Alger Concentrated Equity Fund Expense Example - Class Z Shares [Member] - Alger Concentrated Equity Fund - Class Z	Oct. 31, 2025 USD ($)
Prospectus [Line Items]
Expense Example, with Redemption, 1 Year	$ 57
Expense Example, with Redemption, 3 Years	470
Expense Example, with Redemption, 5 Years	1,055
Expense Example, with Redemption, 10 Years	$ 2,645

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