John Hancock High Yield Fund Investment Objectives and Goals - John Hancock High Yield Fund Classes A C I and R6 [Member] - John Hancock High Yield Fund	May 31, 2026
Prospectus [Line Items]
Risk/Return [Heading]	<span style="color:#000000;font-family:Arial Narrow;font-size:24pt;">John Hancock High Yield Fund</span>
Objective [Heading]	<span style="color:#000000;font-family:Arial Narrow;font-size:10pt;font-weight:bold;">Investment objective</span>
Objective, Primary [Text Block]	To seek high current income. Capital appreciation is a secondary goal.
Objective, Secondary [Text Block]	Capital appreciation is a secondary goal.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form N-1A
-Section 2
-Subsection a

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form N-1A
-Section 2
-Subsection a

Name:	oef_ObjectivePrimaryTextBlock
Namespace Prefix:	oef_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form N-1A
-Section 2
-Subsection a

Name:	oef_ObjectiveSecondaryTextBlock
Namespace Prefix:	oef_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form N-1A
-Section 1
-Subsection a

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Section 2
-Name Form N-1A
-Subsection a

Name:	dei_DocumentInformationDocumentAxis=jhf_JohnHancockHighYieldFundClassesACIandR6Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	dei_LegalEntityAxis=jhf_S000000614Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: