John Hancock Investment Grade Bond Fund Expense Example - John Hancock Bond Trust Class NAV [Member] - John Hancock Investment Grade Bond Fund - Class NAV	May 31, 2025 USD ($)
Prospectus [Line Items]
Expense Example, with Redemption, 1 Year	$ 39
Expense Example, with Redemption, 3 Years	140
Expense Example, with Redemption, 5 Years	250
Expense Example, with Redemption, 10 Years	$ 571

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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