v3.25.4

Alger Responsible Investing Fund Shareholder Fees	Oct. 31, 2025 USD ($)
Class Z Shares [Member] \| Alger Responsible Investing Fund \| Class Z
Prospectus [Line Items]
Shareholder Fee, Other	$ 0

X

- References

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

+ Details

Name:	oef_ProspectusLineItems
Namespace Prefix:	oef_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form N-1A
-Section 3
-Subsection instruction
-Paragraph 2

+ Details

Name:	oef_ShareholderFeeOther
Namespace Prefix:	oef_
Data Type:	dtr-types:nonNegativeMonetaryItemType
Balance Type:	na
Period Type:	duration

X

- Details

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

X

- Details

Name:	dei_LegalEntityAxis=af_S000014607Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	oef_ClassAxis=af_C000174226Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: