Label	Element	Value
Risk Return Abstract	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	JOHN HANCOCK VARIABLE INSURANCE TRUST
Prospectus Date	rr_ProspectusDate	Apr. 28, 2025
High Yield Trust
Risk Return Abstract	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	<span style="color:#000000;font-family:Arial Narrow;font-size:24pt;">High Yield Trust</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	The fund seeks high current income.
Objective, Secondary [Text Block]	rr_ObjectiveSecondaryTextBlock	Capital appreciation is a secondary goal.
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;">July 31, 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 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 fund’s performance. During its most recent fiscal year, the fund’s portfolio turnover rate was 38% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	38.00%
Expenses Restated to Reflect Current [Text]	rr_ExpensesRestatedToReflectCurrent	<span style="font-family:Arial Narrow;font-size:8pt;">“Management fee” has been restated to reflect the contractual management fee schedule effective February 7, 2025.</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	Under normal market conditions, the fund invests at least 80% of its net assets (plus any borrowings for investment purposes) in U.S. and foreign fixed-income securities rated BB/Ba or lower and their unrated equivalents. Bonds that are rated at or below BB by S&P Global Ratings (S&P) or Fitch Ratings, Inc. (Fitch Ratings) or Ba by Moody’s Investors Service, Inc. (Moody’s) are considered junk bonds. These may include, but are not limited to, domestic and foreign corporate bonds, government obligations, debentures and notes, convertible securities, preferred securities, and domestic and foreign government obligations. No more than 10% of the fund’s total assets may be invested in securities that are rated in default by S&P or Moody’s. The fund’s investment policies are based on credit ratings at the time of purchase. There is no limit on the fund’s average maturity.In managing the fund’s portfolio, the manager focuses on industry allocation and securities selection, deciding which types of industries to emphasize at a given time and then which individual securities to buy. The manager uses top-down analysis to determine which industries may benefit from current and future changes in the economy. The fund may hold up to 20% of its total assets in the securities of companies in any one industry and up to 10% of its total assets in the securities of any individual issuer. In choosing individual securities, the manager uses bottom-up research to find securities that appear comparatively undervalued. The manager looks at the financial condition of the issuers, as well as the collateralization and other features of the securities themselves. The fund typically invests in a broad range of industries. The fund may invest in both investment-grade and below-investment-grade asset-backed securities, including asset-backed securities rated BB/Ba or lower by S&P, Fitch Ratings or Moody’s and their unrated equivalents. The fund may use certain higher-risk investments, including restricted or illiquid securities, bank loans and derivatives, which include futures contracts on securities, indexes and foreign currency; options on futures contracts, securities, indexes and foreign currency; interest-rate, foreign currency and credit default swaps; and foreign currency forward contracts, in each case for the purposes of reducing risk, obtaining efficient market exposure, and/or enhancing investment returns. Direct investments in loans may be illiquid and holding a loan could expose the fund to the risk of being a direct lender. In addition, the fund may invest up to 20% of its assets in U.S. and foreign common stocks of companies of any size. 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. The fund may trade securities actively, which could increase its transaction costs (thus lowering performance) and increase your taxable distributions. The fund may temporarily invest its assets extensively in investment-grade short-term securities or part or all its assets in cash or cash equivalents for the purpose of meeting redemption requests or making other anticipated cash payments.
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 ICE BofA U.S. High Yield Index and the Bloomberg U.S. High Yield 2% Issuer Capped 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.A note on performancePrior to February 7, 2025, the fund was managed by a different subadvisor pursuant to different investment strategies, and thus, the performance presented prior to this date should not be attributed to the current subadvisor. The fund’s performance shown below might have differed materially had the current subadvisor managed the fund prior to February 7, 2025.
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 I</span>
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Best quarter:Q2 202011.06%Worst quarter:Q1 2020-14.88%
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>
High Yield Trust | 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.
High Yield Trust | 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.
High Yield Trust | Changing Distribution Levels Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Changing distribution levels risk.  The fund may cease or reduce the level of its distribution if income or dividends paid from its investments declines.
High Yield Trust | 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.
High Yield Trust | Defaulted Debt Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Defaulted debt risk.  Investing in defaulted debt securities is speculative and involves substantial risks in addition to those of non-defaulted high-yield securities. Defaulted debt securities generally do not generate interest payments. Principal on defaulted debt might not be repaid, and a fund could lose up to its entire investment.
High Yield Trust | 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.
High Yield Trust | 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.
High Yield Trust | 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.
High Yield Trust | 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.
High Yield Trust | Floating Rate Loans Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Floating rate loans risk.  Floating rate loans are generally rated below investment-grade and are generally considered speculative because they present a greater risk of loss, including default, than higher quality debt instruments.
High Yield Trust | 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.
High Yield Trust | 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 the fund intends to utilize include: credit default swaps; foreign currency forward contracts; foreign currency swaps; futures contracts; interest-rate swaps; and options. Foreign currency forward contracts, futures contracts, options, and swaps generally are subject to counterparty risk. In addition, swaps may be subject to interest-rate and settlement risk, and the risk of default of the underlying reference obligation. Derivatives associated with foreign currency transactions are subject to currency risk.
High Yield Trust | High Portfolio Turnover Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	High portfolio turnover risk.  Trading securities actively and frequently can increase transaction costs (thus lowering performance) and taxable distributions.
High Yield Trust | Illiquid And Restricted Securities Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Illiquid and restricted securities risk.  Illiquid and restricted securities may be difficult to value and may involve greater risks than liquid securities. Illiquidity may have an adverse impact on a particular security’s market price and the fund’s ability to sell the security.
High Yield Trust | 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.
High Yield Trust | LIBOR Discontinuation Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	LIBOR discontinuation risk.  The official publication of the London Interbank Offered Rate (LIBOR), which many debt securities, derivatives and other financial instruments traditionally utilized as the reference or benchmark rate for interest rate calculations, was discontinued as of June 30, 2023. As of September 30, 2024, the UK FCA has confirmed that all publications of LIBOR, including all synthetic publications of the 1-, 3-, and 6-month U.S. dollar LIBOR settings, have ceased. The discontinuation of LIBOR and a transition to replacement rates may lead to volatility and illiquidity in markets and may adversely affect the fund’s performance.
High Yield Trust | 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.
High Yield Trust | Loan Participations Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	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.
High Yield Trust | 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.
High Yield Trust | 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.
High Yield Trust | 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.
High Yield Trust | Preferred And Convertible Securities Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	Preferred and convertible securities risk.  Preferred stock dividends are payable only if declared by the issuer’s board. Preferred stock may be subject to redemption provisions. The market values of convertible securities tend to fall as interest rates rise and rise as interest rates fall. Convertible preferred stock’s value can depend heavily upon the underlying common stock’s value.
High Yield Trust | 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.
High Yield Trust | 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.
High Yield Trust | US Government Agency Obligations Risk [Member]
Risk Return Abstract	rr_RiskReturnAbstract
Risk [Text Block]	rr_RiskTextBlock	U.S. government agency obligations risk.  The fund invests in obligations issued by agencies and instrumentalities of the U.S. government. Government-sponsored entities such as Federal National Mortgage Association (Fannie Mae), Federal Home Loan Mortgage Corporation (Freddie Mac) and the Federal Home Loan Banks, although chartered or sponsored by Congress, are not funded by congressional appropriations and the debt securities that they issue are neither guaranteed nor issued by the U.S. government. Such debt securities are subject to the risk of default on the payment of interest and/or principal, similar to the debt securities of private issuers. The maximum potential liability of the issuers of some U.S. government obligations may greatly exceed their current resources, including any legal right to support from the U.S. government. Although the U.S. government has provided financial support to Fannie Mae and Freddie Mac in the past, there can be no assurance that it will support these or other government-sponsored entities in the future.
High Yield Trust | Series I
Risk Return Abstract	rr_RiskReturnAbstract
Management fee	rr_ManagementFeesOverAssets	0.49%	[1]
Distribution and service (Rule 12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.05%
Other expenses	rr_OtherExpensesOverAssets	0.13%
Total annual fund operating expenses	rr_ExpensesOverAssets	0.67%
Contractual expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.01%)	[2]
Total annual fund operating expenses after expense reimbursements	rr_NetExpensesOverAssets	0.66%
1 year	rr_ExpenseExampleYear01	$ 67
3 years	rr_ExpenseExampleYear03	213
5 years	rr_ExpenseExampleYear05	372
10 years	rr_ExpenseExampleYear10	$ 834
2015	rr_AnnualReturn2015	(8.32%)
2016	rr_AnnualReturn2016	16.26%
2017	rr_AnnualReturn2017	7.50%
2018	rr_AnnualReturn2018	(3.01%)
2019	rr_AnnualReturn2019	15.66%
2020	rr_AnnualReturn2020	5.81%
2021	rr_AnnualReturn2021	5.82%
2022	rr_AnnualReturn2022	(13.25%)
2023	rr_AnnualReturn2023	13.05%
2024	rr_AnnualReturn2024	8.95%
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	11.06%
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	Mar. 31, 2020
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(14.88%)
1 year	rr_AverageAnnualReturnYear01	8.95%
5 year	rr_AverageAnnualReturnYear05	3.65%
10 year	rr_AverageAnnualReturnYear10	4.40%
High Yield Trust | Series II
Risk Return Abstract	rr_RiskReturnAbstract
Management fee	rr_ManagementFeesOverAssets	0.49%	[1]
Distribution and service (Rule 12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other expenses	rr_OtherExpensesOverAssets	0.13%
Total annual fund operating expenses	rr_ExpensesOverAssets	0.87%
Contractual expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.01%)	[2]
Total annual fund operating expenses after expense reimbursements	rr_NetExpensesOverAssets	0.86%
1 year	rr_ExpenseExampleYear01	$ 88
3 years	rr_ExpenseExampleYear03	277
5 years	rr_ExpenseExampleYear05	481
10 years	rr_ExpenseExampleYear10	$ 1,072
1 year	rr_AverageAnnualReturnYear01	8.72%
5 year	rr_AverageAnnualReturnYear05	3.44%
10 year	rr_AverageAnnualReturnYear10	4.19%
High Yield Trust | NAV
Risk Return Abstract	rr_RiskReturnAbstract
Management fee	rr_ManagementFeesOverAssets	0.49%	[1]
Distribution and service (Rule 12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	none
Other expenses	rr_OtherExpensesOverAssets	0.13%
Total annual fund operating expenses	rr_ExpensesOverAssets	0.62%
Contractual expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.01%)	[2]
Total annual fund operating expenses after expense reimbursements	rr_NetExpensesOverAssets	0.61%
1 year	rr_ExpenseExampleYear01	$ 62
3 years	rr_ExpenseExampleYear03	198
5 years	rr_ExpenseExampleYear05	345
10 years	rr_ExpenseExampleYear10	$ 773
1 year	rr_AverageAnnualReturnYear01	9.19%
5 year	rr_AverageAnnualReturnYear05	3.69%
10 year	rr_AverageAnnualReturnYear10	4.46%
High Yield Trust | 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%	[3]
5 year	rr_AverageAnnualReturnYear05	(0.33%)	[3]
10 year	rr_AverageAnnualReturnYear10	1.35%	[3]
High Yield Trust | ICE BofA U.S. High Yield Index (reflects no deduction for fees, expenses, or taxes)
Risk Return Abstract	rr_RiskReturnAbstract
1 year	rr_AverageAnnualReturnYear01	8.20%	[4]
5 year	rr_AverageAnnualReturnYear05	4.04%	[4]
10 year	rr_AverageAnnualReturnYear10	5.08%	[4]
High Yield Trust | Bloomberg U.S. High Yield 2% Issuer Capped Index (reflects no deduction for fees, expenses, or taxes)
Risk Return Abstract	rr_RiskReturnAbstract
1 year	rr_AverageAnnualReturnYear01	8.19%
5 year	rr_AverageAnnualReturnYear05	4.20%
10 year	rr_AverageAnnualReturnYear10	5.16%

[1] “Management fee” has been restated to reflect the contractual management fee schedule effective February 7, 2025.

[2] The advisor contractually agrees to waive a portion of its management fee and/or reimburse expenses for the fund and certain other John Hancock funds according to an asset level breakpoint schedule that is based on the aggregate net assets of all the funds participating in the waiver or reimbursement, including the fund (the participating portfolios). This waiver equals, on an annualized basis, 0.0100% of that portion of the aggregate net assets of all the participating portfolios that exceeds $75 billion but is less than or equal to $125 billion; 0.0125% of that portion of the aggregate net assets of all the participating portfolios that exceeds $125 billion but is less than or equal to $150 billion; 0.0150% of that portion of the aggregate net assets of all the participating portfolios that exceeds $150 billion but is less than or equal to $175 billion; 0.0175% of that portion of the aggregate net assets of all the participating portfolios that exceeds $175 billion but is less than or equal to $200 billion; 0.0200% of that portion of the aggregate net assets of all the participating portfolios that exceeds $200 billion but is less than or equal to $225 billion; and 0.0225% of that portion of the aggregate net assets of all the participating portfolios that exceeds $225 billion. The amount of the reimbursement is calculated daily and allocated among all the participating portfolios in proportion to the daily net assets of each participating portfolio. During its most recent fiscal year, the fund’s reimbursement amounted to 0.01% of the fund’s average daily net assets. This agreement expires on July 31, 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.

[3] 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.

[4] Prior to February 7, 2025, the fund’s additional benchmark was the Bloomberg U.S. High Yield 2% Issuer Capped Index. Effective February 7, 2025, the fund’s additional benchmark is the ICE BofA U.S. High Yield Index. The ICE BofA U.S. High Yield Index better reflects the universe of investment opportunities based on the fund’s investment strategy.