John Hancock Investment Grade Bond Fund Shareholder Fees - John Hancock Investment Grade Bond Fund Classes A C I R2 R4 and R6 [Member] - John Hancock Investment Grade Bond Fund	May 31, 2026 USD ($)
Class A
Prospectus [Line Items]
Maximum Cumulative Sales Charge (as a percentage of Offering Price)	4.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price)	0.75%
Maximum Account Fee	$ 20
Class C
Prospectus [Line Items]
Maximum Cumulative Sales Charge (as a percentage of Offering Price)	0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price)	1.00%
Maximum Account Fee	$ 20
Class I
Prospectus [Line Items]
Maximum Cumulative Sales Charge (as a percentage of Offering Price)	0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price)	0.00%
Maximum Account Fee	$ 0
Class R2
Prospectus [Line Items]
Maximum Cumulative Sales Charge (as a percentage of Offering Price)	0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price)	0.00%
Maximum Account Fee	$ 0
Class R4
Prospectus [Line Items]
Maximum Cumulative Sales Charge (as a percentage of Offering Price)	0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price)	0.00%
Maximum Account Fee	$ 0
Class R6
Prospectus [Line Items]
Maximum Cumulative Sales Charge (as a percentage of Offering Price)	0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price)	0.00%
Maximum Account Fee	$ 0