Expense Example - Alger Mid Cap Growth Fund - Alger Mid Cap Growth Fund Class Z	Oct. 31, 2025 USD ($)
Prospectus [Line Items]
Expense Example, with Redemption, 1 Year	$ 81
Expense Example, with Redemption, 3 Years	272
Expense Example, with Redemption, 5 Years	488
Expense Example, with Redemption, 10 Years	$ 1,112

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