rr_ProspectusTable

rr_ObjectiveHeading

Investment objective

rr_ObjectivePrimaryTextBlock

To seek long-term capital growth.

rr_ExpenseHeading

Fees and expenses

rr_ExpenseNarrativeTextBlock

This table describes the fees and expenses you may pay if you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.

rr_ShareholderFeesCaption

Shareholder fees (%) (fees paid directly from your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_OperatingExpensesCaption

Annual fund operating expenses (%) (expenses that you pay each year as a percentage of the value of your investment)

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

July 31, 2023

rr_ExpenseExampleHeading

Expense example

rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds. Please see below a hypothetical example showing the expenses of a $10,000 investment for the time periods indicated and then assuming you sell all of your shares at the end of those periods. The example assumes a 5% average annual return and that fund expenses will not change over the periods. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:

rr_PortfolioTurnoverHeading

Portfolio turnover

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 and may result in higher taxes when fund shares are held in a taxable account. 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 76% of the average value of its portfolio.

rr_PortfolioTurnoverRate

76.00%

rr_StrategyHeading

Principal investment strategies

rr_StrategyNarrativeTextBlock

The fund pursues its investment objective by investing, under normal circumstances, at least 80% of its net assets (plus any borrowings for investment purposes) in a portfolio of equity and equity-related securities issued by non-U.S. companies of any capitalization size. The fund may invest in all types of equity and equity-related securities, including, without limitation, exchange-traded and over-the-counter common and preferred stocks, warrants, options, rights, convertible securities, sponsored and unsponsored depositary receipts and shares, trust certificates, participatory notes, limited partnership interests, shares of other investment companies (including exchange-traded funds (ETFs)), real estate investment trusts (REITs), and equity participations. Equity participations are loans that give the lender a portion of equity ownership in a property, in addition to principal and interest payments. A convertible security is a bond, debenture, note, preferred stock, or other security that may be converted into or exchanged for a prescribed amount of common stock of the same or a different issuer within a particular period of time at a specified price or formula.

The fund defines non-U.S. companies as companies: (i) that are organized under the laws of a foreign country; (ii) whose principal trading market is in a foreign country; or (iii) that have a majority of their assets, or that derive a significant portion of their revenue or profits, from businesses, investments, or sales outside of the United States. The fund’s non-U.S. investments, which may be denominated in U.S. or foreign currencies, primarily focus on developed markets, but may include emerging- and frontier-market investments.

The fund generally invests in the equity securities of issuers the manager believes are undervalued. The manager applies a bottom-up stock selection process using a combination of fundamental and quantitative analysis of issuer-specific factors such as price-to-book value, price-to-sales and earnings ratios, dividend yields, strength of management, and cash flow.

The fund may invest in derivatives. Derivatives may be used to reduce risk, obtain efficient market exposure, and/or enhance investment returns, and may include put and call options, futures, forward contracts, and swaps. The fund may invest up to 15% of its net assets in illiquid securities and may participate as a purchaser in Initial Public Offerings (IPOs). The fund may also seek to increase its income by lending portfolio securities.

rr_RiskHeading

Principal risks

rr_RiskNarrativeTextBlock

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. Many factors affect performance, and fund shares will fluctuate in price, meaning you could lose money. The fund’s investment strategy may not produce the intended results.

During periods of heightened market volatility or reduced liquidity, governments, their agencies, or other regulatory bodies, both within the United States and abroad, may take steps to intervene. These actions, which could include legislative, regulatory, or economic initiatives, might have unforeseeable consequences and could adversely affect the fund’s performance or otherwise constrain the fund’s ability to achieve its investment objective.

The fund’s main risks are listed below in alphabetical order, not in order of importance. Before investing, be sure to read the additional descriptions of these risks beginning on page 66 of the prospectus.

Credit and counterparty risk. 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.

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. The price of equity securities may decline due to changes in a company’s financial condition or overall market conditions. 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.

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.

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. If applicable, depositary receipts are subject to most of the risks associated with investing in foreign securities directly because the value of a depositary receipt is dependent upon the market price of the underlying foreign equity security. Depositary receipts are also subject to liquidity risk.

Frontier-market risk. Frontier-market countries generally have smaller economies and less-developed capital markets and political systems than traditional emerging-market countries, which magnifies emerging-market risks.

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.

Initial public offerings (IPOs) risk. IPO share prices are frequently volatile and may significantly impact fund performance.

Investment company securities risk. The fund may invest in securities of other investment companies. Fund shareholders indirectly bear their proportionate share of the expenses of each such investment company. The total return on such investments will be reduced by the operating expenses and fees of such other investment companies, including advisory fees.

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.

Master limited partnership (MLP) risk. MLPs generally reflect the risks associated with their underlying assets and with pooled investment vehicles. MLPs with credit-related holdings are subject to interest-rate risk and risk of default.

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.

Participatory notes risk. Participatory notes (p-notes) represent interests in securities listed on certain foreign exchanges. Due to transaction costs and other expenses, p-notes will not replicate exactly the performance of their underlying securities. P-notes are general unsecured contractual obligations of the financial institutions issuing the notes and are subject to liquidity risk and a high degree of counterparty risk.

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.

Real estate investment trust (REIT) risk. REITs, pooled investment vehicles that typically invest in real estate directly or in loans collateralized by real estate, carry risks associated with owning real estate, including the potential for a decline in value due to economic or market conditions.

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.

Value investment style risk. Value securities may underperform the market as a whole, which may cause value-oriented funds to underperform equity funds with other investment strategies. Securities the manager believes are undervalued may never perform as expected.

Warrants risk. The prices of warrants may not precisely reflect the prices of their underlying securities. Warrant holders do not receive dividends or have voting or credit rights. A warrant ceases to have value if not exercised prior to its expiration date.

rr_RiskLoseMoney

Many factors affect performance, and fund shares will fluctuate in price, meaning you could lose money.

rr_RiskNotInsuredDepositoryInstitution

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.

rr_BarChartAndPerformanceTableHeading

Past performance

Performance Information Illustrates Variability of Returns [Text]

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 market index. Past performance (before and after taxes) does not indicate future results. All figures assume dividend reinvestment. Performance information is updated daily, monthly, and quarterly and may be obtained at our website, jhinvestments.com, or by calling 800-344-1029 between 8:00 A.M. and 7:00 P.M., Eastern time, on most business days.

A note on performance

The fund is the successor to Robeco Boston Partners International Equity Fund, a series of The RBB Fund, Inc. (the predecessor fund), which commenced operations on December 30, 2011. Class R6 and Class NAV shares commenced operations on September 29, 2014 and April 13, 2015, respectively. The returns prior to the commencement date of Class NAV shares are those of Class R6 shares. The returns prior to the commencement date of Class R6 shares is the actual performance of the sole share class of the predecessor fund and has not been adjusted to reflect the fees and expenses of Class R6 shares. As a result, the performance shown below may be higher than if adjusted to reflect the fees and expenses of Class R6 shares.

Please note that after-tax returns reflect the highest individual federal marginal income-tax rate in effect as of the date provided and do not reflect any state or local taxes. Your actual after-tax returns may be different. After-tax returns are not relevant to shares held in an IRA, 401(k), or other tax-advantaged investment plan.

rr_PerformanceInformationIllustratesVariabilityOfReturns

rr_PerformanceAvailabilityPhone

800-344-1029

rr_PerformanceAvailabilityWebSiteAddress

jhinvestments.com

rr_PerformancePastDoesNotIndicateFuture

Past performance (before and after taxes) does not indicate future results.

rr_BarChartHeading

Calendar year total returns (%)—Class NAV

rr_PerformanceTableUsesHighestFederalRate

Please note that after-tax returns reflect the highest individual federal marginal income-tax rate in effect as of the date provided and do not reflect any state or local taxes.

rr_PerformanceTableNotRelevantToTaxDeferred

Your actual after-tax returns may be different. After-tax returns are not relevant to shares held in an IRA, 401(k), or other tax-advantaged investment plan.

rr_BarChartClosingTextBlock

Best quarter: 2020, Q4, 19.47%
Worst quarter: 2020, Q1, -26.78%

(John Hancock Investment Trust - Class NAV) | (Disciplined Value International Fund) | MSCI EAFE Index (reflects no deduction for fees, expenses, or taxes)

rr_PerformanceTableHeading

Average annual total returns (%)—as of 12/31/21

rr_ProspectusTable

rr_AverageAnnualReturnYear01

11.26%

rr_AverageAnnualReturnYear05

9.55%

(John Hancock Investment Trust - Class NAV) | (Disciplined Value International Fund) | Class NAV

rr_AverageAnnualReturnYear10

8.03%

rr_ProspectusTable

rr_MaximumCumulativeSalesChargeOverOther

none

rr_MaximumDeferredSalesChargeOverOther

none

rr_ManagementFeesOverAssets

0.77%

rr_OtherExpensesOverAssets

0.07%

rr_ExpensesOverAssets

0.84%

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.01%)

^[1]

rr_NetExpensesOverAssets

0.83%

rr_ExpenseExampleYear01

$ 85

rr_ExpenseExampleYear03

267

rr_ExpenseExampleYear05

465

rr_ExpenseExampleYear10

$ 1,036

Annual Return 2012

rr_AnnualReturn2012

16.89%

Annual Return 2013

rr_AnnualReturn2013

29.84%

rr_AnnualReturn2014

(5.03%)

rr_AnnualReturn2015

1.86%

rr_AnnualReturn2016

(0.18%)

rr_AnnualReturn2017

25.37%

rr_AnnualReturn2018

(18.49%)

rr_AnnualReturn2019

15.47%

rr_AnnualReturn2020

4.95%

rr_AnnualReturn2021

13.04%

rr_HighestQuarterlyReturnLabel

Best quarter: 2020, Q4, 19.47%

rr_BarChartHighestQuarterlyReturn

19.47%

rr_BarChartHighestQuarterlyReturnDate

Dec. 31, 2020

rr_LowestQuarterlyReturnLabel

Worst quarter: 2020, Q1, -26.78%

rr_BarChartLowestQuarterlyReturn

(26.78%)

rr_BarChartLowestQuarterlyReturnDate

Mar. 31, 2020

rr_AverageAnnualReturnYear01

13.04%

rr_AverageAnnualReturnYear05

6.96%

(John Hancock Investment Trust - Class NAV) | (Disciplined Value International Fund) | Class NAV | after tax on distributions

rr_AverageAnnualReturnYear10

7.45%

rr_ProspectusTable

rr_AverageAnnualReturnYear01

11.44%

rr_AverageAnnualReturnYear05

5.83%

(John Hancock Investment Trust - Class NAV) | (Disciplined Value International Fund) | Class NAV | after tax on distributions, with sale

rr_AverageAnnualReturnYear10

6.23%

rr_ProspectusTable

rr_AverageAnnualReturnYear01

7.69%

rr_AverageAnnualReturnYear05

4.99%

(John Hancock Investment Trust - Class NAV) | (Diversified Macro Fund)

rr_AverageAnnualReturnYear10

5.58%

rr_ProspectusTable

rr_ObjectiveHeading

Investment objective

rr_ObjectivePrimaryTextBlock

To seek long-term capital appreciation.

rr_ExpenseHeading

Fees and expenses

rr_ExpenseNarrativeTextBlock

rr_ShareholderFeesCaption

Shareholder fees (%) (fees paid directly from your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_OperatingExpensesCaption

Annual fund operating expenses (%) (expenses that you pay each year as a percentage of the value of your investment)

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

July 31, 2023

rr_ExpenseExampleHeading

Expense example

rr_ExpenseExampleNarrativeTextBlock

rr_PortfolioTurnoverHeading

Portfolio turnover

rr_PortfolioTurnoverTextBlock

rr_PortfolioTurnoverRate

none

rr_StrategyHeading

Principal investment strategies

rr_StrategyNarrativeTextBlock

The fund pursues its investment objective by utilizing a multi-asset, quantitatively-driven investment strategy that seeks to provide exposure to diversified sources of return. The fund’s investment strategy is a directional, long and short strategy that utilizes fundamental and price-based indicators to establish return forecasts across a broad range of asset classes globally. The investment strategy incorporates a variety of models that generate macro fundamental forecasts, assess yield and earnings differentials, compare current valuations relative to historic fair value, and analyze directional price trends across markets.

The manager will allocate the fund’s assets across a range of asset classes comprising equities, fixed income, foreign currencies, and commodities. Exposure to these asset classes will be implemented by investing in derivative instruments, including futures (including equity index futures, interest rate futures, bond futures and commodity futures) and foreign currency forward contracts.

Quantitative risk management and portfolio construction techniques will be employed to control exposure across individual markets and sectors in an effort to enhance returns as well as to maintain the fund’s diversification and volatility objectives. The fund is actively managed and the fund’s asset class exposures will vary over time based on the manager’s proprietary investment models and, in part, on maintaining portfolio diversification. The fund expects to maintain exposure to all models at all times. The fund, on average, will target an annualized volatility of approximately 8%. Volatility is a statistical measurement of the dispersion of returns of a security or fund or index. The fund’s actual or realized volatility level for longer or shorter periods of time may be materially higher or lower depending on market conditions.

The fund is generally intended to have a low correlation to the equity and bond markets. The fund is not designed to match the performance of any hedge fund index or benchmark and may be characterized as “macro” or “multi-asset” in nature.

The fund’s use of derivatives will have the economic effect of financial leverage. Financial leverage magnifies exposure to the swings in prices of an asset class underlying an instrument and results in increased volatility, which means the fund will have the potential for greater gains as well as the potential for greater losses than if the fund does not use instruments that have a leveraging effect.

Due to the fund’s use of derivative instruments such as futures, foreign currency futures and forward contracts, a significant portion of the fund’s assets will be invested directly or indirectly in money market instruments, which may include U.S. Government securities, U.S. Government agency securities, overnight and/or fixed-term repurchase agreements, money market mutual fund shares and cash and cash equivalents for use as margin or collateral for these derivative instruments. Such investments may generate income for the fund.

Investment in the Subsidiary. The fund may gain exposure to the commodities markets by investing up to 25% of its total assets in a wholly-owned subsidiary of the fund organized as a company under the laws of the Cayman Islands: John Hancock Diversified Macro Offshore Subsidiary Fund, Ltd. (the Subsidiary). The Subsidiary is advised by the subadvisor, under the supervision of the advisor, and seeks to gain commodities exposure.

The Subsidiary primarily obtains its commodity exposure by investing in commodity-linked derivative instruments, which may include but are not limited to total return swaps, commodity (U.S. or foreign) futures and commodity-linked notes. Neither the fund nor the Subsidiary intends to invest directly in physical commodities. The Subsidiary may also invest in other instruments, including fixed-income securities, either as investments or to serve as margin or collateral for its swap positions, and foreign currency transactions (including forward contracts).

rr_RiskHeading

Principal risks

rr_RiskNarrativeTextBlock

Asset allocation risk. Although allocation among asset categories generally limits exposure to any one category, the management team may favor a category that performs poorly relative to the others.

Cash and cash equivalents risk. Under certain market conditions, such as during a rising stock market, rising interest rate or rising credit spread markets, the use of cash and/or cash equivalents, including money market instruments, could have a negative effect on the fund’s ability to achieve its investment objective and may negatively impact the fund’s performance.

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. 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.

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.

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. If applicable, depositary receipts are subject to most of the risks associated with investing in foreign securities directly because the value of a depositary receipt is dependent upon the market price of the underlying foreign equity security. Depositary receipts are also subject to liquidity risk.

High portfolio turnover risk. Trading securities actively and frequently can increase transaction costs (thus lowering performance) and taxable distributions.

Leveraging risk. Using derivatives may result in a leveraged portfolio. Leveraging tends to magnify, sometimes significantly, the effect of any increase or decrease in the fund’s exposure to an asset class and may cause the fund’s net asset value per share (NAV) to experience greater volatility. Leveraging long exposures increases a fund’s losses when the value of its investments declines. Some derivatives have the potential for unlimited loss, regardless of the size of the initial investment.

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.

Quantitative modeling risk. Quantitative models may not accurately predict future market movements or characteristics, which may negatively impact performance. Models also may perform differently than expected due to implementation problems, technological malfunction, or programming or data inaccuracies, among other possible issues.

Repurchase agreements risk. The risk of a repurchase agreement transaction is limited to the ability of the seller to pay the agreed-upon sum on the delivery date. In the event of bankruptcy or other default by the seller, the instrument purchased may decline in value, interest payable on the instrument may be lost and there may be possible difficulties and delays in obtaining collateral and delays and expense in liquidating the instrument.

Short sales risk. In a short sale, a fund pays interest on a borrowed security. The fund will lose money if the price of the borrowed security increases between the short sale and the replacement date.

Subsidiary investment risk. By investing in the Subsidiary, the fund is indirectly exposed to the risks associated with the Subsidiary’s investments and operations. The Subsidiary is not subject to U.S. laws, including securities laws and their protections. Because the Subsidiary is not registered under U.S. law, it may not be able to negotiate terms with its counterparties equivalent to those negotiated by a registered fund. Changes in applicable law could result in the inability of the Subsidiary to operate as described, and could adversely affect the fund’s investment approach.

Tax risk. The tax treatment of commodity-related investments and income from the Subsidiary may be adversely affected by future U.S. tax legislation, regulation, or guidance.

rr_RiskLoseMoney

Many factors affect performance, and fund shares will fluctuate in price, meaning you could lose money.

rr_RiskNotInsuredDepositoryInstitution

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.

rr_BarChartAndPerformanceTableHeading

Past performance

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceNarrativeTextBlock

rr_PerformanceInformationIllustratesVariabilityOfReturns

rr_PerformanceAvailabilityPhone

800-344-1029

rr_PerformanceAvailabilityWebSiteAddress

jhinvestments.com

rr_PerformancePastDoesNotIndicateFuture

Past performance (before and after taxes) does not indicate future results.

rr_BarChartHeading

Calendar year total returns (%)—Class NAV

rr_PerformanceTableUsesHighestFederalRate

Please note that after-tax returns reflect the highest individual federal marginal income-tax rate in effect as of the date provided and do not reflect any state or local taxes.

rr_PerformanceTableNotRelevantToTaxDeferred

Your actual after-tax returns may be different. After-tax returns are not relevant to shares held in an IRA, 401(k), or other tax-advantaged investment plan.

rr_BarChartClosingTextBlock

Best quarter: 2020, Q4, 3.35%
Worst quarter: 2020, Q1, -8.98%

(John Hancock Investment Trust - Class NAV) | (Diversified Macro Fund) | ICE BofA 0-3 Month U.S. Treasury Bill Index

rr_PerformanceTableHeading

Average annual total returns (%)—as of 12/31/21

rr_ProspectusTable

rr_AverageAnnualReturnYear01

0.05%

(John Hancock Investment Trust - Class NAV) | (Diversified Macro Fund) | Class NAV

rr_AverageAnnualReturnSinceInception

0.58%

rr_ProspectusTable

rr_MaximumCumulativeSalesChargeOverOther

none

rr_MaximumDeferredSalesChargeOverOther

none

rr_ManagementFeesOverAssets

1.20%

rr_OtherExpensesOverAssets

0.10%

rr_ExpensesOverAssets

1.30%

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.01%)

^[2]

rr_NetExpensesOverAssets

1.29%

rr_ExpenseExampleYear01

$ 131

rr_ExpenseExampleYear03

411

rr_ExpenseExampleYear05

712

rr_ExpenseExampleYear10

$ 1,567

rr_AnnualReturn2020

(2.24%)

rr_AnnualReturn2021

(2.08%)

rr_HighestQuarterlyReturnLabel

Best quarter: 2020, Q4, 3.35%

rr_BarChartHighestQuarterlyReturn

3.35%

rr_BarChartHighestQuarterlyReturnDate

Dec. 31, 2020

rr_LowestQuarterlyReturnLabel

Worst quarter: 2020, Q1, -8.98%

rr_BarChartLowestQuarterlyReturn

(8.98%)

rr_BarChartLowestQuarterlyReturnDate

Mar. 31, 2020

rr_AverageAnnualReturnYear01

(2.08%)

(John Hancock Investment Trust - Class NAV) | (Diversified Macro Fund) | Class NAV | after tax on distributions

rr_AverageAnnualReturnSinceInception

(1.11%)

rr_ProspectusTable

rr_AverageAnnualReturnYear01

(3.45%)

(John Hancock Investment Trust - Class NAV) | (Diversified Macro Fund) | Class NAV | after tax on distributions, with sale

rr_AverageAnnualReturnSinceInception

(2.49%)

rr_ProspectusTable

rr_AverageAnnualReturnYear01

(1.23%)

(John Hancock Investment Trust - Class NAV) | (Emerging Markets Equity Fund)

rr_AverageAnnualReturnSinceInception

(1.30%)

rr_ProspectusTable

rr_ObjectiveHeading

Investment objective

rr_ObjectivePrimaryTextBlock

To seek long-term capital growth.

rr_ExpenseHeading

Fees and expenses

rr_ExpenseNarrativeTextBlock

rr_ShareholderFeesCaption

Shareholder fees (%) (fees paid directly from your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_OperatingExpensesCaption

Annual fund operating expenses (%) (expenses that you pay each year as a percentage of the value of your investment)

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

July 31, 2023

rr_ExpenseExampleHeading

Expense example

rr_ExpenseExampleNarrativeTextBlock

rr_PortfolioTurnoverHeading

Portfolio turnover

rr_PortfolioTurnoverTextBlock

rr_PortfolioTurnoverRate

46.00%

rr_StrategyHeading

Principal investment strategies

rr_StrategyNarrativeTextBlock

Under normal market conditions, the fund invests at least 80% of its net assets (plus any borrowings for investment purposes) in equity and equity-related securities of emerging-market issuers. The manager may consider, but is not limited to, the classifications by the World Bank, the International Finance Corporation, or the United Nations and its agencies in determining whether a country is an emerging- or a developed-market country. The fund seeks to invest in securities that the manager considers to be undervalued or otherwise offer good prospects for capital growth.

The fund intends to invest in equity securities listed on bona fide securities exchanges or actively traded on over-the-counter markets. Equity and equity-related securities include common stocks, preferred stocks, convertible securities, warrants, and other similar securities. The fund may also

invest in other investment companies (including closed-end funds) and other pooled investment vehicles that also invest in developing or emerging market economies.

Fundamentals-based stock selection lies at the heart of the manager’s investment process, which focuses on high quality companies within a diverse range of dynamic emerging economies. The manager seeks to invest in companies with strong assets that exhibit balance sheet strength, superior management, and high levels of free cash-flow to support a sustainable dividend payout. Although, there is no sector or geographical bias, the fund may focus its investments in a particular sector or sectors of the economy. The fund may invest in companies of any market capitalization.

The manager considers environmental, social, and/or governance (ESG) factors, alongside other relevant factors, as part of its investment process. 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.

Due to volatile conditions in emerging markets, the fund’s investment process may result in a higher-than-average portfolio turnover ratio, which could increase transaction costs.

The fund may attempt to mitigate the risk of unintended currency fluctuations through the use of exchange-listed or over-the-counter financial derivatives instruments, including currency forwards, non-deliverable forwards, currency options, and index options. The fund may also enter into forward currency contracts to facilitate the settlement of foreign securities purchases, repatriation of foreign currency balances, or exchange of one currency to another. The fund may use derivatives such as futures contracts and options on futures contracts to gain market exposure on uninvested cash, pending investment in securities, or to maintain liquidity to pay redemptions.

rr_RiskHeading

Principal risks

rr_RiskNarrativeTextBlock

Credit and counterparty risk. 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.

Emerging-market risk. The risks of investing in foreign securities are magnified in emerging markets. Emerging-market countries may experience higher inflation, interest rates, and unemployment and greater social, economic, and political uncertainties than more developed countries.

Greater China risk. Investments in the Greater China region may be subject to less developed trading markets, acute political risks such as possible negative repercussions resulting from China’s relationship with Taiwan or Hong Kong, and restrictions on monetary repatriation or other adverse government actions. For example, a government may restrict investment in companies or industries considered important to national interests, or intervene in the financial markets, such as by imposing trading restrictions, or banning or curtailing short selling. A small number of companies and industries may generally represent a relatively large portion of the Greater China market as a whole.

Hong Kong Stock Connect Program (Stock Connect) risk. Trading in China A-Shares through Stock Connect, a mutual market access program that enables foreign investment in the People’s Republic of China (PRC), is subject to certain restrictions and risks. Securities listed on Stock Connect may lose purchase eligibility, which could adversely affect the fund’s performance. Trading through Stock Connect is subject to trading, clearance, and settlement procedures that may continue to develop as the program matures. Any changes in laws, regulations and policies applicable to Stock Connect may affect China A-Share prices. These risks are heightened by the underdeveloped state of the PRC’s investment and banking systems in general.

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. The manager considers ESG factors that it deems relevant or additive, along with other material factors and analysis, when managing the fund. 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 utilize different ESG criteria, or an ESG investment strategy.

Financial services sector risk. Financial services companies can be significantly affected by economic, market, and business developments, borrowing costs, interest-rate fluctuations, competition, and government regulation, among other factors.

High portfolio turnover risk. Trading securities actively and frequently can increase transaction costs (thus lowering performance) and taxable distributions.

Information technology companies risk. Information technology companies can be significantly affected by rapid obsolescence, short product cycles, competition from new market entrants, and heightened cybersecurity risk, among other factors.

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. To the extent that a fund invests in securities of companies in the financial services sector, the fund may be significantly affected by economic, market, and business developments, borrowing costs, interest-rate fluctuations, competition, and government regulation, among other factors, impacting that sector.

rr_RiskLoseMoney

Many factors affect performance, and fund shares will fluctuate in price, meaning you could lose money.

rr_RiskNotInsuredDepositoryInstitution

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.

rr_BarChartAndPerformanceTableHeading

Past performance

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceNarrativeTextBlock

rr_PerformanceInformationIllustratesVariabilityOfReturns

rr_PerformanceAvailabilityPhone

800-344-1029

rr_PerformanceAvailabilityWebSiteAddress

jhinvestments.com

rr_PerformancePastDoesNotIndicateFuture

Past performance (before and after taxes) does not indicate future results.

rr_BarChartHeading

Calendar year total returns (%)—Class NAV

rr_PerformanceTableUsesHighestFederalRate

Please note that after-tax returns reflect the highest individual federal marginal income-tax rate in effect as of the date provided and do not reflect any state or local taxes.

rr_PerformanceTableNotRelevantToTaxDeferred

Your actual after-tax returns may be different. After-tax returns are not relevant to shares held in an IRA, 401(k), or other tax-advantaged investment plan.

rr_BarChartClosingTextBlock

Best quarter: 2020, Q2, 28.40%
Worst quarter: 2020, Q1, -22.79%

(John Hancock Investment Trust - Class NAV) | (Emerging Markets Equity Fund) | MSCI Emerging Markets Index (reflects no deduction for fees, expenses, or taxes)

rr_PerformanceTableHeading

Average annual total returns (%)—as of 12/31/21

rr_ProspectusTable

rr_AverageAnnualReturnYear01

(2.54%)

rr_AverageAnnualReturnYear05

9.87%

(John Hancock Investment Trust - Class NAV) | (Emerging Markets Equity Fund) | Class NAV

rr_AverageAnnualReturnSinceInception

6.18%

rr_ProspectusTable

rr_MaximumCumulativeSalesChargeOverOther

none

rr_MaximumDeferredSalesChargeOverOther

none

rr_ManagementFeesOverAssets

0.90%

rr_OtherExpensesOverAssets

0.08%

rr_ExpensesOverAssets

0.98%

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.16%)

^[3]

rr_NetExpensesOverAssets

0.82%

rr_ExpenseExampleYear01

$ 84

rr_ExpenseExampleYear03

296

rr_ExpenseExampleYear05

526

rr_ExpenseExampleYear10

$ 1,187

rr_AnnualReturn2016

2.72%

rr_AnnualReturn2017

42.25%

rr_AnnualReturn2018

(16.87%)

rr_AnnualReturn2019

26.55%

rr_AnnualReturn2020

33.02%

rr_AnnualReturn2021

(7.35%)

rr_HighestQuarterlyReturnLabel

Best quarter: 2020, Q2, 28.40%

rr_BarChartHighestQuarterlyReturn

28.40%

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2020

rr_LowestQuarterlyReturnLabel

Worst quarter: 2020, Q1, -22.79%

rr_BarChartLowestQuarterlyReturn

(22.79%)

rr_BarChartLowestQuarterlyReturnDate

Mar. 31, 2020

rr_AverageAnnualReturnYear01

(7.35%)

rr_AverageAnnualReturnYear05

13.02%

(John Hancock Investment Trust - Class NAV) | (Emerging Markets Equity Fund) | Class NAV | after tax on distributions

rr_AverageAnnualReturnSinceInception

7.57%

rr_ProspectusTable

rr_AverageAnnualReturnYear01

(9.83%)

rr_AverageAnnualReturnYear05

11.39%

(John Hancock Investment Trust - Class NAV) | (Emerging Markets Equity Fund) | Class NAV | after tax on distributions, with sale

rr_AverageAnnualReturnSinceInception

6.33%

rr_ProspectusTable

rr_AverageAnnualReturnYear01

(2.93%)

rr_AverageAnnualReturnYear05

10.04%

(John Hancock Investment Trust - Class NAV) | (ESG International Equity Fund)

rr_AverageAnnualReturnSinceInception

5.70%

rr_ProspectusTable

rr_ObjectiveHeading

Investment objective

rr_ObjectivePrimaryTextBlock

To seek long-term capital appreciation.

rr_ExpenseHeading

Fees and expenses

rr_ExpenseNarrativeTextBlock

rr_ShareholderFeesCaption

Shareholder fees (%) (fees paid directly from your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_OperatingExpensesCaption

Annual fund operating expenses (%) (expenses that you pay each year as a percentage of the value of your investment)

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

July 31, 2023

rr_ExpenseExampleHeading

Expense example

rr_ExpenseExampleNarrativeTextBlock

rr_PortfolioTurnoverHeading

Portfolio turnover

rr_PortfolioTurnoverTextBlock

rr_PortfolioTurnoverRate

28.00%

rr_StrategyHeading

Principal investment strategies

rr_StrategyNarrativeTextBlock

Under normal market conditions, the fund invests at least 80% of its net assets (plus any borrowings for investment purposes) in stocks of foreign companies having a market capitalization of $2 billion or more at the time of purchase that meet the manager’s sustainability criteria. The manager seeks companies meeting its sustainability criteria with high-quality characteristics, including strong or improving environmental, social, and governance (ESG) records.

The fund primarily invests in a diversified portfolio of equity securities of foreign companies in a number of developed and emerging markets outside of the United States. The fund defines foreign companies as companies: (i) that are organized under the laws of a country outside the United States; or (ii) that have a minimum of 50% of their assets, or that derive a minimum of 50% of their revenue or profits, from businesses, investments, or sales outside of the United States.

The manager seeks to preserve and build capital over the long term through investing in a diversified portfolio of international-developed and emerging-market stocks of companies it believes are high quality and under-valued. The manager looks for companies with sound governance and a history of responsible financial management that, in its opinion, are capable of consistent profitability over a long time horizon. The manager seeks to fully integrate ESG criteria into the stock selection and portfolio construction process and expresses a preference for best-in-class firms with innovative approaches to the environmental and social challenges their industries, society, and the world face. “Best-in-class” refers to firms that the manager views as having better records on ESG criteria than other firms in the same industry or sector.

The manager seeks to identify companies with a demonstrated overall high level of accountability to all stakeholders, including providing safe, desirable, high-quality products or services and marketing them in responsible ways. ESG criteria reflect a variety of key sustainability issues that can influence company risks and opportunities and span a range of metrics including board diversity, climate change policies, water management policies, and supply chain and human rights policies. The fund may focus its investments in a particular sector or sectors of the economy. The fund will avoid investments that in the judgment of the manager have material direct revenues from production of nuclear power, tobacco, and/or weapons/firearms.

The manager selects stocks through bottom-up, fundamental research, while maintaining a disciplined approach to valuation and risk control. The manager may sell a security when its price reaches a set target, if it believes that other investments are more attractive, when in its opinion ESG performance significantly deteriorates, or for other reasons it may determine.

The manager employs active shareowner engagement to raise environmental, social, and governance issues with the management of select portfolio companies. Through this effort, the manager seeks to encourage company managements toward greater transparency, accountability, disclosure, and commitment to ESG issues.

rr_RiskHeading

Principal risks

rr_RiskNarrativeTextBlock

ESG investing risk. Incorporating ESG criteria and investing primarily in instruments that have certain ESG characteristics, as determined by the manager, carries the risk that the fund may perform differently, including underperforming, funds that do not utilize an ESG investment strategy, or funds that utilize different ESG criteria.

Liquidity risk. The extent (if at all) to which a security may be sold without negatively impacting its market value may be impaired by reduced market activity or participation, legal restrictions, or other economic and market impediments.

rr_RiskLoseMoney

Many factors affect performance, and fund shares will fluctuate in price, meaning you could lose money.

rr_RiskNotInsuredDepositoryInstitution

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.

rr_BarChartAndPerformanceTableHeading

Past performance

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceNarrativeTextBlock

A note on performance

Class A shares commenced operations on December 14, 2016. Because Class NAV shares of the fund had not commenced operations as of the date of this prospectus, the returns shown are those of Class A shares, except that they do not include sales charges and would be lower if they did. Returns for Class NAV shares would have been substantially similar to returns of Class A shares because each share class is invested in the same portfolio of securities and returns would differ only to the extent that expenses of the classes are different. To the extent expenses of a class would have been higher than expenses of Class A shares for the periods shown, performance would have been lower.

rr_PerformanceInformationIllustratesVariabilityOfReturns

rr_PerformanceAvailabilityPhone

800-344-1029

rr_PerformanceAvailabilityWebSiteAddress

jhinvestments.com

rr_PerformancePastDoesNotIndicateFuture

Past performance (before and after taxes) does not indicate future results.

rr_BarChartHeading

Calendar year total returns (%)—Class NAV

rr_PerformanceTableUsesHighestFederalRate

Please note that after-tax returns reflect the highest individual federal marginal income-tax rate in effect as of the date provided and do not reflect any state or local taxes.

rr_PerformanceTableNotRelevantToTaxDeferred

Your actual after-tax returns may be different. After-tax returns are not relevant to shares held in an IRA, 401(k), or other tax-advantaged investment plan.

rr_BarChartClosingTextBlock

Best quarter: 2020, Q2, 20.11%
Worst quarter: 2020, Q1, -20.81%

(John Hancock Investment Trust - Class NAV) | (ESG International Equity Fund) | MSCI ACWI ex USA Index (reflects no deduction for fees, expenses, or taxes)

rr_PerformanceTableHeading

Average annual total returns (%)—as of 12/31/21

rr_ProspectusTable

rr_AverageAnnualReturnYear01

7.82%

rr_AverageAnnualReturnYear05

9.61%

(John Hancock Investment Trust - Class NAV) | (ESG International Equity Fund) | Class NAV

rr_AverageAnnualReturnSinceInception

9.28%

rr_ProspectusTable

rr_MaximumCumulativeSalesChargeOverOther

none

rr_MaximumDeferredSalesChargeOverOther

none

rr_ManagementFeesOverAssets

0.85%

rr_OtherExpensesOverAssets

0.26%

rr_ExpensesOverAssets

1.11%

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.26%)

^[4]

rr_NetExpensesOverAssets

0.85%

rr_ExpenseExampleYear01

$ 87

rr_ExpenseExampleYear03

327

rr_ExpenseExampleYear05

586

rr_ExpenseExampleYear10

$ 1,328

rr_AnnualReturn2017

30.34%

rr_AnnualReturn2018

(13.08%)

rr_AnnualReturn2019

23.30%

rr_AnnualReturn2020

24.88%

rr_AnnualReturn2021

(1.40%)

rr_HighestQuarterlyReturnLabel

Best quarter: 2020, Q2, 20.11%

rr_BarChartHighestQuarterlyReturn

20.11%

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2020

rr_LowestQuarterlyReturnLabel

Worst quarter: 2020, Q1, -20.81%

rr_BarChartLowestQuarterlyReturn

(20.81%)

rr_BarChartLowestQuarterlyReturnDate

Mar. 31, 2020

rr_AverageAnnualReturnYear01

(1.40%)

rr_AverageAnnualReturnYear05

11.46%

(John Hancock Investment Trust - Class NAV) | (ESG International Equity Fund) | Class NAV | after tax on distributions

rr_AverageAnnualReturnSinceInception

11.40%

rr_ProspectusTable

rr_AverageAnnualReturnYear01

(2.55%)

rr_AverageAnnualReturnYear05

11.00%

(John Hancock Investment Trust - Class NAV) | (ESG International Equity Fund) | Class NAV | after tax on distributions, with sale

rr_AverageAnnualReturnSinceInception

10.96%

rr_ProspectusTable

rr_AverageAnnualReturnYear01

(0.04%)

rr_AverageAnnualReturnYear05

9.18%

(John Hancock Investment Trust - Class NAV) | (ESG Large Cap Core Fund)

rr_AverageAnnualReturnSinceInception

9.14%

rr_ProspectusTable

rr_ObjectiveHeading

Investment objective

rr_ObjectivePrimaryTextBlock

To seek long-term capital appreciation.

rr_ExpenseHeading

Fees and expenses

rr_ExpenseNarrativeTextBlock

rr_ShareholderFeesCaption

Shareholder fees (%) (fees paid directly from your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_OperatingExpensesCaption

Annual fund operating expenses (%) (expenses that you pay each year as a percentage of the value of your investment)

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

July 31, 2023

rr_ExpenseExampleHeading

Expense example

rr_ExpenseExampleNarrativeTextBlock

rr_PortfolioTurnoverHeading

Portfolio turnover

rr_PortfolioTurnoverTextBlock

rr_PortfolioTurnoverRate

14.00%

rr_StrategyHeading

Principal investment strategies

rr_StrategyNarrativeTextBlock

Under normal market conditions, the fund invests at least 80% of its net assets (plus any borrowings for investment purposes) in equity securities of large-capitalization companies or sectors that meet the manager’s sustainability criteria. The fund considers large-capitalization companies to be those companies in the capitalization range of the S&P 500 Index, which was approximately $3.98 billion to $2,913 billion as of December 31, 2021.

Equity securities include common and preferred stocks and their equivalents. The manager seeks companies meeting its sustainability criteria with high quality characteristics including strong environmental, social, and governance (ESG) records.

The manager employs a bottom-up financial analysis that includes a review of ESG issues and how they may impact stock valuation or performance. ESG factors reflect a variety of key sustainability issues that can influence company risks and opportunities and span a range of metrics including board diversity, climate change policies, and supply chain and human rights policies. Companies that meet the manager’s ESG requirements or sustainability criteria typically have strong sustainability data and policy reporting, for example publishing a comprehensive corporate sustainability report. The fund may also invest up to 20% of its total assets in the equity securities of foreign issuers, including American Depositary Receipts (ADRs) and Global Depositary Receipts (GDRs). The fund may focus its investments in a particular sector or sectors of the economy. The manager may sell stocks for several reasons, including when the stock no longer meets the manager’s ESG or sustainability criteria, or when the stock declines in value and no longer reflects the manager’s investment thesis. The fund will not invest in any companies with material exposure to agricultural biotechnology, coal mining, hard rock mining, tobacco, or weapons/firearms. The fund also will not invest in any companies with major recent or ongoing controversies involving animal welfare, environmental, governance, human rights, product safety, or workplace matters. The fund will also not invest in energy or power companies with fossil fuel production or generation capacity that have not demonstrated a commitment to aligning their business model with a low-carbon economy, such as companies making investments in new fossil fuel production or refining; fossil fuel power generation capacity; or nuclear power generation.

The manager employs active shareowner engagement to raise environmental, social, and governance issues with the management of select portfolio companies, and may file shareholder proposals on behalf of the fund. Through this effort, the manager seeks to encourage company managements toward greater transparency, accountability, disclosure, and commitment to ESG issues.

rr_RiskHeading

Principal risks

rr_RiskNarrativeTextBlock

Equity securities risk. The price of equity securities may decline due to changes in a company’s financial condition or overall market conditions.

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. If applicable, depositary receipts are subject to most of the risks associated with investing in foreign securities directly because the value of a depositary receipt is dependent upon the market price of the underlying foreign equity security. Depositary receipts are also subject to liquidity risk.

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.

rr_RiskLoseMoney

Many factors affect performance, and fund shares will fluctuate in price, meaning you could lose money.

rr_RiskNotInsuredDepositoryInstitution

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.

rr_BarChartAndPerformanceTableHeading

Past performance

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceNarrativeTextBlock

A note on performance

Class C shares commenced operations on June 6, 2016. Because Class NAV shares of the fund had not commenced operations as of the date of this prospectus, the returns shown are those of Class C shares, except that they do not include sales charges and would be lower if they did. Returns for Class NAV shares would have been substantially similar to returns of Class C shares because each share class is invested in the same portfolio of securities and returns would differ only to the extent that expenses of the classes are different. To the extent expenses of a class would have been higher than expenses of Class C shares for the periods shown, performance would have been lower.

rr_PerformanceInformationIllustratesVariabilityOfReturns

rr_PerformanceAvailabilityPhone

800-344-1029

rr_PerformanceAvailabilityWebSiteAddress

jhinvestments.com

rr_PerformancePastDoesNotIndicateFuture

Past performance (before and after taxes) does not indicate future results.

rr_BarChartHeading

Calendar year total returns (%)—Class NAV

rr_PerformanceTableUsesHighestFederalRate

Please note that after-tax returns reflect the highest individual federal marginal income-tax rate in effect as of the date provided and do not reflect any state or local taxes.

rr_PerformanceTableNotRelevantToTaxDeferred

Your actual after-tax returns may be different. After-tax returns are not relevant to shares held in an IRA, 401(k), or other tax-advantaged investment plan.

rr_BarChartClosingTextBlock

Best quarter: 2020, Q2, 21.98%
Worst quarter: 2020, Q1, -21.13%

(John Hancock Investment Trust - Class NAV) | (ESG Large Cap Core Fund) | S&P 500 Index (reflects no deduction for fees, expenses, or taxes)

rr_PerformanceTableHeading

Average annual total returns (%)—as of 12/31/21

rr_ProspectusTable

rr_AverageAnnualReturnYear01

28.71%

rr_AverageAnnualReturnYear05

18.47%

(John Hancock Investment Trust - Class NAV) | (ESG Large Cap Core Fund) | Class NAV

rr_AverageAnnualReturnSinceInception

18.04%

rr_ProspectusTable

rr_MaximumCumulativeSalesChargeOverOther

none

rr_MaximumDeferredSalesChargeOverOther

none

rr_ManagementFeesOverAssets

0.75%

rr_OtherExpensesOverAssets

0.18%

rr_ExpensesOverAssets

0.93%

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.18%)

^[5]

rr_NetExpensesOverAssets

0.75%

rr_ExpenseExampleYear01

$ 77

rr_ExpenseExampleYear03

278

rr_ExpenseExampleYear05

497

rr_ExpenseExampleYear10

$ 1,127

rr_AnnualReturn2017

15.39%

rr_AnnualReturn2018

(0.97%)

rr_AnnualReturn2019

29.38%

rr_AnnualReturn2020

17.32%

rr_AnnualReturn2021

28.79%

rr_HighestQuarterlyReturnLabel

Best quarter: 2020, Q2, 21.98%

rr_BarChartHighestQuarterlyReturn

21.98%

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2020

rr_LowestQuarterlyReturnLabel

Worst quarter: 2020, Q1, -21.13%

rr_BarChartLowestQuarterlyReturn

(21.13%)

rr_BarChartLowestQuarterlyReturnDate

Mar. 31, 2020

rr_AverageAnnualReturnYear01

28.79%

rr_AverageAnnualReturnYear05

17.44%

(John Hancock Investment Trust - Class NAV) | (ESG Large Cap Core Fund) | Class NAV | after tax on distributions

rr_AverageAnnualReturnSinceInception

16.58%

rr_ProspectusTable

rr_AverageAnnualReturnYear01

27.87%

rr_AverageAnnualReturnYear05

16.98%

(John Hancock Investment Trust - Class NAV) | (ESG Large Cap Core Fund) | Class NAV | after tax on distributions, with sale

rr_AverageAnnualReturnSinceInception

16.15%

rr_ProspectusTable

rr_AverageAnnualReturnYear01

17.67%

rr_AverageAnnualReturnYear05

14.08%

(John Hancock Investment Trust - Class NAV) | (Fundamental Large Cap Core Fund)

rr_AverageAnnualReturnSinceInception

13.45%

rr_ProspectusTable

rr_ObjectiveHeading

Investment objective

rr_ObjectivePrimaryTextBlock

To seek long-term capital appreciation.

rr_ExpenseHeading

Fees and expenses

rr_ExpenseNarrativeTextBlock

rr_ShareholderFeesCaption

Shareholder fees (%) (fees paid directly from your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_OperatingExpensesCaption

Annual fund operating expenses (%) (expenses that you pay each year as a percentage of the value of your investment)

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

July 31, 2023

rr_ExpenseExampleHeading

Expense example

rr_ExpenseExampleNarrativeTextBlock

rr_PortfolioTurnoverHeading

Portfolio turnover

rr_PortfolioTurnoverTextBlock

rr_PortfolioTurnoverRate

16.00%

rr_StrategyHeading

Principal investment strategies

rr_StrategyNarrativeTextBlock

Under normal market conditions, the fund invests at least 80% of its net assets (plus any borrowings for investment purposes) in equity securities of large-capitalization companies. The fund considers large-capitalization companies to be those in the capitalization range of the S&P 500 Index, which was approximately $3.98 billion to $2,913 billion as of December 31, 2021. Equity securities include common and preferred stocks and their equivalents.

The manager looks to invest in companies that are undervalued and/or offer the potential for above-average earnings growth, using a combination of proprietary financial models and bottom-up, fundamental financial research to identify companies with substantial cash flows, reliable revenue streams, superior competitive positions, and strong management.

The fund manages risk by typically holding between 45 and 65 large companies in a broad range of industries. The fund may focus its investments in a particular sector or sectors of the economy. The fund may attempt to take advantage of short-term market volatility by investing in corporate restructurings or pending acquisitions. The fund may invest up to 35% of its assets in foreign securities and may trade securities actively.

The fund may invest up to 20% of its assets in bonds of any maturity, including up to 15% of net assets in below-investment-grade bonds (i.e., junk bonds) rated as low as CC by S&P Global Ratings or Ca by Moody’s Investors Service, Inc. and their unrated equivalents. The manager looks for bonds with the most favorable risk/return ratios. The fund’s investment policies are based on credit ratings at the time of purchase.

The fund may invest in derivatives to a limited extent. Derivatives may be used to reduce risk and/or obtain efficient market exposure, and may include futures contracts, options, and foreign currency forward contracts.

rr_RiskHeading

Principal risks

rr_RiskNarrativeTextBlock

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. A downgrade or default affecting any of the fund’s securities could affect the fund’s performance.

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. If applicable, depositary receipts are subject to most of the risks associated with investing in foreign securities directly because the value of a depositary receipt is dependent upon the market price of the underlying foreign equity security. Depositary receipts are also subject to liquidity risk.

currency forward contracts, futures contracts, and options generally are subject to counterparty risk. Derivatives associated with foreign currency transactions are subject to currency risk.

High portfolio turnover risk. Trading securities actively and frequently can increase transaction costs (thus lowering performance) and taxable distributions.

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.

Merger and restructuring investment risk. A merger or other restructuring, tender offer, or exchange offer proposed or pending at the time of investment in a merger arbitrage transaction may not be completed on the terms contemplated, resulting in losses.

rr_RiskLoseMoney

Many factors affect performance, and fund shares will fluctuate in price, meaning you could lose money.

rr_RiskNotInsuredDepositoryInstitution

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.

rr_BarChartAndPerformanceTableHeading

Past performance

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceNarrativeTextBlock

A note on performance

Class A and Class NAV shares commenced operations on September 30, 1984 and February 8, 2017, respectively. Returns shown prior to Class NAV’s commencement date are those of Class A shares, except that they do not include sales charges and would be lower if they did. Returns for Class NAV shares would have been substantially similar to returns of Class A shares because both share classes are invested in the same portfolio of securities and returns would differ only to the extent that expenses of the classes are different. To the extent expenses of a class would have been higher than expenses of Class A shares for the periods shown, performance would have been lower.

rr_PerformanceInformationIllustratesVariabilityOfReturns

rr_PerformanceAvailabilityPhone

800-344-1029

rr_PerformanceAvailabilityWebSiteAddress

jhinvestments.com

rr_PerformancePastDoesNotIndicateFuture

Past performance (before and after taxes) does not indicate future results.

rr_BarChartHeading

Calendar year total returns (%)—Class NAV

rr_PerformanceTableUsesHighestFederalRate

Please note that after-tax returns reflect the highest individual federal marginal income-tax rate in effect as of the date provided and do not reflect any state or local taxes.

rr_PerformanceTableNotRelevantToTaxDeferred

Your actual after-tax returns may be different. After-tax returns are not relevant to shares held in an IRA, 401(k), or other tax-advantaged investment plan.

rr_BarChartClosingTextBlock

Best quarter: 2020, Q2, 29.59%
Worst quarter: 2020, Q1, -24.62%

(John Hancock Investment Trust - Class NAV) | (Fundamental Large Cap Core Fund) | S&P 500 Index (reflects no deduction for fees, expenses, or taxes)

rr_PerformanceTableHeading

Average annual total returns (%)—as of 12/31/21

rr_ProspectusTable

rr_AverageAnnualReturnYear01

28.71%

rr_AverageAnnualReturnYear05

18.47%

(John Hancock Investment Trust - Class NAV) | (Fundamental Large Cap Core Fund) | Class NAV

rr_AverageAnnualReturnYear10

16.55%

rr_ProspectusTable

rr_MaximumCumulativeSalesChargeOverOther

none

rr_MaximumDeferredSalesChargeOverOther

none

rr_ManagementFeesOverAssets

0.61%

rr_OtherExpensesOverAssets

0.04%

rr_ExpensesOverAssets

0.65%

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.01%)

^[6]

rr_NetExpensesOverAssets

0.64%

rr_ExpenseExampleYear01

$ 65

rr_ExpenseExampleYear03

207

rr_ExpenseExampleYear05

361

rr_ExpenseExampleYear10

$ 809

Annual Return 2012

rr_AnnualReturn2012

20.18%

Annual Return 2013

rr_AnnualReturn2013

32.23%

rr_AnnualReturn2014

7.84%

rr_AnnualReturn2015

5.79%

rr_AnnualReturn2016

10.07%

rr_AnnualReturn2017

20.58%

rr_AnnualReturn2018

(13.56%)

rr_AnnualReturn2019

35.52%

rr_AnnualReturn2020

21.03%

rr_AnnualReturn2021

29.69%

rr_HighestQuarterlyReturnLabel

Best quarter: 2020, Q2, 29.59%

rr_BarChartHighestQuarterlyReturn

29.59%

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2020

rr_LowestQuarterlyReturnLabel

Worst quarter: 2020, Q1, -24.62%

rr_BarChartLowestQuarterlyReturn

(24.62%)

rr_BarChartLowestQuarterlyReturnDate

Mar. 31, 2020

rr_AverageAnnualReturnYear01

29.69%

rr_AverageAnnualReturnYear05

17.26%

(John Hancock Investment Trust - Class NAV) | (Fundamental Large Cap Core Fund) | Class NAV | after tax on distributions

rr_AverageAnnualReturnYear10

16.03%

rr_ProspectusTable

rr_AverageAnnualReturnYear01

27.41%

rr_AverageAnnualReturnYear05

15.42%

(John Hancock Investment Trust - Class NAV) | (Fundamental Large Cap Core Fund) | Class NAV | after tax on distributions, with sale

rr_AverageAnnualReturnYear10

14.95%

rr_ProspectusTable

rr_AverageAnnualReturnYear01

19.07%

rr_AverageAnnualReturnYear05

13.29%

(John Hancock Investment Trust - Class NAV) | (Global Environmental Opportunities Fund)

rr_AverageAnnualReturnYear10

13.22%

rr_ProspectusTable

rr_ObjectiveHeading

Investment objective

rr_ObjectivePrimaryTextBlock

To seek growth through capital appreciation by investing primarily in Environmental Companies (as defined below).

rr_ExpenseHeading

Fees and expenses

rr_ExpenseNarrativeTextBlock

rr_ShareholderFeesCaption

Shareholder fees (%) (fees paid directly from your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_OperatingExpensesCaption

Annual fund operating expenses (%) (expenses that you pay each year as a percentage of the value of your investment)

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

July 31, 2023

rr_ExpenseExampleHeading

Expense example

rr_ExpenseExampleNarrativeTextBlock

rr_PortfolioTurnoverHeading

Portfolio turnover

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 and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. During the fiscal period from July 21, 2021 (commencement of operations) through October 31, 2021, the fund’s portfolio turnover rate was 7% of the average value of its portfolio.

rr_PortfolioTurnoverRate

7.00%

rr_StrategyHeading

Principal investment strategies

rr_StrategyNarrativeTextBlock

Under normal circumstances, the fund invests at least 80% of its net assets (plus any borrowings for investment purposes) in securities of Environmental Companies.

The Planetary Boundaries

The Planetary Boundaries (PB) is the scientific environmental framework which the manager uses to identify Environmental Companies. The PB framework was developed by a group of universities across the world. The PB framework identifies a set of nine boundaries considered most crucial for maintaining the stability of the earth’s ecosystems on which human society depends. Remaining within these nine boundaries is considered the “Safe Operating Space,” within which human society and the planet can continue to thrive. Exceeding those boundaries (i.e., being outside the Safe Operating Space) will increase the risk of large-scale adverse or irreversible environmental changes that will negatively impact the future of human society and development.

The nine environmental boundaries as originally identified and quantified in 2009 are: climate change; rate of biodiversity loss (terrestrial and marine); interference with the nitrogen and phosphorus cycles (i.e., biogeochemical flows); stratospheric ozone depletion; ocean acidification; global freshwater use; change in land use; chemical pollution; and atmospheric aerosol. Further information on each of the boundaries is set forth below under “Information Regarding the Planetary Boundaries.”

As of June 28, 2021, the following boundaries have been crossed: climate change, rate of biodiversity loss, land-system change and biogeochemical flows. This does not impact the manager’s investment process, as a boundary that has been crossed simply implies a greater need to reduce stress on that boundary to reverse the trend. The PB framework is not a static framework but subject to change based on evolving scientific research. The following is a graphic representation of the boundaries as of March 2021, this is used for illustrative purposes to demonstrate the PB framework and may change.

Defining Environmental Companies

The manager defines Environmental Companies as:

1	Companies that operate within the Safe Operating Space of the Planetary Boundaries, and

2	Companies, all or a portion of whose business activities reduce stress in at least one of the boundaries in the PB framework.

The two-step process to identify investable Environmental Companies applied by the manager is detailed below.

Step One: The manager screens the global universe of equity companies (approximately 40,000 companies) for those that have environmental footprints within the Safe Operating Space of the PB framework. Environmental footprint is defined as the effect that a person, company, and/or activity has on the environment, such as the amount of natural resources that they use and the amount of harmful gases that they produce.

This first step is achieved by a screening process that includes a Life Cycle Assessment (LCA) analysis to identify companies whose activities, operations and products across their whole life cycle are within the Safe Operating Space of the PB framework. The LCA analysis assesses the impact on the nine boundaries associated with all the stages of the life of a company’s products, services or activities. To facilitate this analysis, the manager has developed a proprietary LCA database using their own data as well as inputs from various external databases. The underlying data used as inputs for the manager’s proprietary LCA database include over 30 different types of environmental impact measures (for example, Methane emission, CFC (Chlorofluorocarbon) emissions, Water consumption, and CO2 emissions). External databases used to develop the LCA database include those from universities, other third-party providers and other proprietary LCA databases. The LCA analysis may be complemented by input from environmental consulting companies that specialize in Life Cycle Assessments and have partnered exclusively with the manager. The inputs the manager uses for the LCA database, and any current partnerships with external environmental consultants, are subject to change.

If a company is operating beyond the Safe Operating Space of one boundary, but is within the Safe Operating Space of another boundary, the manager would consider the average impact of the company across all boundaries and the company would not be prohibited from passing the screen. Typically, 4,000 companies pass through the screen at this part of the process.

Step Two: After screening for companies that are within the Safe Operating Space defined by the Planetary Boundaries in Step One, the manager then narrows this investable universe to identify Environmental Companies. To be eligible as an Environmental Company, all or a portion of a company’s

business activities must reduce stress in at least one or more of the planetary boundaries. Specifically, the company must reduce the impact of human activity on such boundary so that the boundary is not exceeded or further exceeded.

Business activities are defined as selling and/or creating products, technologies and/or services, including the provision of related support services. These business activities include those related to water usage, energy efficiency, renewable energy, sustainable forestry, organic agriculture, pollution control, dematerialized economy, waste management and recycling, as well as any the manager identifies as reducing stress on one or more Planetary Boundaries.

To measure whether a business activity reduces stress in any boundary, the manager uses quantitative inputs from the proprietary LCA analysis and database referred to above. The manager is able to complement this with qualitative judgement based on its knowledge of the company and experience with environmental business activities to determine whether an Environmental Company reduces stress on one or more boundaries. Typically, 400 stocks are identified and defined as Environmental Companies after Step One and Step Two.

Portfolio Construction

Once the universe of Environmental Companies is identified, the manager applies in-depth fundamental research to select the companies that the manager believes present the most attractive risk-return characteristics. In this analysis, the manager considers fundamental characteristics such as the company’s competitiveness, management quality, valuation and industry risk factors. The analysis also systematically integrates Social and Governance ESG factors at this stage of the portfolio construction process. Environmental and Social factors are evaluated as part of a company’s competitiveness and business franchise characteristics. The manager forms its own view based on primary research but is also supported by external data from third-party providers. The manager’s view on a company’s Governance is also integrated as part of the analysis on management quality, where the manager’s primary research and views are complemented by third-party data providers. A low ESG score would affect the overall score assigned to the security by the manager and, therefore, whether the security is chosen for the fund and, if chosen, the weight of that security in the portfolio. The ESG factors utilized during this stage of the portfolio construction process may change over time. The final result is a high conviction portfolio of between 40 to 60 Environmental Companies.

The fund may invest in equity and equity-related securities issued by U.S. and non-U.S. companies, including common, convertible and preferred stock, warrants and depositary receipts. The fund does not limit its investments to companies in a particular market capitalization range and, at times, may invest a substantial portion of its assets in one or more particular market capitalization ranges.

The fund seeks investment exposure to a number of countries throughout the world. Under normal circumstances, the fund will invest in companies domiciled, incorporated, organized or headquartered in at least three countries outside the U.S., including developing and emerging market countries (Foreign Companies). The manager will consider, but is not limited to, the MSCI market classifications in determining whether a country is a developed or emerging market country. Although the fund can invest up to 100% of its assets in the securities of Foreign Companies, under normal circumstances it generally expects to invest at least 40% of its assets in the securities of such companies. However, if the manager determines, in its sole discretion, that market conditions are not favorable, the fund may invest less than 40% of its assets in Foreign Companies, but will not invest less than 30% of its assets in Foreign Companies.

rr_RiskHeading

Principal risks

rr_RiskNarrativeTextBlock

Environmentally focused investing risk. The fund’s environmental criteria limit the available investments compared to funds with no such criteria. The fund’s incorporation of environmental criteria may affect the fund’s exposure to certain sectors and/or types of investments, and under certain economic conditions, this could cause the fund to underperform funds that invest in a broader array of investments depending on whether such sectors or investments are in or out of favor in the market. The data provided by third parties may be incomplete, inaccurate or unavailable, which could cause the manager to incorrectly assess environmental data related to a particular company.

Equity securities risk. The price of equity securities may decline due to changes in a company’s financial condition or overall market conditions.

Geographic focus risk. The fund’s performance will be closely tied to the market, currency, economic, political, regulatory, geopolitical, and other conditions in the countries or regions in which the fund’s assets are invested and may be more volatile than the performance of more geographically-diversified funds.

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. The industrials sector may be affected by general economic conditions, commodity production and pricing, supply and demand fluctuations, environmental and other government regulations, and technological developments, among other factors.

rr_RiskLoseMoney

Many factors affect performance, and fund shares will fluctuate in price, meaning you could lose money.

rr_RiskNotInsuredDepositoryInstitution

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.

rr_BarChartAndPerformanceTableHeading

Past performance

(John Hancock Investment Trust - Class NAV) | (Global Environmental Opportunities Fund) | Class NAV

rr_PerformanceNarrativeTextBlock

This section normally shows how the fund’s total return has varied from year to year, along with a broad-based market index for reference. Performance information is not shown because the fund had been in operation for less than a full calendar year as of the date of this prospectus.

rr_ProspectusTable

rr_MaximumCumulativeSalesChargeOverOther

none

rr_MaximumDeferredSalesChargeOverOther

none

rr_ManagementFeesOverAssets

0.82%

rr_OtherExpensesOverAssets

0.50%

rr_ExpensesOverAssets

1.32%

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.48%)

^[7]

rr_NetExpensesOverAssets

0.84%

rr_ExpenseExampleYear01

$ 86

(John Hancock Investment Trust - Class NAV) | (Global Thematic Opportunities Fund)

rr_ExpenseExampleYear03

$ 371

rr_ProspectusTable

rr_ObjectiveHeading

Investment objective

rr_ObjectivePrimaryTextBlock

To seek growth through capital appreciation by investing mainly in equities of companies that may benefit from global long-term market themes.

rr_ExpenseHeading

Fees and expenses

rr_ExpenseNarrativeTextBlock

rr_ShareholderFeesCaption

Shareholder fees (%) (fees paid directly from your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_OperatingExpensesCaption

Annual fund operating expenses (%) (expenses that you pay each year as a percentage of the value of your investment)

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

July 31, 2023

rr_ExpenseExampleHeading

Expense example

rr_ExpenseExampleNarrativeTextBlock

rr_PortfolioTurnoverHeading

Portfolio turnover

rr_PortfolioTurnoverTextBlock

rr_PortfolioTurnoverRate

43.00%

rr_StrategyHeading

Principal investment strategies

rr_StrategyNarrativeTextBlock

The fund aims to achieve capital growth by investing mainly in equities and equity-related securities (including American, Global, and European Depositary Receipts (ADRs, GDRs, and EDRs)) issued by companies throughout the world. Under normal market conditions, at least 40% of the value of the fund’s net assets will be invested in securities of issuers domiciled outside of the United States, including in emerging markets (Foreign Companies), unless the manager deems market conditions and/or company valuations to be less favorable to Foreign Companies, in which case, the

fund will invest at least 30% of its net assets in Foreign Companies. This includes securities of foreign issuers that trade on U.S. exchanges. The fund may employ a thematic investing approach, which refers to the process of identifying significant macroeconomic trends and the underlying investments that stand to benefit from the materialization of those trends. The fund will invest mainly in securities anticipated to benefit from global long-term market themes resulting from changes in economic and social factors such as demographics, lifestyles, regulations, or the environment.

The fund may invest in all types of equity and equity-related securities, including, without limitation, exchange-traded and over-the-counter common and preferred stocks, warrants, options, rights, convertible securities, sponsored and unsponsored depositary receipts and shares, trust certificates, participatory notes, limited partnership interests, shares of other investment companies (including exchange-traded funds (ETFs)), real estate investment trusts (REITs), and equity participations. The fund may invest in companies of any market capitalization.

The fund may invest in any country (including emerging market countries), in any economic sector and in any currency. However, depending on market conditions, the investments may be focused in one or more countries, sectors and/or currencies.

The fund may invest in China A-shares listed and traded on the certain Chinese stock exchanges through Stock Connect programs. The fund’s investment process may result in a high portfolio turnover ratio and increased trading expenses.

The fund may invest in or use derivatives for hedging and non-hedging purposes in a manner consistent with the investment objective of the fund. Derivatives may be used for hedging purposes in the event of significant cash flows into or out of the fund and to provide protection for the fund, and may include futures and options. Derivatives may be used for non-hedging purposes in order to invest indirectly in securities or financial markets and to gain exposure to other currencies.

rr_RiskHeading

Principal risks

rr_RiskNarrativeTextBlock

Credit and counterparty risk. 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.

Equity securities risk. The price of equity securities may decline due to changes in a company’s financial condition or overall market conditions.

Connect may lose purchase eligibility, which could adversely affect the fund’s performance. Trading through Stock Connect is subject to trading, clearance, and settlement procedures that may continue to develop as the program matures. Any changes in laws, regulations and policies applicable to Stock Connect may affect China A-Share prices. These risks are heightened by the underdeveloped state of the PRC’s investment and banking systems in general.

High portfolio turnover risk. Trading securities actively and frequently can increase transaction costs (thus lowering performance) and taxable distributions.

Thematic investing risk. Thematic investing involves the risk that long-term market themes are incorrectly identified or that the securities chosen to represent those themes underperform.

rr_RiskLoseMoney

Many factors affect performance, and fund shares will fluctuate in price, meaning you could lose money.

rr_RiskNotInsuredDepositoryInstitution

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.

rr_BarChartAndPerformanceTableHeading

Past performance

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceNarrativeTextBlock

rr_PerformanceInformationIllustratesVariabilityOfReturns

rr_PerformanceAvailabilityPhone

800-344-1029

rr_PerformanceAvailabilityWebSiteAddress

jhinvestments.com

rr_PerformancePastDoesNotIndicateFuture

Past performance (before and after taxes) does not indicate future results.

rr_BarChartHeading

Calendar year total returns (%)—Class NAV

rr_PerformanceTableUsesHighestFederalRate

Please note that after-tax returns reflect the highest individual federal marginal income-tax rate in effect as of the date provided and do not reflect any state or local taxes.

rr_PerformanceTableNotRelevantToTaxDeferred

Your actual after-tax returns may be different. After-tax returns are not relevant to shares held in an IRA, 401(k), or other tax-advantaged investment plan.

rr_BarChartClosingTextBlock

Best quarter: 2020, Q2, 20.57%
Worst quarter: 2020, Q1, -20.23%

(John Hancock Investment Trust - Class NAV) | (Global Thematic Opportunities Fund) | MSCI ACWI (reflects no deduction for fees, expenses, or taxes)

rr_PerformanceTableHeading

Average annual total returns (%)—as of 12/31/21

rr_ProspectusTable

rr_AverageAnnualReturnYear01

18.54%

(John Hancock Investment Trust - Class NAV) | (Global Thematic Opportunities Fund) | Class NAV

rr_AverageAnnualReturnSinceInception

18.35%

rr_ProspectusTable

rr_MaximumCumulativeSalesChargeOverOther

none

rr_MaximumDeferredSalesChargeOverOther

none

rr_ManagementFeesOverAssets

0.82%

rr_OtherExpensesOverAssets

0.10%

rr_ExpensesOverAssets

0.92%

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.08%)

^[8]

rr_NetExpensesOverAssets

0.84%

rr_ExpenseExampleYear01

$ 86

rr_ExpenseExampleYear03

285

rr_ExpenseExampleYear05

501

rr_ExpenseExampleYear10

$ 1,124

rr_AnnualReturn2019

31.35%

rr_AnnualReturn2020

17.57%

rr_AnnualReturn2021

16.23%

rr_HighestQuarterlyReturnLabel

Best quarter: 2020, Q2, 20.57%

rr_BarChartHighestQuarterlyReturn

20.57%

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2020

rr_LowestQuarterlyReturnLabel

Worst quarter: 2020, Q1, -20.23%

rr_BarChartLowestQuarterlyReturn

(20.23%)

rr_BarChartLowestQuarterlyReturnDate

Mar. 31, 2020

rr_AverageAnnualReturnYear01

16.23%

(John Hancock Investment Trust - Class NAV) | (Global Thematic Opportunities Fund) | Class NAV | after tax on distributions

rr_AverageAnnualReturnSinceInception

20.19%

rr_ProspectusTable

rr_AverageAnnualReturnYear01

13.22%

(John Hancock Investment Trust - Class NAV) | (Global Thematic Opportunities Fund) | Class NAV | after tax on distributions, with sale

rr_AverageAnnualReturnSinceInception

17.82%

rr_ProspectusTable

rr_AverageAnnualReturnYear01

10.98%

(John Hancock Investment Trust - Class NAV) | (Infrastructure Fund)

rr_AverageAnnualReturnSinceInception

15.26%

rr_ProspectusTable

rr_ObjectiveHeading

Investment objective

rr_ObjectivePrimaryTextBlock

To seek total return from capital appreciation and income, with an emphasis on absolute returns over a full market cycle.

rr_ExpenseHeading

Fees and expenses

rr_ExpenseNarrativeTextBlock

rr_ShareholderFeesCaption

Shareholder fees (%) (fees paid directly from your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_OperatingExpensesCaption

Annual fund operating expenses (%) (expenses that you pay each year as a percentage of the value of your investment)

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

July 31, 2023

rr_ExpenseExampleHeading

Expense example

rr_ExpenseExampleNarrativeTextBlock

rr_PortfolioTurnoverHeading

Portfolio turnover

rr_PortfolioTurnoverTextBlock

rr_PortfolioTurnoverRate

27.00%

rr_StrategyHeading

Principal investment strategies

Strategy Portfolio Concentration [Text]

rr_StrategyNarrativeTextBlock

The fund pursues its objective by investing, under normal circumstances, at least 80% of its net assets (plus borrowings for investment purposes) in global securities of companies with infrastructure-related assets. Because the fund normally invests more than 25% of its assets in global securities of infrastructure-related assets, the fund is considered to be “concentrated” in industries represented by infrastructure companies. For purposes of this policy, global securities include: common stock, depositary receipts, real estate securities (including real estate investment trusts (REITs)), master limited partnerships (MLPs) (up to a maximum of 25% of the fund’s net assets), preferred stock, rights, warrants, exchange-traded funds (ETFs), and debt securities (up to a maximum of 20% of the fund’s net assets). Also for purposes of this policy, infrastructure-related assets are long-lived physical assets that are held by companies, including financial holding companies, that engage in the ownership, management, construction, development, renovation, operation, use or financing of infrastructure assets, or that provide the services and raw materials necessary for the construction and

maintenance of infrastructure assets. Infrastructure assets are the physical structures, networks and systems which provide necessary services for the function, growth and development of society, including but not limited to utilities, pipelines, toll roads, airports, railroads, ports, telecommunications and other infrastructure companies.

Companies with long-lived physical assets are those that the manager believes possess an advantageous competitive position due to factors such as a long track record, resilience in the face of technological advances, rising replacement costs, and limited substitution risk. The manager believes investment in these types of companies can contribute to attractive, long-term absolute returns. The fund also seeks to mitigate losses during periods of unfavorable equity market conditions by attempting to limit volatility relative to the wider market. While not managed explicitly for yield, the securities in which the fund invests may often provide higher dividend yields than the broader equity market. The fund is not managed to track a benchmark index.

The fund may invest in debt securities, including convertible bonds, without any maturity limit and of any credit quality, including high-yield securities (i.e., junk bonds). The fund may also invest in cash, cash equivalents, and derivative instruments. Derivatives may be used to reduce risk, obtain efficient market exposure, and/or enhance investment returns, and may include swaps, forward contracts, options, currency derivatives (including currency forwards, futures, options, and spot transactions), and similar instruments or combinations thereof. Country and regional weights are driven by bottom-up security selection and are typically unconstrained; however, the fund will generally be diversified regionally across global equity markets, including emerging markets. The fund invests in companies across the market-capitalization spectrum.

The fund seeks to outperform global equity markets during periods of flat or negative market performance and may underperform during periods of strong market performance. The fund’s investment returns may be volatile over short periods of time and returns over any period of time may not be positive. The maximum position in any individual security will typically be less than 10% of the fund’s net assets. Generally, less than 10% of the fund’s net assets will be invested in cash and cash equivalents, but can be as high as 20%.

rr_StrategyPortfolioConcentration

rr_RiskHeading

Principal risks

rr_RiskNarrativeTextBlock

Concentration risk. Because the fund may focus on one or more industries or sectors of the economy, its performance depends in large part on the performance of those industries or sectors. As a result, the value of an investment may fluctuate more widely since it is more susceptible to market, economic, political, regulatory, and other conditions and risks affecting those industries or sectors than a fund that invests more broadly across industries and sectors.

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. A downgrade or default affecting any of the fund’s securities could affect the fund’s performance.

Equity securities risk. The price of equity securities may decline due to changes in a company’s financial condition or overall market conditions.

Midstream energy infrastructure sector risk. Midstream energy infrastructure companies, such as companies that provide crude oil, refined product, and natural gas services, are subject to supply-and-demand fluctuations in the markets they serve, which may be impacted by a wide range of factors.

Natural resources industry risk. The natural resources industry can be significantly affected by international political and economic developments, energy conservation and exploration efforts, natural disasters or other extreme weather conditions, commodity prices, and taxes and other governmental regulations, among other factors.

Real estate securities risk. Securities of companies in the real estate industry carry risks associated with owning real estate, including the potential for a decline in value due to economic or market conditions.

Telecommunications sector risk. Telecommunication services companies are subject to government regulation of services and rates of return and can be significantly affected by intense competition, among other factors.

Transportation sector risk. Transportation companies can be significantly affected by economic changes, fuel, maintenance, and insurance costs, labor relations, and government regulation, among other factors.

Utilities sector risk. Utilities companies’ performance may be volatile due to variable fuel, service, and financing costs, conservation efforts, government regulation, and other factors.

rr_RiskLoseMoney

Many factors affect performance, and fund shares will fluctuate in price, meaning you could lose money.

rr_RiskNotInsuredDepositoryInstitution

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.

rr_BarChartAndPerformanceTableHeading

Past performance

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceNarrativeTextBlock

rr_PerformanceInformationIllustratesVariabilityOfReturns

rr_PerformanceAvailabilityPhone

800-344-1029

rr_PerformanceAvailabilityWebSiteAddress

jhinvestments.com

rr_PerformancePastDoesNotIndicateFuture

Past performance (before and after taxes) does not indicate future results.

rr_BarChartHeading

Calendar year total returns (%)—Class NAV

rr_PerformanceTableUsesHighestFederalRate

Please note that after-tax returns reflect the highest individual federal marginal income-tax rate in effect as of the date provided and do not reflect any state or local taxes.

rr_PerformanceTableNotRelevantToTaxDeferred

Your actual after-tax returns may be different. After-tax returns are not relevant to shares held in an IRA, 401(k), or other tax-advantaged investment plan.

rr_BarChartClosingTextBlock

Best quarter: 2020, Q4, 11.62%
Worst quarter: 2020, Q1, -15.70%

(John Hancock Investment Trust - Class NAV) | (Infrastructure Fund) | MSCI ACWI (reflects no deduction for fees, expenses, or taxes)

rr_PerformanceTableHeading

Average annual total returns (%)—as of 12/31/21

rr_ProspectusTable

rr_AverageAnnualReturnYear01

18.54%

rr_AverageAnnualReturnYear05

14.40%

(John Hancock Investment Trust - Class NAV) | (Infrastructure Fund) | Class NAV

rr_AverageAnnualReturnSinceInception

10.33%

rr_ProspectusTable

rr_MaximumCumulativeSalesChargeOverOther

none

rr_MaximumDeferredSalesChargeOverOther

none

rr_ManagementFeesOverAssets

0.77%

rr_OtherExpensesOverAssets

0.10%

rr_ExpensesOverAssets

0.87%

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.01%)

^[9]

rr_NetExpensesOverAssets

0.86%

rr_ExpenseExampleYear01

$ 88

rr_ExpenseExampleYear03

277

rr_ExpenseExampleYear05

481

rr_ExpenseExampleYear10

$ 1,072

rr_AnnualReturn2014

8.25%

rr_AnnualReturn2015

(3.19%)

rr_AnnualReturn2016

4.59%

rr_AnnualReturn2017

17.63%

rr_AnnualReturn2018

(1.32%)

rr_AnnualReturn2019

23.49%

rr_AnnualReturn2020

2.66%

rr_AnnualReturn2021

14.19%

rr_HighestQuarterlyReturnLabel

Best quarter: 2020, Q4, 11.62%

rr_BarChartHighestQuarterlyReturn

11.62%

rr_BarChartHighestQuarterlyReturnDate

Dec. 31, 2020

rr_LowestQuarterlyReturnLabel

Worst quarter: 2020, Q1, -15.70%

rr_BarChartLowestQuarterlyReturn

(15.70%)

rr_BarChartLowestQuarterlyReturnDate

Mar. 31, 2020

rr_AverageAnnualReturnYear01

14.19%

rr_AverageAnnualReturnYear05

10.94%

(John Hancock Investment Trust - Class NAV) | (Infrastructure Fund) | Class NAV | after tax on distributions

rr_AverageAnnualReturnSinceInception

8.12%

rr_ProspectusTable

rr_AverageAnnualReturnYear01

11.77%

rr_AverageAnnualReturnYear05

9.39%

(John Hancock Investment Trust - Class NAV) | (Infrastructure Fund) | Class NAV | after tax on distributions, with sale

rr_AverageAnnualReturnSinceInception

6.83%

rr_ProspectusTable

rr_AverageAnnualReturnYear01

8.99%

rr_AverageAnnualReturnYear05

8.09%

(John Hancock Investment Trust - Class NAV) | (International Dynamic Growth Fund)

rr_AverageAnnualReturnSinceInception

5.94%

rr_ProspectusTable

rr_ObjectiveHeading

Investment objective

rr_ObjectivePrimaryTextBlock

To seek capital appreciation.

rr_ExpenseHeading

Fees and expenses

rr_ExpenseNarrativeTextBlock

rr_ShareholderFeesCaption

Shareholder fees (%) (fees paid directly from your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_OperatingExpensesCaption

Annual fund operating expenses (%) (expenses that you pay each year as a percentage of the value of your investment)

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

July 31, 2023

rr_ExpenseExampleHeading

Expense example

rr_ExpenseExampleNarrativeTextBlock

rr_PortfolioTurnoverHeading

Portfolio turnover

rr_PortfolioTurnoverTextBlock

rr_PortfolioTurnoverRate

133.00%

rr_StrategyHeading

Principal investment strategies

rr_StrategyNarrativeTextBlock

The manager seeks to achieve the fund’s investment objective by investing in equity investments that the manager believes will provide higher returns than the MSCI ACWI ex USA Growth Index.

The fund primarily invests in a diversified portfolio of equity securities of foreign companies in a number of developed and emerging markets. The fund defines foreign companies as companies: (i) that are organized under the laws of a foreign country; (ii) whose principal trading market is in a foreign

country; or (iii) that have a majority of their assets, or that derive a majority of their revenue or profit growth, from businesses, investments or sales outside of the United States. The manager will consider, but is not limited to, MSCI market classifications in determining whether a country is a developed or emerging market country. Although the fund may invest in companies of any market-capitalization, the fund typically invests in companies with a market capitalization over $250 million. The fund may focus its investments in a particular sector or sectors of the economy. The fund invests primarily in common stocks, but may also invest in participatory notes.

The manager’s growth philosophy and process is focused on fundamental, bottom-up stock selection and includes three key elements: (i) positive fundamental changes, (ii) sustainable earnings growth, and (iii) an attractive valuation. The manager’s investment process generally begins with the broad universe of securities included in international equity indices, including China A-shares. The manager then focuses its fundamental research by collecting, scoring and monitoring forward-looking operational data related to specific companies, industries, and sectors. It then seeks to identify quantifiable changes by consistently tracking these data points. Once the manager has identified a positive change, it holistically assesses the key company, industry, secular, macro and country stock drivers and compares them to consensus expectations. The manager then determines a risk/return rating for each company it has identified. This ranking is utilized by the portfolio management team to build a portfolio with consistent and balanced risk/return characteristics.

The operational metrics and investment thesis of the portfolio’s holdings are continuously monitored to ensure the ranking and weighting of each security in the portfolio is appropriate given the level of risk/return. The fund may trade securities actively as the investment thesis improves or deteriorates.

rr_RiskHeading

Principal risks

rr_RiskNarrativeTextBlock

Credit and counterparty risk. A borrower of fund securities may not make timely payments or otherwise honor its obligations.

applicable to Stock Connect may affect China A-Share prices. These risks are heightened by the underdeveloped state of the PRC’s investment and banking systems in general.

High portfolio turnover risk. Trading securities actively and frequently can increase transaction costs (thus lowering performance) and taxable distributions.

rr_RiskLoseMoney

Many factors affect performance, and fund shares will fluctuate in price, meaning you could lose money.

rr_RiskNotInsuredDepositoryInstitution

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.

rr_BarChartAndPerformanceTableHeading

Past performance

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceNarrativeTextBlock

rr_PerformanceInformationIllustratesVariabilityOfReturns

rr_PerformanceAvailabilityPhone

800-344-1029

rr_PerformanceAvailabilityWebSiteAddress

jhinvestments.com

rr_PerformancePastDoesNotIndicateFuture

Past performance (before and after taxes) does not indicate future results.

rr_BarChartHeading

Calendar year total returns (%)—Class NAV

rr_PerformanceTableUsesHighestFederalRate

Please note that after-tax returns reflect the highest individual federal marginal income-tax rate in effect as of the date provided and do not reflect any state or local taxes.

rr_PerformanceTableNotRelevantToTaxDeferred

Your actual after-tax returns may be different. After-tax returns are not relevant to shares held in an IRA, 401(k), or other tax-advantaged investment plan.

rr_BarChartClosingTextBlock

Best quarter: 2020, Q2, 26.92%
Worst quarter: 2020, Q1, -16.73%

(John Hancock Investment Trust - Class NAV) | (International Dynamic Growth Fund) | MSCI ACWI ex USA Growth Index (reflects no deduction for fees, expenses, or taxes)

rr_PerformanceTableHeading

Average annual total returns (%)—as of 12/31/21

rr_ProspectusTable

rr_AverageAnnualReturnYear01

5.09%

(John Hancock Investment Trust - Class NAV) | (International Dynamic Growth Fund) | Class NAV

rr_AverageAnnualReturnSinceInception

13.71%

rr_ProspectusTable

rr_MaximumCumulativeSalesChargeOverOther

none

rr_MaximumDeferredSalesChargeOverOther

none

rr_ManagementFeesOverAssets

0.81%

rr_OtherExpensesOverAssets

0.11%

rr_ExpensesOverAssets

0.92%

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.09%)

^[10]

rr_NetExpensesOverAssets

0.83%

rr_ExpenseExampleYear01

$ 85

rr_ExpenseExampleYear03

284

rr_ExpenseExampleYear05

500

rr_ExpenseExampleYear10

$ 1,123

rr_AnnualReturn2020

36.75%

rr_AnnualReturn2021

18.67%

rr_HighestQuarterlyReturnLabel

Best quarter: 2020, Q2, 26.92%

rr_BarChartHighestQuarterlyReturn

26.92%

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2020

rr_LowestQuarterlyReturnLabel

Worst quarter: 2020, Q1, -16.73%

rr_BarChartLowestQuarterlyReturn

(16.73%)

rr_BarChartLowestQuarterlyReturnDate

Mar. 31, 2020

rr_AverageAnnualReturnYear01

18.67%

(John Hancock Investment Trust - Class NAV) | (International Dynamic Growth Fund) | Class NAV | after tax on distributions

rr_AverageAnnualReturnSinceInception

24.96%

rr_ProspectusTable

rr_AverageAnnualReturnYear01

10.71%

(John Hancock Investment Trust - Class NAV) | (International Dynamic Growth Fund) | Class NAV | after tax on distributions, with sale

rr_AverageAnnualReturnSinceInception

21.17%

rr_ProspectusTable

rr_AverageAnnualReturnYear01

14.31%

(John Hancock Investment Trust - Class NAV) | (Seaport Long/Short Fund)

rr_AverageAnnualReturnSinceInception

19.04%

rr_ProspectusTable

rr_ObjectiveHeading

Investment objective

rr_ObjectivePrimaryTextBlock

To seek capital appreciation.

rr_ExpenseHeading

Fees and expenses

rr_ExpenseNarrativeTextBlock

rr_ShareholderFeesCaption

Shareholder fees (%) (fees paid directly from your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_OperatingExpensesCaption

Annual fund operating expenses (%) (expenses that you pay each year as a percentage of the value of your investment)

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

July 31, 2023

Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text]

rr_ExpensesNotCorrelatedToRatioDueToAcquiredFundFees

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.”

rr_ExpenseExampleHeading

Expense example

rr_ExpenseExampleNarrativeTextBlock

rr_PortfolioTurnoverHeading

Portfolio turnover

rr_PortfolioTurnoverTextBlock

rr_PortfolioTurnoverRate

259.00%

rr_StrategyHeading

Principal investment strategies

rr_StrategyNarrativeTextBlock

The fund allocates its assets to a number of investment strategies (Strategies), through which the fund will take both physical and synthetic long positions and synthetic short exposures in a variety of equity and derivative instruments. The fund may hold significant synthetic long and short exposures. Each Strategy will be managed by a separate portfolio management team pursuant to allocations provided by the advisor from time to time. For long positions, the manager generally uses bottom-up fundamental analysis to identify companies throughout the world that the manager believes are undervalued or expects to experience high levels of growth. The manager also seeks to identify sectors, industries, or asset classes that

may be overvalued or may experience low levels of growth, and the fund may take significant synthetic long and short exposures in such areas. The fund generally will not invest in companies with a market capitalization below $500 million at the time of purchase. The fund’s synthetic short exposures will primarily be maintained in derivatives on exchange-traded pooled investment vehicles (e.g., exchange-traded funds (ETFs)) and/or indices, but may be maintained in other vehicles. In certain circumstances, the fund’s overall synthetic short exposures may equal or exceed the size of the fund’s long positions. Generally, the fund does not intend to take synthetic short exposures to individual stocks. The fund also may invest in master limited partnerships. The fund may trade securities actively.

Derivative instruments in which the fund may hold physical and synthetic long positions or synthetic short exposures include futures and forward contracts, such as interest-rate futures and foreign currency forward contracts; swaps, such as interest-rate swaps, credit default swaps, or total return swaps; call and put options; or warrants and rights, and may be used to reduce risk, obtain efficient market exposure, and/or enhance investment returns. The fund may also invest in repurchase agreements and reverse repurchase agreements.

The Strategies are typically diversified across sectors or focus on individual sectors, including financial services, healthcare, information technology, energy, biotechnology, and/or natural resources. Strategies and the allocations among them may vary. Each Strategy has a distinct investment philosophy and an analytical process based on a number of factors, such as business environment, management quality, balance sheet, income statement, anticipated earnings, expected growth rates, revenues, dividends, and other measures of value. As a result, the aggregate portfolio will represent a wide range of investment philosophies, companies, industries, and market capitalizations.

The manager may also invest in debt instruments, including high yield debt instruments (i.e., junk bonds). Such instruments may include, but are not limited to, bonds, bank loans (including loan participations), asset-backed securities, mortgage-backed securities, convertible securities, foreign currency-denominated foreign securities, U.S. and foreign government securities, hybrid securities (including convertible bonds, contingent convertible/capital securities, and similarly structured securities), derivatives, currencies, and reverse repurchase agreements. Some loans may be illiquid. Derivative instruments also may magnify the fund’s gains and losses. The fund’s derivative transactions will be fully collateralized.

rr_RiskHeading

Principal risks

rr_RiskNarrativeTextBlock

Biotechnology industry risk. Biotechnology companies are subject to regulatory requirements, intense competition, rapid technological and other developments that could negatively affect the price, profitability, viability, and availability of their products and services. Investments in this industry are often based on speculation regarding future research and product developments.

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.

Energy sector risk. The energy sector is cyclical and highly dependent on commodities prices, which may be volatile. The market value of energy companies can be significantly affected by a number of factors, including global energy price volatility, supply and demand, exchange- and interest-rate fluctuation, and domestic and foreign political and economic developments. Energy companies also face a significant risk of civil liability.

Healthcare sector risk. Health sciences companies may be significantly affected by product obsolescence, thin capitalization, limited product lines and markets, civil liability claims, and legislative or regulatory activities, among other factors.

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, futures contracts, options, interest rate swaps, total return swaps, reverse repurchase agreements, and swaps. 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. An event of default or insolvency of the counterparty to a reverse repurchase agreement could result in delays or restrictions with respect to the fund’s ability to dispose of the underlying securities. In addition, a reverse repurchase agreement may be considered a form of leverage and may, therefore, increase fluctuations in the fund’s net asset value per share (NAV).

High portfolio turnover risk. Trading securities actively and frequently can increase transaction costs (thus lowering performance) and taxable distributions.

Hybrid instrument risk. Hybrid instruments (a type of potentially high-risk derivative) combine the elements of futures contracts or options with those of debt, preferred equity or a depository instrument. Hybrid instruments entail greater market risk and may be more volatile than traditional debt instruments, may bear interest or pay preferred dividends at below-market rates, and may be illiquid. The risks of investing in hybrid instruments are a combination of the risks of investing in securities, options, futures, and currencies.

Leveraging risk. Using derivatives may result in a leveraged portfolio. Leveraging long exposures increases a fund’s losses when the value of its investments declines. Some derivatives have the potential for unlimited loss, regardless of the size of the initial investment.

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.

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.

Synthetic short exposure risk. The fund will gain synthetic short exposure through a forward commitment through a swap agreement. Synthetic short exposures involve the risk that losses may be exaggerated, potentially losing more money than the actual cost of the investment.

Technology companies risk. Technology companies can be significantly affected by rapid obsolescence, short product cycles, competition, and government regulation, among other factors. Investments in the technology sector may be susceptible to heightened risk of cybersecurity breaches, which may allow an unauthorized party to gain access to personally identifiable information and other customer data.

rr_RiskLoseMoney

Many factors affect performance, and fund shares will fluctuate in price, meaning you could lose money.

rr_RiskNotInsuredDepositoryInstitution

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.

rr_BarChartAndPerformanceTableHeading

Past performance

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceNarrativeTextBlock

rr_PerformanceInformationIllustratesVariabilityOfReturns

rr_PerformanceAvailabilityPhone

800-344-1029

rr_PerformanceAvailabilityWebSiteAddress

jhinvestments.com

rr_PerformancePastDoesNotIndicateFuture

Past performance (before and after taxes) does not indicate future results.

rr_BarChartHeading

Calendar year total returns (%)—Class NAV

rr_PerformanceTableUsesHighestFederalRate

Please note that after-tax returns reflect the highest individual federal marginal income-tax rate in effect as of the date provided and do not reflect any state or local taxes.

rr_PerformanceTableNotRelevantToTaxDeferred

Your actual after-tax returns may be different. After-tax returns are not relevant to shares held in an IRA, 401(k), or other tax-advantaged investment plan.

rr_BarChartClosingTextBlock

Best quarter: 2020, Q2, 9.87%
Worst quarter: 2020, Q1, -9.52%

(John Hancock Investment Trust - Class NAV) | (Seaport Long/Short Fund) | MSCI World Index (reflects no deduction for fees, expenses, or taxes)

rr_PerformanceTableHeading

Average annual total returns (%)—as of 12/31/21

rr_ProspectusTable

rr_AverageAnnualReturnYear01

21.82%

rr_AverageAnnualReturnYear05

15.03%

(John Hancock Investment Trust - Class NAV) | (Seaport Long/Short Fund) | Class NAV

rr_AverageAnnualReturnSinceInception

11.00%

rr_ProspectusTable

rr_MaximumCumulativeSalesChargeOverOther

none

rr_MaximumDeferredSalesChargeOverOther

none

rr_ManagementFeesOverAssets

1.46%

Acquired Fund Fees and Expenses

rr_OtherExpensesOverAssets

0.09%

rr_AcquiredFundFeesAndExpensesOverAssets

0.01%

^[11]

rr_ExpensesOverAssets

1.56%

^[12]

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.01%)

^[13]

rr_NetExpensesOverAssets

1.55%

rr_ExpenseExampleYear01

$ 158

rr_ExpenseExampleYear03

492

rr_ExpenseExampleYear05

849

rr_ExpenseExampleYear10

$ 1,856

rr_AnnualReturn2014

1.99%

rr_AnnualReturn2015

8.14%

rr_AnnualReturn2016

(4.58%)

rr_AnnualReturn2017

15.97%

rr_AnnualReturn2018

(4.11%)

rr_AnnualReturn2019

14.73%

rr_AnnualReturn2020

10.45%

rr_AnnualReturn2021

3.60%

rr_HighestQuarterlyReturnLabel

Best quarter: 2020, Q2, 9.87%

rr_BarChartHighestQuarterlyReturn

9.87%

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2020

rr_LowestQuarterlyReturnLabel

Worst quarter: 2020, Q1, -9.52%

rr_BarChartLowestQuarterlyReturn

(9.52%)

rr_BarChartLowestQuarterlyReturnDate

Mar. 31, 2020

rr_AverageAnnualReturnYear01

3.60%

rr_AverageAnnualReturnYear05

7.86%

(John Hancock Investment Trust - Class NAV) | (Seaport Long/Short Fund) | Class NAV | after tax on distributions

rr_AverageAnnualReturnSinceInception

5.56%

rr_ProspectusTable

rr_AverageAnnualReturnYear01

1.86%

rr_AverageAnnualReturnYear05

6.66%

(John Hancock Investment Trust - Class NAV) | (Seaport Long/Short Fund) | Class NAV | after tax on distributions, with sale

rr_AverageAnnualReturnSinceInception

4.81%

rr_ProspectusTable

rr_AverageAnnualReturnYear01

3.04%

rr_AverageAnnualReturnYear05

6.00%

(John Hancock Investment Trust - Class NAV) | (Small Cap Core Fund)

rr_AverageAnnualReturnSinceInception

4.29%

rr_ProspectusTable

rr_ObjectiveHeading

Investment objective

rr_ObjectivePrimaryTextBlock

To seek long-term capital appreciation.

rr_ExpenseHeading

Fees and expenses

rr_ExpenseNarrativeTextBlock

rr_ShareholderFeesCaption

Shareholder fees (%) (fees paid directly from your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_OperatingExpensesCaption

Annual fund operating expenses (%) (expenses that you pay each year as a percentage of the value of your investment)

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

July 31, 2023

rr_ExpenseExampleHeading

Expense example

rr_ExpenseExampleNarrativeTextBlock

rr_PortfolioTurnoverHeading

Portfolio turnover

rr_PortfolioTurnoverTextBlock

rr_PortfolioTurnoverRate

64.00%

rr_StrategyHeading

Principal investment strategies

rr_StrategyNarrativeTextBlock

Under normal market conditions, the fund invests at least 80% of its net assets (plus any borrowings for investment purposes) in equity securities of small-capitalization companies. The fund considers small-capitalization companies to be those that, at the time of investment, are in the capitalization range of the Russell 2000 Index, with a maximum capitalization of $13.98 billion as of December 31, 2021. The fund generally will not invest in companies that, at the time of purchase, have market capitalizations of $5 billion or more. Equity securities include common and preferred stocks, rights, warrants, and depositary receipts.

The manager emphasizes a fundamental, bottom-up approach to individual stock selection, looking for companies with durable, niche business models with the potential for high returns on capital and that the manager believes are undervalued. Companies are screened based on a number of factors, including balance sheet quality, profitability, liquidity, size, and risk profile.

The fund intends to invest in a number of different sectors based on stock selection and sector weightings may vary significantly from its benchmark. The fund may focus its investments in a particular sector or sectors. The fund may invest up to 10% of its total assets in foreign securities including emerging-market securities and securities of non-U.S. companies traded on a U.S. exchange.

The fund may invest in initial public offerings (IPOs), real estate investment trusts (REITs) or other real estate-related equity securities, and certain exchange-traded funds (ETFs).

The fund normally will invest 10% or less of its total assets in cash and cash equivalents, including repurchase agreements, money market securities, U.S. government securities, and other short-term investments. The fund may invest in derivatives to a limited extent. Derivatives may be used to reduce risk and/or obtain efficient market exposure, and may include futures contracts and foreign currency forward contracts.

rr_RiskHeading

Principal risks

rr_RiskNarrativeTextBlock

Credit and counterparty risk. 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 based on the nature of their support.

High portfolio turnover risk. Trading securities actively and frequently can increase transaction costs (thus lowering performance) and taxable distributions.

Initial public offerings (IPOs) risk. IPO share prices are frequently volatile and may significantly impact fund performance.

Preferred stock risk. Preferred stock generally ranks senior to common stock with respect to dividends and liquidation but ranks junior to debt securities. Unlike interest payments on debt securities, preferred stock dividends are payable only if declared by the issuer’s board of directors. Preferred stock may be subject to optional or mandatory redemption provisions.

rr_RiskLoseMoney

Many factors affect performance, and fund shares will fluctuate in price, meaning you could lose money.

rr_RiskNotInsuredDepositoryInstitution

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.

rr_BarChartAndPerformanceTableHeading

Past performance

Performance Information Illustrates Variability of Returns [Text]

rr_PerformanceNarrativeTextBlock

rr_PerformanceInformationIllustratesVariabilityOfReturns

rr_PerformanceAvailabilityPhone

800-344-1029

rr_PerformanceAvailabilityWebSiteAddress

jhinvestments.com

rr_PerformancePastDoesNotIndicateFuture

Past performance (before and after taxes) does not indicate future results.

rr_BarChartHeading

Calendar year total returns (%)—Class NAV

rr_PerformanceTableUsesHighestFederalRate

Please note that after-tax returns reflect the highest individual federal marginal income-tax rate in effect as of the date provided and do not reflect any state or local taxes.

rr_PerformanceTableNotRelevantToTaxDeferred

Your actual after-tax returns may be different. After-tax returns are not relevant to shares held in an IRA, 401(k), or other tax-advantaged investment plan.

rr_BarChartClosingTextBlock

Best quarter: 2020, Q4, 27.35%
Worst quarter: 2020, Q1, -26.27%

(John Hancock Investment Trust - Class NAV) | (Small Cap Core Fund) | Russell 2000 Index (reflects no deduction for fees, expenses, or taxes)

rr_PerformanceTableHeading

Average annual total returns (%)—as of 12/31/21

rr_ProspectusTable

rr_AverageAnnualReturnYear01

14.82%

rr_AverageAnnualReturnYear05

12.02%

(John Hancock Investment Trust - Class NAV) | (Small Cap Core Fund) | Class NAV

rr_AverageAnnualReturnSinceInception

10.44%

rr_ProspectusTable

rr_MaximumCumulativeSalesChargeOverOther

none

rr_MaximumDeferredSalesChargeOverOther

none

rr_ManagementFeesOverAssets

0.83%

rr_OtherExpensesOverAssets

0.05%

rr_ExpensesOverAssets

0.88%

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.01%)

^[14]

rr_NetExpensesOverAssets

0.87%

rr_ExpenseExampleYear01

$ 89

rr_ExpenseExampleYear03

280

rr_ExpenseExampleYear05

487

rr_ExpenseExampleYear10

$ 1,083

rr_AnnualReturn2014

(0.80%)

rr_AnnualReturn2015

(1.21%)

rr_AnnualReturn2016

27.18%

rr_AnnualReturn2017

16.25%

rr_AnnualReturn2018

(18.18%)

rr_AnnualReturn2019

27.02%

rr_AnnualReturn2020

26.12%

rr_AnnualReturn2021

24.15%

rr_HighestQuarterlyReturnLabel

Best quarter: 2020, Q4, 27.35%

rr_BarChartHighestQuarterlyReturn

27.35%

rr_BarChartHighestQuarterlyReturnDate

Dec. 31, 2020

rr_LowestQuarterlyReturnLabel

Worst quarter: 2020, Q1, -26.27%

rr_BarChartLowestQuarterlyReturn

(26.27%)

rr_BarChartLowestQuarterlyReturnDate

Mar. 31, 2020

rr_AverageAnnualReturnYear01

24.15%

rr_AverageAnnualReturnYear05

13.60%

(John Hancock Investment Trust - Class NAV) | (Small Cap Core Fund) | Class NAV | after tax on distributions

rr_AverageAnnualReturnSinceInception

11.56%

rr_ProspectusTable

rr_AverageAnnualReturnYear01

20.10%

rr_AverageAnnualReturnYear05

11.67%

(John Hancock Investment Trust - Class NAV) | (Small Cap Core Fund) | Class NAV | after tax on distributions, with sale

rr_AverageAnnualReturnSinceInception

10.13%

rr_ProspectusTable

rr_AverageAnnualReturnYear01

15.80%

rr_AverageAnnualReturnYear05

10.21%