Focused Appreciation Portfolio Investment Strategy - Focused Appreciation Portfolio	Dec. 31, 2025
Prospectus [Line Items]
Strategy [Heading]	<span style="color:#000000;font-family:Arial;font-size:10.02pt;font-weight:bold;">PRINCIPAL INVESTMENT STRATEGIES</span>
Strategy Narrative [Text Block]	The Portfolio invests primarily in the equity securities of companies selected for their growth potential. The Portfolio focuses on stocks of large-capitalization companies, but may invest in companies of any size. For this purpose, large-capitalization companies are those with a market capitalization in excess of $5 billion at the time of purchase. The adviser employs a growth style of equity management that emphasizes companies with sustainable competitive advantages versus others, long-term structural growth drivers that will lead to above-average future cash flow growth, attractive cash flow returns or invested capital, and management teams focused on creating long-term value for shareholders. Long-term structural growth drivers are dynamics that in the manager’s opinion are not likely to change for five years or longer such as the transition of consumer shopping from in-store to online. The adviser aims to invest in companies when they trade at a significant discount to the estimate of their intrinsic value. The intrinsic value of a company is the true worth of its business as perceived by the portfolio managers, which may not be fully reflected in the market price of its stock. The adviser calculates the intrinsic value of a company by the discounted net present value of future cash flows. The Portfolio normally invests across a wide range of sectors and industries. The Portfolio’s sector exposure relative to its benchmark is driven by the adviser’s stock selection process and, as a result, may at times have a relatively high percentage of its assets invested in a particular sector, such as the information technology sector. The adviser utilizes a “focused” investment strategy resulting in the Portfolio investing primarily in a core group of 30-40 securities. The Portfolio may at times exceed this range. The Portfolio invests primarily in common stocks. The Portfolio may invest up to 20% of its net assets in foreign securities, including American Depositary Receipts (ADRs) and emerging market securities. The Portfolio may also invest in real estate investment trusts (REITs). The Portfolio is classified as “non-diversified” under the Investment Company Act of 1940, as amended, which means it may hold a larger position in a particular company or smaller number of companies than a “diversified” fund. The Portfolio may sell an investment when the portfolio manager believes an unfavorable structural change occurs within a given business or the markets in which it operates, a critical underlying investment assumption is flawed, when a more attractive reward-to-risk opportunity becomes available, when the current price reflects intrinsic value, or for other investment reasons which the portfolio manager deems appropriate.

Focused Appreciation Portfolio Investment Strategy - Focused Appreciation Portfolio

Dec. 31, 2025

<span style="color:#000000;font-family:Arial;font-size:10.02pt;font-weight:bold;">PRINCIPAL INVESTMENT STRATEGIES</span>

Strategy Narrative [Text Block]

The Portfolio invests primarily in the equity securities of companies selected for their growth potential. The Portfolio focuses on stocks of large-capitalization companies, but may invest in companies of any size. For this purpose, large-capitalization companies are those with a market capitalization in excess of $5 billion at the time of purchase. The adviser employs a growth style of equity management that emphasizes companies with sustainable competitive advantages versus others, long-term structural growth drivers that will lead to above-average future cash flow growth, attractive cash flow returns or invested capital, and management teams focused on creating long-term value for shareholders. Long-term structural growth drivers are dynamics that in the manager’s opinion are not likely to change for five years or longer such as the transition of consumer shopping from in-store to online. The adviser aims to invest in companies when they trade at a significant discount to the estimate of their intrinsic value. The intrinsic value of a company is the true worth of its business as perceived by the portfolio managers, which may not be fully reflected in the market price of its stock. The adviser calculates the intrinsic value of a company by the discounted net present value of future cash flows. The Portfolio normally invests across a wide range of sectors and industries. The Portfolio’s sector exposure relative to its benchmark is driven by the adviser’s stock selection process and, as a result, may at times have a relatively high percentage of its assets invested in a particular sector, such as the information technology sector. The adviser utilizes a “focused” investment strategy resulting in the Portfolio investing primarily in a core group of 30-40 securities. The Portfolio may at times exceed this range. The Portfolio invests primarily in common stocks. The Portfolio may invest up to 20% of its net assets in foreign securities, including American Depositary Receipts (ADRs) and emerging market securities. The Portfolio may also invest in real estate investment trusts (REITs). The Portfolio is classified as “non-diversified” under the Investment Company Act of 1940, as amended, which means it may hold a larger position in a particular company or smaller number of companies than a “diversified” fund. The Portfolio may sell an investment when the portfolio manager believes an unfavorable structural change occurs within a given business or the markets in which it operates, a critical underlying investment assumption is flawed, when a more attractive reward-to-risk opportunity becomes available, when the current price reflects intrinsic value, or for other investment reasons which the portfolio manager deems appropriate.