Label	Element	Value
TCW Enhanced Commodity Strategy Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	TCW Enhanced Commodity Strategy Fund (Please note that TCW Enhanced Commodity Fund is not currently available to the public.)
Objective [Heading]	rr_ObjectiveHeading	Investment Objective
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Fund’s investment objective is to seek total return which exceeds that of its commodity benchmark.
Expense [Heading]	rr_ExpenseHeading	Fees and Expenses of the Fund
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	This table describes the fees and expenses you may pay if you buy and hold shares of the Fund. You may pay additional fees or commissions to broker-dealers or other financial intermediaries for the purchase of Class I shares of the Fund, which are not reflected in the table 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)
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	March 1, 2022
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	Portfolio Turnover
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The Fund pays transaction costs when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate 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 Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 54.50% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	54.50%
Expense Example [Heading]	rr_ExpenseExampleHeading	Example
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. This example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all your shares at the end of those periods. The example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. The cost of investing in the Fund reflects the net expenses of the Fund that result from the contractual expense limitation in the first year only. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:
Strategy [Heading]	rr_StrategyHeading	Principal Investment Strategies
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	Under normal circumstances, the Fund seeks to achieve its investment objective by investing primarily in commodity-linked derivative instruments backed by a portfolio of Fixed Income Instruments. “Fixed Income Instruments” refers to securities of varying maturities issued by domestic and foreign corporations and governments (and their agencies and instrumentalities), including bonds, notes, mortgage-backed securities, asset-backed securities (including collateralized debt obligations, which in turn include collateralized bond obligations and collateralized loan obligations), bank loans, money-market securities, swaps and derivatives (including futures, options and credit default swaps), private placements, defaulted debt securities and Rule 144A securities. The Fund invests in commodity-linked derivative instruments, including commodity index-linked notes, swap agreements, commodity options, futures and options on futures, that provide exposure to the investment returns of the commodities markets, without investing directly in physical commodities. Commodities are assets that have tangible properties, such as oil, metals, and agricultural products. The value of commodity-linked derivative instruments may be affected by overall market movements and other factors affecting the value of a particular industry or commodity, such as weather, disease, embargoes, or political and regulatory developments. The Fund may also invest in common and preferred stocks as well as convertible securities of issuers in commodity-related industries. The Fund may seek to gain exposure to the commodity markets through investments in leveraged or unleveraged commodity index-linked notes, which are derivative debt instruments with principal and/or coupon payments linked to the performance of commodity indices, and through investments in the Subsidiary, a wholly-owned subsidiary of the Fund organized under the laws of the Cayman Islands. Commodity index-linked notes are sometimes referred to as “structured notes” because the terms of these notes may be structured by the issuer and the purchaser of the note. They are derivative securities with one or more commodity-linked components that have payment features similar to commodity futures contracts, commodity options, or similar instruments. Commodity-linked structured products may be either debt or equity securities, leveraged or unleveraged, and have both security and commodity-like characteristics. A portion of the value of these instruments may be derived from the value of a commodity, futures contract, index or other commodity variable. The value of these notes will rise or fall in response to changes in the underlying commodity or related index of investment. The Subsidiary is advised by the Advisor and has the same investment objective as the Fund. As discussed in greater detail elsewhere in this Prospectus, the Subsidiary may invest in commodity-linked swap agreements and other commodity-linked derivative instruments to an extent greater than the Fund may make such investments. The Fund’s investment in the Subsidiary generally will not exceed 25% of the value of the Fund’s total assets, except to the limited extent a higher amount is allowed under applicable tax law. The derivative instruments in which the Fund and the Subsidiary primarily invest are instruments linked to certain commodity indices and instruments linked to the value of a particular commodity or commodity futures contract, or a subset of commodities or commodity futures contracts. These instruments may specify exposure to commodity futures with different roll dates, reset dates or contract terms than those specified by a particular commodity index. As a result, the commodity-linked derivatives component of the Fund’s portfolio may deviate from the returns of any particular commodity index. The Fund or the Subsidiary may over-weigh or under-weigh its exposure to a particular commodity index, or a subset of commodities, such that the Fund has greater or lesser exposure to that index than the value of the Fund’s net assets, or greater or lesser exposure to a subset of commodities than is represented by a particular commodity index. Assets not invested in commodity-linked derivative instruments or the Subsidiary may be invested in inflation-indexed securities and other Fixed Income Instruments, including derivative Fixed Income Instruments. In addition, the Fund may invest its assets in particular sectors of the commodities market. The average duration of the Fixed Income Instruments held by the Fund is not expected to exceed 3 years, under normal market conditions. Duration is a measure of the expected life of a fixed income security that is used to determine the sensitivity of a security’s price to changes in interest rates. The Fund may invest up to 5% of its net assets in below investment grade bonds (commonly known as “junk bonds”), which are bonds rated below BBB by Fitch Ratings, Inc., below BBB by S&P Global Ratings and below Baa by Moody’s Investors Service, Inc., or, if unrated, bonds deemed by the Advisor to be of comparable quality. The Fund may invest up to 15% of its assets in foreign securities that are denominated in U.S. dollars. The Fund may invest up to 5% of its assets in securities of foreign issuers that are not denominated in U.S. dollars. The Fund may invest up to 5% of its assets in emerging market securities. The Fund reserves the right to hedge its exposure to foreign currencies to reduce the risk of loss due to fluctuations in currency exchange rates.
Risk [Heading]	rr_RiskHeading	Principal Risks
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	Since the Fund holds securities with fluctuating market prices, the value of the Fund’s shares will vary as its portfolio securities increase or decrease in value. Therefore, the value of your investment in the Fund could go down as well as up. You can lose money by investing in the Fund. The principal risks affecting the Fund that can cause a decline in value are:   •   debt securities risk: the risk that the value of a debt security may increase or decrease as a result of various factors,     including changes in interest rates, actual or perceived inability or unwillingness of issuers to make principal or interest payments, market fluctuations and illiquidity in the debt securities market. •   market risk: the risk that returns from the securities in which the Fund invests may underperform returns from the general securities markets or other types of securities. •   public health emergency risks: the risk that pandemics and other public health emergencies, including outbreaks of infectious diseases such as the current outbreak of the novel coronavirus (“COVID-19”), can result, and in the case of COVID-19 is resulting, in market volatility and disruption, and materially and adversely impact economic conditions in ways that cannot be predicted, all of which could result in substantial investment losses. Containment efforts and related restrictive actions by governments and businesses have significantly diminished and disrupted global economic activity across many industries. Less developed countries and their health systems may be more vulnerable to these impacts. The ultimate impact of COVID-19 or other health emergencies on global economic conditions and businesses is impossible to predict accurately. Ongoing and potential additional material adverse economic effects of indeterminate duration and severity are possible. The resulting adverse impact on the value of an investment in the Fund could be significant and prolonged. •   interest rate risk: the risk that debt securities will decline in value because of changes in interest rates. •   credit risk: the risk that an issuer will default in the payment of principal and/or interest on a security. •   price volatility risk: the risk that the value of the Fund’s investment portfolio will change as the prices of its investments go up or down. •   issuer risk: the risk that the value of a security may decline for reasons directly related to the issuer such as management performance, financial leverage and reduced demand for the issuer’s goods or services. •   liquidity risk: the risk that lack of a ready market or restrictions on resale may limit the ability of the Fund to sell a security at an advantageous time or price. In addition, the Fund, by itself or together with other accounts managed by the investment advisor, may hold a position in a security that is large relative to the typical trading volume for that security, which can make it difficult for the Fund to dispose of the position at an advantageous time or price. Over recent years, the fixed-income markets have grown more than the ability of dealers to make markets, which can further constrain liquidity and increase the volatility of     portfolio valuations. High levels of redemptions in bond funds in response to market conditions could cause greater losses as a result. Regulations such as the Volcker Rule or future regulations may further constrain the ability of market participants to create liquidity, particularly in times of increased market volatility. The liquidity of the Fund’s assets may change over time. •   valuation risk: the risk that the portfolio instruments may be sold at prices different from the values established by the Fund, particularly for investments that trade in low volume, in volatile markets or over the counter or that are fair valued. •   commodity risk: the risk that investing in commodity-linked derivative instruments, including commodity index-linked notes, may subject the Fund to greater volatility than investments in traditional securities. The value of commodity-linked derivative instruments may be affected by changes in overall market movements, commodity index volatility, changes in interest rates, or factors affecting a particular industry or commodity, such as drought, weather, livestock disease, embargoes, tariffs and international economic, political and regulatory developments. •   subsidiary risk: the risk that, by investing in the Subsidiary, the Fund is indirectly exposed to the risks associated with the Subsidiary’s investments. There is no guarantee that the investment objective of the Subsidiary will be achieved. •   tax risk: the risk that the ability of the Fund to gain commodity exposure as contemplated may be adversely affected by future legislation, regulatory developments, interpretive guidance or other actions by the Internal Revenue Service or the Treasury Department as discussed under “Distributions and Taxes.” •   derivatives risk: the risk of investing in derivative instruments, which includes liquidity, interest rate, market, credit and management risks as well as risks related to mispricing or improper valuation. Changes in the value of a derivative may not correlate perfectly with the underlying asset, reference rate or index, and the Fund could lose more than the principal amount invested. These investments can create investment leverage and may create additional risks that may subject the Fund to greater volatility and less liquidity than investments in more traditional securities. •   leverage risk: the risk that leverage may result from certain transactions, including the use of derivatives and borrowing. This may impair the Fund’s liquidity, cause it to liquidate positions at an unfavorable time, increase its volatility or otherwise cause it not to achieve its intended result. To     the extent required by applicable law or regulation, the Fund will reduce leverage risk by either segregating an equal amount of liquid assets or “covering” the transactions that introduce such risk. •   counterparty risk: the risk that the other party to a contract, such as a derivatives contract, will not fulfill its contractual obligations. •   foreign investing risk: the risk that Fund share prices will fluctuate with market conditions, currency exchange rates and the economic and political climates of the foreign countries in which the Fund invests or has exposure. Investments in foreign securities may involve greater risks than investing in U.S. securities due to, among others, less publicly available information, less stringent and less uniform accounting, auditing and financial reporting standards, less liquid and more volatile markets, higher transaction and custody costs, additional taxes, less investor protection, delayed or less frequent settlement, political or social instability, civil unrest, acts of terrorism, and regional economic volatility. •   foreign currency risk: the risk that foreign currencies will decline in value relative to the U.S. dollar and affect the Fund’s investments in foreign currencies, in securities that are denominated, trade, and/or receive revenues in foreign currencies, or in derivatives that provide exposure to foreign currencies. •   portfolio management risk: the risk that an investment strategy may fail to produce the intended results. •   securities selection risk: the risk that the securities held by the Fund may underperform those held by other funds investing in the same asset class or benchmarks that are representative of the asset class because of the portfolio managers’ choice of securities. •   prepayment risk: the risk that in times of declining interest rates, the Fund’s higher yielding securities may be prepaid and the Fund may have to replace them with securities having a lower yield. •   extension risk: the risk that in times of rising interest rates, borrowers may pay off their debt obligations more slowly, causing securities considered short- or intermediate-term to become longer-term securities that fluctuate more widely in response to changes in interest rates than shorter-term securities. •   U.S. treasury obligations risk: the risk that the value of U.S. treasury obligations may decline as a result of changes in interest rates, certain political events in the U.S., and strained relations with certain foreign countries. •   mortgage-backed securities risk: the risk of investing in mortgage-backed securities, including prepayment risk and extension risk. Mortgage-backed securities react differently to changes in interests rates than other bonds, and some mortgage-backed securities are not backed by the full faith and credit of the U.S. government. •   junk bond risk: the risk that junk bonds have a higher degree of default risk and may be less liquid and subject to greater price volatility than investment grade bonds. •   frequent trading risk: the risk that frequent trading will lead to increased portfolio turnover and higher transaction costs, which may reduce the Fund’s performance and may cause higher levels of current tax liability to shareholders in the Fund. •   emerging market country risks: the risks of investing in emerging market countries, which are substantial due to, among others, different accounting standards; thinner trading markets as compared to those in developed countries; the possibility of currency transfer restrictions; and the risk of expropriation, nationalization or other adverse political, economic or social developments. •   equity risk: the risk that stocks and other equity securities generally fluctuate in value more than bonds and may decline in value over short or extended periods as a result of changes in a company’s financial condition or in overall market, economic and political conditions. Please see “Principal Risks of the Funds” for a more detailed description of the risks of investing in the Fund. Your investment in the Fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency entity or person.
Risk Lose Money [Text]	rr_RiskLoseMoney	You can lose money by investing in the Fund.
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	Your investment in the Fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency entity or person.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Investment Results
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The bar chart below shows how the Fund’s investment results have varied from year to year and the table below shows how the Fund’s average annual total returns for various periods compare with a broad measure of market performance. This information provides some indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year. The bar chart shows performance of the Fund’s Class I shares. Class N performance may be lower than Class I performance because of the potentially lower expenses paid by Class I shares. Past results (before and after taxes) are not predictive of future results. Updated information on the Fund’s investment results can be obtained by visiting www.TCW.com.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The bar chart below shows how the Fund’s investment results have varied from year to year and the table below shows how the Fund’s average annual total returns for various periods compare with a broad measure of market performance.
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.TCW.com
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	Past results (before and after taxes) are not predictive of future results.
Bar Chart [Heading]	rr_BarChartHeading	Calendar Year Total Returns For Class I Shares
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Highest/Lowest quarterly results during this period were:Highest 13.10% (quarter ended 6/30/2016) Lowest -24.08% (quarter ended 3/31/2020)
Performance Table Heading	rr_PerformanceTableHeading	Average Annual Total Returns (For the period ended December 31, 2020)
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	After-tax returns are calculated using the highest individual federal income tax rates in effect each year and do not reflectthe impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred	rr_PerformanceTableNotRelevantToTaxDeferred	Your actual after-taxreturns depend on your individual tax situation and likely will differ from the results shown above, and after-tax returns shown are not relevant if you hold your Fund shares through a tax-deferred arrangement, such as a 401(k) plan or individual retirement account (IRA).
Performance Table One Class of after Tax Shown [Text]	rr_PerformanceTableOneClassOfAfterTaxShown	After-tax returns are shown for only one class of shares, and after-tax returns for the other class of shares will vary.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	After-tax returns are calculated using the highest individual federal income tax rates in effect each year and do not reflectthe impact of state and local taxes. Your actual after-tax returns depend on your individual tax situation and likely will differ from the results shown above, and after-tax returns shown are not relevant if you hold your Fund shares through a tax-deferred arrangement, such as a 401(k) plan or individual retirement account (IRA). After-tax returns are shown for only one class of shares, and after-tax returns for the other class of shares will vary.
TCW Enhanced Commodity Strategy Fund | Class I
Risk/Return:	rr_RiskReturnAbstract
Shareholder Fees (Fees paid directly from your investment)	rr_ShareholderFeeOther	none
Management Fees	rr_ManagementFeesOverAssets	0.50%	[1]
Distribution and/or Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Expenses of the Subsidiary	rr_Component1OtherExpensesOverAssets	6.86%
Other Expenses	rr_OtherExpensesOverAssets	9.56%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	16.92%
Fee Waiver and/or Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	16.22%	[2]
Total Annual Operating Expenses After Fee Waiver and/or Expense Reimbursement	rr_NetExpensesOverAssets	0.70%	[2]
1 Year	rr_ExpenseExampleYear01	$ 72
3 Years	rr_ExpenseExampleYear03	3,193
5 Years	rr_ExpenseExampleYear05	5,614
10 Years	rr_ExpenseExampleYear10	$ 9,551
2012	rr_AnnualReturn2012	4.63%
2013	rr_AnnualReturn2013	(6.87%)
2014	rr_AnnualReturn2014	(14.74%)
2015	rr_AnnualReturn2015	(24.61%)
2016	rr_AnnualReturn2016	12.26%
2017	rr_AnnualReturn2017	4.04%
2018	rr_AnnualReturn2018	(11.76%)
2019	rr_AnnualReturn2019	10.32%
2020	rr_AnnualReturn2020	0.42%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Highest
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Jun. 30, 2016
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	13.10%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Lowest
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Mar. 31, 2020
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(24.08%)
1 Year	rr_AverageAnnualReturnYear01	0.42%
5 years	rr_AverageAnnualReturnYear05	2.69%
Since Inception	rr_AverageAnnualReturnSinceInception	(5.19%)
Inception Date	rr_AverageAnnualReturnInceptionDate	Mar. 31, 2011
TCW Enhanced Commodity Strategy Fund | Class N
Risk/Return:	rr_RiskReturnAbstract
Shareholder Fees (Fees paid directly from your investment)	rr_ShareholderFeeOther	none
Management Fees	rr_ManagementFeesOverAssets	0.50%	[1]
Distribution and/or Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Expenses of the Subsidiary	rr_Component1OtherExpensesOverAssets	6.86%
Other Expenses	rr_OtherExpensesOverAssets	9.99%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	17.60%
Fee Waiver and/or Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	16.85%	[2]
Total Annual Operating Expenses After Fee Waiver and/or Expense Reimbursement	rr_NetExpensesOverAssets	0.75%	[2]
1 Year	rr_ExpenseExampleYear01	$ 77
3 Years	rr_ExpenseExampleYear03	3,298
5 Years	rr_ExpenseExampleYear05	5,759
10 Years	rr_ExpenseExampleYear10	$ 9,661
1 Year	rr_AverageAnnualReturnYear01	0.35%
5 years	rr_AverageAnnualReturnYear05	2.63%
Since Inception	rr_AverageAnnualReturnSinceInception	(5.20%)
Inception Date	rr_AverageAnnualReturnInceptionDate	Mar. 31, 2011
TCW Enhanced Commodity Strategy Fund | After taxes on distributions | Class I
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	(1.15%)
5 years	rr_AverageAnnualReturnYear05	1.56%
Since Inception	rr_AverageAnnualReturnSinceInception	(6.05%)
Inception Date	rr_AverageAnnualReturnInceptionDate	Mar. 31, 2011
TCW Enhanced Commodity Strategy Fund | After taxes on distributions and sale of fund shares | Class I
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	0.14%
5 years	rr_AverageAnnualReturnYear05	1.59%
Since Inception	rr_AverageAnnualReturnSinceInception	(3.97%)
Inception Date	rr_AverageAnnualReturnInceptionDate	Mar. 31, 2011
TCW Enhanced Commodity Strategy Fund | Bloomberg Commodity Total Return Index (reflects no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	(3.12%)	[3]
5 years	rr_AverageAnnualReturnYear05	1.03%	[3]
Since Inception	rr_AverageAnnualReturnSinceInception	(7.07%)	[3]
Inception Date	rr_AverageAnnualReturnInceptionDate	Mar. 31, 2011	[3]

[1] The Fund may invest a portion of its assets in TCW Cayman Enhanced Commodity Fund, Ltd., a wholly-owned subsidiary of the Fund organized under the laws of the Cayman Islands (the “Subsidiary”). The Subsidiary has entered into a separate advisory agreement with the Fund’s investment advisor, TCW Investment Management Company LLC (the “Advisor”), for the management of the Subsidiary’s portfolio, pursuant to which the Subsidiary is obligated to pay the Advisor a management fee at the same rate that the Fund pays the Advisor for services provided to the Fund. The Advisor is contractually obligated to waive the management fee it receives from the Fund in an amount equal to the management fee paid to the Advisor by the Subsidiary for the management of the portion of the Fund’s assets invested in the Subsidiary. This waiver may not be terminated without the consent of the Board of Directors.

[2] The Advisor has agreed to waive fees and/or reimburse expenses to limit the Fund’s total annual operating expenses (excluding interest, brokerage, extraordinary expenses and acquired fund fees and expenses, if any) to 0.70% of average daily net assets with respect to Class I shares and 0.75% of average daily net assets with respect to Class N shares. This contractual fee waiver/expense reimbursement will remain in place through March 1, 2022 and before that date, theinvestment advisor may not terminate this arrangement without approval of the Board of Directors. At the conclusion of this period, the Fund’s investment advisor may, in its sole discretion, terminate the contractual fee waiver/expense reimbursement or, with the Board of Directors’ approval, extend or modify that arrangement.

[3] The Bloomberg Commodity Total Return Index is a total return index based on the Bloomberg Commodity Index (“BCOM”), which is a highly liquid and diversified benchmark for commodity investments. The Bloomberg Commodity Total Return Index is composed of futures contracts and reflects the returns on a fully collateralized investment in the BCOM.