Alger Capital Appreciation Portfolio Performance Management - Class S Shares [Member] - Alger Capital Appreciation Portfolio |
Dec. 31, 2025 |
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| 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] | The following bar chart and the table beneath it provide some indication of the risks of investing in the Portfolio by showing changes in the Portfolio’s performance from year to year. The bar chart shows how the Portfolio’s average annual returns have varied over the indicated periods. The table shows how the Portfolio’s average annual returns compare with those of an appropriate broad-based securities market index that represents the overall domestic equity market and a more narrowly based index that reflects the market sectors in which the Portfolio invests. The Portfolio’s additional index, the Russell 1000 Growth Index, is an index of common stocks designed to track performance of large capitalization companies with greater than average growth orientation.Performance in the bar chart does not reflect fees, expenses, or charges that may be imposed by qualified pension or retirement plans or under variable annuity contracts or variable life insurance policies. If the bar chart reflected the applicable fees, expenses, or charges, returns would be less than those shown.The Portfolio’s past performance is not necessarily an indication of how it will perform in the future. Updated performance information is available on the Portfolio’s website www.alger.com. |
| Performance Past Does Not Indicate Future [Text] | <span style="color:#262626;font-family:Arial;font-size:9pt;">The Portfolio’s past performance is not necessarily an indication of how it will perform in the future.</span> |
| Performance Information Illustrates Variability of Returns [Text] | <span style="color:#262626;font-family:Arial;font-size:9pt;">The following bar chart and the table beneath it provide some indication of the risks of investing in the Portfolio by showing changes in the Portfolio’s performance from year to year.</span><span style="color:#262626;font-family:Arial;font-size:9pt;line-height:11pt;"> </span><span style="color:#262626;font-family:Arial;font-size:9pt;">The bar chart shows how the Portfolio’s average annual returns have varied over the indicated periods.</span><span style="color:#262626;font-family:Arial;font-size:9pt;line-height:11pt;"> </span><span style="color:#262626;font-family:Arial;font-size:9pt;">The table shows how the Portfolio’s average annual returns compare with those of an appropriate broad-based securities market index that represents the overall domestic equity market and a more narrowly based index that reflects the market sectors in which the Portfolio invests. </span> |
| Performance Additional Market Index [Text] | <span style="color:#262626;font-family:Arial;font-size:9pt;">The Portfolio’s additional index, the Russell 1000 Growth </span><span style="color:#262626;font-family:Arial;font-size:9pt;">Index, is an index of common stocks designed to track performance of large capitalization companies with greater than average growth orientation.</span> |
| Bar Chart Does Not Reflect Sales Loads [Text] | <span style="color:#262626;font-family:Arial;font-size:9pt;">Performance in the bar chart does not reflect fees, expenses, or charges that may be imposed by qualified pension or retirement plans or under variable annuity contracts or variable life insurance policies. If the bar chart reflected the applicable fees, expenses,</span><span style="color:#262626;font-family:Arial;font-size:9pt;line-height:11pt;"> </span><span style="color:#262626;font-family:Arial;font-size:9pt;">or charges,</span><span style="color:#262626;font-family:Arial;font-size:9pt;line-height:11pt;"> </span><span style="color:#262626;font-family:Arial;font-size:9pt;">returns would be less than those shown.</span> |
| Bar Chart [Heading] | <span style="color:#262626;font-family:Arial;font-size:10pt;font-weight:bold;">Annual Total Return for Class S Shares</span><span style="color:#262626;font-family:Arial;font-size:10pt;line-height:12pt;"> </span><span style="color:#262626;font-family:Arial;font-size:10pt;font-style:italic;">as of December 31 (%)</span> |
| Bar Chart Closing [Text Block] | Best Quarter:Q2 202528.94%Worst Quarter:Q2 2022-24.88% |
| Performance Table Heading | <span style="color:#0064FA;font-family:Arial;font-size:10pt;font-weight:bold;">Average Annual Total Return as of December 31, 2025</span> |
| Performance Availability Website Address [Text] | <span style="color:#262626;font-family:Arial;font-size:9pt;">www.alger.com</span> |
| Class S | |
| Prospectus [Line Items] | |
| Highest Quarterly Return, Label [Optional Text] | <span style="color:#262626;font-family:Arial;font-size:8pt;font-weight:bold;">Best Quarter:</span> |
| Highest Quarterly Return | 28.94% |
| Highest Quarterly Return, Date | Jun. 30, 2025 |
| Lowest Quarterly Return, Label [Optional Text] | <span style="color:#262626;font-family:Arial;font-size:8pt;font-weight:bold;">Worst Quarter:</span> |
| Lowest Quarterly Return | (24.88%) |
| Lowest Quarterly Return, Date | Jun. 30, 2022 |