Technology 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 MFS Technology 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 MFS Technology Portfolio | Class IB
Risk Return Abstract	rr_RiskReturnAbstract
Shareholder Fees (fees paid directly from your investment)	rr_ShareholderFeeOther
Management Fee	rr_ManagementFeesOverAssets	0.74%
Distribution and/or Service Fees (12b-1 fees)	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other Expenses	rr_OtherExpensesOverAssets	0.12%
Total Annual Portfolio Operating Expenses	rr_ExpensesOverAssets	1.11%
1 Year	rr_ExpenseExampleYear01	$ 113
3 Years	rr_ExpenseExampleYear03	353
5 Years	rr_ExpenseExampleYear05	612
10 Years	rr_ExpenseExampleYear10	$ 1,352
2019	rr_AnnualReturn2019	35.84%
2020	rr_AnnualReturn2020	46.83%
2021	rr_AnnualReturn2021	13.76%
2022	rr_AnnualReturn2022	(36.29%)
2023	rr_AnnualReturn2023	54.10%
2024	rr_AnnualReturn2024	36.09%
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	30.61%
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	(21.69%)
OneYear	rr_AverageAnnualReturnYear01	36.09%
FiveYears	rr_AverageAnnualReturnYear05	17.42%
SinceInception	rr_AverageAnnualReturnSinceInception	17.52%
InceptionDate	rr_AverageAnnualReturnInceptionDate	Oct. 22, 2018
EQ MFS Technology Portfolio | Class K
Risk Return Abstract	rr_RiskReturnAbstract
Shareholder Fees (fees paid directly from your investment)	rr_ShareholderFeeOther
Management Fee	rr_ManagementFeesOverAssets	0.74%
Distribution and/or Service Fees (12b-1 fees)	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	0.12%	[1]
Total Annual Portfolio Operating Expenses	rr_ExpensesOverAssets	0.86%
1 Year	rr_ExpenseExampleYear01	$ 88
3 Years	rr_ExpenseExampleYear03	274
5 Years	rr_ExpenseExampleYear05	477
10 Years	rr_ExpenseExampleYear10	$ 1,061
EQ MFS Technology 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%
EQ MFS Technology Portfolio | S&P North American Technology Sector Index (reflects no deduction for fees, expenses, or taxes)
Risk Return Abstract	rr_RiskReturnAbstract
OneYear	rr_AverageAnnualReturnYear01	36.08%
FiveYears	rr_AverageAnnualReturnYear05	21.06%
SinceInception	rr_AverageAnnualReturnSinceInception	21.45%

[1] Based on estimated amounts for the current fiscal year.