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DFA Inflation-Protected Securities Portfolio

Risk/Return:

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Risk/Return [Heading]

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DFA Inflation-Protected Securities Portfolio

Objective [Heading]

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Investment Objective

Objective, Primary [Text Block]

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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]

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Fees and Expenses of the Portfolio

Expense Narrative [Text Block]

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This table describes the fees and expenses you may pay if you buy, hold or sell shares of the Inflation-Protected 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]

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Shareholder Fees (fees paid directly from your investment):

Operating Expenses Caption [Text]

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Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Portfolio Turnover [Heading]

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PORTFOLIO TURNOVER

Portfolio Turnover [Text Block]

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The Inflation-Protected Portfolio 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 Portfolio 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 1% of the average value of its investment portfolio.

Portfolio Turnover, Rate

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1.00%

Expense Example [Heading]

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EXAMPLE

Expense Example Narrative [Text Block]

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This Example is meant to help you compare the cost of investing in the Inflation-Protected Portfolio with the cost of investing in other mutual 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 would be:

Strategy [Heading]

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Principal Investment Strategies

Strategy Narrative [Text Block]

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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 an average duration similar to its benchmark, the Bloomberg U.S. TIPS Index, which was approximately 7.66 years as of December 31, 2021. 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]

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Principal Risks

Risk Narrative [Text Block]

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Because the value of your investment in the Inflation-Protected 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.

Market Risk: Even a long-term investment approach cannot guarantee a profit. Economic, political, and issuer-specific events will cause the value of securities, and the Portfolio that owns them, to rise or fall.

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. 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. The Portfolio may be subject to a greater risk of rising interest rates due to the current period of historically low interest rates.

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

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.

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 Portfolio’s performance. 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.

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 the Portfolio 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. Also, inflation-protected securities, including those issued by the U.S. Treasury, are not protected against deflation. As a result, in a period of deflation, the principal and income of inflation-protected securities held by the Portfolio will decline and the Portfolio 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 Portfolio’s value. For example, if interest rates rise due to reasons other than inflation, the Portfolio’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 the Portfolio at the time of such adjustments (which generally would be distributed by the Portfolio 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.

Income Risk: Income risk is the risk that falling interest rates will cause the Portfolio’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.

Liquidity Risk: Liquidity risk exists when particular portfolio investments are difficult to purchase or sell. To the extent that the Portfolio holds illiquid investments, the Portfolio’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 the Portfolio due to low trading volume, adverse investor perceptions and/or other market developments. Liquidity risk includes the risk that the Portfolio 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 the Portfolio are concentrated in one or a few investors.

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 the Portfolio 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 the Portfolio uses derivatives, the Portfolio 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 the Portfolio could lose more than the principal amount invested.

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, the Portfolio may lose money and there may be a delay in recovering the loaned securities. The Portfolio 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.

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 the Advisor’s control, including instances at third parties. The Portfolio and the Advisor seek to reduce these operational risks through controls and procedures. However, these measures do not address every possible risk and may be inadequate to address these risks.

Cyber Security Risk: The Portfolio’s and its service providers’ use of internet, technology and information systems may expose the Portfolio 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 Portfolio and/or its service providers to suffer data corruption or lose operational functionality.

Risk Lose Money [Text]

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Because the value of your investment in the Inflation-Protected Portfolio will fluctuate, there is the risk that you will lose money.

Risk Not Insured Depository Institution [Text]

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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.

Bar Chart and Performance Table [Heading]

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Performance

Performance Narrative [Text Block]

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The bar chart and table immediately following illustrate the variability of the Inflation-Protected 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 one year, five year and ten year returns, 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 http://us.dimensional.com.

The after‑tax returns presented in the table for the Inflation-Protected 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]

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Performance Availability Website Address [Text]

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http://us.dimensional.com

Performance Past Does Not Indicate Future [Text]

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The Portfolio’s past performance (before and after taxes) is not an indication of future results.

Bar Chart [Heading]

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DFA Inflation-Protected Securities Portfolio Institutional Class Shares—Total Returns

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January 2012-December 2021
Highest Quarter		Lowest Quarter
5.01% (1/16–3/16)		‑7.95% (4/13–6/13)

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Annualized Returns (%) Periods ending December 31, 2021

Performance Table Uses Highest Federal Rate

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Performance Table Not Relevant to Tax Deferred

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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.

DFA Inflation-Protected Securities Portfolio | Institutional Class

Risk/Return:

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Shareholder Fees (fees paid directly from your investment)

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none

Management Fee

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0.09%

Other Expenses

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0.02%