Label	Element	Value
TCW Developing Markets Equity Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	TCW Developing Markets Equity Fund
Objective [Heading]	rr_ObjectiveHeading	Investment Objective
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Fund’s investment objective is to seek long-term capital appreciation. This investment objective may be changed without shareholder approval.
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 148.22% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	148.22%
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 invests at least 80% of the value of its net assets, plus any borrowings for investment purposes, in equity securities of Developing Market Country (as defined below) companies. If the Fund changes this investment policy, it will notify shareholders in writing at least 60 days in advance of such change. Equity securities include common and preferred stock; rights, warrants or options to purchase common or preferred stock; securities that may be converted into or exchanged for common or preferred stock, such as convertible preferred stock, convertible debt and Eurodollar convertible securities; equity securities of foreign companies listed on established exchanges, including NASDAQ; exchange-traded funds (“ETFs”); American Depository Receipts (ADRs); Global Depository Receipts (GDRs); equity linked notes or similar structures; and other securities with equity characteristics. The Fund may invest in securities or other financial instruments issued by companies in the financial services sector, including, without limitation, the banking, brokerage and insurance industries. The Fund may invest in foreign equity securities, which may or may not be listed on a recognized securities exchange or be publicly traded. These securities may be denominated in U.S. dollars, local currencies or other foreign currencies. The Fund has no limit on the portion of its assets that may be invested in any country, and may invest in companies of any size. The portfolio managers invest in those securities that they think provide the best opportunity to achieve the Fund’s investment objective. For purposes of the Fund’s investment strategy, a Developing Market Country company is a company or financial institution domiciled or with primary business operations in, or with the majority of their net assets in or revenues or net income deriving from, a Developing Market Country. A “Developing Market Country” is a country that has a developing economy or market and includes all of the countries in the MSCI Total Return Emerging Markets Index (Net), the MSCI Frontier Markets Index, and the JP Morgan Emerging Markets Bond Index Global Diversified. The Fund may invest in other pooled investment vehicles (both investment companies registered under the Investment Company Act of 1940, as amended (the “1940 Act”), and collective investments not subject to registration under the 1940 Act), including, without limitation, ETFs, exchange-traded notes (“ETNs”), and real estate investment trusts (“REITs”), to the extent permitted by the 1940 Act. In allocating investments among various Developing Market Countries, the portfolio managers attempt to analyze internal political, market and economic factors. These factors include, but are not limited to: •   Public finances; •   Monetary policy; •   External accounts; •   Financial markets; •   Foreign investment regulations; •   Exchange rate policy; •   Labor conditions; •   Political outlook; •   Structural reform policy; and •   ESG factors. Certain countries require governmental approval prior to direct equity investments by foreign persons such as the Fund. If considered likely to help the Fund in achieving its investment objective, the Fund may seek authorization to effect direct equity investments in such countries from their respective governments. The Fund may invest up to 20% of its net assets, plus any borrowings for investment purposes, in derivative instruments, such as credit-linked notes, structured investments, options, futures, options on futures (including those related to options, securities, foreign currencies, indexes and interest rates), forward contracts, and swaps for investment management (e.g., as a substitute for investing directly in specific securities or currencies or to increase returns) and hedging purposes. The investment process employed by the Fund emphasizes bottom-up fundamental research. The Fund aims to build a portfolio of the portfolio managers’ best stock ideas, while also taking into account diversification and risk management requirements and considerations. Portfolio securities may be sold for a number of reasons, including when a company fails to meet expectations or when the portfolio managers believe that (i) there has been a deterioration in the underlying fundamentals of a company, (ii) the intermediate- and long-term prospects for a company are poor, (iii) another security may offer a better investment opportunity, (iv) an individual security has reached its sell target, or (v) the portfolio should be rebalanced for diversification or portfolio weighting purposes.
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:   •   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. •   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. •   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. •   developing market country risks: the risks of investing in developing market countries, which are substantial due to, among others, higher brokerage costs in certain countries; 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. •   China investing risks: the risks of investing in companies located or operating in China, including Hong Kong, such as nationalization, expropriation, or confiscation of     property; difficulty in obtaining and/or enforcing judgments; alteration or discontinuation of economic reforms; military conflicts; inflation, currency fluctuations and fluctuations in inflation and interest rates that may have negative effects on the economy and securities markets of China; and China’s dependency on the economies of other Asian countries, many of which are developing countries. Health events, such as the recent coronavirus outbreak, may cause uncertainty and volatility in the Chinese economy. Certain securities issued by companies located or operating in China are subject to trading restrictions, quota limitations, and clearing and settlement risks. Significant portions of the Chinese securities markets may become rapidly illiquid, as Chinese issuers have the ability to suspend the trading of their equity securities, or as a result of adverse economic, market or political events, or adverse investor perceptions, whether or not accurate. •   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. The liquidity of the Fund’s assets may change over time. •   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. •   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. •   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. •   financial services sector risk: the risk that the Fund may be susceptible to the impact of market, economic, regulatory, and other factors affecting the financial services sector and that the value of the Fund may fluctuate more widely than it would for a fund that invests more broadly across varying sectors. Companies in the financial services sector may be affected by the overall economic conditions as well as by factors particular to the financial services sector, including changes in government regulations, changes in interest rates, availability of capital and cost to borrow, credit rating downgrades, and decreased liquidity in the credit market. •   information technology sector risk: the risk that the Fund may be susceptible to the impact of market, economic, regulatory, and other factors affecting the information technology sector and that the value of the Fund may fluctuate more widely than it would for a fund that invests more broadly across varying sectors. Companies in the information technology sector may be affected by the overall economic conditions as well as by factors particular to the information technology sector, including intense competition, short product cycle, rapid product obsolescence, possible loss or impairment of intellectual property rights, and changes in government regulations. •   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. •   ETF risk: the risk that the value of the Fund’s investments will fluctuate in response to the performance of the ETFs owned by the Fund. The lack of liquidity in an ETF could result in its value being more volatile than its portfolio securities, and an ETF’s performance may not match the performance of a particular market segment or index it     seeks to track. In addition, the Fund’s shareholders will indirectly bear a proportionate share of an ETF’s expenses, in addition to paying the Fund’s expenses. •   ETN risk: the risk that the value of the Fund’s investments will fluctuate in response to the performance of the ETNs owned by the Fund. An ETN is subject to possible sudden and unpredictable changes in value, the risk of default by the issuer, the risk of downgrade of the issuer’s credit rating, and liquidity risk. The Fund’s shareholders will indirectly bear a proportionate share of an ETN’s expenses, in addition to paying the Fund’s expenses. •   REIT risk: the risk that the value of the Fund’s investments in REITs may be negatively impacted by factors generally affecting the value of real estate and the earnings of companies engaged in the real estate industry as well as factors that specifically relate to the structure and operations of REITs, including heavy cash flow dependency, self-liquidation and the possibility of failing to qualify for tax-free “pass-through” of income under the federal tax law. •   mid-capitalization company risk: the risk that mid-capitalization companies may have more volatile stock performance than large-capitalization companies and are more likely to experience business failures, which may increase the risk of loss to the Fund. •   small-capitalization company risk: the risk that small-capitalization companies may have more volatile stock performance than larger companies and are more susceptible to adverse business and economic developments and adverse effects due to the loss of personnel, which may increase the risk of loss to the Fund. 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 from the past calendar 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 from the past calendar 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       21.29%     (quarter ended 6/30/2020) Lowest       -21.37%     (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 reflect the impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred	rr_PerformanceTableNotRelevantToTaxDeferred	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).
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 reflect the 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 Developing Markets Equity Fund | Class I
Risk/Return:	rr_RiskReturnAbstract
Shareholder Fees (Fees paid directly from your investment)	rr_ShareholderFeeOther	none
Management Fees	rr_ManagementFeesOverAssets	0.80%
Distribution and/or Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	3.26%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	4.06%
Fee Waiver and/or Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	3.11%	[1]
Total Annual Operating Expenses After Fee Waiver and/or Expense Reimbursement	rr_NetExpensesOverAssets	0.95%	[1],[2]
1 Year	rr_ExpenseExampleYear01	$ 97
3 Years	rr_ExpenseExampleYear03	950
5 Years	rr_ExpenseExampleYear05	1,819
10 Years	rr_ExpenseExampleYear10	$ 4,064
2016	rr_AnnualReturn2016	5.24%
2017	rr_AnnualReturn2017	35.66%
2018	rr_AnnualReturn2018	(21.47%)
2019	rr_AnnualReturn2019	19.22%
2020	rr_AnnualReturn2020	23.93%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Highest
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Jun. 30, 2020
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	21.29%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Lowest
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Mar. 31, 2020
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(21.37%)
1 Year	rr_AverageAnnualReturnYear01	23.93%
5 Years	rr_AverageAnnualReturnYear05	10.62%
Since Inception	rr_AverageAnnualReturnSinceInception	5.99%
Inception Date	rr_AverageAnnualReturnInceptionDate	Jun. 30, 2015
TCW Developing Markets Equity Fund | Class N
Risk/Return:	rr_RiskReturnAbstract
Shareholder Fees (Fees paid directly from your investment)	rr_ShareholderFeeOther	none
Management Fees	rr_ManagementFeesOverAssets	0.80%
Distribution and/or Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other Expenses	rr_OtherExpensesOverAssets	4.12%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	5.17%
Fee Waiver and/or Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	4.02%	[1]
Total Annual Operating Expenses After Fee Waiver and/or Expense Reimbursement	rr_NetExpensesOverAssets	1.15%	[1],[2]
1 Year	rr_ExpenseExampleYear01	$ 117
3 Years	rr_ExpenseExampleYear03	1,189
5 Years	rr_ExpenseExampleYear05	2,258
10 Years	rr_ExpenseExampleYear10	$ 4,913
1 Year	rr_AverageAnnualReturnYear01	23.93%
5 Years	rr_AverageAnnualReturnYear05	10.62%
Since Inception	rr_AverageAnnualReturnSinceInception	5.99%
Inception Date	rr_AverageAnnualReturnInceptionDate	Jun. 30, 2015
TCW Developing Markets Equity Fund | After taxes on distributions | Class I
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	23.97%
5 Years	rr_AverageAnnualReturnYear05	10.60%
Since Inception	rr_AverageAnnualReturnSinceInception	5.98%
Inception Date	rr_AverageAnnualReturnInceptionDate	Jun. 30, 2015
TCW Developing Markets Equity Fund | After taxes on distributions and sale of fund shares | Class I
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	14.27%
5 Years	rr_AverageAnnualReturnYear05	8.55%
Since Inception	rr_AverageAnnualReturnSinceInception	4.79%
Inception Date	rr_AverageAnnualReturnInceptionDate	Jun. 30, 2015
TCW Developing Markets Equity Fund | MSCI Total Return Emerging Markets Index (Net) (reflects no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	18.31%	[3]
5 Years	rr_AverageAnnualReturnYear05	12.81%	[3]
Since Inception	rr_AverageAnnualReturnSinceInception	7.77%	[3]
Inception Date	rr_AverageAnnualReturnInceptionDate	Jun. 30, 2015	[3]

[1] The Fund’s investment 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 0.95% of average daily net assets with respect to Class I Shares and 1.15% 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 the investment 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.

[2] The “Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement” does not correlate to the corresponding ratio included in the Fund’s Financial Highlights for each class of shares because the contractual fee waiver/expense reimbursement was changed subsequent to the fiscal year ended October 31, 2020 and was not in effect for that fiscal year.

[3] The MSCI Total Return Emerging Markets Index (Net) is a free float-adjusted market capitalization-weighted index that is designed to measure the performance of large- and mid-cap securities in emerging markets.