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Prospectus Summary | DFA Inflation-Protected Securities Portfolio  
Risk/Return: rr_RiskReturnAbstract  
Risk/Return [Heading] rr_RiskReturnHeading DFA Inflation-Protected Securities Portfolio
Objective [Heading] rr_ObjectiveHeading Investment Objective
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The investment objective of the DFA Inflation-Protected Securities Portfolio (the “Inflation-Protected Portfolio” or the “Portfolio”) is to provide inflation protection and earn current income consistent with inflation-protected securities.
Expense [Heading] rr_ExpenseHeading Fees and Expenses of the Portfolio
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock

This table describes the fees and expenses you may pay if you buy, hold or sell shares of the Portfolio. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the table and Example below.
Shareholder Fees Caption [Text] rr_ShareholderFeesCaption Shareholder Fees (fees paid directly from your investment)
Operating Expenses Caption [Text] rr_OperatingExpensesCaption Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Portfolio Turnover [Heading] rr_PortfolioTurnoverHeading PORTFOLIO TURNOVER
Portfolio Turnover [Text Block] rr_PortfolioTurnoverTextBlock

A fund generally pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in Annual Fund Operating Expenses or in the Example, affect the Portfolio’s performance. During the most recent fiscal year, the Portfolio's portfolio turnover rate was 7% of the average value of its investment portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 7.00%
Expense Example [Heading] rr_ExpenseExampleHeading EXAMPLE
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock

This Example is meant to help you compare the cost of investing in the Portfolio with the cost of investing in other funds. The Example assumes that you invest $10,000 in the Portfolio for the time periods indicated. The Example also assumes that your investment has a 5% return each year and that the Portfolio’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs whether you redeem or hold your shares would be:

Strategy [Heading] rr_StrategyHeading Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

The Inflation-Protected Portfolio seeks its investment objective by investing in a universe of inflation-protected securities that are structured to provide returns linked to the rate of inflation over the long-term. The Portfolio ordinarily invests in inflation-protected securities issued by the U.S. Government and its agencies and instrumentalities and the credit quality of such inflation-protected securities will be that of such applicable U.S. government, agency or instrumentality issuer.

As a non-fundamental policy, under normal circumstances, the Inflation-Protected Portfolio will invest at least 80% of its net assets in inflation-protected securities. Inflation-protected securities (also known as inflation-indexed securities) are securities whose principal and/or interest payments are adjusted for inflation, unlike conventional debt

securities that make fixed principal and interest payments. Inflation-protected securities include Treasury Inflation-Protected Securities (“TIPS”), which are securities issued by the U.S. Treasury. The principal value of TIPS is adjusted for inflation (payable at maturity) and the semi-annual interest payments by TIPS equal a fixed percentage of the inflation-adjusted principal amount. These inflation adjustments are based upon the Consumer Price Index for Urban Consumers (CPI-U). The original principal value of TIPS is guaranteed. At maturity, TIPS are redeemed at the greater of their inflation-adjusted principal or par amount at original issue. Other types of inflation-protected securities may use other methods to adjust for inflation and other measures of inflation. In addition, inflation-protected securities issued by entities other than the U.S. Treasury may not provide a guarantee of principal value at maturity.

Generally, the Inflation-Protected Portfolio will purchase inflation-protected securities with maturities between five and twenty years from the date of settlement, although at times, the Portfolio may purchase securities outside of this range. Under normal circumstances, when determining its duration, the Portfolio will consider a weighted average duration similar to the Bloomberg U.S. TIPS Index, which was approximately 6.46 years as of December 31, 2024. Duration is a measure of the sensitivity of a security’s price to changes in interest rates. The longer a security’s duration, the more sensitive it will be to changes in interest rates.

The Inflation-Protected Portfolio is authorized to invest more than 25% of its total assets in U.S. Treasury bonds, bills and notes and obligations of U.S. government agencies and instrumentalities. The Portfolio may also invest in money market funds. The Portfolio will not shift the maturity of its investments in anticipation of interest rate movements.

The Inflation-Protected Portfolio may purchase or sell futures contracts and options on futures contracts, to hedge its interest rate exposure or for non-hedging purposes, such as a substitute for direct investment or to increase or decrease market exposure based on actual or expected cash inflows to or outflows from the Portfolio.

The Inflation-Protected Portfolio may lend its portfolio securities to generate additional income.
Risk [Heading] rr_RiskHeading Principal Risks
Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

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 bar chart shows the changes in the Portfolio’s performance from year to year. The table illustrates how annualized returns for certain periods, both before and after taxes, compare with those of a broad measure of market performance. The table also includes the performance of an additional index with a similar investment universe as the Portfolio. 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 Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns 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 bar chart shows the changes in the Portfolio’s performance from year to year.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress https://www.dimensional.com/us-en/funds
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture The Portfolio’s past performance (before and after taxes) is not an indication of future results.
Bar Chart [Heading] rr_BarChartHeading DFA Inflation-Protected Securities Portfolio Institutional Class Shares —Total Returns
Performance Table Heading rr_PerformanceTableHeading Annualized Returns (%)
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate 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 rr_PerformanceTableNotRelevantToTaxDeferred 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.
Prospectus Summary | DFA Inflation-Protected Securities Portfolio | Principal Risks  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock

Principal Risks

Because the value of your investment in the Portfolio will fluctuate, there is the risk that you will lose money. An investment in the Portfolio is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The following is a description of principal risks of investing in the Portfolio.
Prospectus Summary | DFA Inflation-Protected Securities Portfolio | Risk Lose Money [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock Because the value of your investment in the Portfolio will fluctuate, there is the risk that you will lose money.
Prospectus Summary | DFA Inflation-Protected Securities Portfolio | Risk Not Insured [Member]  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock An investment in the Portfolio is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
Prospectus Summary | DFA Inflation-Protected Securities Portfolio | Market Risk  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock

Market Risk: Even a long-term investment approach cannot guarantee a profit. Economic, market, political, and issuer-specific conditions and events will cause the value of securities, and a fund that owns them, to rise or fall.
Prospectus Summary | DFA Inflation-Protected Securities Portfolio | Interest Rate Risk  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock

Interest Rate Risk: Fixed income securities are subject to interest rate risk because the prices of fixed income securities tend to move in the opposite direction of interest rates. When interest rates rise, fixed income security prices fall. During periods of very low or negative interest rates, a fund may be subject to a greater risk of rising interest rates. When interest rates fall, fixed income security prices rise. In general, fixed income securities with longer maturities are more sensitive to changes in interest rates.
Prospectus Summary | DFA Inflation-Protected Securities Portfolio | Inflation-Protected Securities Tax Risk  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock

Inflation-Protected Securities Tax Risk: Any increase in the principal amount of an inflation-protected security may be included for tax purposes in a fund’s gross income, even though no cash attributable to such gross income has been received by a fund. In such event, a fund may be required to make annual gross distributions to shareholders that exceed the cash it has otherwise received. In order to pay such distributions, a fund may be required to raise cash by selling its investments. The sale of such investments could result in capital gains to a fund and additional capital gain distributions to shareholders. In addition, adjustments during the taxable year for deflation to an inflation-indexed bond held by a fund may cause amounts previously distributed to shareholders in the taxable year as income to be characterized as a return of capital, which could increase or decrease a fund’s ordinary income distributions to shareholders, and may cause some of a fund’s distributed income to be classified as a return of capital.
Prospectus Summary | DFA Inflation-Protected Securities Portfolio | Inflation-Protected Securities Interest Rate Risk  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock

Inflation-Protected Securities Interest Rate Risk: Inflation-protected securities may react differently from other fixed income securities to changes in interest rates. Because interest rates on inflation-protected securities are adjusted for inflation, the values of these securities are not materially affected by inflation expectations. Therefore, the value of inflation-protected securities are anticipated to change in response to changes in “real” interest rates, which

represent nominal (stated) interest rates reduced by the expected impact of inflation. Generally, the value of an inflation-protected security will fall when real interest rates rise and will rise when real interest rates fall.
Prospectus Summary | DFA Inflation-Protected Securities Portfolio | Credit Risk  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock

Credit Risk: Credit risk is the risk that the issuer of a security may be unable to make interest payments and/or repay principal when due. A downgrade to an issuer’s credit rating or a perceived change in an issuer’s financial strength may affect a security’s value, and thus, impact the performance of a fund holding such securities. Government agency obligations have different levels of credit support and, therefore, different degrees of credit risk. Securities issued by agencies and instrumentalities of the U.S. Government that are supported by the full faith and credit of the United States, such as the Federal Housing Administration and Ginnie Mae, present little credit risk. Other securities issued by agencies and instrumentalities sponsored by the U.S. Government, that are supported only by the issuer’s right to borrow from the U.S. Treasury, subject to certain limitations, and securities issued by agencies and instrumentalities sponsored by the U.S. Government that are sponsored by the credit of the issuing agencies, such as Freddie Mac and Fannie Mae, are subject to a greater degree of credit risk. U.S. government agency securities issued or guaranteed by the credit of the agency may still involve a risk of non-payment of principal and/or interest.
Prospectus Summary | DFA Inflation-Protected Securities Portfolio | Risks of Investing for Inflation Protection  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock

Risks of Investing for Inflation Protection: Because the interest and/or principal payments on an inflation-protected security are adjusted periodically for changes in inflation, the income distributed by a fund investing in such securities may be irregular. Although the U.S. Treasury guarantees to pay at maturity at least the original face value of any inflation-protected securities the Treasury issues, other issuers may not offer the same guarantee. Inflation-protected securities are not protected against deflation. As a result, in a period of deflation, the principal and income of inflation-protected securities held by a fund will decline and the fund may suffer a loss during such periods. While inflation-protected securities are expected to be protected from long-term inflationary trends, short-term increases in inflation may lead to a decline in the value of a fund holding such securities. For example, if interest rates rise due to reasons other than inflation, a fund’s investment in these securities may not be protected to the extent that the increase is not reflected in the securities’ inflation measures. In addition, positive adjustments to principal generally will result in taxable income to a fund at the time of such adjustments (which generally would be distributed by the fund as part of its taxable dividends), even though the principal amount is not paid until maturity. The current market value of inflation-protected securities is not guaranteed and will fluctuate.
Prospectus Summary | DFA Inflation-Protected Securities Portfolio | Income Risk  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock

Income Risk: Income risk is the risk that falling interest rates will cause a fund’s income to decline because, among other reasons, the proceeds from maturing short-term securities in its portfolio may be reinvested in lower-yielding securities.
Prospectus Summary | DFA Inflation-Protected Securities Portfolio | Liquidity Risk  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock

Liquidity Risk: Liquidity risk exists when particular portfolio investments are difficult to purchase or sell. To the extent that a fund holds illiquid investments, the fund’s performance may be reduced due to an inability to sell the investments at opportune prices or times. Liquid portfolio investments may become illiquid or less liquid after purchase by a fund due to low trading volume, adverse investor perceptions and/or other market developments. Liquidity risk includes the risk that a fund will experience significant net redemptions at a time when it cannot find willing buyers for its portfolio securities or can only sell its portfolio securities at a material loss or at increased costs. Liquidity risk can be more pronounced in periods of market turmoil or in situations where ownership of shares of a fund are concentrated in one or a few investors.

Prospectus Summary | DFA Inflation-Protected Securities Portfolio | Derivatives Risk  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock

Derivatives Risk: Derivatives are instruments, such as futures contracts, and options thereon, whose value is derived from that of other assets, rates or indices. Derivatives can be used for hedging (attempting to reduce risk by offsetting one investment position with another) or non-hedging purposes. Hedging with derivatives may increase expenses, and there is no guarantee that a hedging strategy will work. While hedging can reduce or eliminate losses, it can also reduce or eliminate gains or cause losses if the market moves in a manner different from that anticipated by a fund or if the cost of the derivative outweighs the benefit of the hedge. The use of derivatives for non-hedging purposes may be considered to carry more risk than other types of investments. When a fund uses derivatives, the fund will be directly exposed to the risks of those derivatives. Derivative instruments are subject to a number of risks including counterparty, liquidity, interest rate, market, credit and management risks, as well as the risk of improper valuation. Changes in the value of a derivative may not correlate perfectly with the underlying asset, rate or index, and a fund could lose more than the principal amount invested.

Prospectus Summary | DFA Inflation-Protected Securities Portfolio | Securities Lending Risk  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock

Securities Lending Risk: Securities lending involves the risk that the borrower may fail to return the securities in a timely manner or at all. As a result, a fund may lose money and there may be a delay in recovering the loaned securities. A fund could also lose money if it does not recover the securities and/or the value of the collateral falls,

including the value of investments made with cash collateral. Securities lending also may have certain adverse tax consequences.
Prospectus Summary | DFA Inflation-Protected Securities Portfolio | Operational Risk  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock

Operational Risk: Operational risks include human error, changes in personnel, system changes, faults in communication, and failures in systems, technology, or processes. Various operational events or circumstances are outside a fund’s or its advisor’s control, including instances at third parties. A fund and its advisor seek to reduce these operational risks through controls and procedures. However, measures that seek to reduce these operational risks through controls and procedures may not address every possible risk and may be inadequate to address these risks.
Prospectus Summary | DFA Inflation-Protected Securities Portfolio | Cyber Security Risk  
Risk/Return: rr_RiskReturnAbstract  
Risk [Text Block] rr_RiskTextBlock

Cyber Security Risk: A fund and its service providers’ use of internet, technology and information systems may expose the fund to potential risks linked to cyber security breaches of those technological or information systems. Cyber security breaches, amongst other things, could allow an unauthorized party to gain access to proprietary information, customer data, or fund assets, or cause the fund and/or its service providers to suffer data corruption or lose operational functionality.
Prospectus Summary | DFA Inflation-Protected Securities Portfolio | Bloomberg U.S. TIPS Index  
Risk/Return: rr_RiskReturnAbstract  
Index No Deduction for Fees, Expenses, Taxes [Text] rr_IndexNoDeductionForFeesExpensesTaxes (reflects no deduction for fees, expenses or taxes on sales)
Label rr_AverageAnnualReturnLabel Bloomberg U.S. TIPS Index
Prospectus Summary | DFA Inflation-Protected Securities Portfolio | Bloomberg U.S. TIPS Index  
Risk/Return: rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 1.84%
5 Years rr_AverageAnnualReturnYear05 1.87%
10 Years rr_AverageAnnualReturnYear10 2.24%
Prospectus Summary | DFA Inflation-Protected Securities Portfolio | Bloomberg U.S. Aggregate Bond Index  
Risk/Return: rr_RiskReturnAbstract  
Index No Deduction for Fees, Expenses, Taxes [Text] rr_IndexNoDeductionForFeesExpensesTaxes (reflects no deduction for fees, expenses or taxes on sales)
Label rr_AverageAnnualReturnLabel Bloomberg U.S. Aggregate Bond Index1 [1]
Prospectus Summary | DFA Inflation-Protected Securities Portfolio | Bloomberg U.S. Aggregate Bond Index  
Risk/Return: rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 1.25%
5 Years rr_AverageAnnualReturnYear05 (0.33%)
10 Years rr_AverageAnnualReturnYear10 1.35%
Prospectus Summary | DFA Inflation-Protected Securities Portfolio | Institutional Class  
Risk/Return: rr_RiskReturnAbstract  
Management Fee rr_ManagementFeesOverAssets 0.09%
Other Expenses rr_OtherExpensesOverAssets 0.02%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.11%
1 Year rr_ExpenseExampleYear01 $ 11
3 Years rr_ExpenseExampleYear03 35
5 Years rr_ExpenseExampleYear05 62
10 Years rr_ExpenseExampleYear10 141
1 Year rr_ExpenseExampleNoRedemptionYear01 11
3 Years rr_ExpenseExampleNoRedemptionYear03 35
5 Years rr_ExpenseExampleNoRedemptionYear05 62
10 Years rr_ExpenseExampleNoRedemptionYear10 $ 141
Annual Return 2015 rr_AnnualReturn2015 (1.22%)
Annual Return 2016 rr_AnnualReturn2016 4.67%
Annual Return 2017 rr_AnnualReturn2017 3.28%
Annual Return 2018 rr_AnnualReturn2018 (1.29%)
Annual Return 2019 rr_AnnualReturn2019 8.46%
Annual Return 2020 rr_AnnualReturn2020 11.65%
Annual Return 2021 rr_AnnualReturn2021 5.55%
Annual Return 2022 rr_AnnualReturn2022 (12.22%)
Annual Return 2023 rr_AnnualReturn2023 3.93%
Annual Return 2024 rr_AnnualReturn2024 2.01%
Label rr_HighestQuarterlyReturnLabel Highest Quarter
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Mar. 31, 2016
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 5.01%
Label rr_LowestQuarterlyReturnLabel Lowest Quarter
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Jun. 30, 2022
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (6.52%)
Label rr_AverageAnnualReturnLabel Return Before Taxes
1 Year rr_AverageAnnualReturnYear01 2.01%
5 Years rr_AverageAnnualReturnYear05 1.86%
10 Years rr_AverageAnnualReturnYear10 2.29%
Prospectus Summary | DFA Inflation-Protected Securities Portfolio | Institutional Class | After Taxes on Distributions  
Risk/Return: rr_RiskReturnAbstract  
Label rr_AverageAnnualReturnLabel Return After Taxes on Distributions
1 Year rr_AverageAnnualReturnYear01 0.92%
5 Years rr_AverageAnnualReturnYear05 0.19%
10 Years rr_AverageAnnualReturnYear10 1.04%
Prospectus Summary | DFA Inflation-Protected Securities Portfolio | Institutional Class | After Taxes on Distributions and Sales  
Risk/Return: rr_RiskReturnAbstract  
Label rr_AverageAnnualReturnLabel Return After Taxes on Distributions and Sale of Portfolio Shares
1 Year rr_AverageAnnualReturnYear01 1.20%
5 Years rr_AverageAnnualReturnYear05 0.74%
10 Years rr_AverageAnnualReturnYear10 1.23%
[1]

The Portfolio incorporated this broad-based securities market index to reflect the overall applicable securities market of the Portfolio.