Lifestyle Growth Portfolio Investment Risks - Lifestyle Growth Portfolio	Dec. 31, 2025
Advance Trade Estimate Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	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.
Affiliated Insurance Companies [Member]
Prospectus [Line Items]
Risk [Text Block]	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.
Allocation Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	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.
Commodity Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	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.
Credit And Counterparty Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	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.
Economic And Market Events Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	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.
Equity Securities Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	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.
ESG Integration Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	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. Integration of ESG factors into the fund’s investment process does not preclude the fund from including companies with low ESG characteristics or excluding companies with high ESG characteristics in 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.
Exchange Traded Funds Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Exchange-traded fund (ETF) investment 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 fund (ETF) investment 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 Notes ETNs Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	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.
Fixed Income Securities Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	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.
Fund Of Funds Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	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.
Hedging Derivatives And Other Strategic Transactions Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	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 the 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 the fund intends to utilize include: futures contracts and options. Futures contracts and options generally are subject to counterparty risk.
Inflation Protected Securities Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Inflation-protected securities risk.  Increases in real interest rates generally cause the price of inflation-protected debt securities to decrease.Inflation-protected securities risk.  Increases in real interest rates generally cause the price of inflation-protected debt securities to decrease.
Investment Company Securities Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	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.
JHVIT Lifestyle Portfolio Asset Transfer Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	JHVIT Lifestyle Portfolio asset transfer risk.  The Lifestyle Growth 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.
Liquidity Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	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.
Operational And Cybersecurity Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	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.
Target Allocation Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Target allocation risk.  The fund's risk profile will change due to reallocation or rebalancing of portfolio assets.
Convertible Securities Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	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.
Foreign Securities Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	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.
Index Management Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	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.
Initial Public Offerings Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Initial public offerings (IPOs) risk.  IPO share prices are frequently volatile and may significantly impact fund performance.
Large Company Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	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.
Loan Participations Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	Loan participations risk.  Participations and assignments involve special types of risks, including credit risk, interest-rate risk, counterparty risk, liquidity risk, risks associated with extended settlement, and the risks of being a lender.
Lower Rated And High Yield Fixed Income Securities Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	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.
Mortgage Backed And Asset Backed Securities Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	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.
Sector Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	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.
Short Sales Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	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.
Small And Mid Sized Company Risk [Member]
Prospectus [Line Items]
Risk [Text Block]	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.
Risk Lose Money [Member]
Prospectus [Line Items]
Risk [Text Block]	Many factors affect performance, and fund shares will fluctuate in price, meaning you could lose money.
Risk Not Insured Depository Institution [Member]
Prospectus [Line Items]
Risk [Text Block]	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.
Risk Nondiversified Status [Member]
Prospectus [Line Items]
Risk [Text Block]	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.