Label	Element	Value
Risk Return Abstract	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	EQ ADVISORS TRUST
Prospectus Date	rr_ProspectusDate	May 01, 2025
1290 VT Small Cap Value Portfolio
Risk Return Abstract	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	<span style="color:#000000;font-family:Arial;font-size:11pt;font-weight:bold;">1290 VT Small Cap Value Portfolio</span><span style="color:#000000;font-family:Arial;font-size:11pt;font-weight:bold;line-height:13pt;">  </span><span style="color:#000000;font-family:Arial;font-size:11pt;font-weight:bold;">— Class IB and Class K Shares</span>
Objective [Heading]	rr_ObjectiveHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Investment Objective:</span>
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	Seeks to achieve long-term growth of capital.
Expense [Heading]	rr_ExpenseHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;text-transform:uppercase;">Fees and Expenses of the Portfolio</span>
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	The following table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Portfolio. The table below does not reflect any fees and expenses associated with variable life insurance contracts and variable annuity certificates and contracts (“Contracts”), which would increase overall fees and expenses. See the Contract prospectus for a description of those fees and expenses.
Shareholder Fees Caption [Text]	rr_ShareholderFeesCaption	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Shareholder Fees</span> <br/><span style="color:#000000;font-family:Arial;font-size:10pt;">(fees paid directly from your investment)</span>
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Annual Portfolio Operating Expenses</span><span style="color:#000000;font-family:Arial;font-size:10pt;">(expenses that you pay each year as a percentage of the value of your investment)</span>
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	<span style="font-family:Arial;font-size:8pt;">April 30, 2026</span>
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;text-transform:uppercase;">Portfolio Turnover</span>
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs. These costs, which are not reflected in annual fund operating expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio’s portfolio turnover rate was 23% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	23.00%
Expense Example [Heading]	rr_ExpenseExampleHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Example</span>
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This Example is intended to help you compare the cost of investing in the Portfolio with the cost of investing in other portfolios. The Example assumes that you invest $10,000 in the Portfolio for the periods indicated, that your investment has a 5% return each year, that the Portfolio’s operating expenses remain the same, and that the Expense Limitation Arrangement is not renewed. This Example does not reflect any Contract-related fees and expenses including redemption fees (if any) at the Contract level. If such fees and expenses were reflected, the total expenses would be higher. Although your actual costs may be higher or lower, based on these assumptions, whether you redeem or hold your shares, your costs would be:
Strategy [Heading]	rr_StrategyHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;text-transform:uppercase;">Investments, Risks, and Performance</span><span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Principal Investment Strategy</span>
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	Under normal circumstances, the Portfolio invests at least 80% of its net assets, plus borrowings for investment purposes, in securities of companies with small market capitalizations (or other financial instruments that derive their value from the securities of such companies). For purposes of this Portfolio, small market capitalization companies are those companies with market capitalizations within the range of companies in the Russell 2000® Index (“Russell 2000”) at the time of investment (as of December 31, 2024, the market capitalizations of the companies in the Russell 2000 ranged from $9.1 million to $13.2 billion). The size of companies in the Russell 2000 changes with market conditions, which can result in changes to the market capitalization range of companies in the index. The Portfolio intends to invest primarily in common stocks, but it may also invest in other securities that a Sub-Adviser believes provide opportunities for capital growth. The Portfolio may invest up to 20% of its assets in foreign securities, including securities of companies based in developing countries and depositary receipts of foreign-based companies. The Portfolio’s investments may include real estate investment trusts (“REITs”). The Portfolio’s assets normally are allocated among two or more investment managers, each of which manages its portion of the Portfolio using a different but complementary investment strategy. One portion of the Portfolio is actively managed (“Active Allocated Portion”) and one portion of the Portfolio seeks to track the performance of a particular index (“Index Allocated Portion”). Under normal circumstances, the Active Allocated Portion consists of approximately 50% of the Portfolio’s net assets and the Index Allocated Portion consists of approximately 50% of the Portfolio’s net assets. The Sub-Adviser to the Active Allocated Portion of the Portfolio believes that favorable investment opportunities are available through companies that exhibit a number of the following characteristics: are selling below their perceived intrinsic value, have limited or no institutional ownership, have had short-term earnings shortfalls, have had a recent initial public offering but have not attracted significant analyst coverage, are selling at or below book or replacement value, and have price to earnings ratios that are less than one half of their projected growth rate. The Sub-Adviser focuses on undervalued and “special situation” small capitalization equities (including common stocks, convertible securities, warrants and other equity securities having the characteristics of common stocks, such as depositary receipts) that the Sub-Adviser believes have the potential for rewarding long-term investment results. The Sub-Adviser selects securities from companies that are engaged in a number of industries, including the media, financial services, retailing, manufacturing and consumer products, and utilities industries. The Sub-Adviser considers a company’s fundamentals by reviewing its balance sheets, corporate revenues, earnings and dividends. The Sub-Adviser also looks at the amount of capital a company spends on research and development. The Active Allocated Portion may invest up to 15% of its assets in exchange traded funds (“ETFs”). The Active Allocated Portion may invest a significant portion of its assets in a single issuer or a small group of issuers. Sell decisions are generally triggered by adequate value being achieved, as determined by the Sub-Adviser, or by an adverse change in a company’s operating performance or a deterioration of the company’s business model, as determined by the Sub-Adviser. A sell trigger also may occur if the Sub-Adviser discovers an investment opportunity that it believes is more compelling and represents a better risk/reward profile than other investments held by the Active Allocated Portion. The Index Allocated Portion of the Portfolio seeks to track the performance (before fees and expenses) of the Russell 2000® Value Index with minimal tracking error. This strategy is commonly referred to as an indexing strategy. The Index Allocated Portion may use a full replication technique or a sampling approach in pursuing its indexing strategy. The Portfolio may hold a significant portion of its assets in cash or cash equivalents as part of its investment strategy.
Risk [Heading]	rr_RiskHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Principal Risks</span>
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Risk/Return Bar Chart and Table</span>
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The bar chart and table below provide some indication of the risks of investing in the Portfolio by showing changes in the Portfolio’s performance from year to year and by showing how the Portfolio’s average annual total returns for the past one, five and ten years through December 31, 2024, compared to the returns of a broad-based securities market index.The additional securities market index shows how the Portfolio's performance compared with the returns of another index that has characteristics relevant to the Portfolio's investment strategies.Past performance is not an indication of future performance.Class IB shares were not operational for the period from April 14, 2015 through April 30, 2015. The returns of Class IB were calculated assuming the shares were in operation for the entire period.The performance results do not reflect any Contract-related fees and expenses, which would reduce the performance results.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	<span style="font-family:Arial;font-size:10pt;margin-left:0%;">The bar chart and table below provide some indication of the risks of investing in the Portfolio by showing changes in the Portfolio’s performance from year to year and by showing how the Portfolio’s average annual total returns for the past one</span><span style="font-family:Arial;font-size:10pt;">, five and ten years </span><span style="font-family:Arial;font-size:10pt;margin-left:0%;">through December 31, </span><span style="font-family:Arial;font-size:10pt;">2024, compared to the returns of a broad-based securities market index.</span>
Performance Additional Market Index [Text]	rr_PerformanceAdditionalMarketIndex	<span style="font-family:Arial;font-size:10pt;">The additional securities market </span><span style="font-family:Arial;font-size:10pt;margin-left:0%;">index shows how the Portfolio's performance compared with the returns of another index that has characteristics relevant to the </span><span style="font-family:Arial;font-size:10pt;">Portfolio's investment strategies.</span>
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	<span style="font-family:Arial;font-size:10pt;">Past performance is not an indication of future performance.</span>
Bar Chart [Heading]	rr_BarChartHeading	<span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Calendar Year Annual Total Returns — Class IB</span>
Bar Chart Does Not Reflect Sales Loads [Text]	rr_BarChartDoesNotReflectSalesLoads	<span style="color:#000000;font-family:Arial;font-size:10pt;">The performance results do not reflect any Contract-related fees and expenses, which would reduce the performance results.</span>
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Best quarter (% and time period)32.07%2021 1st QuarterWorst quarter (% and time period)-37.38%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 Small Cap Value 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 Small Cap Value 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 Small Cap Value 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 Small Cap Value 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 Small Cap Value Portfolio | Small-Cap Company Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Small-Cap Company Risk —  Small-cap companies carry additional risks because the operating histories of these companies tend to be more limited, their earnings and revenues less predictable (and some companies may be experiencing significant losses), and their share prices more volatile than those of larger, more established companies. The shares of smaller companies tend to trade less frequently than those of larger, more established companies, which can adversely affect the pricing of these securities and the Portfolio’s ability to purchase or sell these securities.
1290 VT Small Cap Value Portfolio | Focused Portfolio Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Focused Portfolio Risk —  From time to time, the Portfolio may have significant positions in one or more issuers. As a result, the Portfolio may incur more risk because changes in the value of a single issuer or group of issuers may have a more significant effect, either positive or negative, on the Portfolio’s net asset value. To the extent the Portfolio is invested more heavily in particular issuers, it may experience greater performance volatility than a portfolio that is more broadly invested.
1290 VT Small Cap Value Portfolio | Investment Style Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Investment Style Risk —  The Portfolio may use a particular style or set of styles — in this case, a “value” style — to select investments. A particular style may be out of favor or may not produce the best results over short or longer time periods. 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.
1290 VT Small Cap Value Portfolio | Index Strategy Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Index Strategy Risk —  The Portfolio employs an index strategy for a portion of the Portfolio and generally will not modify its index strategy to respond to changes in market trends or the economy, which means that the Portfolio may be particularly susceptible to a general decline in the market segment relating to the relevant index. In addition, although the index strategy attempts to closely track the relevant index, the Portfolio may not invest in all of the securities in the index. Therefore, there can be no assurance that the performance of the index strategy will match that of the relevant index. To the extent that the Portfolio utilizes a representative sampling approach, it may experience greater tracking error than it would if the Portfolio sought to replicate the index.
1290 VT Small Cap Value 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.
1290 VT Small Cap Value 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 Small Cap Value 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.
1290 VT Small Cap Value Portfolio | Convertible Securities Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Convertible Securities Risk —  A convertible security is a form of hybrid security; that is, a security with both debt and equity characteristics. The value of a convertible security fluctuates in relation to changes in interest rates and the credit quality of the issuer and also fluctuates in relation to changes in the price of the underlying common stock. A convertible security may be subject to redemption at the option of the issuer at a price established in the convertible security’s governing instrument, which may be less than the current market price of the security. If a convertible security held by the Portfolio is called for redemption, the Portfolio will be required to permit the issuer to redeem the security, convert it into the underlying common stock, or sell it to a third party. Convertible securities are subject to equity risk, interest rate risk, and credit risk and are often lower-quality securities. Lower quality may lead to greater volatility in the price of a security and may negatively affect a security’s liquidity. Since it derives a portion of its value from the common stock into which it may be converted, a convertible security is also subject to the same types of market and issuer-specific risks that apply to the underlying common stock.
1290 VT Small Cap Value Portfolio | ETFs Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	ETFs Risk —  When the Portfolio invests in an ETF, it will indirectly bear its proportionate share of the fees and expenses incurred by the ETF. These fees and expenses are in addition to the advisory fees and other expenses that the Portfolio and its shareholders bear directly in connection with the Portfolio’s own operations. As a result, the Portfolio’s shareholders will be subject to two layers of fees and expenses with respect to investments in the Portfolio. The cost of investing in the Portfolio, therefore, may be higher than the cost of investing in a mutual fund that invests directly in individual stocks and bonds. In addition, the Portfolio’s net asset value will be subject to fluctuations in the market values of the ETFs in which it invests. The Portfolio is also subject to the risks associated with the securities or other investments in which the ETFs invest, and the ability of the Portfolio to meet its investment objective will directly depend on the ability of the ETFs to meet their investment objectives. A passively managed (or index-based) ETF’s performance may not match that of the index it seeks to track. An actively managed ETF’s performance will reflect its manager’s ability to make investment decisions that are suited to achieving the ETF’s investment objective. Furthermore, it is possible that an active trading market for an ETF may not develop or be maintained, in which case the liquidity and value of the Portfolio’s investment in the ETF could be substantially and adversely affected. The extent to which the investment performance and risks associated with the Portfolio correlate to those of a particular ETF will depend upon the extent to which the Portfolio’s assets are allocated from time to time for investment in the ETF, which will vary.
1290 VT Small Cap Value 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.
1290 VT Small Cap Value 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 Small Cap Value Portfolio | Real Estate Investing Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Real Estate Investing Risk —  Real estate-related investments may decline in value as a result of factors affecting the overall real estate industry. Real estate is a cyclical business, highly sensitive to supply and demand and general and local economic conditions and characterized by intense competition and periodic overbuilding. Real estate income and values also may be greatly affected by demographic trends, such as population shifts or changing tastes, preferences (such as remote work arrangements or online shopping) and values. Losses may occur from, for example, casualty or condemnation, or extended vacancies of properties, and government actions, such as tax law changes, zoning law changes, regulatory limitations on rents, or environmental regulations, also may have a major impact on real estate. The availability of mortgages and changes in interest rates may also affect real estate values. Changing interest rates and credit quality requirements also will affect the cash flow of real estate companies and their ability to meet capital needs or refinance their obligations. In addition, global climate change may have a significant adverse effect on property and security values and may exacerbate the risks of natural disasters. Real estate investment trusts (“REITs”) generally invest directly in real estate (equity REITs), in mortgages secured by interests in real estate (mortgage REITs) or in some combination of the two (hybrid REITs). Investing in REITs exposes investors to the risks of owning real estate directly, as well as to risks that relate specifically to the way in which REITs are organized and operated. Equity REITs may be affected by changes in the value of the underlying property owned by the REIT, while mortgage REITs may be affected by the quality of any credit extended. Equity and mortgage REITs are also subject to heavy cash flow dependency, defaults by mortgagors and other borrowers, and self-liquidations. Operating REITs requires specialized management skills, and a portfolio that invests in REITs indirectly bears REIT management and administration expenses along with the direct expenses of the portfolio. Individual REITs may own a limited number of properties and may concentrate in a particular region or property type. Domestic REITs also must satisfy specific Internal Revenue Code requirements to qualify for the tax-free pass-through of net investment income and net realized gains distributed to shareholders. Failure to meet these requirements may have adverse consequences on the Portfolio. In addition, even the larger REITs in the industry tend to be small- to medium-sized companies in relation to the equity markets as a whole. Moreover, shares of REITs may trade less frequently and, therefore, are subject to more erratic price movements than securities of larger issuers.
1290 VT Small Cap Value 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 Small Cap Value Portfolio | Class IB
Risk Return Abstract	rr_RiskReturnAbstract
Shareholder Fees (fees paid directly from your investment)	rr_ShareholderFeeOther
Management Fee	rr_ManagementFeesOverAssets	0.80%
Distribution and/or Service Fees (12b-1 fees)	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other Expenses	rr_OtherExpensesOverAssets	0.19%
Acquired Fund Fees and Expenses	rr_AcquiredFundFeesAndExpensesOverAssets	0.05%
Total Annual Portfolio Operating Expenses	rr_ExpensesOverAssets	1.29%
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	1.20%
1 Year	rr_ExpenseExampleYear01	$ 122
3 Years	rr_ExpenseExampleYear03	400
5 Years	rr_ExpenseExampleYear05	699
10 Years	rr_ExpenseExampleYear10	$ 1,549
2015	rr_AnnualReturn2015	(8.71%)
2016	rr_AnnualReturn2016	24.19%
2017	rr_AnnualReturn2017	12.80%
2018	rr_AnnualReturn2018	(11.44%)
2019	rr_AnnualReturn2019	25.84%
2020	rr_AnnualReturn2020	(1.51%)
2021	rr_AnnualReturn2021	38.52%
2022	rr_AnnualReturn2022	0.07%
2023	rr_AnnualReturn2023	5.79%
2024	rr_AnnualReturn2024	20.75%
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	Mar. 31, 2021
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	32.07%
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	(37.38%)
OneYear	rr_AverageAnnualReturnYear01	20.75%
FiveYears	rr_AverageAnnualReturnYear05	11.77%
TenYears	rr_AverageAnnualReturnYear10	9.53%
1290 VT Small Cap Value Portfolio | Class K
Risk Return Abstract	rr_RiskReturnAbstract
Shareholder Fees (fees paid directly from your investment)	rr_ShareholderFeeOther
Management Fee	rr_ManagementFeesOverAssets	0.80%
Distribution and/or Service Fees (12b-1 fees)	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	0.19%
Acquired Fund Fees and Expenses	rr_AcquiredFundFeesAndExpensesOverAssets	0.05%
Total Annual Portfolio Operating Expenses	rr_ExpensesOverAssets	1.04%
Fee Waiver and/or Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.09%)	[1]
Total Annual Portfolio Operating Expenses After Fee Waiver and/or Expense Reimbursement	rr_NetExpensesOverAssets	0.95%
1 Year	rr_ExpenseExampleYear01	$ 97
3 Years	rr_ExpenseExampleYear03	322
5 Years	rr_ExpenseExampleYear05	565
10 Years	rr_ExpenseExampleYear10	$ 1,263
OneYear	rr_AverageAnnualReturnYear01	21.03%
FiveYears	rr_AverageAnnualReturnYear05	12.05%
TenYears	rr_AverageAnnualReturnYear10	9.79%
1290 VT Small Cap Value Portfolio | Russell 3000® Index (reflects no deduction for fees, expenses, or taxes)
Risk Return Abstract	rr_RiskReturnAbstract
OneYear	rr_AverageAnnualReturnYear01	23.81%
FiveYears	rr_AverageAnnualReturnYear05	13.86%
TenYears	rr_AverageAnnualReturnYear10	12.55%
1290 VT Small Cap Value Portfolio | Russell 2000® Value Index (reflects no deduction for fees, expenses, or taxes)
Risk Return Abstract	rr_RiskReturnAbstract
OneYear	rr_AverageAnnualReturnYear01	8.05%
FiveYears	rr_AverageAnnualReturnYear05	7.29%
TenYears	rr_AverageAnnualReturnYear10	7.14%

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