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John Hancock Investment Grade Bond Fund Average Annual Total Returns - John Hancock Bond Trust Class NAV [Member]
12 Months Ended 60 Months Ended 78 Months Ended 120 Months Ended
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Bloomberg U.S. Aggregate Bond Index (reflects no deduction for fees, expenses, or taxes)[Member]        
Prospectus [Line Items]        
Average Annual Return, Percent 7.30% (0.36%) 1.26% 2.01%
Class NAV        
Prospectus [Line Items]        
Average Annual Return, Percent 7.36% (0.51%)   2.00%
Class NAV | After Taxes on Distributions        
Prospectus [Line Items]        
Average Annual Return, Percent 5.62% (1.85%)   0.71%
Class NAV | After Taxes on Distributions and Sales        
Prospectus [Line Items]        
Average Annual Return, Percent 4.62% (0.94%)   0.98%