Label	Element	Value
Risk Return Abstract	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	EQ ADVISORS TRUST
Prospectus Date	rr_ProspectusDate	May 01, 2025
1290 VT GAMCO Mergers & Acquisitions Portfolio
Risk Return Abstract	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	<span style="font-family:Arial;font-size:11pt;font-weight:bold;">1290 VT GAMCO Mergers & Acquisitions 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 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 177% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	177.00%
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 primarily in arbitrage opportunities by investing in equity securities of companies that are involved in publicly announced mergers, takeovers, tender offers, leveraged buyouts, spin-offs, liquidations and other corporate re-organizations and in equity securities of companies that the Sub-Adviser believes are likely acquisition targets within 12 to 18 months. When a company agrees to be acquired by another company, its stock price often quickly rises to just below the stated acquisition price. If the Sub-Adviser determines that the acquisition is likely to be consummated on schedule at the stated acquisition price, then the Portfolio may purchase (if it does not already hold) or increase its investment in the selling company’s securities, offering the Portfolio the possibility of generous returns in excess of the return on cash equivalents with a limited risk of excessive loss of capital. At times, the stock of the acquiring company may also be purchased or shorted. The Portfolio may hold a significant portion of its assets in cash or cash equivalents in anticipation of arbitrage opportunities. The Portfolio may invest in companies of any size and from time to time may invest in companies with small, mid, and large market capitalizations. The Portfolio generally invests in securities of U.S. companies, but also may invest up to 20% of its assets in foreign securities, including those in emerging markets. The Portfolio intends to invest primarily in common stocks, but it may also invest in other securities that the Sub-Adviser believes provide opportunities for capital appreciation, such as preferred stocks and warrants. It is expected that the Portfolio will engage in active or frequent trading of portfolio securities to achieve its investment objective. In this connection, it is expected that the Portfolio may have a portfolio turnover rate of 150% or more. In choosing investments, the Sub-Adviser searches for the best values on securities that it believes have the potential to achieve the Portfolio’s investment objective of capital appreciation. In seeking to identify companies that are likely to be acquisition targets, the Sub-Adviser considers, among other things, consolidation trends within particular industries, whether a particular industry or company is undergoing a fundamental change or restructuring, the Sub-Adviser’s assessment of the “private market value” of individual companies and the potential for an event or catalyst to occur that enhances a company’s underlying value. The “private market value” of a company is the value that the Sub-Adviser believes informed investors would be willing to pay to acquire the entire company. The Sub-Adviser seeks to limit excessive risk of capital loss by utilizing various investment strategies, including investing in value oriented equity securities that should trade at a significant discount to the Sub-Adviser’s assessment of their private market value. In evaluating arbitrage opportunities with respect to companies involved in publicly announced mergers or other corporate restructurings, the Sub-Adviser seeks to acquire target companies at a rate of return that provides compensation for assuming deal completion risk. Since such investments are ordinarily short-term in nature, they will tend to increase the turnover rate of the Portfolio, thereby increasing its brokerage and other transaction expenses. The Sub-Adviser may sell a security for a variety of reasons, such as when the security is selling in the public market at or near the Sub-Adviser’s estimate of its private market value or if the catalyst expected to happen fails to materialize. The Portfolio may invest its uninvested cash in high-quality, short-term debt securities, including repurchase agreements and high-quality money market instruments, and also may invest uninvested cash in money market funds, including money market funds managed by the Adviser. Generally, these securities offer less potential for gains than other types of securities.
Risk [Heading]	rr_RiskHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Principal Risks</span>
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Risk/Return Bar Chart and Table</span>
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The bar chart and table below provide some indication of the risks of investing in the Portfolio by showing changes in the Portfolio’s performance from year to year and by showing how the Portfolio’s average annual total returns for the past one, five and ten years through December 31, 2024, compared to the returns of a broad-based securities market index.The additional securities market index shows how the Portfolio’s performance compared with the returns of another index that has characteristics relevant to the Portfolio’s investment strategies.Past performance is not an indication of future performance.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 shows how the Portfolio’s performance compared with the returns of another index that has characteristics relevant to the </span><span style="font-family:Arial;font-size:10pt;">Portfolio’s investment strategies.</span>
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	<span style="font-family:Arial;font-size:10pt;">Past performance is not an indication of future performance.</span>
Bar Chart [Heading]	rr_BarChartHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Calendar Year Annual Total Returns — Class IB</span>
Bar Chart Does Not Reflect Sales Loads [Text]	rr_BarChartDoesNotReflectSalesLoads	<span style="color:#000000;font-family:Arial;font-size:10pt;">The performance results do not reflect any Contract-related fees and expenses, which would reduce the performance results.</span>
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Best quarter (% and time period)8.09%2020 2nd QuarterWorst quarter (% and time period)-18.99%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>
1290 VT GAMCO Mergers &amp; Acquisitions 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.
1290 VT GAMCO Mergers &amp; Acquisitions 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.
1290 VT GAMCO Mergers &amp; Acquisitions 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.
1290 VT GAMCO Mergers &amp; Acquisitions 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.
1290 VT GAMCO Mergers &amp; Acquisitions Portfolio | Special Situations Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Special Situations Risk —  The Portfolio may seek to benefit from “special situations,” such as mergers, consolidations, bankruptcies, liquidations, reorganizations, restructurings, tender or exchange offers, or other unusual events expected to affect a particular issuer. In general, securities of companies which are the subject of a tender or exchange offer or a merger, consolidation, bankruptcy, liquidation, reorganization or restructuring proposal sell at a premium to their historic market price immediately prior to the announcement of the transaction. However, it is possible that the value of securities of a company involved in such a transaction will not rise and in fact may fall, in which case the Portfolio would lose money. It is also possible that the transaction may not be completed as anticipated or may take an excessive amount of time to be completed, in which case the Portfolio may not realize any premium on its investment and could lose money if the value of the securities declines during the Portfolio’s holding period. In some circumstances, the securities purchased may be illiquid, making it difficult for the Portfolio to dispose of them at an advantageous price.
1290 VT GAMCO Mergers &amp; Acquisitions 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. Cash may be invested in institutional money market funds. An institutional money market fund does not maintain a stable $1.00 net asset value per share; rather the fund’s net asset value fluctuates with changes in the values of the securities in which the fund invests, and the fund's shares may be worth more or less than their original purchase price. An institutional money market fund is permitted to impose a liquidity fee upon the redemption of fund shares and generally is required to impose a liquidity fee when the fund experiences daily net redemptions of fund shares that exceed certain levels.
1290 VT GAMCO Mergers &amp; Acquisitions Portfolio | Portfolio Turnover Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Portfolio Turnover Risk —  High portfolio turnover (generally, turnover in excess of 100% in any given fiscal year) may result in increased transaction costs to the Portfolio, which may result in higher fund expenses and lower total return.
1290 VT GAMCO Mergers &amp; Acquisitions 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.
1290 VT GAMCO Mergers &amp; Acquisitions 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.
1290 VT GAMCO Mergers &amp; Acquisitions 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.
1290 VT GAMCO Mergers &amp; Acquisitions 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.
1290 VT GAMCO Mergers &amp; Acquisitions 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.
1290 VT GAMCO Mergers &amp; Acquisitions 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.
1290 VT GAMCO Mergers &amp; Acquisitions Portfolio | Money Market Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Money Market Risk —  Although a money market fund is designed to be a relatively low risk investment, it is not free of risk. Despite the short maturities and high credit quality of a money market fund’s investments, increases in interest rates and deteriorations in the credit quality of the instruments the money market fund has purchased may reduce the money market fund’s yield and can cause the price of a money market security to decrease. In addition, a money market fund is subject to the risk that the value of an investment may be eroded over time by inflation. Money market funds are subject to specific rules that affect the manner in which money market funds are structured and operated and may impact a money market fund’s expenses, operations, returns and liquidity. A low- or negative-interest rate environment may prevent a money market fund from providing a positive yield and could negatively impact a money market fund’s ability to maintain a stable $1.00 net asset value per share.
1290 VT GAMCO Mergers &amp; Acquisitions Portfolio | Preferred Stock Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Preferred Stock Risk —  Preferred stock is subject to issuer-specific and market risks applicable generally to equity securities; however, unlike common stock, participation in the growth of an issuer may be limited. Preferred stock also is subject to many of the risks associated with debt securities, including credit and interest rate risk. Unlike interest payments on debt securities, dividends on preferred stock are generally payable at the discretion of the issuer’s board of directors. Preferred shareholders may suffer a loss of value if dividends are not paid. In addition, in the event an issuer is liquidated or declares bankruptcy, the claims of owners of the issuer’s debt securities take precedence over the claims of owners of the issuer’s preferred and common stock. For these reasons, preferred stocks are subject to greater credit, interest rate, and liquidation risk than debt securities, and the market prices of preferred stocks are generally more sensitive to actual or perceived changes in the issuer’s financial condition or prospects than are the prices of debt securities.
1290 VT GAMCO Mergers &amp; Acquisitions Portfolio | Class IB
Risk Return Abstract	rr_RiskReturnAbstract
Shareholder Fees (fees paid directly from your investment)	rr_ShareholderFeeOther
Management Fee	rr_ManagementFeesOverAssets	0.90%
Distribution and/or Service Fees (12b-1 fees)	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other Expenses	rr_OtherExpensesOverAssets	0.19%
Acquired Fund Fees and Expenses	rr_AcquiredFundFeesAndExpensesOverAssets	0.07%
Total Annual Portfolio Operating Expenses	rr_ExpensesOverAssets	1.41%
Fee Waiver and/or Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.09%)	[1]
Total Annual Portfolio Operating Expenses After Fee Waiver and/or Expense Reimbursement	rr_NetExpensesOverAssets	1.32%
1 Year	rr_ExpenseExampleYear01	$ 134
3 Years	rr_ExpenseExampleYear03	437
5 Years	rr_ExpenseExampleYear05	763
10 Years	rr_ExpenseExampleYear10	$ 1,683
2015	rr_AnnualReturn2015	2.43%
2016	rr_AnnualReturn2016	7.65%
2017	rr_AnnualReturn2017	6.17%
2018	rr_AnnualReturn2018	(4.88%)
2019	rr_AnnualReturn2019	8.67%
2020	rr_AnnualReturn2020	(1.33%)
2021	rr_AnnualReturn2021	11.34%
2022	rr_AnnualReturn2022	(5.97%)
2023	rr_AnnualReturn2023	9.53%
2024	rr_AnnualReturn2024	9.02%
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	8.09%
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	(18.99%)
OneYear	rr_AverageAnnualReturnYear01	9.02%
FiveYears	rr_AverageAnnualReturnYear05	4.29%
TenYears	rr_AverageAnnualReturnYear10	4.09%
1290 VT GAMCO Mergers &amp; Acquisitions Portfolio | Class K
Risk Return Abstract	rr_RiskReturnAbstract
Shareholder Fees (fees paid directly from your investment)	rr_ShareholderFeeOther
Management Fee	rr_ManagementFeesOverAssets	0.90%
Distribution and/or Service Fees (12b-1 fees)	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	0.19%
Acquired Fund Fees and Expenses	rr_AcquiredFundFeesAndExpensesOverAssets	0.07%
Total Annual Portfolio Operating Expenses	rr_ExpensesOverAssets	1.16%
Fee Waiver and/or Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.09%)	[1]
Total Annual Portfolio Operating Expenses After Fee Waiver and/or Expense Reimbursement	rr_NetExpensesOverAssets	1.07%
1 Year	rr_ExpenseExampleYear01	$ 109
3 Years	rr_ExpenseExampleYear03	360
5 Years	rr_ExpenseExampleYear05	630
10 Years	rr_ExpenseExampleYear10	$ 1,401
OneYear	rr_AverageAnnualReturnYear01	9.35%
FiveYears	rr_AverageAnnualReturnYear05	4.57%
TenYears	rr_AverageAnnualReturnYear10	4.35%
1290 VT GAMCO Mergers &amp; Acquisitions 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%
1290 VT GAMCO Mergers &amp; Acquisitions Portfolio | S&P Long-Only Merger Arbitrage Index (reflects no deduction for fees, expenses, or taxes)
Risk Return Abstract	rr_RiskReturnAbstract
OneYear	rr_AverageAnnualReturnYear01	2.91%
FiveYears	rr_AverageAnnualReturnYear05	2.73%
TenYears	rr_AverageAnnualReturnYear10	3.36%

[1] Pursuant to a contract, Equitable Investment Management Group, LLC (the “Adviser”) has agreed to waive its and its affiliates’ management, administrative and other fees and, if necessary, make payments to the Portfolio to limit the expenses of the Portfolio through April 30, 2026 (unless the Board of Trustees consents to an earlier revision or termination of this arrangement) (“Expense Limitation Arrangement”) so that the annual operating expenses of the Portfolio (exclusive of taxes, interest, brokerage commissions, dividend and interest expenses on securities sold short, capitalized expenses, acquired fund fees and expenses, and extraordinary expenses not incurred in the ordinary course of the Portfolio’s business) do not exceed an annual rate of average daily net assets of 1.25% for Class IB shares and 1.00% 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.