Label

Element

Value

Prospectus:

rr_ProspectusTable

Supplement Text Block

jharpf-20191218_SupplementTextBlock

Prospectus Supplement

John Hancock Investment Trust

John Hancock Alternative Risk Premia Fund (the fund)

Supplement dated December 18, 2019 to the current Prospectus, as may be supplemented

Effective immediately, the Annual fund operating expenses table and the Expense example table for the fund in the "Fund summary" section are revised and restated as follows:

Annual fund operating expenses (%)
(expenses that you pay each year as a percentage of the value of your investment)	A	C	I
Management fee	1.00	1.00	1.00
Distribution and service (Rule 12b-1) fees	0.25	1.00	0.00
Other expenses1	0.38	0.38	0.38
Total annual fund operating expenses	1.63	2.38	1.38
Contractual expense reimbursement2	-0.01	-0.01	-0.01
Total annual fund operating expenses after expense reimbursements	1.62	2.37	1.37

1

"Other expenses" have been estimated for the fund's first year of operations.

2

The advisor contractually agrees to waive a portion of its management fee and/or reimburse expenses for the fund and certain other John Hancock funds according to an asset level breakpoint schedule that is based on the aggregate net assets of all the funds participating in the waiver or reimbursement. This waiver is allocated proportionally among the participating funds. This agreement expires on July 31, 2021, unless renewed by mutual agreement of the fund and the advisor based upon a determination that this is appropriate under the circumstances at that time.

Expense example

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, except as shown below, 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:

Expenses ($)	A		C	I
Shares		Sold	Not Sold
1 year	657	340	240	139
3 years	988	742	742	436

Prospectus Supplement

John Hancock Investment Trust

John Hancock Alternative Risk Premia Fund (the fund)

Supplement dated December 18, 2019 to the current Class NAV Prospectus, as may be supplemented

Effective immediately, the Annual fund operating expenses table and the Expense example table for the fund in the "Fund summary" section are revised and restated as follows:

Annual fund operating expenses (%)
(expenses that you pay each year as a percentage of the value of your investment)	NAV
Management fee	1.00
Other expenses1	0.26
Total annual fund operating expenses	1.26
Contractual expense reimbursement2	-0.01
Total annual fund operating expenses after expense reimbursements	1.25

1

"Other expenses" have been estimated for the fund's first year of operations.

2

The advisor contractually agrees to waive a portion of its management fee and/or reimburse expenses for the fund and certain other John Hancock funds according to an asset level breakpoint schedule that is based on the aggregate net assets of all the funds participating in the waiver or reimbursement. This waiver is allocated proportionally among the participating funds. This agreement expires on July 31, 2021, unless renewed by mutual agreement of the fund and the advisor based upon a determination that this is appropriate under the circumstances at that time.

Expense example

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:

Expenses ($)	NAV
1 year	127
3 years	399

Prospectus Supplement

John Hancock Investment Trust

John Hancock Alternative Risk Premia Fund (the fund)

Supplement dated December 18, 2019 to the current Prospectus, as may be supplemented

Effective immediately, the Annual fund operating expenses table and the Expense example table for the fund in the "Fund summary" section are revised and restated as follows:

Annual fund operating expenses (%)
(expenses that you pay each year as a percentage of the value of your investment)	R6
Management fee	1.00
Other expenses1	0.27
Total annual fund operating expenses	1.27
Contractual expense reimbursement2	-0.01
Total annual fund operating expenses after expense reimbursements	1.26

1

"Other expenses" have been estimated for the fund's first year of operations.

2

The advisor contractually agrees to waive a portion of its management fee and/or reimburse expenses for the fund and certain other John Hancock funds according to an asset level breakpoint schedule that is based on the aggregate net assets of all the funds participating in the waiver or reimbursement. This waiver is allocated proportionally among the participating funds. This agreement expires on July 31, 2021, unless renewed by mutual agreement of the fund and the advisor based upon a determination that this is appropriate under the circumstances at that time.

Expense example

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:

Expenses ($)	R6
1 year	128
3 years	402

(John Hancock Alternative Risk Premia Fund - Classes A, C and I) | (John Hancock Alternative Risk Premia Fund)

Prospectus:

rr_ProspectusTable

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

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

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

Jul. 31, 2021

Other Expenses, New Fund, Based on Estimates [Text]

rr_OtherExpensesNewFundBasedOnEstimates

"Other expenses" have been estimated for the fund's first year of operations.

Expense Example [Heading]

rr_ExpenseExampleHeading

Expense example

Expense Example Narrative [Text Block]

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, except as shown below, 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:

Expense Example by, Year, Caption [Text]

rr_ExpenseExampleByYearCaption

Sold

Expense Example, No Redemption, By Year, Caption [Text]

rr_ExpenseExampleNoRedemptionByYearCaption

Not Sold

(John Hancock Alternative Risk Premia Fund - Classes A, C and I) | (John Hancock Alternative Risk Premia Fund) | Class A

Prospectus:

rr_ProspectusTable

Management fee

rr_ManagementFeesOverAssets

1.00%

Distribution and service (Rule 12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other expenses

rr_OtherExpensesOverAssets

0.38%

^[1]

Total annual fund operating expenses

rr_ExpensesOverAssets

1.63%

Contractual expense reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.01%)

^[2]

Total annual fund operating expenses after expense reimbursements

rr_NetExpensesOverAssets

1.62%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 657

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

$ 988

(John Hancock Alternative Risk Premia Fund - Classes A, C and I) | (John Hancock Alternative Risk Premia Fund) | Class C

Prospectus:

rr_ProspectusTable

Management fee

rr_ManagementFeesOverAssets

1.00%

Distribution and service (Rule 12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

0.38%

^[1]

Total annual fund operating expenses

rr_ExpensesOverAssets

2.38%

Contractual expense reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.01%)

^[2]

Total annual fund operating expenses after expense reimbursements

rr_NetExpensesOverAssets

2.37%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 340

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

742

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

240

Expense Example, No Redemption, 3 Years

rr_ExpenseExampleNoRedemptionYear03

$ 742

(John Hancock Alternative Risk Premia Fund - Classes A, C and I) | (John Hancock Alternative Risk Premia Fund) | Class I

Prospectus:

rr_ProspectusTable

Management fee

rr_ManagementFeesOverAssets

1.00%

Distribution and service (Rule 12b-1) fees

rr_DistributionAndService12b1FeesOverAssets

none

Other expenses

rr_OtherExpensesOverAssets

0.38%

^[1]

Total annual fund operating expenses

rr_ExpensesOverAssets

1.38%

Contractual expense reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.01%)

^[2]

Total annual fund operating expenses after expense reimbursements

rr_NetExpensesOverAssets

1.37%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 139

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

$ 436

(John Hancock Alternative Risk Premia Fund - Class NAV) | (John Hancock Alternative Risk Premia Fund)

Prospectus:

rr_ProspectusTable

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

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

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

Jul. 31, 2021

Other Expenses, New Fund, Based on Estimates [Text]

rr_OtherExpensesNewFundBasedOnEstimates

"Other expenses" have been estimated for the fund's first year of operations.

Expense Example [Heading]

rr_ExpenseExampleHeading

Expense example

Expense Example Narrative [Text Block]

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:

(John Hancock Alternative Risk Premia Fund - Class NAV) | (John Hancock Alternative Risk Premia Fund) | Class NAV

Prospectus:

rr_ProspectusTable

Management fee

rr_ManagementFeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

0.26%

^[1]

Total annual fund operating expenses

rr_ExpensesOverAssets

1.26%

Contractual expense reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.01%)

^[2]

Total annual fund operating expenses after expense reimbursements

rr_NetExpensesOverAssets

1.25%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 127

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

$ 399

(John Hancock Alternative Risk Premia Fund - Class R6) | (John Hancock Alternative Risk Premia Fund)

Prospectus:

rr_ProspectusTable

Operating Expenses Caption [Text]

rr_OperatingExpensesCaption

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

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

Jul. 31, 2021

Other Expenses, New Fund, Based on Estimates [Text]

rr_OtherExpensesNewFundBasedOnEstimates

"Other expenses" have been estimated for the fund's first year of operations.

Expense Example [Heading]

rr_ExpenseExampleHeading

Expense example

Expense Example Narrative [Text Block]

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:

(John Hancock Alternative Risk Premia Fund - Class R6) | (John Hancock Alternative Risk Premia Fund) | Class R6

Prospectus:

rr_ProspectusTable

Management fee

rr_ManagementFeesOverAssets

1.00%

Other expenses

rr_OtherExpensesOverAssets

0.27%

^[1]

Total annual fund operating expenses

rr_ExpensesOverAssets

1.27%

Contractual expense reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.01%)

^[2]

Total annual fund operating expenses after expense reimbursements

rr_NetExpensesOverAssets

1.26%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

$ 128

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

$ 402

[1] "Other expenses" have been estimated for the fund's first year of operations.

[2] The advisor contractually agrees to waive a portion of its management fee and/or reimburse expenses for the fund and certain other John Hancock funds according to an asset level breakpoint schedule that is based on the aggregate net assets of all the funds participating in the waiver or reimbursement. This waiver is allocated proportionally among the participating funds. This agreement expires on July 31, 2021, unless renewed by mutual agreement of the fund and the advisor based upon a determination that this is appropriate under the circumstances at that time.