v3.25.4
Performance Management - U.S. LARGE COMPANY PORTFOLIO
Oct. 31, 2025
Prospectus [Line Items]  
Bar Chart and Performance Table [Heading] Performance
Performance Narrative [Text Block]

The bar chart and table immediately following illustrate the variability of the Portfolio’s returns and are meant to provide some indication of the risks of investing in the Portfolio. The ETF Class shares of the Portfolio are a new

class of shares for which performance information is not available, and therefore, for periods prior to the inception of the ETF Class shares, the bar chart and table show performance information for the Institutional Class shares of the Portfolio, a mutual fund class of shares of the Portfolio not offered in this Prospectus. Returns of the ETF Class shares of the Portfolio may vary from the returns of the Institutional Class shares due to differences in expenses. The bar chart shows the changes in performance of the Institutional Class shares of the Portfolio from year to year. The table illustrates how annualized returns of the Institutional Class shares of the Portfolio for certain periods, both before and after taxes, compare with those of a broad measure of market performance. The Portfolio’s past performance (before and after taxes) is not an indication of future results. Updated performance information for the Portfolio can be obtained by visiting https://www.dimensional.com/us-en/funds.

The after-tax returns presented in the table for the Portfolio are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown in the table. In addition, the after-tax returns shown are not relevant to investors who hold shares of the Portfolio through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts.
Performance Past Does Not Indicate Future [Text] The Portfolio’s past performance (before and after taxes) is not an indication of future results.
Performance Information Illustrates Variability of Returns [Text] The bar chart and table immediately following illustrate the variability of the Portfolio’s returns and are meant to provide some indication of the risks of investing in the Portfolio. The ETF Class shares of the Portfolio are a new class of shares for which performance information is not available, and therefore, for periods prior to the inception of the ETF Class shares, the bar chart and table show performance information for the Institutional Class shares of the Portfolio, a mutual fund class of shares of the Portfolio not offered in this Prospectus. Returns of the ETF Class shares of the Portfolio may vary from the returns of the Institutional Class shares due to differences in expenses. The bar chart shows the changes in performance of the Institutional Class shares of the Portfolio from year to year.
Bar Chart [Heading] U.S. Large Company Portfolio Institutional Class Shares1 —Total Returns
Performance Table Heading Annualized Returns (%)
Performance Table Uses Highest Federal Rate The after-tax returns presented in the table for the Portfolio are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred In addition, the after-tax returns shown are not relevant to investors who hold shares of the Portfolio through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts.
Performance [Table]
Average Annual Total Returns - U.S. LARGE COMPANY PORTFOLIO
 12 Months Ended 60 Months Ended 120 Months Ended
Oct. 31, 2025
Dec. 31, 2024
Dec. 31, 2024
Dec. 31, 2024
S&P 500® Index2 | Average Annual Return, Label [Optional Text] [1],[2] S&P 500® Index2      
S&P 500® Index2 | Average Annual Return, Percent [2]   25.02% 14.53% 13.10%
Institutional Class | Average Annual Return, Label [Optional Text] [2] Return Before Taxes      
Institutional Class | Average Annual Return, Percent [2]   24.91% 14.46% 13.04%
Institutional Class | After Taxes on Distributions | Average Annual Return, Label [Optional Text] [2] Return After Taxes on Distributions      
Institutional Class | After Taxes on Distributions | Average Annual Return, Percent [2]   24.52% 13.27% 12.10%
Institutional Class | After Taxes on Distributions and Sales | Average Annual Return, Label [Optional Text] [2] Return After Taxes on Distributions and Sale of Portfolio Shares      
Institutional Class | After Taxes on Distributions and Sales | Average Annual Return, Percent [2]   14.99% 11.35% 10.62%
[1]

Copyright® 2024 S&P Dow Jones Indices LLC, a division of S&P Global. All rights reserved.
[2]

As of December 31, 2024, the ETF Class shares of the Portfolio had not yet incepted. Performance shown prior to the inception date of the ETF Class shares is from the Portfolio's Institutional Class shares, a mutual fund class of shares of the Portfolio not offered in this Prospectus. Returns for the ETF Class shares and Institutional Class shares may vary due to differences in their expenses.
Index No Deduction for Fees, Expenses, or Taxes [Text] (reflects no deduction for fees, expenses or taxes) [1]
Performance Availability Website Address [Text] https://www.dimensional.com/us-en/funds
Institutional Class  
Prospectus [Line Items]  
Highest Quarterly Return, Label [Optional Text] Highest Quarter
Highest Quarterly Return 20.55% [1]
Highest Quarterly Return, Date Jun. 30, 2020
Lowest Quarterly Return, Label [Optional Text] Lowest Quarter
Lowest Quarterly Return (19.61%) [1]
Lowest Quarterly Return, Date Mar. 31, 2020
[1]

As of December 31, 2024, the ETF Class shares of the Portfolio had not yet incepted. Performance shown prior to the inception date of the ETF Class shares is from the Portfolio's Institutional Class shares, a mutual fund class of shares of the Portfolio not offered in this Prospectus. Returns for the ETF Class shares and Institutional Class shares may vary due to differences in their expenses.