Large Company Value Portfolio Investment Strategy - Large Company Value 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]	Normally, the Portfolio invests at least 80% of net assets (plus any borrowings for investment purposes) in securities of large-capitalization value companies. For purposes of the Portfolio, large-capitalization companies are those companies with market capitalizations within the capitalization range of the Russell 1000® Index. As of March 31, 2026, the market capitalization range of the Russell 1000® Index was approximately $907.10 million to $4.24 trillion. Value companies, as defined by the adviser, are those included in a third-party value index or those that exhibit certain financial characteristics (e.g., price-to-earnings ratio, price-to-book ratio, enterprise value-to-EBITDA ratio, cash flow trends or dividend payment history and projections) determined by the adviser to indicate the company is undervalued by the market. For this purpose, a third-party value index is an index developed, calculated, and maintained by a third-party that measures the performance of value stocks. Companies may be undervalued due to market declines, poor economic conditions, actual or anticipated bad news regarding the issuer or its industry, or because they have been overlooked by the market. The adviser attempts to purchase the stocks of these undervalued companies and hold each stock until it has returned to favor in the market and the price has increased to, or is higher than, a level the adviser believes more accurately reflects the fair value of the company. The Portfolio’s sector exposure relative to its benchmark is driven by the adviser’s stock selection process, and, as a result, the Portfolio may at times have a relatively high percentage of its assets invested in a particular sector. The adviser uses a variety of analytical research tools and techniques to help make decisions about buying or holding securities of companies that meet its investment criteria and sell the securities of companies that do not. The Portfolio normally invests in a relatively limited number of Companies, generally 30-50. While most assets will be invested in U.S. equity securities, which includes common stocks, preferred stocks, warrants and securities convertible into common or preferred stocks, in keeping with the Portfolio’s objectives, it may also invest in American Depositary Receipts (ADRs) and foreign securities (up to 20% of net assets), including those of companies located in emerging markets. The Portfolio may utilize futures for cash management purposes and forwards to hedge foreign currency exposure. The adviser may sell stocks from the Portfolio if it believes a stock no longer meets established valuation criteria.

Large Company Value Portfolio Investment Strategy - Large Company Value 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]

Normally, the Portfolio invests at least 80% of net assets (plus any borrowings for investment purposes) in securities of large-capitalization value companies. For purposes of the Portfolio, large-capitalization companies are those companies with market capitalizations within the capitalization range of the Russell 1000® Index. As of March 31, 2026, the market capitalization range of the Russell 1000® Index was approximately $907.10 million to $4.24 trillion. Value companies, as defined by the adviser, are those included in a third-party value index or those that exhibit certain financial characteristics (e.g., price-to-earnings ratio, price-to-book ratio, enterprise value-to-EBITDA ratio, cash flow trends or dividend payment history and projections) determined by the adviser to indicate the company is undervalued by the market. For this purpose, a third-party value index is an index developed, calculated, and maintained by a third-party that measures the performance of value stocks. Companies may be undervalued due to market declines, poor economic conditions, actual or anticipated bad news regarding the issuer or its industry, or because they have been overlooked by the market. The adviser attempts to purchase the stocks of these undervalued companies and hold each stock until it has returned to favor in the market and the price has increased to, or is higher than, a level the adviser believes more accurately reflects the fair value of the company. The Portfolio’s sector exposure relative to its benchmark is driven by the adviser’s stock selection process, and, as a result, the Portfolio may at times have a relatively high percentage of its assets invested in a particular sector. The adviser uses a variety of analytical research tools and techniques to help make decisions about buying or holding securities of companies that meet its investment criteria and sell the securities of companies that do not. The Portfolio normally invests in a relatively limited number of Companies, generally 30-50. While most assets will be invested in U.S. equity securities, which includes common stocks, preferred stocks, warrants and securities convertible into common or preferred stocks, in keeping with the Portfolio’s objectives, it may also invest in American Depositary Receipts (ADRs) and foreign securities (up to 20% of net assets), including those of companies located in emerging markets. The Portfolio may utilize futures for cash management purposes and forwards to hedge foreign currency exposure. The adviser may sell stocks from the Portfolio if it believes a stock no longer meets established valuation criteria.