Alger Growth & Income Portfolio Investment Strategy - Class I2 [Member] - Alger Growth & Income Portfolio	Dec. 31, 2025
Prospectus [Line Items]
Strategy [Heading]	<span style="color:#0064FA;font-family:Arial;font-size:10pt;font-weight:bold;">Principal Investment Strategy</span>
Strategy Narrative [Text Block]	Fred Alger Management, LLC (the “Manager”) believes companies undergoing Positive Dynamic Change offer the best opportunities. Positive Dynamic Change refers to companies realizing High Unit Volume Growth or companies undergoing Positive Lifecycle Change. High Unit Volume Growth companies are traditional growth companies experiencing, for example, rapidly growing demand or market dominance. Positive Lifecycle Change companies are, for example, companies benefitting from new regulations, a new product innovation or new management.The Portfolio invests primarily in equity securities such as common or preferred stocks which the Manager believes offer opportunities for capital appreciation and which also pay dividends. In considering such companies, the Manager classifies them into three categories: Dividend Leaders – companies that generate high dividend yields; Dividend Growers – companies that have a history of strong and consistent dividend growth; and Kings of Cash Flow – companies that have strong potential for generating capital appreciation and the ability to return significant amounts of cash to investors as a result of their free cash flow. It is a fundamental policy of the Portfolio to invest at least 65% of its total assets in dividend paying equity securities. The Portfolio may invest up to 35% of its total assets in equity securities that do not pay dividends or in money market instruments and repurchase agreements. The Portfolio focuses on growing companies that, at the time of purchase of the securities, have a market capitalization within the range of companies included in the S&P 500 Index. The index is designed to track the performance of large-capitalization stocks. At December 31, 2025, the market capitalization of the companies in this index ranged from $5.8 billion to $4.5 trillion.The Portfolio may sell a stock when it reaches a target price, it fails to perform as expected, or other opportunities appear more attractive. As a result, the Portfolio may engage in active trading of portfolio securities.The Portfolio may invest a significant portion of its assets in securities of companies conducting business within a single sector, as defined by third party sources, including, but not limited to, the information technology, communication services, and financials sectors. For the purpose of categorizing companies, sectors are a broader category than industries and industries comprise sectors.The Portfolio may invest in cash (and cash equivalents) when the Portfolio is unable to find enough attractive long-term investments to meet its investment objective, to meet redemptions and/or when the Manager believes it is advisable to do so during times of short-term market volatility. During these times, cash (and cash equivalents) will not exceed 35% of the Portfolio’s net assets. The Portfolio is classified as diversified within the meaning of the Investment Company Act of 1940, as amended. The diversification of the Portfolio’s holdings is measured at the time the Portfolio purchases a security. Because of its long-term approach, the Portfolio could have a significant percentage of its assets invested in securities that have appreciated beyond their market capitalizations at the time of the Portfolio’s investment.

Alger Growth & Income Portfolio Investment Strategy - Class I2 [Member] - Alger Growth & Income Portfolio

Dec. 31, 2025

<span style="color:#0064FA;font-family:Arial;font-size:10pt;font-weight:bold;">Principal Investment Strategy</span>

Fred Alger Management, LLC (the “Manager”) believes companies undergoing Positive Dynamic Change offer the best opportunities. Positive Dynamic Change refers to companies realizing High Unit Volume Growth or companies undergoing Positive Lifecycle Change. High Unit Volume Growth companies are traditional growth companies experiencing, for example, rapidly growing demand or market dominance. Positive Lifecycle Change companies are, for example, companies benefitting from new regulations, a new product innovation or new management.The Portfolio invests primarily in equity securities such as common or preferred stocks which the Manager believes offer opportunities for capital appreciation and which also pay dividends. In considering such companies, the Manager classifies them into three categories: Dividend Leaders – companies that generate high dividend yields; Dividend Growers – companies that have a history of strong and consistent dividend growth; and Kings of Cash Flow – companies that have strong potential for generating capital appreciation and the ability to return significant amounts of cash to investors as a result of their free cash flow. It is a fundamental policy of the Portfolio to invest at least 65% of its total assets in dividend paying equity securities. The Portfolio may invest up to 35% of its total assets in equity securities that do not pay dividends or in money market instruments and repurchase agreements. The Portfolio focuses on growing companies that, at the time of purchase of the securities, have a market capitalization within the range of companies included in the S&P 500 Index. The index is designed to track the performance of large-capitalization stocks. At December 31, 2025, the market capitalization of the companies in this index ranged from $5.8 billion to $4.5 trillion.The Portfolio may sell a stock when it reaches a target price, it fails to perform as expected, or other opportunities appear more attractive. As a result, the Portfolio may engage in active trading of portfolio securities.The Portfolio may invest a significant portion of its assets in securities of companies conducting business within a single sector, as defined by third party sources, including, but not limited to, the information technology, communication services, and financials sectors. For the purpose of categorizing companies, sectors are a broader category than industries and industries comprise sectors.The Portfolio may invest in cash (and cash equivalents) when the Portfolio is unable to find enough attractive long-term investments to meet its investment objective, to meet redemptions and/or when the Manager believes it is advisable to do so during times of short-term market volatility. During these times, cash (and cash equivalents) will not exceed 35% of the Portfolio’s net assets. The Portfolio is classified as diversified within the meaning of the Investment Company Act of 1940, as amended. The diversification of the Portfolio’s holdings is measured at the time the Portfolio purchases a security. Because of its long-term approach, the Portfolio could have a significant percentage of its assets invested in securities that have appreciated beyond their market capitalizations at the time of the Portfolio’s investment.