2.4.0.8000091 - Document - Risk/Return Summary {Unlabeled} - Metropolitan West Floating Rate Income Fundfalsefalsetrue1false falsefalseDuration_30Jul2012_29Jul2013S000041255_Memberhttp://www.sec.gov/CIK0001028621duration2012-07-30T00:00:002013-07-29T00:00:001false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00Metropolitan West Floating Rate Income Fundfalsefalsefalse1false truefalseDuration_30Jul2012_29Jul2013S000041255_Memberhttp://www.sec.gov/CIK0001028621duration2012-07-30T00:00:002013-07-29T00:00:00falsefalsemwf_S000041255Memberdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldimwf_S000041255Memberdei_LegalEntityAxisexplicitMembernanafalse0Metropolitan West Floating Rate Income Fund2false 3rr_RiskReturnHeadingrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00METROPOLITAN WEST FLOATING RATE INCOME FUNDfalsefalsefalsexbrli:stringItemTypestringRisk/Return Summary Investment Objectives/Goals Include the following information, in plain English under rule 421(d) under the Securities Act, in the order and subject matter indicatedReference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 false0Risk/Return [Heading]3false 3rr_ObjectiveHeadingrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00INVESTMENT OBJECTIVE falsefalsefalsexbrli:stringItemTypestringInvestment Objectives/Goals. Disclose the Fund's investment objectives or goals. A Fund also may identify its type or category (e.g., that it is a Money Market Fund or a balanced fund).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 -Subsection a false0Objective [Heading]4false 3rr_ObjectivePrimaryTextBlockrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The Floating Rate Income Fund (the “Fund”) seeks primarily to maximize current income,falsefalsefalsenonnum:textBlockItemTypenaInvestment Objectives/Goals. Disclose the Fund's investment objectives or goals. A Fund also may identify its type or category (e.g., that it is a Money Market Fund or a balanced fund).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 -Subsection a false0Objective, Primary [Text Block]5false 3rr_ObjectiveSecondaryTextBlockrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00with a secondary objective of long-term capital appreciation.falsefalsefalsenonnum:textBlockItemTypenaInvestment Objectives/Goals. Disclose the Fund's investment objectives or goals. A Fund also may identify its type or category (e.g., that it is a Money Market Fund or a balanced fund).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 -Subsection a false0Objective, Secondary [Text Block]6false 3rr_ExpenseHeadingrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00FEES AND EXPENSES OF THE FUND falsefalsefalsexbrli:stringItemTypestringRisk/Return Summary Fee Table Includes the following information, in plain English under rule 421(d) under the Securities Act, after Item 2 Fees and expenses of the Fund This table describes the fees and expenses that you may pay if you buy and hold shared of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $[_____] in [name of fund family] funds. Shareholder Fees (fees paid directly from your investment) Example This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be You would pay the following expenses if you did not redeem your shares The Example does not reflect sales charges (loads) on reinvested dividends [and other distributions]. If these sales charges (loads) were included, your costs would be higher. Portfolio Turnover The Fund 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. 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 __% of the average value of its whole portfolio. Instructions. A.3.instructions.6 New Funds. For purposes of this Item, a "New Fund" is a Fund that does not include in Form N-1A financial statements reporting operating results or that includes financial statements for the Fund's initial fiscal year reporting operating results for a period of 6 months or less. The following Instructions apply to New Funds.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection instructions -Paragraph 1 -Subparagraph d false0Expense [Heading]7false 3rr_ExpenseNarrativeTextBlockrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The table below describes the fees and expenses that you may pay if you buy and hold shares of the Fund.falsefalsefalsenonnum:textBlockItemTypenaThis table describes the fees and expenses that you may pay if you buy and hold shared of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $[_____] in [name of fund family] funds. Include the narrative explanations in the order indicated. A Fund may modify the narrative explanations if the explanation contains comparable information to that shown. The narrative explanation regarding sales charge discounts is only required by a Fund that offers such discounts and should specify the minimum level of investment required to qualify for a discount. Modify the narrative explanation to state that Fund shares are sold on a national securities exchange at the end of the time periods indicated, and that brokerage commissions for buying and selling Fund shares through a broker are not reflected.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection instructions -Paragraph 1 -Subparagraph b false0Expense Narrative [Text Block]8false 3rr_ShareholderFeesCaptionrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00SHAREHOLDER FEES (fees paid directly from your investment)falsefalsefalsexbrli:stringItemTypestringShareholder Fees (fees paid directly from your investment).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection table -Paragraph 1 false0Shareholder Fees Caption [Text]9false 3rr_ShareholderFeesTableTextBlockrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div style="display:none">~ http://www.mwamllc.com/role/ScheduleShareholderFeesMetropolitanWestFloatingRateIncomeFund column period compact * ~</div>falsefalse<div style="display:none">~ http://www.mwamllc.com/role/ScheduleShareholderFeesMetropolitanWestFloatingRateIncomeFund column period compact * ~</div>falsehttp://www.mwamllc.com/role/ScheduleShareholderFeesMetropolitanWestFloatingRateIncomeFund000092 - 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Schedule - Annual Fund Operating Expenses {- Metropolitan West Floating Rate Income Fund}truefalsefalse1falseColumnperiodPeriod*Columndei_LegalEntityAxisAxis*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*duration2012-07-30T00:00:002013-07-29T00:00:00falsefalseMetropolitan West Floating Rate Income Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldimwf_S000041255Memberdei_LegalEntityAxisexplicitMemberfalsefalseCLASS Mrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldimwf_C000127912Memberrr_ProspectusShareClassAxisexplicitMemberMetropolitan West Floating Rate Income FundCLASS MpureStandardhttp://www.xbrl.org/2003/instancepure0Standard0 USDfalsefalseduration2012-07-30T00:00:002013-07-29T00:00:00$2falseColumnperiodPeriod*Columndei_LegalEntityAxisAxis*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*duration2012-07-30T00:00:002013-07-29T00:00:00falsefalseMetropolitan West Floating Rate Income Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldimwf_S000041255Memberdei_LegalEntityAxisexplicitMemberfalsefalseCLASS Irr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldimwf_C000127913Memberrr_ProspectusShareClassAxisexplicitMemberMetropolitan West Floating Rate Income FundCLASS IpureStandardhttp://www.xbrl.org/2003/instancepure0Standard0 USDfalsefalseduration2012-07-30T00:00:002013-07-29T00:00:00$1falseRowprimaryElement*3false 3rr_ManagementFeesOverAssetsrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabelrr:NonNegativePure4TypepureManagement Fees include investment advisory fees (including any fees based on the Fund's performance), any other management fees payable to the investment adviser or its affiliates, and administrative fees payable to the investment adviser or its affiliates that are not included as "Other Expenses."Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection instructions -Paragraph 3 -Subparagraph a false0Management Fees 0rr_ManagementFeesOverAssetsrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truetruetrue0.00550.0055falsefalsefalse2truetruetrue0.00550.0055falsefalsefalserr:NonNegativePure4TypepureManagement Fees include investment advisory fees (including any fees based on the Fund's performance), any other management fees payable to the investment adviser or its affiliates, and administrative fees payable to the investment adviser or its affiliates that are not included as "Other Expenses."Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection instructions -Paragraph 3 -Subparagraph a false0Management Fees2falseRowprimaryElement*4false 3rr_DistributionAndService12b1FeesOverAssetsrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabelrr:NonNegativePure4TypepureDistribution [and/or Service] (12b-1) Fees" include all distribution or other expenses incurred during the most recent fiscal year under a plan adopted pursuant to rule 12b-1 [17 CFR 270.12b-1]. Under an appropriate caption or a subcaption of "Other Expenses," disclose the amount of any distribution or similar expenses deducted from the Fund's assets other than pursuant to a rule 12b-1 plan.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection table -Paragraph 1 -Subparagraph 9 false0Distribution (12b-1) Fees 0rr_DistributionAndService12b1FeesOverAssetsrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel1truetruetrue0.00250.0025falsefalsefalse2truetruetrue00falsefalsefalserr:NonNegativePure4TypepureDistribution [and/or Service] (12b-1) Fees" include all distribution or other expenses incurred during the most recent fiscal year under a plan adopted pursuant to rule 12b-1 [17 CFR 270.12b-1]. Under an appropriate caption or a subcaption of "Other Expenses," disclose the amount of any distribution or similar expenses deducted from the Fund's assets other than pursuant to a rule 12b-1 plan.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection table -Paragraph 1 -Subparagraph 9 false0Distribution (12b-1) Fees3falseRowprimaryElement*5false 3rr_OtherExpensesOverAssetsrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabelrr:NonNegativePure4Typepure"Other Expenses" include all expenses not otherwise disclosed in the table that are deducted from the Fund's assets or charged to all shareholder accounts. The amount of expenses deducted from the Fund's assets are the amounts shown as expenses in the Fund's statement of operations (including increases resulting from complying with paragraph 2(g) of rule 6-07 of Regulation S-X [17 CFR 210.6-07]). "Other Expenses" do not include extraordinary expenses as determined under generally accepted accounting principles (see Accounting Principles Board Opinion No. 30). If extraordinary expenses were incurred that materially affected the Fund's "Other Expenses," disclose in a footnote to the table what "Other Expenses" would have been had the extraordinary expenses been included.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection instructions -Paragraph 3 -Subparagraph c -Clause i false0Other Expenses 0rr_OtherExpensesOverAssetsrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel[1]1truetruetrue0.0150.015falsefalsefalse2truetruetrue0.0150.015falsefalsefalserr:NonNegativePure4Typepure"Other Expenses" include all expenses not otherwise disclosed in the table that are deducted from the Fund's assets or charged to all shareholder accounts. The amount of expenses deducted from the Fund's assets are the amounts shown as expenses in the Fund's statement of operations (including increases resulting from complying with paragraph 2(g) of rule 6-07 of Regulation S-X [17 CFR 210.6-07]). "Other Expenses" do not include extraordinary expenses as determined under generally accepted accounting principles (see Accounting Principles Board Opinion No. 30). If extraordinary expenses were incurred that materially affected the Fund's "Other Expenses," disclose in a footnote to the table what "Other Expenses" would have been had the extraordinary expenses been included.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection instructions -Paragraph 3 -Subparagraph c -Clause i false0Other Expenses4falseRowprimaryElement*6false 3rr_ExpensesOverAssetsrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalsetotalLabelrr:NonNegativePure4TypepureTotal Annual Fund Operating Expenses. If the Fund is a Feeder Fund, reflect the aggregate expenses of the Feeder Fund and the Master Fund in a single fee table using the captions provided. In a footnote to the fee table, state that the table and Example reflect the expenses of both the Feeder and Master Funds. If the prospectus offers more than one Class of a Multiple Class Fund or more than one Feeder Fund that invests in the same Master Fund, provide a separate response for each Class or Feeder Fund. Base the percentages of "Annual Fund Operating Expenses" on amounts incurred during the Fund's most recent fiscal year, but include in expenses amounts that would have been incurred absent expense reimbursement or fee waiver arrangements. If the Fund has changed its fiscal year and, as a result, the most recent fiscal year is less than three months, use the fiscal year prior to the most recent fiscal year as the basis for determining "Annual Fund Operating Expenses."Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection instructions -Paragraph 3 -Subparagraph d true0Total Annual Fund Operating Expenses 0rr_ExpensesOverAssetsrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalsetotalLabel1truetruetrue0.0230.023falsefalsefalse2truetruetrue0.02050.0205falsefalsefalserr:NonNegativePure4TypepureTotal Annual Fund Operating Expenses. If the Fund is a Feeder Fund, reflect the aggregate expenses of the Feeder Fund and the Master Fund in a single fee table using the captions provided. In a footnote to the fee table, state that the table and Example reflect the expenses of both the Feeder and Master Funds. If the prospectus offers more than one Class of a Multiple Class Fund or more than one Feeder Fund that invests in the same Master Fund, provide a separate response for each Class or Feeder Fund. Base the percentages of "Annual Fund Operating Expenses" on amounts incurred during the Fund's most recent fiscal year, but include in expenses amounts that would have been incurred absent expense reimbursement or fee waiver arrangements. If the Fund has changed its fiscal year and, as a result, the most recent fiscal year is less than three months, use the fiscal year prior to the most recent fiscal year as the basis for determining "Annual Fund Operating Expenses."Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection instructions -Paragraph 3 -Subparagraph d true0Total Annual Fund Operating Expenses5falseRowprimaryElement*7false 3rr_FeeWaiverOrReimbursementOverAssetsrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabelrr:NonPositivePure4TypepureTotal Annual Fund Operating Expenses. If there were expense reimbursement or fee waiver arrangements that reduced any Fund operating expenses and will continue to reduce them for no less than one year from the effective date of the Fund's registration statement, a Fund may add two captions to the table one caption showing the amount of the expense reimbursement or fee waiver, and a second caption showing the Fund's net expenses after subtracting the fee reimbursement or expense waiver from the total fund operating expenses. The Fund should place these additional captions directly below the "Total Annual Fund Operating Expenses" caption of the table and should use appropriate descriptive captions, such as "Fee Waiver [and/or Expense Reimbursement]" and "Total Annual Fund Operating Expenses After Fee Waiver [and/or Expense Reimbursement]," respectively. If the Fund provides this disclosure, also disclose the period for which the expense reimbursement or fee waiver arrangement is expected to continue, and briefly describe who can terminate the arrangement and under what circumstances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection table -Paragraph 1 -Subparagraph 11 false0Fee Waiver and/or Expense Reimbursement 0rr_FeeWaiverOrReimbursementOverAssetsrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabel[2]1truetruetrue-0.0145-0.0145falsefalsefalse2truetruetrue-0.014-0.014falsefalsefalserr:NonPositivePure4TypepureTotal Annual Fund Operating Expenses. If there were expense reimbursement or fee waiver arrangements that reduced any Fund operating expenses and will continue to reduce them for no less than one year from the effective date of the Fund's registration statement, a Fund may add two captions to the table one caption showing the amount of the expense reimbursement or fee waiver, and a second caption showing the Fund's net expenses after subtracting the fee reimbursement or expense waiver from the total fund operating expenses. The Fund should place these additional captions directly below the "Total Annual Fund Operating Expenses" caption of the table and should use appropriate descriptive captions, such as "Fee Waiver [and/or Expense Reimbursement]" and "Total Annual Fund Operating Expenses After Fee Waiver [and/or Expense Reimbursement]," respectively. If the Fund provides this disclosure, also disclose the period for which the expense reimbursement or fee waiver arrangement is expected to continue, and briefly describe who can terminate the arrangement and under what circumstances.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection table -Paragraph 1 -Subparagraph 11 false0Fee Waiver and/or Expense Reimbursement6falseRowprimaryElement*8false 3rr_NetExpensesOverAssetsrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalsetotalLabelrr:NonNegativePure4TypepureTotal Annual Fund Operating Expenses.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection table -Paragraph 1 -Subparagraph 11 true0Total Annual Fund Operating Expenses after Fee Waiver and/or Expense Reimbursement 0rr_NetExpensesOverAssetsrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalsetotalLabel[2]1truetruetrue0.00850.0085falsefalsefalse2truetruetrue0.00650.0065falsefalsefalserr:NonNegativePure4TypepureTotal Annual Fund Operating Expenses.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection table -Paragraph 1 -Subparagraph 11 true0Total Annual Fund Operating Expenses after Fee Waiver and/or Expense Reimbursement1Based on estimated amounts for the current fiscal year.2Metropolitan West Asset Management, LLC (the "Adviser") has contractually agreed to reduce advisory fees and/or reimburse expenses, including distribution expenses, to limit the Fund's total annual operating expense to 0.85% for Class M shares and 0.65% for Class I shares, respectively. For purposes of the expense limitation, operating expenses do not include interest, taxes, brokerage commissions, short sale dividend expenses, swap interest expenses, and any expenses incurred in connection with any merger or reorganization or extraordinary expenses such as litigation. The Adviser may recoup reduced fees and expenses within three years, subject to any applicable expense limit at the time of recoupment. This contract will remain in place until July 31, 2014. Although it does not expect to do so, the Board of Trustees is permitted to terminate that contract sooner in its discretion with written notice to the Adviser.falseAnnual Fund Operating Expenses Metropolitan West Floating Rate Income FundUnKnownUnKnownUnKnownUnKnownfalsefalsefalseSheet2661026018ColumnperiodPeriod*Columndei_LegalEntityAxisAxis*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*RowprimaryElement*falsenonnum:textBlockItemTypenaContains a command for the SEC Viewer for the role corresponding to OperatingExpensesData.No definition available.false0Annual Fund Operating Expenses [Table]12false 3rr_ExpenseExampleHeadingrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Examplefalsefalsefalsexbrli:stringItemTypestringHeading for Expense Example.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection instructions -Paragraph 4 false0Expense Example [Heading]13false 3rr_ExpenseExampleNarrativeTextBlockrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The cost for the Fund reflects the net expenses of the Fund that result from the contractual expense limitation in the first year only. The example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:falsefalsefalsenonnum:textBlockItemTypenaThe Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection example -Paragraph 1 -Subparagraph 1 false0Expense Example Narrative [Text Block]14false 3rr_ExpenseExampleWithRedemptionTableTextBlockrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div style="display:none">~ http://www.mwamllc.com/role/ScheduleExpenseExampleTransposedMetropolitanWestFloatingRateIncomeFund column period compact * ~</div>falsefalse<div style="display:none">~ http://www.mwamllc.com/role/ScheduleExpenseExampleTransposedMetropolitanWestFloatingRateIncomeFund column period compact * ~</div>truehttp://www.mwamllc.com/role/ScheduleExpenseExampleTransposedMetropolitanWestFloatingRateIncomeFund000094 - Schedule - Expense Example {Transposed} {- Metropolitan West Floating Rate Income Fund}truefalsefalse1falseColumnprimaryElement*3false 3rr_ExpenseExampleYear01rr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabelrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection instructions -Paragraph 4 false21 Year USDfalsefalse$2falseColumnprimaryElement*4false 3rr_ExpenseExampleYear03rr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseverboseLabelrr:NonNegativeMonetaryTypemonetaryThe Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection example -Paragraph 1 -Subparagraph 2 false23 Years USDfalsefalse$1falseRowperiodPeriod*Rowdei_LegalEntityAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2012-07-30T00:00:002013-07-29T00:00:00falsefalseMetropolitan West Floating Rate Income Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldimwf_S000041255Memberdei_LegalEntityAxisexplicitMemberfalsefalseClass Mrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldimwf_C000127912Memberrr_ProspectusShareClassAxisexplicitMemberMetropolitan West Floating Rate Income FundClass MUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170 0truefalsefalsefalsefalsefalsefalsefalsefalse1truefalsetrue8787falsefalsefalse2truefalsetrue579579falsefalsefalsenanafalse0Class M2falseRowperiodPeriod*Rowdei_LegalEntityAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2012-07-30T00:00:002013-07-29T00:00:00falsefalseMetropolitan West Floating Rate Income Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldimwf_S000041255Memberdei_LegalEntityAxisexplicitMemberfalsefalseClass Irr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldimwf_C000127913Memberrr_ProspectusShareClassAxisexplicitMemberMetropolitan West Floating Rate Income FundClass IUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170 0truefalsefalsefalsefalsefalsefalsefalsefalse1truefalsetrue6666falsefalsefalse2truefalsetrue507507falsefalsefalsenanafalse0Class IfalseExpense Example Metropolitan West Floating Rate Income Fund (USD $)UnKnownUnKnownUnKnownUnKnownfalsefalsefalseSheet222222014ColumnprimaryElement*RowperiodPeriod*Rowdei_LegalEntityAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*falsenonnum:textBlockItemTypenaContains a command for the SEC Viewer for the role corresponding to ExpenseExample.No definition available.false0Expense Example, With Redemption [Table]15false 3rr_PortfolioTurnoverHeadingrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00PORTFOLIO TURNOVERfalsefalsefalsexbrli:stringItemTypestringDisclose the portfolio turnover rate provided in response to Item 14(a) for the most recent fiscal year (or for such shorter period as the Fund has been in operation). Disclose the period for which the information is provided if less than a full fiscal year. A Fund that is a Money Market Fund may omit the portfolio turnover information required by this Item.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection instructions -Paragraph 5 false0Portfolio Turnover [Heading]16false 3rr_PortfolioTurnoverTextBlockrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The Fund 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 Fund’s performance.falsefalsefalsenonnum:textBlockItemTypenaDisclose the portfolio turnover rate provided in response to Item 14(a) for the most recent fiscal year (or for such shorter period as the Fund has been in operation). Disclose the period for which the information is provided if less than a full fiscal year. A Fund that is a Money Market Fund may omit the portfolio turnover information required by this Item.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Subsection example -Paragraph 3 false0Portfolio Turnover [Text Block]17false 3rr_StrategyHeadingrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00PRINCIPAL INVESTMENT STRATEGIESfalsefalsefalsexbrli:stringItemTypestringPrincipal investment strategies of the Fund. Summarize how the Fund intends to achieve its investment objectives by identifying the Fund's principal investment strategies (including the type or types of securities in which the Fund invests or will invest principally) and any policy to concentrate in securities of issuers in a particular industry or group of industries.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection a false0Strategy [Heading]18false 3rr_StrategyNarrativeTextBlockrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The Fund normally invests at least 80% of its net assets, which includes borrowings for investment purposes, in floating rate investments and in investments that are the economic equivalent of floating rate investments. We expect the Fund’s portfolio of these investments to produce a floating rate of income over time. These investments may include, but are not limited to, any combination of the following items: (i) senior secured floating rate loans or debt; (ii) second lien or other subordinated or unsecured floating rate loans or debt; (iii) fixed-rate loans or debt, such as corporate bonds, preferred securities, convertible securities, mezzanine investments, collateralized loan obligations, senior loans, second lien loans, structured products and U.S. government debt securities, with respect to which the Fund has entered into derivative instruments that have the effect of converting the fixed-rate interest payments into floating-rate interest payments; and (iv) writing credit derivatives, which would give the Fund exposure to the credit of a single issuer or an index. The market value of written credit derivatives would count toward the 80% test specified above. The Fund may also purchase, without limitation, participations or assignments in senior floating rate loans or second lien floating rate loans. Debt instruments include convertible or preferred securities that produce income. The portfolio managers may consider many factors in purchasing and selling investments for the Fund, such as a fundamental analysis of the issuer, the credit quality of the issuer and collateral for the investment, capital structure, leverage, operating results for the issuer and the business outlook for the issuer, industry or broader economy. The Fund’s investments may have any credit quality without limitation, including investments rated below investment grade. Under current market conditions, a substantial portion of the Fund’s portfolio will consist of leveraged loans rated below investment grade or unrated. These investments will have credit risks similar to high yield securities, which are commonly referred to as “junk bonds.” The Fund may invest up to 20% of its assets in fixed income securities with respect to which the Fund has not entered into derivative instruments to effectively convert the fixed-rate interest payments into floating-rate interest payments. Those fixed income securities may include, but are not limited to, corporate bonds, preferred securities, convertible securities, mezzanine investments, collateralized loan obligations, senior loans, second lien loans, structured products and U.S. government debt securities. The Fund’s portfolio securities may have any duration or maturity. The Fund may invest in securities of foreign issuers, including issuers located in emerging markets. Under normal conditions, the Fund will invest at least 80% of its net assets in loans and other securities of U.S. issuers or issuers with their primary operations, assets or management activities in the U.S. (including limited purpose controlled affiliates outside of the U.S. that borrow or issue securities primarily for the benefit of their U.S. parent companies or affiliates). Up to 15% of the Fund’s net assets may be invested in illiquid securities. The Fund may also invest in companies whose financial condition is uncertain, where the borrower has defaulted in the payment of interest or principal or in the performance of its covenants or agreements, or that may be involved in bankruptcy proceedings, reorganizations or financial restructurings. The Fund may invest up to 10% of its net assets in common stocks or other equity securities. In addition, the Fund may acquire and hold those securities (or rights to acquire such securities) in unit offerings with fixed income securities, in connection with an amendment, waiver, conversion or exchange of fixed income securities, in connection with the bankruptcy or workout of a distressed fixed income security, or upon the exercise of a right or warrant obtained on account of a fixed income security. The Fund may buy or sell options or futures on a security or an index of securities, buy or sell options on futures or enter into credit default swaps and interest rate or foreign currency transactions, including swaps and forward contracts (which are commonly known as derivatives). The Fund may use derivatives for hedging purposes, but is not required to do so, as well as to increase the total return on its portfolio investments.falsefalsefalsenonnum:textBlockItemTypenaPrincipal investment strategies of the Fund. Summarize how the Fund intends to achieve its investment objectives by identifying the Fund's principal investment strategies (including the type or types of securities in which the Fund invests or will invest principally) and any policy to concentrate in securities of issuers in a particular industry or group of industries.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection a false0Strategy Narrative [Text Block]19false 3rr_RiskHeadingrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00PRINCIPAL RISKS falsefalsefalsexbrli:stringItemTypestringNarrative Risk Disclosure.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection b -Paragraph 1 false0Risk [Heading]20false 3rr_RiskNarrativeTextBlockrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Because the Fund holds investments with fluctuating market prices, the value of the Fund’s shares will vary as its portfolio holdings 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: Market Risk:    the risk that returns from the investments held by the Fund will underperform returns from the general securities markets or other types of securities. Interest Rate Risk:    the risk that investments held by the Fund will decline in value because of changes in interest rates. Issuer/Credit Risk:    The risk that an issuer will default on payment of principal and/or interest on a bond or other fixed-income security. The financial strength of an issuer may decline after the Fund purchases its security. A default or increased risk of default can reduce the value of the Fund’s investment. High Yield Risk:    The Adviser expects to invest in high yield and unrated securities, which are considered speculative and are subject to greater volatility and risk of loss than investment grade securities, particularly in deteriorating economic conditions. In addition, the issuers of high yield securities may default in the payment of principal and/or interest on the security, resulting in loss of the Fund. Loan Risks:    Commercial banks and other financial institutions or institutional investors make corporate loans to companies that need capital to grow or restructure. Borrowers generally pay interest on corporate loans at rates that change in response to changes in market interest rates such as the London Interbank Offered Rate (“LIBOR”) or the prime rates of U.S. banks. As a result, the value of corporate loan investments is generally less exposed to the adverse effects of shifts in market interest rates than investments that pay a fixed rate of interest. Investments in loans are generally subject to the same risks as investments in other types of debt securities, including, in many cases, investments in high-yield/junk bonds. They may be difficult to value, have wide bid-ask spreads and may be illiquid. If the Fund holds a loan through another financial institution, or relies on a financial institution to administer the loan, its receipt of principal and interest on the loan may be subject to the credit risk of that financial institution. It is possible that any collateral securing a loan may be insufficient or unavailable to the Fund, and that the Fund’s rights to collateral may be limited by bankruptcy or insolvency laws. There may be limited public information available regarding the loan. Transactions in loans may settle on a delayed basis, and the Fund may not receive the proceeds from the sale of a loan for a substantial period of time after the sale. Distressed Investment Risks:    A security held by the Fund (or the issuer of that security) may become distressed after the Fund’s investment. Distressed securities are speculative and involve substantial risks in addition to the risks of investing in junk bonds. The Fund will generally not receive interest payments on the distressed securities and may incur costs to protect its investment. In addition, distressed securities involve the substantial risk that principal will not be repaid. These securities may present a substantial risk of default or may be in default at the time of investment. The Fund may incur additional expenses to the extent it is required to seek recovery upon a default in the payment of principal of or interest on its portfolio holdings. In any reorganization or liquidation proceeding relating to a portfolio company, the Fund may lose its entire investment or may be required to accept cash or securities with a value less than its original investment. Distressed securities and any securities received in an exchange for such securities may be subject to restrictions on resale. Derivatives and Swaps Risks:    the risk that changes in the value of a derivative may be volatile and may not correlate perfectly with the underlying asset, reference rate or index and the Fund could lose more than the principal amount invested. Swaps also involve the risks that the counterparty may default and the potential lack of liquidity. Leverage Risk:    the risk that leverage may result from certain transactions, including the use of derivatives, borrowing and reverse repurchase agreements. Leverage may exaggerate the effect of a change in the value of the Fund’s portfolio securities, causing the Fund to be more volatile than if leverage was not used. The Fund will reduce leverage risk either by segregating an equal amount of liquid assets or by “covering” the transactions that introduce such risk through the use of off-setting or hedging transactions. Foreign Securities Risk:    the value of the Fund’s investments in foreign securities also depends on changing currency values, different political and economic environments and other overall economic conditions in the countries where the Fund invests. Emerging market debt securities tend to be of lower credit quality and subject to greater risk of default than higher rated securities from more developed markets. Investments by the Fund in currencies other than U.S. dollars may decline in value against the U.S. dollar if not properly hedged. Equities Risk:    the risk that equity securities are susceptible to general stock market fluctuations and to volatile increases and decreases in value. Liquidity Risk:    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 Adviser 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. Some loans held by the Fund may also experience delayed settlement, which can impair the ability of the Fund pay redemptions or to re-invest proceeds, or may require the Fund to borrow to meet redemptions. Senior Loan Risks:    There is less readily available, reliable information about most senior loans than is the case for many other types of securities. An economic downturn generally leads to a higher non-payment rate, and a senior loan may lose significant value before a default occurs. Moreover, any specific collateral used to secure a senior loan may decline in value or become illiquid, which would adversely affect the senior loan’s value. No active trading market may exist for certain senior loans, which may impair the ability of the Fund to realize full value in the event of the need to sell a senior loan and which may make it difficult to value senior loans. Although senior loans in which the Fund will invest generally will be secured by specific collateral, there can be no assurance that liquidation of such collateral would satisfy the borrower’s obligation in the event of non-payment of scheduled interest or principal or that such collateral could be readily liquidated. To the extent that a senior loan is collateralized by stock in the borrower or its subsidiaries, such stock may lose all of its value in the event of the bankruptcy of the borrower. Uncollateralized senior loans involve a greater risk of loss. The senior loans in which the Fund invests are usually rated below investment grade. Senior loans made in connection with highly leveraged transactions are subject to greater risks than other senior loans. For example, the risks of default or bankruptcy of the borrower or the risks that other creditors of the borrower may seek to nullify or subordinate the Fund’s claims on any collateral securing the loan are greater in highly leveraged transactions. Second Lien Loan Risks:    Second lien loans generally are subject to similar risks as those associated with investments in senior loans. Because second lien loans are subordinated or unsecured and thus lower in priority of payment to senior loans, they are subject to the additional risk that the cash flow of the borrower and property securing the loan or debt, if any, may be insufficient to meet scheduled payments after giving effect to the senior secured obligations of the borrower. Please see “Principal Risks” and “Other Risks” 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.falsefalsefalsenonnum:textBlockItemTypenaNarrative Risk Disclosure. A Fund may, in responding to this Item, describe the types of investors for whom the Fund is intended or the types of investment goals that may be consistent with an investment in the Fund.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection b -Paragraph 1 -Subparagraph i -Clause instruction false0Risk Narrative [Text Block]21false 3rr_BarChartAndPerformanceTableHeadingrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00PERFORMANCE INFORMATION falsefalsefalsexbrli:stringItemTypestringRisk/Return Bar Chart and Table.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection b -Paragraph 2 false0Bar Chart and Performance Table [Heading]22false 3rr_PerformanceNarrativeTextBlockrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The Fund is new and does not have a full calendar year of performance or financial information to present. Once it has been in operation a full calendar year, performance (including total return) and financial information will be presented. Updated performance information for the Fund is available on our website at www.mwamllc.com or by calling (800) 241-4671.falsefalsefalsenonnum:textBlockItemTypenaRisk/Return Bar Chart and Table.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection b -Paragraph 2 false0Performance Narrative [Text Block]falseRisk/Return Summary - Metropolitan West Floating Rate Income Fund (Metropolitan West Floating Rate Income Fund)UnKnownUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.mwamllc.com/role/DocumentRiskReturnSummaryUnlabeledMetropolitanWestFloatingRateIncomeFund122