Label	Element	Value
Risk Return Abstract	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	JOHN HANCOCK VARIABLE INSURANCE TRUST
Prospectus Date	rr_ProspectusDate	Apr. 28, 2025
Lifestyle Moderate Portfolio
Risk Return Abstract	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	<span style="color:#000000;font-family:Arial Narrow;font-size:24pt;">Lifestyle Moderate Portfolio</span>
Objective [Heading]	rr_ObjectiveHeading	<span style="color:#000000;font-family:Arial Narrow;font-size:10pt;font-weight:bold;">Investment objective</span>
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	To seek a balance between a high level of current income and growth of capital, with a greater emphasis on income.
Expense [Heading]	rr_ExpenseHeading	<span style="color:#000000;font-family:Arial Narrow;font-size:10pt;font-weight:bold;">Fees and expenses</span>
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	This table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the fund. The fees and expenses do not reflect fees and expenses of any variable insurance or variable annuities contract that may use the fund as its underlying investment option and would be higher if they did.
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	<span style="font-family:Arial Narrow;font-size:8pt;font-weight:bold;margin-left:0.0pt;">Annual fund operating expenses (%) </span><span style="font-family:Arial Narrow;font-size:8pt;margin-left:0.0pt;">(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 Narrow;font-size:8pt;">April 30, 2026</span>
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	<span style="color:#000000;font-family:Arial Narrow;font-size:10pt;font-weight:bold;">Portfolio turnover</span>
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The fund, which operates as a fund of funds and invests in underlying funds, does not pay transaction costs, such as commissions, when it buys and sells shares of underlying funds (or “turns over” its portfolio). An underlying fund does pay transaction costs when it turns over its portfolio, and 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 performance of the underlying funds and of the fund. During its most recent fiscal year, the fund’s portfolio turnover rate was 9% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	9.00%
Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text]	rr_ExpensesNotCorrelatedToRatioDueToAcquiredFundFees	<span style="color:#000000;font-family:Arial Narrow;font-size:8pt;">The “Total annual fund operating expenses” shown may not correlate to the fund’s ratios of expenses to average daily net assets shown in the “Financial highlights” section of the fund’s prospectus, which does not include “Acquired fund fees and expenses.”</span>
Expense Example [Heading]	rr_ExpenseExampleHeading	<span style="color:#000000;font-family:Arial Narrow;font-size:10pt;font-weight:bold;">Expense example</span>
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	The examples are intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds. The examples assume that $10,000 is invested in the fund for the periods indicated and then all shares are redeemed at the end of those periods. The examples also assume that the investment has a 5% return each year and that the fund’s operating expenses remain the same. The expense example does not reflect fees and expenses of any variable insurance contract that may use the fund as its underlying investment option and would be higher if they did. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading]	rr_StrategyHeading	<span style="color:#000000;font-family:Arial Narrow;font-size:10pt;font-weight:bold;">Principal investment strategies</span>
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The fund, except as otherwise described below, operates as a fund of funds and normally invests approximately 40% of its assets in underlying funds that invest primarily in equity securities or in futures contracts on equity markets (the “Equity Allocation”) and approximately 60% of its assets in underlying funds that invest primarily in fixed-income securities or in futures contracts on fixed-income markets (the “Fixed Income Allocation”). Underlying funds may include exchange traded funds (“ETFs”) and the fund may invest a significant portion of its assets in ETFs. At the discretion of the subadvisor, the Equity Allocation may also include direct investments in equity securities and the Fixed Income Allocation may also include direct investments in fixed-income securities. The subadvisor may also determine in light of market or economic conditions that the normal percentage limitations should be exceeded to protect the fund or achieve its investment objective. Within the prescribed percentage allocation, the subadvisor selects the percentage level to be maintained in specific underlying funds and in futures contracts on equity or fixed-income markets. These allocations may be changed at any time by the subadvisor. The fund may invest in various underlying funds that as a group hold a wide range of equity type securities. These include small-, mid- and large-capitalization stocks, domestic and foreign securities (including emerging market securities) and sector holdings such as utilities, science, and technology stocks. Each of these underlying funds has its own investment strategy which, for example, may focus on growth stocks or value stocks or may employ a strategy combining growth and income stocks and/or may invest in derivatives such as options on securities and futures contracts. The fund may also invest in underlying funds that purchase futures contracts on equity markets. Certain of these underlying funds focus their investment strategy on fixed-income securities, which may include investment grade and below investment grade debt securities with maturities that range from short to longer term. The fixed-income underlying funds collectively hold various types of debt instruments such as corporate bonds and mortgage backed, U.S. and foreign government issued, domestic and international securities. The fund may invest in derivatives, which are financial contracts with a value that depends on, or is derived from, the value of underlying assets, reference rates or indexes. Derivatives may relate to stocks, bonds, interest rates, currencies or currency exchange rates and related indexes. The fund may use derivatives for hedging and nonhedging purposes including, without limitation, the following purposes: ●To establish a position in the derivatives markets as a method of gaining exposure to a particular security or market; ●To attempt to protect against possible changes in the market value of securities held or to be purchased by the fund or an underlying fund; ●To manage the effective maturity or duration of the securities of the fund or an underlying fund; and ●To facilitate the repatriation of foreign currency and the settlement of purchases of foreign securities. The fund may invest in other types of investments including exchange-traded notes (ETNs)  as described under “Other Permitted Investments of the Fund of Funds.” The fund bears its own expenses and, in addition, indirectly bears its proportionate share of the expenses of the underlying funds in which it invests. The manager considers environmental, social, and/or governance (ESG) factors, alongside other relevant factors, as part of its investment process. ESG factors may include, but are not limited to, matters regarding board diversity, climate change policies, and supply chain and human rights policies. The ESG characteristics utilized in the fund’s investment process may change over time and one or more characteristics may not be relevant with respect to all issuers that are eligible fund investments. Because ESG factors are considered alongside other relevant factors, the manager may determine that an investment is appropriate notwithstanding its relative ESG characteristics.
Risk [Heading]	rr_RiskHeading	<span style="color:#000000;font-family:Arial Narrow;font-size:10pt;font-weight:bold;">Principal risks</span>
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	<span style="color:#000000;font-family:Arial Narrow;font-size:10pt;font-weight:bold;">Past performance</span>
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The following information illustrates the variability of the fund’s returns and provides some indication of the risks of investing in the fund by showing changes in the fund’s performance from year to year and by showing how the fund’s average annual returns compared with a broad-based securities market index.Past performance does not indicate future results. The Morningstar U.S. Moderately Conservative Target Allocation Index and 28% Russell 3000 Index/12% MSCI EAFE Index/60% Bloomberg U.S. Aggregate Bond Index show how the fund’s performance compares against the returns of similar investments. All figures assume dividend reinvestment. The performance information below does not reflect fees and expenses of any variable insurance contract which may use JHVIT as its underlying investment option. If such fees and expenses had been reflected, performance would be lower.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	<span style="font-family:Arial Narrow;font-size:9pt;">The following information illustrates the variability of the fund’s returns and provides some indication of the risks of investing in the fund by showing changes in the fund’s performance from year to year and by showing how the fund’s average annual returns compared with a broad-based securities market index.</span>
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	<span style="font-family:Arial Narrow;font-size:9pt;">Past performance does not indicate future results.</span>
Bar Chart [Heading]	rr_BarChartHeading	<span style="font-family:Arial Narrow;font-size:9pt;font-weight:bold;">Calendar year total returns (%)—Series II</span>
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Best quarter:Q2 202010.81%Worst quarter:Q2 2022-9.58%
Performance Table Heading	rr_PerformanceTableHeading	<span style="font-family:Arial Narrow;font-size:8pt;font-weight:bold;margin-left:0.0pt;">Average annual total returns (%)—as of 12/31/2024</span>
Performance Table Market Index Changed	rr_PerformanceTableMarketIndexChanged	<span style="font-family:Arial Narrow;font-size:8pt;">The fund has designated the Bloomberg U.S. Aggregate Bond Index as its new broad-based securities market index in accordance with the revised definition for such an index.</span>
Lifestyle Moderate Portfolio | Risk Nondiversified Status [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Non-diversified risk.  Adverse events affecting a particular issuer or group of issuers may magnify losses for non-diversified funds, which may invest a large portion of assets in any one issuer or a small number of issuers.
Lifestyle Moderate Portfolio | Risk Lose Money [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Many factors affect performance, and fund shares will fluctuate in price, meaning you could lose money.
Lifestyle Moderate Portfolio | Risk Not Insured Depository Institution [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	An investment in the fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
Lifestyle Moderate Portfolio | Advance Trade Estimate Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Advance trade estimate risk.  The JHVIT Lifestyle Portfolio may seek to mitigate asset transfer risk by adjusting its portfolio based on advance estimates of automatic transfers of Contract value under the Contracts. The John Hancock Issuers have provided the JHVIT Lifestyle Portfolio’s subadvisor with an analytical tool that calculates estimates of automatic transfers based on several factors, including the mathematical process for automatic transfers and market movements before the daily close of trading. The subadvisor may, but is not required to, use the tool to adjust the JHVIT Lifestyle Portfolio’s portfolio with the goal of trading in securities or purchasing shares of underlying funds as close to the market close as possible in order to limit the JHVIT Lifestyle Portfolio’s exposure to cash drag (i.e., holding cash while markets are rising) and adverse overnight market fluctuations. For example, in a rising market, if the analytical tool suggests that the JHVIT Lifestyle Portfolio will receive inflows that day (the “Trade Date”), the subadvisor could buy securities or shares of an underlying fund close to or at the closing prices on the Trade Date, as opposed to the following business day, when the actual transfer amount would be known. In a falling market, if the analytical tool suggests that the JHVIT Lifestyle Portfolio will experience outflows on Trade Date, the subadvisor could sell securities or shares of an underlying fund close to or at the closing prices on Trade Date, as opposed to the following business day, when the actual transfer amount would be known. If the subadvisor relies on the analytical tool or its own judgment and places trades in anticipation of purchases and redemptions of JHVIT Lifestyle shares, there can be no assurance that the prices paid by the JHVIT Lifestyle Portfolio will be better than if the JHVIT Lifestyle Portfolio had traded the following business day. The estimated transfer amount may be different from the actual transfer amount for various reasons, including changes in market direction, contract owner behavior and faulty inputs. If the estimated transfer amount is different from the actual transfer amount, the JHVIT Lifestyle Portfolio will buy or sell securities or shares of an underlying fund the following business day to adjust for this difference. For example, if cash flows into the JHVIT Lifestyle Portfolio are less than estimated, the JHVIT Lifestyle Portfolio could be forced to liquidate positions it had purchased. Conversely, if cash flows out of the JHVIT Lifestyle Portfolio are less than estimated, the JHVIT Lifestyle Portfolio may be required to repurchase positions it had sold. In addition, purchasing securities or shares of an underlying fund early could cause the JHVIT Lifestyle Portfolio to spend more money than it has available and, in the event of a market decline, such leverage will magnify losses because the decline also affects the securities purchased with amounts in excess of the JHVIT Lifestyle Portfolio’s assets. Due to these various factors, trading on the basis of advance estimates of automatic transfers may cause higher portfolio turnover than that based solely on automatic transfers of Contract value under the Contracts, increase JHVIT Lifestyle Portfolio expenses and adversely affect the performance of the JHVIT Lifestyle Portfolio.
Lifestyle Moderate Portfolio | Affiliated Insurance Companies [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Affiliated insurance companies risk.  The advisor may be influenced by the benefits to its affiliated life insurance companies in managing the fund and overseeing its subadvisors. The John Hancock insurance companies issuing guaranteed benefits on variable annuity and insurance contracts investing in the fund have a financial interest in preserving the value of the funds and reducing their volatility due to their obligations for these guaranteed benefits (the cost of providing these guaranteed benefits is related to several factors including the performance and volatility of the fund). To the extent the fund is successful in managing the volatility of returns and downside risk, the John Hancock insurance companies issuing guaranteed benefits on variable annuity and insurance contracts investing in the fund will also benefit from a reduction in their potential investment risk which will reduce their costs of hedging this risk and may reduce their reserve and capital requirements. These financial benefits to the John Hancock insurance companies may be material. The fund and the fund’s investment advisor have adopted procedures that are intended to address these conflicts and ensure that the fund is managed in accordance with its disclosed investment objectives and strategies.
Lifestyle Moderate Portfolio | Allocation Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Allocation risk.  The fund is subject to risks related to conflicts of interest associated with the advisor’s ability to determine the fund’s strategic asset allocation among general investment categories, which are executed by multiple unaffiliated and/or affiliated subadvisors.
Lifestyle Moderate Portfolio | Commodity Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Commodity risk.  Commodity prices may be volatile due to fluctuating demand, supply disruption, speculation, and other factors. Certain commodity investments may have no active trading market at times.
Lifestyle Moderate Portfolio | Credit And Counterparty Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Credit and counterparty risk.  The issuer or guarantor of a fixed-income security, the counterparty to an over-the-counter derivatives contract, or a borrower of fund securities may not make timely payments or otherwise honor its obligations. U.S. government securities are subject to varying degrees of credit risk depending upon the nature of their support. A downgrade or default affecting any of the fund’s securities could affect the fund’s performance.Credit and counterparty risk.  The issuer or guarantor of a fixed-income security, the counterparty to an over-the-counter derivatives contract, or a borrower of fund securities may not make timely payments or otherwise honor its obligations. U.S. government securities are subject to varying degrees of credit risk depending upon the nature of their support. A downgrade or default affecting any of the fund’s securities could affect the fund’s performance.
Lifestyle Moderate Portfolio | Economic And Market Events Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Economic and market events risk.  Events in the U.S. and global financial markets, including actions taken by the U.S. Federal Reserve or foreign central banks to stimulate or stabilize economic growth, may at times result in unusually high market volatility, which could negatively impact performance. Reduced liquidity in credit and fixed-income markets could adversely affect issuers worldwide. Banks and financial services companies could suffer losses if interest rates rise or economic conditions deteriorate.Economic and market events risk.  Events in the U.S. and global financial markets, including actions taken by the U.S. Federal Reserve or foreign central banks to stimulate or stabilize economic growth, may at times result in unusually high market volatility, which could negatively impact performance. Reduced liquidity in credit and fixed-income markets could adversely affect issuers worldwide. Banks and financial services companies could suffer losses if interest rates rise or economic conditions deteriorate.
Lifestyle Moderate Portfolio | Equity Securities Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Equity securities risk.  The price of equity securities may decline due to changes in a company’s financial condition or overall market conditions.Equity securities risk.  The price of equity securities may decline due to changes in a company’s financial condition or overall market conditions. Growth company securities may fluctuate more in price than other securities because of the greater emphasis on earnings expectations. Securities the manager believes are undervalued may never realize their full potential value, and in certain markets value stocks may underperform the market as a whole.
Lifestyle Moderate Portfolio | ESG Integration Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	ESG integration risk.  The manager considers ESG factors that it deems relevant or additive, along with other material factors and analysis, when managing the fund. ESG factors may include, but are not limited to, matters regarding board diversity, climate change policies, and supply chain and human rights policies. The manager may consider these ESG factors on all or a meaningful portion of the fund’s investments. Incorporating ESG criteria and making investment decisions based on certain ESG characteristics, as determined by the manager, carries the risk that the fund may perform differently, including underperforming, funds that do not utilize ESG criteria, or funds that utilize different ESG criteria.
Lifestyle Moderate Portfolio | Exchange Traded Funds Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Exchange-traded funds (ETFs) risk.  The risks of owning shares of an ETF include the risks of owning the underlying securities the ETF holds. Lack of liquidity in an ETF could result in the ETF being more volatile than its underlying securities. An ETF’s shares could trade at a significant premium or discount to its net asset value (NAV). A fund bears ETF fees and expenses indirectly.Exchange-traded funds (ETFs) risk.  The risks of owning shares of an ETF include the risks of owning the underlying securities the ETF holds. Lack of liquidity in an ETF could result in the ETF being more volatile than its underlying securities. An ETF’s shares could trade at a significant premium or discount to its net asset value (NAV). A fund bears ETF fees and expenses indirectly.
Lifestyle Moderate Portfolio | Exchange Traded Notes ETNs Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Exchange-traded notes (ETNs) risk.  An ETN generally reflects the risks associated with the assets composing the underlying market benchmark or strategy it is designed to track. ETNs also are subject to issuer and fixed-income risks.
Lifestyle Moderate Portfolio | Fixed Income Securities Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Fixed-income securities risk.  A rise in interest rates typically causes bond prices to fall. The longer the average maturity or duration of the bonds held by a fund, the more sensitive it will likely be to interest-rate fluctuations. An issuer may not make all interest payments or repay all or any of the principal borrowed. Changes in a security’s credit quality may adversely affect fund performance.Fixed-income securities risk.  A rise in interest rates typically causes bond prices to fall. The longer the average maturity or duration of the bonds held by a fund, the more sensitive it will likely be to interest-rate fluctuations. An issuer may not make all interest payments or repay all or any of the principal borrowed. Changes in a security’s credit quality may adversely affect fund performance.
Lifestyle Moderate Portfolio | Fund Of Funds Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Fund of funds risk.  The fund’s ability to achieve its investment objective will depend largely, in part, on: (i) the underlying funds’ performance, expenses and ability to meet their investment objectives; and (ii) properly rebalancing assets among underlying funds and different asset classes. The fund is also subject to risks related to: (i) layering of fees of the underlying funds; and (ii) conflicts of interest associated with the subadvisor’s ability to allocate fund assets without limit to other funds it advises and/or other funds advised by affiliated subadvisors. There is no assurance that either the fund or the underlying funds will achieve their investment objectives. A fund bears underlying fund fees and expenses indirectly.
Lifestyle Moderate Portfolio | Hedging Derivatives And Other Strategic Transactions Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Hedging, derivatives, and other strategic transactions risk.  Hedging, derivatives, and other strategic transactions may increase a fund’s volatility and could produce disproportionate losses, potentially more than the fund’s principal investment. Risks of these transactions are different from and possibly greater than risks of investing directly in securities and other traditional instruments. Under certain market conditions, derivatives could become harder to value or sell and may become subject to liquidity risk (i.e., the inability to enter into closing transactions). Derivatives and other strategic transactions that a fund intends to utilize include: futures contracts and options. Futures contracts and options generally are subject to counterparty risk.Hedging, derivatives, and other strategic transactions risk.  Hedging, derivatives, and other strategic transactions may increase a fund’s volatility and could produce disproportionate losses, potentially more than the fund’s principal investment. Risks of these transactions are different from and possibly greater than risks of investing directly in securities and other traditional instruments. Under certain market conditions, derivatives could become harder to value or sell and may become subject to liquidity risk (i.e., the inability to enter into closing transactions). Derivatives and other strategic transactions that a fund intends to utilize include: futures contracts and options. Futures contracts and options generally are subject to counterparty risk.
Lifestyle Moderate Portfolio | Investment Company Securities Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Investment company securities risk.  Fund shareholders indirectly bear their proportionate share of the expenses of any investment company in which the fund invests. The total return on such investments will be reduced by the operating expenses and fees of such other investment companies, including advisory fees.
Lifestyle Moderate Portfolio | JHVIT Lifestyle Portfolio Asset Transfer Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	JHVIT Lifestyle Portfolio asset transfer risk.  The Lifestyle Moderate Portfolio (the “JHVIT Lifestyle Portfolio”) is offered in connection with specific guaranteed benefits under variable annuity contracts (the “Contracts”) issued by John Hancock Life Insurance Company (U.S.A.) and John Hancock Life Insurance Company of New York (collectively, the “John Hancock Issuers”). The Contracts provide that the John Hancock Issuers can automatically transfer contract value between the JHVIT Lifestyle Portfolio and the Select Bond Trust through a non-discretionary, systematic mathematical process. The purpose of these transfers is to attempt to protect contract value from declines due to market volatility, and thereby limit the John Hancock Issuers’ exposure to risk under the guaranteed benefits under the Contracts. The timing and amount of any transfer of contract value under the John Hancock Issuers’ process will depend on several factors including market movements. In general, the higher the equity component of a JHVIT Lifestyle Portfolio, the more likely that contract value will be reallocated from the JHVIT Lifestyle Portfolio to the Select Bond Trust when equity markets fall. These asset flows may negatively affect the performance of the JHVIT Lifestyle Portfolio and an underlying fund in which the JHVIT Lifestyle Portfolio invests by increasing the underlying fund’s transaction costs and causing it to purchase or sell securities when it would not normally do so. It could be particularly disadvantageous for the underlying fund if it experiences outflows and needs to sell securities at a time of volatility in the markets, when values could be falling. Because the JHVIT Lifestyle Portfolio bears its proportionate share of the transaction costs of the underlying funds, increased underlying fund expenses may indirectly negatively affect the performance of the JHVIT Lifestyle Portfolio.
Lifestyle Moderate Portfolio | Liquidity Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Liquidity risk.  The extent (if at all) to which a security may be sold or a derivative position closed without negatively impacting its market value may be impaired by reduced market activity or participation, legal restrictions, or other economic and market impediments. Liquidity risk may be magnified in rising interest rate environments due to higher than normal redemption rates. Widespread selling of fixed-income securities to satisfy redemptions during periods of reduced demand may adversely impact the price or salability of such securities. Periods of heavy redemption could cause the fund to sell assets at a loss or depressed value, which could negatively affect performance. Redemption risk is heightened during periods of declining or illiquid markets.Liquidity risk.  The extent (if at all) to which a security may be sold or a derivative position closed without negatively impacting its market value may be impaired by reduced market activity or participation, legal restrictions, or other economic and market impediments. Liquidity risk may be magnified in rising interest rate environments due to higher than normal redemption rates. Widespread selling of fixed-income securities to satisfy redemptions during periods of reduced demand may adversely impact the price or salability of such securities. Periods of heavy redemption could cause the fund to sell assets at a loss or depressed value, which could negatively affect performance. Redemption risk is heightened during periods of declining or illiquid markets.
Lifestyle Moderate Portfolio | Operational And Cybersecurity Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Operational and cybersecurity risk.  Cybersecurity breaches may allow an unauthorized party to gain access to fund assets, customer data, or proprietary information, or cause a fund or its service providers to suffer data corruption or lose operational functionality. Similar incidents affecting issuers of a fund’s securities may negatively impact performance. Operational risk may arise from human error, error by third parties, communication errors, or technology failures, among other causes.Operational and cybersecurity risk.  Cybersecurity breaches may allow an unauthorized party to gain access to fund assets, customer data, or proprietary information, or cause a fund or its service providers to suffer data corruption or lose operational functionality. Similar incidents affecting issuers of a fund’s securities may negatively impact performance. Operational risk may arise from human error, error by third parties, communication errors, or technology failures, among other causes.
Lifestyle Moderate Portfolio | Target Allocation Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Target allocation risk.  The fund's risk profile will change due to reallocation or rebalancing of portfolio assets.
Lifestyle Moderate Portfolio | Convertible Securities Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Convertible securities risk.  Convertible securities are subject to certain risks of both equity and debt securities. The market values of convertible securities tend to fall as interest rates rise and rise as interest rates fall. As the market price of underlying common stock declines below the conversion price, the market value of the convertible security tends to be increasingly influenced by its yield.
Lifestyle Moderate Portfolio | Foreign Securities Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Foreign securities risk.  Less information may be publicly available regarding foreign issuers, including foreign government issuers. Foreign securities may be subject to foreign taxes and may be more volatile than U.S. securities. Currency fluctuations and political and economic developments may adversely impact the value of foreign securities. The risks of investing in foreign securities are magnified in emerging markets.
Lifestyle Moderate Portfolio | Index Management Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Index management risk.  Certain factors may cause a fund that is an index fund to track its target index less closely. For example, a subadvisor may select securities that are not fully representative of the index, and the fund’s operating expenses and transaction costs, and the size and timing of its cash flows, may result in the fund’s performance being different than that of its index. Moreover, the fund will generally reflect the performance of its target index even when the index does not perform well.
Lifestyle Moderate Portfolio | Initial Public Offerings Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Initial public offerings (IPOs) risk.  IPO share prices are frequently volatile and may significantly impact fund performance.
Lifestyle Moderate Portfolio | Large Company Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Large company risk.  Larger companies may grow more slowly than smaller companies or be slower to respond to business developments. Large-capitalization securities may underperform the market as a whole.
Lifestyle Moderate Portfolio | Lower Rated And High Yield Fixed Income Securities Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Lower-rated and high-yield fixed-income securities risk.  Lower-rated and high-yield fixed-income securities (junk bonds) are subject to greater credit quality risk, risk of default, and price volatility than higher-rated fixed-income securities, may be considered speculative, and can be difficult to resell.
Lifestyle Moderate Portfolio | Mortgage Backed And Asset Backed Securities Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Mortgage-backed and asset-backed securities risk.  Mortgage-backed and asset-backed securities are subject to different combinations of prepayment, extension, interest-rate, and other market risks. Factors that impact the value of these securities include interest rate changes, the reliability of available information, credit quality or enhancement, and market perception.
Lifestyle Moderate Portfolio | Sector Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Sector risk.  When a fund focuses its investments in certain sectors of the economy, its performance may be driven largely by sector performance and could fluctuate more widely than if the fund were invested more evenly across sectors.
Lifestyle Moderate Portfolio | Short Sales Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Short sales risk.  Short sales involve costs and risk. A fund must pay the lender interest on a security it borrows, and the fund will lose money if the price of the borrowed security increases between the time of the short sale and the date when the fund replaces the borrowed security.
Lifestyle Moderate Portfolio | Small And Mid Sized Company Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Small and mid-sized company risk.  Small and mid-sized companies are generally less established and may be more volatile than larger companies. Small and/or mid-capitalization securities may underperform the market as a whole.
Lifestyle Moderate Portfolio | Series I
Risk Return Abstract	rr_RiskReturnAbstract
Management fee	rr_ManagementFeesOverAssets	0.04%
Distribution and service (Rule 12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.05%
Other expenses	rr_OtherExpensesOverAssets	0.06%
Acquired fund fees and expenses	rr_AcquiredFundFeesAndExpensesOverAssets	0.56%	[1]
Total annual fund operating expenses	rr_ExpensesOverAssets	0.71%	[2]
Contractual expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.02%)	[3]
Total annual fund operating expenses after expense reimbursements	rr_NetExpensesOverAssets	0.69%
1 year	rr_ExpenseExampleYear01	$ 70
3 years	rr_ExpenseExampleYear03	225
5 years	rr_ExpenseExampleYear05	393
10 years	rr_ExpenseExampleYear10	$ 881
1 year	rr_AverageAnnualReturnYear01	7.14%
5 year	rr_AverageAnnualReturnYear05	4.14%
10 year	rr_AverageAnnualReturnYear10	4.79%
Lifestyle Moderate Portfolio | Series II
Risk Return Abstract	rr_RiskReturnAbstract
Management fee	rr_ManagementFeesOverAssets	0.04%
Distribution and service (Rule 12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other expenses	rr_OtherExpensesOverAssets	0.06%
Acquired fund fees and expenses	rr_AcquiredFundFeesAndExpensesOverAssets	0.56%	[1]
Total annual fund operating expenses	rr_ExpensesOverAssets	0.91%	[2]
Contractual expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.02%)	[3]
Total annual fund operating expenses after expense reimbursements	rr_NetExpensesOverAssets	0.89%
1 year	rr_ExpenseExampleYear01	$ 91
3 years	rr_ExpenseExampleYear03	288
5 years	rr_ExpenseExampleYear05	502
10 years	rr_ExpenseExampleYear10	$ 1,118
2015	rr_AnnualReturn2015	(0.10%)
2016	rr_AnnualReturn2016	5.28%
2017	rr_AnnualReturn2017	10.28%
2018	rr_AnnualReturn2018	(3.77%)
2019	rr_AnnualReturn2019	15.72%
2020	rr_AnnualReturn2020	11.87%
2021	rr_AnnualReturn2021	7.03%
2022	rr_AnnualReturn2022	(15.34%)
2023	rr_AnnualReturn2023	11.91%
2024	rr_AnnualReturn2024	6.91%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	<span style="color:#000000;font-family:Arial Narrow;font-size:8pt;font-weight:bold;margin-left:0.0pt;">Best quarter:</span>
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Jun. 30, 2020
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	10.81%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	<span style="color:#000000;font-family:Arial Narrow;font-size:8pt;font-weight:bold;margin-left:0.0pt;">Worst quarter:</span>
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Jun. 30, 2022
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(9.58%)
1 year	rr_AverageAnnualReturnYear01	6.91%
5 year	rr_AverageAnnualReturnYear05	3.93%
10 year	rr_AverageAnnualReturnYear10	4.59%
Lifestyle Moderate Portfolio | NAV
Risk Return Abstract	rr_RiskReturnAbstract
Management fee	rr_ManagementFeesOverAssets	0.04%
Distribution and service (Rule 12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	none
Other expenses	rr_OtherExpensesOverAssets	0.06%
Acquired fund fees and expenses	rr_AcquiredFundFeesAndExpensesOverAssets	0.56%	[1]
Total annual fund operating expenses	rr_ExpensesOverAssets	0.66%	[2]
Contractual expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.02%)	[3]
Total annual fund operating expenses after expense reimbursements	rr_NetExpensesOverAssets	0.64%
1 year	rr_ExpenseExampleYear01	$ 65
3 years	rr_ExpenseExampleYear03	209
5 years	rr_ExpenseExampleYear05	366
10 years	rr_ExpenseExampleYear10	$ 821
1 year	rr_AverageAnnualReturnYear01	7.19%
5 year	rr_AverageAnnualReturnYear05	4.21%
10 year	rr_AverageAnnualReturnYear10	4.86%
Lifestyle Moderate Portfolio | Bloomberg U.S. Aggregate Bond Index (reflects no deduction for fees, expenses, or taxes)
Risk Return Abstract	rr_RiskReturnAbstract
1 year	rr_AverageAnnualReturnYear01	1.25%	[4]
5 year	rr_AverageAnnualReturnYear05	(0.33%)	[4]
10 year	rr_AverageAnnualReturnYear10	1.35%	[4]
Lifestyle Moderate Portfolio | Morningstar U.S. Moderately Conservative Target Allocation Index (reflects no deduction for fees, expenses, or taxes)
Risk Return Abstract	rr_RiskReturnAbstract
1 year	rr_AverageAnnualReturnYear01	9.11%
5 year	rr_AverageAnnualReturnYear05	4.85%
10 year	rr_AverageAnnualReturnYear10	5.34%
Lifestyle Moderate Portfolio | 28% Russell 3000 Index/12% MSCI EAFE Index/60% Bloomberg U.S. Aggregate Bond Index (reflects no deduction for fees, expenses, or taxes, except foreign withholding taxes on dividends)
Risk Return Abstract	rr_RiskReturnAbstract
1 year	rr_AverageAnnualReturnYear01	7.57%
5 year	rr_AverageAnnualReturnYear05	4.41%
10 year	rr_AverageAnnualReturnYear10	5.12%

[1] “Acquired fund fees and expenses” are based on indirect net expenses associated with the fund’s investments in underlying investment companies.

[2] The “Total annual fund operating expenses” shown may not correlate to the fund’s ratios of expenses to average daily net assets shown in the “Financial highlights” section of the fund’s prospectus, which does not include “Acquired fund fees and expenses.”

[3] The advisor has contractually agreed to reduce its management fee and/or make payment to the fund in an amount equal to the amount by which “Other expenses” of the fund exceed 0.04% of the average daily net assets of the fund. “Other expenses” means all of the expenses of the fund, excluding certain expenses such as advisory fees, taxes, brokerage commissions, interest expense, litigation and indemnification expenses and other extraordinary expenses not incurred in the ordinary course of the fund’s business, distribution and service (Rule 12b-1) fees, underlying fund expenses (acquired fund fees), and short dividend expense. The current expense limitation agreement expires on April 30, 2026 unless renewed by mutual agreement of the fund and the advisor based upon a determination that this is appropriate under the circumstances at that time.

[4] The fund has designated the Bloomberg U.S. Aggregate Bond Index as its new broad-based securities market index in accordance with the revised definition for such an index.