Alger International Small Cap Fund - Z Performance Management - Class Z Shares [Member] - Alger International Small Cap Fund - Z	Jun. 23, 2025
Prospectus [Line Items]
Bar Chart and Performance Table [Heading]	<span style="color:#0064FA;font-family:Arial;font-size:10pt;font-weight:bold;">Performance</span>
Performance Narrative [Text Block]	No performance information will be presented until the Fund has been in operation for a full calendar year. Annual performance information gives some indication of the risks of an investment in the Fund by comparing the Fund’s performance with a broad measure of market performance. The Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Updated performance information is available on the Fund’s website at www.alger.com.
Performance Past Does Not Indicate Future [Text]	<span style="color:#262626;font-family:Arial;font-size:9pt;">The Fund’s past performance (before and after taxes) is not necessarily an indication of how the </span><span style="color:#262626;font-family:Arial;font-size:9pt;">Fund will perform in the future.</span>
Performance One Year or Less [Text]	<span style="color:#262626;font-family:Arial;font-size:9pt;">No performance information will be presented until the Fund has been in operation for a full calendar year.</span>
Performance Availability Website Address [Text]	<span style="color:#262626;font-family:Arial;font-size:9pt;">www.alger.com</span>