2.2.0.25truefalse010000 - Document - Risk/Return Summary {Unlabeled}falsefalsetrue1falsefalsetruefalse{dei_DocumentInformationDocumentAxis} : American Beacon S&P 500 Index Fund 5/2/2010 - 4/29/2011 TwelveMonthsEnded_29Apr2011_S000001827_Memberhttp://www.sec.gov/CIK0000809593duration2010-05-02T00:00:002011-04-29T00:00:00falsefalseabf809593_S000001827Memberdei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiabf809593_S000001827Memberdei_DocumentInformationDocumentAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli01false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://americanbeaconfunds.com/role/riskreturnsummary1falsefalsefalse00American Beacon S&P 500 Index FundAmerican Beacon S&P 500 Index Fundfalsefalsefalsefalsefalse1falsefalsetruefalse{dei_DocumentInformationDocumentAxis} : American Beacon S&P 500 Index Fund 5/2/2010 - 4/29/2011 TwelveMonthsEnded_29Apr2011_S000001827_Memberhttp://www.sec.gov/CIK0000809593duration2010-05-02T00:00:002011-04-29T00:00:00falsefalseabf809593_S000001827Memberdei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiabf809593_S000001827Memberdei_DocumentInformationDocumentAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli0OthernaNo definition available.No authoritative reference available.falsefalseAmerican Beacon S&P 500 Index Fund3false0rr_RiskReturnHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00American Beacon S&#038;P 500^&#174; Index Fund^SMfalsefalsefalsefalsefalseOtherxbrli: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 falsefalseRisk/Return [Heading]4false0rr_ObjectiveHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<i>Investment Objective</i>falsefalsefalsefalsefalseOtherxbrli: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 -Subsection a falsefalseObjective [Heading]5false0rr_ObjectivePrimaryTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The Fund&#8217;s investment objective is to replicate as closely as possible, before expenses, the performance of the Standard &#038; Poor&#8217;s 500 Index (&#8220;S&#038;P 500 Index&#8221; or &#8220;Index&#8221;).falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringInvestment 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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 -Subsection a falsefalseObjective, Primary [Text Block]6false0rr_ExpenseHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<i>Fees and Expenses of the Fund</i>falsefalsefalsefalsefalseOtherxbrli: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph d -Subsection instructions falsefalseExpense [Heading]7false0rr_ExpenseNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringThis 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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph b -Subsection instructions falsefalseExpense Narrative [Text Block]8false0rr_AnnualFundOperatingExpensesTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div> &lt;div style="display:none;"&gt;~ http://americanbeaconfunds.com/role/AnnualFundOperatingExpensesAmericanBeaconSAndPFiveHundredIndexFund column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact abf809593_S000001827_Member * row dei_LegalEntityAxis compact abf809593_S000001827_Member * ~&lt;/div&gt; </div>falsefalse<div> &lt;div style="display:none;"&gt;~ http://americanbeaconfunds.com/role/AnnualFundOperatingExpensesAmericanBeaconSAndPFiveHundredIndexFund column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact abf809593_S000001827_Member * row dei_LegalEntityAxis compact abf809593_S000001827_Member * ~&lt;/div&gt; </div>falsehttp://americanbeaconfunds.com/role/AnnualFundOperatingExpensesAmericanBeaconSAndPFiveHundredIndexFundfalsefalse0200201 - 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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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 9 -Subsection table falsefalseDistribution and/or service (12b-1) fees0rr_DistributionAndService12b1FeesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.000000.00000falsefalsefalsetruefalse3truetruetrue0.000000.00000falsefalsefalsetruefalseOthernanafalsefalseDistribution and/or service (12b-1) fees5falseRowprimaryElement*8false0rr_OtherExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truetruetrue0.000850.00085falsefalsefalsetruefalse2truetruetrue0.005550.00555falsefalsefalsetruefalse3falsetruetrue00falsefalsefalsetruefalseOtherrr: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subparagraph c -Clause i -Subsection instructions truefalseOther expenses0rr_OtherExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.000850.00085falsefalsefalsetruefalse3truetruetrue0.005550.00555falsefalsefalsetruefalseOthernanafalsefalseOther expenses6falseRowprimaryElement*9false0rr_ExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truetruetrue0.001300.00130falsefalsefalsetruefalse2truetruetrue0.00600.0060falsefalsefalsetruefalse3falsetruetrue00falsefalsefalsetruefalseOtherrr: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subparagraph d -Subsection instructions truefalseTotal annual fund operating expenses0rr_ExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.001300.00130falsefalsefalsetruefalse3truetruetrue0.00600.0060falsefalsefalsetruefalseOthernanafalsefalseTotal annual fund operating expenses1<i>The fees and expenses shown in the table and the example that follows include both the expenses of the Fund and the Fund's share of the allocated expenses of the Equity 500 Index Portfolio of State Street Master Funds.</i>36Annual Fund Operating Expenses - American Beacon S&P 500 Index Fund UnKnownUnKnownUnKnownUnKnownfalsetrueColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*RowprimaryElement*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to OperatingExpensesData.No authoritative reference available.falsefalseAnnual Fund Operating Expenses [Table]9false0rr_ExpenseExampleHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00ExamplefalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringHeading for Expense Example.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 4 -Subsection instructions falsefalseExpense Example [Heading]10false0rr_ExpenseExampleNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00This 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 Example also assumes that your investment has a 5% return each year, that all dividends and distributions are reinvested, and that the Fund&#8217;s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringThe 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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 1 -Subsection example falsefalseExpense Example Narrative [Text Block]11false0rr_ExpenseExampleWithRedemptionTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div> &lt;div style="display:none;"&gt;~ http://americanbeaconfunds.com/role/ExpenseExampleAmericanBeaconSAndPFiveHundredIndexFund column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact abf809593_S000001827_Member * row dei_LegalEntityAxis compact abf809593_S000001827_Member * ~&lt;/div&gt; </div>falsefalse<div> &lt;div style="display:none;"&gt;~ http://americanbeaconfunds.com/role/ExpenseExampleAmericanBeaconSAndPFiveHundredIndexFund column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact abf809593_S000001827_Member * row dei_LegalEntityAxis compact abf809593_S000001827_Member * ~&lt;/div&gt; </div>truehttp://americanbeaconfunds.com/role/ExpenseExampleAmericanBeaconSAndPFiveHundredIndexFundfalsefalse0200301 - Schedule - Expense Example {Transposed}truefalsefalse1falseColumnprimaryElement*4false0rr_ExpenseExampleByYearColumnNamerrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1falsefalsefalse00Institutionalfalsefalsefalsetruefalse2falsefalsefalse00InvestorfalsefalsefalsetruefalseOtherus-types:textBlockItemTypestringThe 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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalseExpense Example, By Year, Column [Text]falseUSDfalsefalse$2falseColumnprimaryElement*5false0rr_ExpenseExampleYear01rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue1313falsefalsefalsetruefalse2truefalsetrue6161falsefalsefalsetruefalseMonetaryrr: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 4 -Subsection instructions falsefalse1 yearfalseUSDfalsefalse$3falseColumnprimaryElement*6false0rr_ExpenseExampleYear03rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue4242falsefalsefalsetruefalse2truefalsetrue192192falsefalsefalsetruefalseMonetaryrr: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalse3 yearsfalseUSDfalsefalse$4falseColumnprimaryElement*7false0rr_ExpenseExampleYear05rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue7373falsefalsefalsetruefalse2truefalsetrue335335falsefalsefalsetruefalseMonetaryrr: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalse5 yearsfalseUSDfalsefalse$5falseColumnprimaryElement*8false0rr_ExpenseExampleYear10rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue166166falsefalsefalsetruefalse2truefalsetrue750750falsefalsefalsetruefalseMonetaryrr: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalse10 yearsfalseUSDfalsefalse$1falseRowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2010-05-02T00:00:002011-04-29T00:00:00falsefalseAmerican Beacon S&P 500 Index Funddei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiabf809593_S000001827Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseInstitutional Class - American Beacon S&P 500 Index Fundrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldiabf809593_C000004791Memberrr_ProspectusShareClassAxisexplicitMemberAmerican Beacon S&P 500 Index FundInstitutional Class - American Beacon S&P 500 Index FundUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00InstitutionalInstitutionalfalsefalsefalsetruefalse2truefalsetrue1313falsefalsefalsetruefalse3truefalsetrue4242falsefalsefalsetruefalse4truefalsetrue7373falsefalsefalsetruefalse5truefalsetrue166166falsefalsefalsetruefalseOthernanafalsefalseInstitutional Class - American Beacon S&P 500 Index Fund2falseRowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2010-05-02T00:00:002011-04-29T00:00:00falsefalseAmerican Beacon S&P 500 Index Funddei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiabf809593_S000001827Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseInvestor Class - American Beacon S&P 500 Index Fundrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldiabf809593_C000004792Memberrr_ProspectusShareClassAxisexplicitMemberAmerican Beacon S&P 500 Index FundInvestor Class - American Beacon S&P 500 Index FundUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00InvestorInvestorfalsefalsefalsetruefalse2truefalsetrue6161falsefalsefalsetruefalse3truefalsetrue192192falsefalsefalsetruefalse4truefalsetrue335335falsefalsefalsetruefalse5truefalsetrue750750falsefalsefalsetruefalseOthernanafalsefalseInvestor Class - American Beacon S&P 500 Index Fund52Expense Example American Beacon S&P 500 Index Fund (USD $)UnKnownUnKnownUnKnownUnKnownfalsetrueColumnprimaryElement*RowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to ExpenseExample.No authoritative reference available.falsefalseExpense Example, With Redemption [Table]12false0rr_PortfolioTurnoverHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Portfolio TurnoverfalsefalsefalsefalsefalseOtherxbrli: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 5 -Subsection instructions falsefalsePortfolio Turnover [Heading]13false0rr_PortfolioTurnoverTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The Fund pays transaction costs, such as commissions, when it buys and sells securities (or &#8220;turns over&#8221; 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&#8217;s performance. The Fund invests substantially all of its investable assets in the State Street Equity 500 Index Portfolio (The &#8220;Equity 500 Index Portfolio&#8221; or the &#8220;Portfolio&#8221;), therefore, the portfolio turnover rate is that of the State Street Equity 500 Index Portfolio. During the most recent fiscal year, the turnover rate was 12% of the average value of its portfolio.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringDisclose 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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subsection example falsefalsePortfolio Turnover [Text Block]14false0rr_StrategyHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<i>Principal Investment Strategies</i>falsefalsefalsefalsefalseOtherxbrli: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection a falsefalseStrategy [Heading]15false0rr_StrategyNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>The Fund seeks its investment objective by investing substantially all of its investable assets in the Equity 500 Index Portfolio which has the same investment objective as, and investment policies that are substantially similar to those of the Fund. The discussion below refers to investments made by the Portfolio. For easier reading, in this Prospectus, the term &#8220;Fund&#8221; includes the Portfolio.</p><p>The Portfolio uses a passive management strategy designed to track the performance of the S&#038;P 500 Index. The Index is a well-known stock market index that includes common stocks of 500 companies from a number of industrial sectors representing a significant portion of the market value of all stocks publicly traded in the United States.</p><p>The Portfolio is not managed according to traditional methods of &#8220;active&#8221; investment management, which involve the buying and selling of securities based upon economic, financial and market analysis and investment judgment. Instead, the Fund, using a &#8220;passive&#8221; or &#8220;indexing&#8221; investment approach, attempts to replicate, before expenses, the performance of the S&#038;P 500 Index.</p><p>The Portfolio generally intends to invest in all 500 stocks comprising the S&#038;P 500 Index in approximate proportion to their weightings in the Index. However, under various circumstances, it may not be possible or practicable to purchase all 500 stocks in those weightings. In those circumstances, the Portfolio may purchase a sample of the stocks in the Index in proportions expected by the Adviser to track generally the performance of the Index as a whole. In addition, from time to time stocks are added to or removed from the Index. The Portfolio may sell securities that are represented in the Index, or purchase securities that are not yet represented in the Index, in anticipation of their removal from or addition to the Index. Under normal market conditions the Portfolio will not invest less than 80% of its total assets in stocks in the Index.</p><p>In addition, the Portfolio may at times purchase or sell futures contracts on the Index, or options on those futures, in lieu of investing directly in the stocks making up the Index. The Portfolio might do so, for example, in order to increase its investment exposure pending investment of cash in the stocks comprising the Index. Alternatively, the Portfolio might use futures or options on futures to reduce its investment exposure in situations where it intends to sell a portion of the stocks in its portfolio but the sale has not yet been completed. The Portfolio may also purchase or sell options or enter into swap transactions to assist in replicating the performance of the Index. The Portfolio may also, to the extent permitted by applicable law, invest in shares of other mutual funds whose investment objectives and policies are similar to those of the Portfolio.</p><p>The Portfolio may lend its securities to broker-dealers and other institutions to earn additional income.</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringPrincipal 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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection a falsefalseStrategy Narrative [Text Block]16false0rr_RiskHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<i>Principal Risks</i>falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNarrative Risk Disclosure.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 1 -Subsection b falsefalseRisk [Heading]17false0rr_RiskNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>There is no assurance that the Fund will achieve its investment objective and you could lose part or all of your investment in the Fund. The Fund is not a complete investment program and may not be appropriate for all investors. Investors should carefully consider their own investment goals and risk tolerance before investing in the Fund. The principal risks of investing in the Fund are:</p><p><b>Market Risk</b></p><p>Since the Portfolio invests most of its assets in stocks, it is subject to stock market risk. Market risk involves the possibility that the value of the Portfolio&#8217;s investments in stocks will vary from day to day in response to the activities of individual companies, as well as general market, regulatory, political and economic conditions. From time to time, certain securities held by the Portfolio may have limited marketability and may be difficult to sell at favorable times or prices. If the Portfolio is forced to sell such securities to meet redemption requests or other cash needs, the Portfolio may have to sell them at a loss.</p><p><b>Large Cap Stock Risks</b></p><p>Because the S&#038;P 500 Index includes mainly large U.S. companies, the Portfolio&#8217;s emphasis on securities issued by large capitalization companies makes it susceptible to the risks of investing in larger companies. For example, larger companies may be unable to respond as quickly as smaller companies to competitive challenges. Larger companies also tend not to be able to maintain the high growth rates of well-managed smaller companies, especially during strong economic periods.</p><p><b>Tracking Error Risk</b></p><p>The Portfolio&#8217;s return may not match the return of the Index for a number of reasons. For example, the Portfolio incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. Other factors that may affect the Portfolio&#8217;s ability to match the return of the Index include a temporary lack of liquidity in the markets for the securities held by the Portfolio, the different closing times of international and U.S. markets, and different valuation methodologies employed by the Portfolio and the Index. In addition, the return on the sample of securities purchased by the Portfolio, or futures or other derivative positions taken by the Portfolio, to replicate the performance of the Index may not correlate precisely with the return on the Index. The Portfolio may not be fully invested at times, either as a result of cash flows into the Portfolio or reserves of cash held by the Portfolio to meet redemptions.</p><p><b>Derivatives Risk</b></p><p>Derivatives may involve significant risk and have the potential for losses in excess of the principal amount invested. Derivatives may be illiquid and may be more volatile than other types of investments. The Portfolio may buy derivatives not traded on an exchange which may be subject to heightened liquidity and valuation risk. Derivative investments can increase portfolio turnover and transaction costs. Derivatives are subject to counterparty credit risk, which is the risk that a counterparty to a derivative instrument becomes bankrupt or otherwise fails to perform its obligations due to financial difficulties. As a result the Portfolio may obtain no recovery of its investment or may only obtain a limited recovery, and any recovery may be delayed. In addition, the Portfolio&#8217;s investments in derivatives are subject to the following risks:</p> <ul><li><i>Futures.</i> There may be an imperfect correlation between the changes in market value of the securities held by the Portfolio and the prices of futures contracts. There may not be a liquid secondary market for the futures contracts.</li></ul><ul><li><i>Hedging Risk.</i> If the Portfolio uses a hedging instrument at the wrong time or judges the market conditions incorrectly, the hedge might be unsuccessful, reduce the Portfolio&#8217;s return, or create a loss.</li></ul><ul><li><i>Options.</i> There may be an imperfect correlation between the prices of options and movements in the price of the securities (or indices) hedged or used for cover which may cause a given hedge not to achieve its objective.</li></ul><ul><li><i>Swap Agreements.</i> Swaps are subject to counterparty risk. Credit default swaps, including credit default swaps on baskets of securities (such as the CDX indices), are subject to credit risk on the underlying investment. Equity swaps are subject to market risk. Total return swaps may be subject to credit risk and market risk.</li></ul><p><b>Investment Risk</b></p><p>An investment in the Fund is not a deposit with a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. When you sell your shares of the Fund, they could be worth less than what you paid for them. Therefore, you could lose money by investing in the Fund.</p><p><b>Passive Strategy/Index Risk</b></p><p>The Portfolio is managed with a passive investment strategy, attempting to track the performance of an unmanaged index of securities. This differs from an actively managed fund, which typically seeks to outperform a benchmark index. As a result, the Portfolio may hold constituent securities of the Index regardless of the current or projected performance of a specific security or a particular industry or market sector. Maintaining investments in securities regardless of market conditions or the performance of individual securities could cause the Portfolio&#8217;s return to be lower than if the Portfolio employed an active strategy.</p><p><b>Securities Lending Risk</b></p><p>The Portfolio has the authority to lend portfolio securities to brokers, dealers and other financial organizations in amounts up to 331/3% of the total value of its assets. Any such loan must be continuously secured by collateral in cash or cash equivalents maintained on a current basis in an amount at least equal to the market value of the securities loaned by the Portfolio. The Portfolio would have the right to call the loan and obtain the securities loaned at any time on notice of not more than five business days. In the event of bankruptcy or other default of the borrower, the Portfolio could experience both delays in liquidating the loan collateral or recovering the loaned securities and losses including (a) possible decline in the value of collateral or in the value of the securities loaned during the period while the Portfolio seeks to enforce its rights thereto, (b) possible sub-normal levels of income and lack of access to income during this period, and (c) expenses of enforcing its rights.</p><p><b>Equity Security Risk</b></p><p>Equity securities generally are subject to market risk. The Portfolio&#8217;s investments in equity securities include common stock and securities convertible into common stock. Common stock ranks bellow preferred stock and debt securities in claims for dividends and for assets of the company in a liquidation or bankruptcy. The value of a company&#8217;s common stock may fall as a result of factors directly or indirectly relating to that company. Convertible securities are subject to the risk that the credit standing of the issuer may have an effect on the convertible securities&#8217; investment value.</p><p><b>Master/Feeder Structure Risk</b></p><p>Unlike a traditional mutual fund that invests directly in securities, the Fund pursues its objective by investing substantially all of its assets in the S&#038;P 500 Index Portfolio, which has substantially the same investment objectives, policies and restrictions. The ability of the Fund to meet its investment objective is directly related to the ability of the Portfolio to meet its objective. The ability of the Fund to meet its objective may be adversely affected by the purchase and redemption activities of other investors in the corresponding Master Portfolio. The ability of the Fund to meet redemption requests depends on its ability to redeem its interest in the Master Portfolio.</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringNarrative 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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 1 -Subparagraph i -Clause instruction -Subsection b falsefalseRisk Narrative [Text Block]18false0rr_BarChartAndPerformanceTableHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<i>Fund Performance</i>falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Bar Chart and Table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subsection b falsefalseBar Chart and Performance Table [Heading]19false0rr_PerformanceNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The bar chart and table below provide an indication of risk by showing how the Fund&#8217;s performance has varied from year to year. The table shows how the Fund&#8217;s performance compares to a broad-based market index and the Lipper S&P 500 Objective Funds Index, a composite of funds comparable to the Fund. The chart and the table below show the performance of the Fund&#8217;s Institutional Class shares for all periods. You may obtain updated performance information on the Fund&#8217;s website atwww.americanbeaconfunds.com. Past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringRisk/Return Bar Chart and Table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subsection b falsefalsePerformance Narrative [Text Block]20false0rr_BarChartHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Calendar year total returns for Institutional Class sharesfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Bar Chart and Table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subsection b falsefalseBar Chart [Heading]21false0rr_AnnualReturnCaptionrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse00Total Return for the Calendar Year Ended 12/31 of each YearfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. Provide annual total returns beginning with the earliest calendar year. Calculate annual returns using the Instructions to Item 8(a), except that the calculations should be based on calendar years. If a Fund's shares are sold subject to a sales load or account fees, state that sales loads or account fees are not reflected in the bar chart and that, if these amounts were reflected, returns would be less than those shown. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets). When a Multiple Class Fund offering one or more Classes offers a new Class in a prospectus that does not offer the shares of any other Class, include the bar chart with annual total returns for any other existing Class for the first year that the Class is offered. Explain in a footnote that the returns are for a Class that is not offered in the prospectus that would have substantially similar annual returns because the shares are invested in the same portfolio of securities and the annual returns would differ only to the extent that the Classes do not have the same expenses. Include return information for the other Class reflected in the bar chart in the performance table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit b -Subsection b falsefalseAnnual Return Caption [Text]22false0rr_BarChartTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div> &lt;div style="display:none;"&gt;~ http://americanbeaconfunds.com/role/AnnualTotalReturnsBarChartAmericanBeaconSAndPFiveHundredIndexFund column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact abf809593_S000001827_Member * row dei_LegalEntityAxis compact abf809593_S000001827_Member * ~&lt;/div&gt; </div>falsefalseBarChart1.jpg<div> &lt;div style="display:none;"&gt;~ http://americanbeaconfunds.com/role/AnnualTotalReturnsBarChartAmericanBeaconSAndPFiveHundredIndexFund column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact abf809593_S000001827_Member * row dei_LegalEntityAxis compact abf809593_S000001827_Member * ~&lt;/div&gt; </div>falsehttp://americanbeaconfunds.com/role/AnnualTotalReturnsBarChartAmericanBeaconSAndPFiveHundredIndexFundfalsefalse0200501 - Schedule - Annual Total Returns (Bar Chart) - American Beacon S&P 500 Index Fundtruefalsefalse1falseColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*duration2010-05-02T00:00:002011-04-29T00:00:00falsefalseAmerican Beacon S&P 500 Index Funddei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiabf809593_S000001827Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseInstitutional Class - American Beacon S&P 500 Index Fundrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldiabf809593_C000004791Memberrr_ProspectusShareClassAxisexplicitMemberAmerican Beacon S&P 500 Index FundInstitutional Class - American Beacon S&P 500 Index FundUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170falseUSDfalsefalse$1falseRowprimaryElement*4false0rr_AnnualReturn2001rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse-0.1212-0.1212falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse20010rr_AnnualReturn2001truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse-0.1212-0.1212falsefalsefalsetruefalseOthernanafalsefalse20012falseRowprimaryElement*5false0rr_AnnualReturn2002rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse-0.2227-0.2227falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse20020rr_AnnualReturn2002truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse-0.2227-0.2227falsefalsefalsetruefalseOthernanafalsefalse20023falseRowprimaryElement*6false0rr_AnnualReturn2003rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse0.28260.2826falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalse20030rr_AnnualReturn2003truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.28260.2826falsefalsefalsetruefalseOthernanafalsefalse20034falseRowprimaryElement*7false0rr_AnnualReturn2004rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse0.10760.1076falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalse20040rr_AnnualReturn2004truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.10760.1076falsefalsefalsetruefalseOthernanafalsefalse20045falseRowprimaryElement*8false0rr_AnnualReturn2005rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse0.04740.0474falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse20050rr_AnnualReturn2005truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.04740.0474falsefalsefalsetruefalseOthernanafalsefalse20056falseRowprimaryElement*9false0rr_AnnualReturn2006rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse0.15690.1569falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse20060rr_AnnualReturn2006truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.15690.1569falsefalsefalsetruefalseOthernanafalsefalse20067falseRowprimaryElement*10false0rr_AnnualReturn2007rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse0.05390.0539falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalse20070rr_AnnualReturn2007truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.05390.0539falsefalsefalsetruefalseOthernanafalsefalse20078falseRowprimaryElement*11false0rr_AnnualReturn2008rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse-0.3708-0.3708falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse20080rr_AnnualReturn2008truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse-0.3708-0.3708falsefalsefalsetruefalseOthernanafalsefalse20089falseRowprimaryElement*12false0rr_AnnualReturn2009rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse0.26700.2670falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalse20090rr_AnnualReturn2009truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.26700.2670falsefalsefalsetruefalseOthernanafalsefalse200910falseRowprimaryElement*13false0rr_AnnualReturn2010rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse0.14960.1496falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. 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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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph d -Subsection instructions falsefalseExpense [Heading]31false0rr_ExpenseNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringThis 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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph b -Subsection instructions falsefalseExpense Narrative [Text Block]32false0rr_AnnualFundOperatingExpensesTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div> &lt;div style="display:none;"&gt;~ http://americanbeaconfunds.com/role/AnnualFundOperatingExpensesAmericanBeaconSmallCapIndexFund column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact abf809593_S000001828_Member * row dei_LegalEntityAxis compact abf809593_S000001828_Member * ~&lt;/div&gt; </div>falsefalse<div> &lt;div style="display:none;"&gt;~ http://americanbeaconfunds.com/role/AnnualFundOperatingExpensesAmericanBeaconSmallCapIndexFund column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact abf809593_S000001828_Member * row dei_LegalEntityAxis compact abf809593_S000001828_Member * ~&lt;/div&gt; </div>falsehttp://americanbeaconfunds.com/role/AnnualFundOperatingExpensesAmericanBeaconSmallCapIndexFundfalsefalse0200202 - Schedule - Annual Fund Operating Expenses - American Beacon Small Cap Index Fundtruefalsefalse1falseColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*duration2010-05-02T00:00:002011-04-29T00:00:00falsefalseAmerican Beacon Small Cap Index Funddei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiabf809593_S000001828Memberdei_DocumentInformationDocumentAxisexplicitMembertruefalseShare Classesrr_ProspectusShareClassAxisrr_ShareClassDomainrr_ProspectusShareClassAxisexplicitMemberAmerican Beacon Small Cap Index FundShare ClassesStandard0falseUSDfalsefalse$2falseColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*duration2010-05-02T00:00:002011-04-29T00:00:00falsefalseAmerican Beacon Small Cap Index Funddei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiabf809593_S000001828Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseInstitutional Class - American Beacon Small Cap Index Fundrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldiabf809593_C000004793Memberrr_ProspectusShareClassAxisexplicitMemberAmerican Beacon Small Cap Index FundInstitutional Class - American Beacon Small Cap Index FundUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170falseUSDfalsefalse$1falseRowprimaryElement*4false0rr_OperatingExpensesCaptionrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsetruefalse2falsefalsefalse00Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)falsefalsefalsetruefalseOtherxbrli:stringItemTypestringAnnual Fund Operating Expenses (ongoing expenses that you pay each year as a percentage of the value of your investment)Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 7 -Subsection table falsefalseOperating Expenses Caption [Text]0rr_OperatingExpensesCaptiontruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)falsefalsefalsetruefalse2falsefalsefalse00falsefalsefalsefalsefalseOthernanafalsefalseOperating Expenses Caption [Text]2falseRowprimaryElement*5false0rr_OperatingExpensesColumnNamerrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00Institutionalfalsefalsefalsetruefalse2falsefalsefalse00falsefalsefalsetruefalseOtherus-types:textBlockItemTypestringAnnual Fund Operating Expenses (ongoing expenses that you pay each year as a percentage of the value of your investment)Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 7 -Subsection table falsefalseShare classes0rr_OperatingExpensesColumnNametruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00InstitutionalInstitutionalfalsefalsefalsetruefalseOthernanafalsefalseShare classes3falseRowprimaryElement*6false0rr_ManagementFeesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruetrue0.00010.0001[1]falsefalsefalsetruefalse2falsetruetrue00falsefalsefalsetruefalseOtherrr: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subparagraph a -Subsection instructions falsefalseManagement fees0rr_ManagementFeesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse[1]1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00010.0001falsefalsefalsetruefalseOthernanafalsefalseManagement fees4falseRowprimaryElement*7false0rr_DistributionAndService12b1FeesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruetrue0.00000.0000falsefalsefalsetruefalse2falsetruetrue00falsefalsefalsetruefalseOtherrr: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 9 -Subsection table falsefalseDistribution and/or service (12b-1) fees0rr_DistributionAndService12b1FeesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00000.0000falsefalsefalsetruefalseOthernanafalsefalseDistribution and/or service (12b-1) fees5falseRowprimaryElement*8false0rr_OtherExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truetruetrue0.00170.0017falsefalsefalsetruefalse2falsetruetrue00falsefalsefalsetruefalseOtherrr: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subparagraph c -Clause i -Subsection instructions truefalseOther expenses0rr_OtherExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00170.0017falsefalsefalsetruefalseOthernanafalsefalseOther expenses6falseRowprimaryElement*9false0rr_ExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truetruetrue0.00180.0018falsefalsefalsetruefalse2falsetruetrue00falsefalsefalsetruefalseOtherrr: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subparagraph d -Subsection instructions truefalseTotal annual fund operating expenses0rr_ExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00180.0018falsefalsefalsetruefalseOthernanafalsefalseTotal annual fund operating expenses1<i>The fees and expenses shown in the table and the example that follows include both the expenses of the Fund and the Fund's shares of the allocated expenses of the Small Cap Index Series ("Portfolio") of the Quantitative Master Series LLC.</i>26Annual Fund Operating Expenses - American Beacon Small Cap Index Fund UnKnownUnKnownUnKnownUnKnownfalsetrueColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*RowprimaryElement*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to OperatingExpensesData.No authoritative reference available.falsefalseAnnual Fund Operating Expenses [Table]33false0rr_ExpenseExampleHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00ExamplefalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringHeading for Expense Example.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 4 -Subsection instructions falsefalseExpense Example [Heading]34false0rr_ExpenseExampleNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00This 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 Example also assumes that your investment has a 5% return each year and that the Fund&#8217;s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringThe 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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 1 -Subsection example falsefalseExpense Example Narrative [Text Block]35false0rr_ExpenseExampleWithRedemptionTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div> &lt;div style="display:none;"&gt;~ http://americanbeaconfunds.com/role/ExpenseExampleAmericanBeaconSmallCapIndexFund column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact abf809593_S000001828_Member * row dei_LegalEntityAxis compact abf809593_S000001828_Member * ~&lt;/div&gt; </div>falsefalse<div> &lt;div style="display:none;"&gt;~ http://americanbeaconfunds.com/role/ExpenseExampleAmericanBeaconSmallCapIndexFund column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact abf809593_S000001828_Member * row dei_LegalEntityAxis compact abf809593_S000001828_Member * ~&lt;/div&gt; </div>truehttp://americanbeaconfunds.com/role/ExpenseExampleAmericanBeaconSmallCapIndexFundfalsefalse0200302 - Schedule - Expense Example - American Beacon Small Cap Index Fund {Transposed}truefalsefalse1falseColumnprimaryElement*4false0rr_ExpenseExampleByYearColumnNamerrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1falsefalsefalse00InstitutionalfalsefalsefalsetruefalseOtherus-types:textBlockItemTypestringThe 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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalseExpense Example, By Year, Column [Text]falseUSDfalsefalse$2falseColumnprimaryElement*5false0rr_ExpenseExampleYear01rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue1818falsefalsefalsetruefalseMonetaryrr: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 4 -Subsection instructions falsefalse1 yearfalseUSDfalsefalse$3falseColumnprimaryElement*6false0rr_ExpenseExampleYear03rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue5858falsefalsefalsetruefalseMonetaryrr: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalse3 yearsfalseUSDfalsefalse$4falseColumnprimaryElement*7false0rr_ExpenseExampleYear05rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue101101falsefalsefalsetruefalseMonetaryrr: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalse5 yearsfalseUSDfalsefalse$5falseColumnprimaryElement*8false0rr_ExpenseExampleYear10rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue230230falsefalsefalsetruefalseMonetaryrr: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalse10 yearsfalseUSDfalsefalse$1falseRowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2010-05-02T00:00:002011-04-29T00:00:00falsefalseAmerican Beacon Small Cap Index Funddei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiabf809593_S000001828Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseInstitutional Class - American Beacon Small Cap Index Fundrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldiabf809593_C000004793Memberrr_ProspectusShareClassAxisexplicitMemberAmerican Beacon Small Cap Index FundInstitutional Class - American Beacon Small Cap Index FundUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00InstitutionalInstitutionalfalsefalsefalsetruefalse2truefalsetrue1818falsefalsefalsetruefalse3truefalsetrue5858falsefalsefalsetruefalse4truefalsetrue101101falsefalsefalsetruefalse5truefalsetrue230230falsefalsefalsetruefalseOthernanafalsefalseAmerican Beacon Small Cap Index Fund Institutional Class - American Beacon Small Cap Index Fund51Expense Example - American Beacon Small Cap Index Fund (USD $)UnKnownUnKnownUnKnownUnKnownfalsetrueColumnprimaryElement*RowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to ExpenseExample.No authoritative reference available.falsefalseExpense Example, With Redemption [Table]36false0rr_PortfolioTurnoverHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Portfolio TurnoverfalsefalsefalsefalsefalseOtherxbrli: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 5 -Subsection instructions falsefalsePortfolio Turnover [Heading]37false0rr_PortfolioTurnoverTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The Fund pays transaction costs, such as commissions, when it buys and sells securities (or &#8220;turns over&#8221; 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&#8217;s performance. The Fund invests all of its investable assets in the Small Cap Index Series of the Quantitative Master Series LLC, therefore, the portfolio turnover rate is that of the Master Small Cap Index Series. During the most recent fiscal year, the Fund&#8217;s portfolio turnover rate was 42% of the average value of its portfolio.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringDisclose 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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subsection example falsefalsePortfolio Turnover [Text Block]38false0rr_StrategyHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<i>Principal Investment Strategies</i>falsefalsefalsefalsefalseOtherxbrli: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection a falsefalseStrategy [Heading]39false0rr_StrategyNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>The Fund seeks its investment objective by investing substantially all of its investable assets in the Small Cap Index Series (&#8220;Portfolio&#8221;) of the Quantitative Master Series LLC (&#8220;Index Trust&#8221;). The discussion below refers to investments made by the Portfolio. For easier reading, in this Prospectus, the term &#8220;Fund&#8221; includes the Portfolio.</p><p>The Portfolio employs a &#8220;passive&#8221; management approach, attempting to invest in a portfolio of assets whose performance is expected to match approximately the performance of the Russell 2000 Index. The Russell 2000 Index measures the performance of the small-cap segment of the U.S. equity universe includes approximately 2,000 of the smallest securities based on a combination of their market cap and current index membership, as determined by the Frank Russell Company. As of December 31, 2010, the market capitalizations of the companies in the Russell 2000 Index ranged from $24 million to $5.0 billion. The Portfolio will be substantially invested in securities in the Russell 2000 Index, and under normal circumstances will invest at least 80% of its assets in securities or other financial instruments or portions thereof, which are components of or have economic characteristics similar to the securities in the Russell 2000 Index. The Fund is also a non-diversified fund.</p><p>Using a statistical sampling technique, the Portfolio invests in a sample of the stocks included in the Russell 2000 Index and aims to create a portfolio that approximates the performance of the Russell 2000 Index. The Portfolio does not invest in all of the common stocks in the Russell 2000 Index, or in the same weightings as in the Russell 2000 Index and so has fewer transaction costs than it would incur through full replication. The Portfolio chooses investments so that the market capitalizations, industry weightings and other fundamental characteristics of the stocks and derivative instruments chosen are similar to the Russell 2000 Index as a whole.</p><p>In addition, the Portfolio may at times invest a significant portion of its assets in options or futures contracts linked to the performance of the Index. These derivatives allow the Portfolio to increase or decrease exposure to the Index quickly and at less cost than buying or selling stocks. The Portfolio may invest in options, futures and other derivative investments in order to gain market exposure quickly in the event of subscriptions, to maintain liquidity in the event of redemptions and to keep trading costs low. The Portfolio may enter into short sales in order to adjust the weightings of particular securities represented in a derivative to more accurately reflect the securities&#8217; weightings in the Index. The Portfolio may use derivatives for hedging purposes, including anticipatory hedges, and to seek to enhance returns. The Portfolio is not required to use hedging and may choose not to do so. The Portfolio may lend its securities to broker-dealers and other institutions to earn additional income.</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringPrincipal 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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection a falsefalseStrategy Narrative [Text Block]40false0rr_RiskHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<i>Principal Risks</i>falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNarrative Risk Disclosure.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 1 -Subsection b falsefalseRisk [Heading]41false0rr_RiskNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>There is no assurance that the Fund will achieve its investment objective and you could lose part or all of your investment in the Fund. The Fund is not a complete investment program and may not be appropriate for all investors. Investors should carefully consider their own investment goals and risk tolerance before investing in the Fund. The principal risks of investing in the Fund are:</p><p><b>Market Risk</b></p><p>Since the Portfolio invests most of its assets in stocks, it is subject to stock market risk. Market risk involves the possibility that the value of the Portfolio&#8217;s investments in stocks will vary from day to day in response to the activities of individual companies, as well as general market, regulatory, political and economic conditions. From time to time, certain securities held by the Portfolio may have limited marketability and may be difficult to sell at favorable times or prices. If the Portfolio is forced to sell such securities to meet redemption requests or other cash needs, the Portfolio may have to sell them at a loss.</p><p><b>Tracking Error Risk</b></p><p>The Portfolio&#8217;s return may not match the return of the Index for a number of reasons. For example, the Portfolio incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. Other factors that may affect the Portfolio&#8217;s ability to match the return of the Index include a temporary lack of liquidity in the markets for the securities held by the Portfolio, the different closing times of international and U.S. markets, and different valuation methodologies employed by the Portfolio and the Index. In addition, the return on the sample of stocks purchased by the Portfolio, or futures or other derivative positions taken by the Portfolio, to replicate the performance of the Index may not correlate precisely with the return on the Index. The Portfolio may not be fully invested at times, either as a result of cash flows into the Portfolio or reserves of cash held by the Portfolio to meet redemptions.</p><p><b>Non-Diversification Risk</b></p><p>The Fund is non-diversified, which means that it may invest a high percentage of its assets in a limited number of securities. Since the Fund is non-diversified, its net asset value and total return may fluctuate more or fall greater in times of weaker markets than a diversified mutual fund.</p><p><b>Small Capitalization Companies Risk</b></p><p>Investing in the securities of small capitalization companies involves greater risk and the possibility of greater price volatility than investing in larger capitalization and more established companies, since smaller companies may have limited operating history, product lines, and financial resources, the securities of these companies may lack sufficient market liquidity, and they can be particularly sensitive to expected changes in interest rates, borrowing costs and earnings.</p><p><b>Passive Strategy/Index Risk</b></p><p>The Portfolio is managed with a passive investment strategy, attempting to track the performance of an unmanaged index of securities. This differs from an actively managed fund, which typically seeks to outperform a benchmark index. As a result, the Portfolio may hold constituent securities of the Index regardless of the current or projected performance of a specific security or a particular industry or market sector. Maintaining investments in securities regardless of market conditions or the performance of individual securities could cause the Portfolio&#8217;s return to be lower than if the Portfolio employed an active strategy.</p><p><b>Securities Lending Risk</b></p><p>To the extent the Portfolio lends its securities, it may be subject to the following risk. Borrowers of the Portfolio&#8217;s securities typically provide collateral in the form of securities issued or guaranteed by the U.S. Government or cash that is reinvested in securities. The securities received as collateral or the securities in which cash collateral is invested may not perform sufficiently to cover the return collateral payments owed to borrowers. In addition, delays may occur in the recovery of securities from borrowers, which could interfere with the Portfolio&#8217;s ability to vote proxies or to settle transactions.</p><p><b>Derivatives Risk</b></p><p>Derivatives may involve significant risk and have the potential for losses in excess of the principal amount invested. Derivatives may be illiquid and may be more volatile than other types of investments. The Portfolio may buy derivatives not traded on an exchange which may be subject to heightened liquidity and valuation risk. Derivative investments can increase portfolio turnover and transaction costs. Derivatives are subject to counterparty credit risk, which is the risk that a counterparty to a derivative instrument becomes bankrupt or otherwise fails to perform its obligations due to financial difficulties. As a result the Portfolio may obtain no recovery of its investment or may only obtain a limited recovery, and any recovery may be delayed. In addition, the Portfolio&#8217;s investments in derivatives are subject to the following risks:</p><ul><li><i>Futures Contracts.</i> There may be an imperfect correlation between the changes in market value of the securities held by the Portfolio and the prices of futures contracts. There may not be a liquid secondary market for the futures contracts.</li></ul> <ul><li><i>Hedging Risk.</i> If the Portfolio uses a hedging instrument at the wrong time or judges the market conditions incorrectly, the hedge might be unsuccessful, reduce the Portfolio&#8217;s return, or create a loss.</li></ul><ul><li><i>Options.</i> There may be an imperfect correlation between the prices of options and movements in the price of the securities (or indices) hedged or used for cover which may cause a given hedge not to achieve its objective.</li></ul><ul><li><i>Swap Agreements.</i> Swaps are subject to counterparty risk. Credit default swaps, including credit default swaps on baskets of securities (such as the CDX indices), are subject to credit risk on the underlying investment. Equity swaps are subject to market risk. Total return swaps may be subject to credit risk and market risk.</li></ul><p><b>Equity Security Risk</b></p><p>Equity securities generally are subject to market risk. The Portfolio&#8217;s investments in equity securities may include common stock, preferred stock, securities convertible into common stock and real estate investment trusts (&#8220;REITs&#8221;). Common stock ranks bellow preferred stock and debt securities in claims for dividends and for assets of the company in a liquidation or bankruptcy. The value of a company&#8217;s common stock may fall as a result of factors directly or indirectly relating to that company. Preferred stocks and convertible securities are sensitive to movements in interest rates. In addition, preferred stock and convertible securities are subject to the risk that the credit standing of the issuer may have an effect on the convertible securities&#8217; investment value. Investments in REITs are subject to the risks associated with investing in the real estate industry such as adverse developments affecting the real estate industry and real property values.</p><p><b>Short Sale Risk</b></p><p>Short sales may involve the potential loss of more money than the actual cost of the investment. Third parties to a short sale may fail to honor the contract terms, causing a loss to the Portfolio.</p><p><b>Investment Risk</b></p><p>An investment in the Fund is not a deposit with a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. When you sell your shares of the Fund, they could be worth less than what you paid for them. Therefore, you could lose money by investing in the Fund.</p><p><b>Master/Feeder Structure Risk</b></p><p>Unlike a traditional mutual fund that invests directly in securities, the Fund pursues its objective by investing substantially all of its assets in the Master Portfolio with substantially the same investment objectives, policies and restrictions. The ability of the Fund to meet its investment objective is directly related to the ability of the Portfolio to meet its objective. The ability of the Fund to meet its objective may be adversely affected by the purchase and redemption activities of other investors in the corresponding Master Portfolio. The ability of the Fund to meet redemption requests depends on its ability to redeem its interest in the Master Portfolio.</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringNarrative 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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 1 -Subparagraph i -Clause instruction -Subsection b falsefalseRisk Narrative [Text Block]42false0rr_BarChartAndPerformanceTableHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<i>Fund Performance</i>falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Bar Chart and Table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subsection b falsefalseBar Chart and Performance Table [Heading]43false0rr_PerformanceNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The bar chart and table below provide an indication of risk by showing how the Fund&#8217;s performance has varied from year to year. 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Past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringRisk/Return Bar Chart and Table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subsection b falsefalsePerformance Narrative [Text Block]44false0rr_BarChartHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Calendar year total returns for Institutional Class sharesfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Bar Chart and Table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subsection b falsefalseBar Chart [Heading]45false0rr_AnnualReturnCaptionrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse00Total Return for the Calendar Year Ended 12/31 of each YearfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. Provide annual total returns beginning with the earliest calendar year. Calculate annual returns using the Instructions to Item 8(a), except that the calculations should be based on calendar years. If a Fund's shares are sold subject to a sales load or account fees, state that sales loads or account fees are not reflected in the bar chart and that, if these amounts were reflected, returns would be less than those shown. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. 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Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. 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If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. 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If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. 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Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalse20040rr_AnnualReturn2004truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.17910.1791falsefalsefalsetruefalseOthernanafalsefalse20045falseRowprimaryElement*8false0rr_AnnualReturn2005rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse0.04510.0451falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse20050rr_AnnualReturn2005truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.04510.0451falsefalsefalsetruefalseOthernanafalsefalse20056falseRowprimaryElement*9false0rr_AnnualReturn2006rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse0.17850.1785falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse20060rr_AnnualReturn2006truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.17850.1785falsefalsefalsetruefalseOthernanafalsefalse20067falseRowprimaryElement*10false0rr_AnnualReturn2007rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse-0.0163-0.0163falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalse20070rr_AnnualReturn2007truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse-0.0163-0.0163falsefalsefalsetruefalseOthernanafalsefalse20078falseRowprimaryElement*11false0rr_AnnualReturn2008rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse-0.3358-0.3358falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. 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If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalse20090rr_AnnualReturn2009truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.27210.2721falsefalsefalsetruefalseOthernanafalsefalse200910falseRowprimaryElement*13false0rr_AnnualReturn2010rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse0.27050.2705falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse20100rr_AnnualReturn2010truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.27050.2705falsefalsefalsetruefalseOthernanafalsefalse2010110Annual Total Returns (Bar Chart) - American Beacon Small Cap Index Fund UnKnownUnKnownUnKnownUnKnownfalsetrueColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*RowprimaryElement*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to BarChartData.No authoritative reference available.falsefalseBar Chart [Table]47false0rr_BarChartClosingTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>Highest Quarterly Return: 23.23% (1/1/01 through 12/31/10) (2nd Quarter 2003)</p><p>Lowest Quarterly Return: -25.96% (1/1/01 through 12/31/10) (4th Quarter 2008)</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalseBar Chart Closing [Text Block]48false0rr_PerformanceTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div> &lt;div style="display:none;"&gt;~ http://americanbeaconfunds.com/role/AverageAnnualTotalReturnsAmericanBeaconSmallCapIndexFund column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact abf809593_S000001828_Member * row dei_LegalEntityAxis compact abf809593_S000001828_Member * ~&lt;/div&gt; </div>falsefalse<div> &lt;div style="display:none;"&gt;~ http://americanbeaconfunds.com/role/AverageAnnualTotalReturnsAmericanBeaconSmallCapIndexFund column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact abf809593_S000001828_Member * row dei_LegalEntityAxis compact abf809593_S000001828_Member * ~&lt;/div&gt; </div>truehttp://americanbeaconfunds.com/role/AverageAnnualTotalReturnsAmericanBeaconSmallCapIndexFundfalsefalse0200602 - Schedule - Average Annual Total Returns - American Beacon Small Cap Index Fund {Transposed}truefalsefalse1falseColumnprimaryElement*4false0rr_AverageAnnualReturnCaptionrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse00falsefalsefalsetruefalse2falsetruefalse00falsefalsefalsetruefalse3falsetruefalse00falsefalsefalsetruefalse4falsetruefalse00falsefalsefalsetruefalse5falsetruefalse00falsefalsefalsetruefalse6falsetruefalse00Average Annual Total Returns For the periods ended December 31, 2010[1]falsefalsefalsetruefalseOtherxbrli:stringItemTypestringThis item represents Average Anuual Total Returns. 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Actual after-tax returns depend on an investor's tax situation and may differ from those shown. If you hold your Fund shares through a tax-deferred arrangement, such as an IRA or a 401(k), the after-tax returns do not apply to your situation.</i>86Average Annual Total Returns - American Beacon Small Cap Index Fund UnKnownUnKnownUnKnownUnKnownfalsetrueColumnprimaryElement*RowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_PerformanceMeasureAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to PerformanceTableData.No authoritative reference available.falsefalsePerformance [Table]49false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://americanbeaconfunds.com/role/riskreturnsummary1falsefalsefalse00American Beacon International Equity Index FundAmerican Beacon International Equity Index Fundfalsefalsefalsefalsefalse3falsefalsetruefalse{dei_DocumentInformationDocumentAxis} : American Beacon International Equity Index Fund 5/2/2010 - 4/29/2011 TwelveMonthsEnded_29Apr2011_S000001829_Memberhttp://www.sec.gov/CIK0000809593duration2010-05-02T00:00:002011-04-29T00:00:00falsefalseabf809593_S000001829Memberdei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiabf809593_S000001829Memberdei_DocumentInformationDocumentAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli0OthernaNo definition available.No authoritative reference available.falsefalseAmerican Beacon International Equity Index Fund51false0rr_RiskReturnHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00American Beacon International Equity Index Fund<sup>SM</>falsefalsefalsefalsefalseOtherxbrli: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 falsefalseRisk/Return [Heading]52false0rr_ObjectiveHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<i>Investment Objective</i>falsefalsefalsefalsefalseOtherxbrli: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 -Subsection a falsefalseObjective [Heading]53false0rr_ObjectivePrimaryTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The Fund&#8217;s investment objective is to match the performance of the Morgan Stanley Capital International EAFE Index (the &#8220;MSCI EAFE Index&#8221; or &#8220;Index&#8221;) as closely as possible before the deduction of Fund expenses.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringInvestment 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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 2 -Subsection a falsefalseObjective, Primary [Text Block]54false0rr_ExpenseHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<i>Fees and Expenses of the Fund</i>falsefalsefalsefalsefalseOtherxbrli: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph d -Subsection instructions falsefalseExpense [Heading]55false0rr_ExpenseNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringThis 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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph b -Subsection instructions falsefalseExpense Narrative [Text Block]56false0rr_AnnualFundOperatingExpensesTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div> &lt;div style="display:none;"&gt;~ http://americanbeaconfunds.com/role/AnnualFundOperatingExpensesAmericanBeaconInternationalEquityIndexFund column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact abf809593_S000001829_Member * row dei_LegalEntityAxis compact abf809593_S000001829_Member * ~&lt;/div&gt; </div>falsefalse<div> &lt;div style="display:none;"&gt;~ http://americanbeaconfunds.com/role/AnnualFundOperatingExpensesAmericanBeaconInternationalEquityIndexFund column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact abf809593_S000001829_Member * row dei_LegalEntityAxis compact abf809593_S000001829_Member * ~&lt;/div&gt; </div>falsehttp://americanbeaconfunds.com/role/AnnualFundOperatingExpensesAmericanBeaconInternationalEquityIndexFundfalsefalse0200203 - Schedule - Annual Fund Operating Expenses - American Beacon International Equity Index Fundtruefalsefalse1falseColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*duration2010-05-02T00:00:002011-04-29T00:00:00falsefalseAmerican Beacon International Equity Index Funddei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiabf809593_S000001829Memberdei_DocumentInformationDocumentAxisexplicitMembertruefalseShare Classesrr_ProspectusShareClassAxisrr_ShareClassDomainrr_ProspectusShareClassAxisexplicitMemberAmerican Beacon International Equity Index FundShare ClassesStandard0falseUSDfalsefalse$2falseColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*duration2010-05-02T00:00:002011-04-29T00:00:00falsefalseAmerican Beacon International Equity Index Funddei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiabf809593_S000001829Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseInstitutional Class - American Beacon International Equity Index Fundrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldiabf809593_C000004794Memberrr_ProspectusShareClassAxisexplicitMemberAmerican Beacon International Equity Index FundInstitutional Class - American Beacon International Equity Index FundUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170falseUSDfalsefalse$1falseRowprimaryElement*4false0rr_OperatingExpensesCaptionrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsetruefalse2falsefalsefalse00Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)falsefalsefalsetruefalseOtherxbrli:stringItemTypestringAnnual Fund Operating Expenses (ongoing expenses that you pay each year as a percentage of the value of your investment)Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 7 -Subsection table falsefalseOperating Expenses Caption [Text]0rr_OperatingExpensesCaptiontruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)falsefalsefalsetruefalse2falsefalsefalse00falsefalsefalsefalsefalseOthernanafalsefalseOperating Expenses Caption [Text]2falseRowprimaryElement*5false0rr_OperatingExpensesColumnNamerrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00Institutionalfalsefalsefalsetruefalse2falsefalsefalse00falsefalsefalsetruefalseOtherus-types:textBlockItemTypestringAnnual Fund Operating Expenses (ongoing expenses that you pay each year as a percentage of the value of your investment)Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 7 -Subsection table falsefalseShare classes0rr_OperatingExpensesColumnNametruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00InstitutionalInstitutionalfalsefalsefalsetruefalseOthernanafalsefalseShare classes3falseRowprimaryElement*6false0rr_ManagementFeesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruetrue0.00010.0001[1]falsefalsefalsetruefalse2falsetruetrue00falsefalsefalsetruefalseOtherrr: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subparagraph a -Subsection instructions falsefalseManagement fees0rr_ManagementFeesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse[1]1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00010.0001falsefalsefalsetruefalseOthernanafalsefalseManagement fees4falseRowprimaryElement*7false0rr_DistributionAndService12b1FeesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruetrue0.00000.0000falsefalsefalsetruefalse2falsetruetrue00falsefalsefalsetruefalseOtherrr: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 9 -Subsection table falsefalseDistribution and/or service (12b-1) fees0rr_DistributionAndService12b1FeesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00000.0000falsefalsefalsetruefalseOthernanafalsefalseDistribution and/or service (12b-1) fees5falseRowprimaryElement*8false0rr_OtherExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truetruetrue0.00200.0020falsefalsefalsetruefalse2falsetruetrue00falsefalsefalsetruefalseOtherrr: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subparagraph c -Clause i -Subsection instructions truefalseOther expenses0rr_OtherExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00200.0020falsefalsefalsetruefalseOthernanafalsefalseOther expenses6falseRowprimaryElement*9false0rr_ExpensesOverAssetsrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truetruetrue0.00210.0021falsefalsefalsetruefalse2falsetruetrue00falsefalsefalsetruefalseOtherrr: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subparagraph d -Subsection instructions truefalseTotal annual fund operating expenses0rr_ExpensesOverAssetstruefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2truetruetrue0.00210.0021falsefalsefalsetruefalseOthernanafalsefalseTotal annual fund operating expenses1<i>The fees and expenses and the example shown in the table that follows include both the expenses of the Fund and the Fund's shares of the allocated expenses of the International Index Series ("Portfolio") of the Quantitative Master Series LLC.</i>26Annual Fund Operating Expenses - American Beacon International Equity Index Fund UnKnownUnKnownUnKnownUnKnownfalsetrueColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*RowprimaryElement*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to OperatingExpensesData.No authoritative reference available.falsefalseAnnual Fund Operating Expenses [Table]57false0rr_ExpenseExampleHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00ExamplefalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringHeading for Expense Example.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 4 -Subsection instructions falsefalseExpense Example [Heading]58false0rr_ExpenseExampleNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00This 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 Example also assumes that your investment has a 5% return each year and that the Fund&#8217;s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringThe 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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 1 -Subsection example falsefalseExpense Example Narrative [Text Block]59false0rr_ExpenseExampleWithRedemptionTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div> &lt;div style="display:none;"&gt;~ http://americanbeaconfunds.com/role/ExpenseExampleAmericanBeaconInternationalEquityIndexFund column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact abf809593_S000001829_Member * row dei_LegalEntityAxis compact abf809593_S000001829_Member * ~&lt;/div&gt; </div>falsefalse<div> &lt;div style="display:none;"&gt;~ http://americanbeaconfunds.com/role/ExpenseExampleAmericanBeaconInternationalEquityIndexFund column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact abf809593_S000001829_Member * row dei_LegalEntityAxis compact abf809593_S000001829_Member * ~&lt;/div&gt; </div>truehttp://americanbeaconfunds.com/role/ExpenseExampleAmericanBeaconInternationalEquityIndexFundfalsefalse0200303 - Schedule - Expense Example - American Beacon International Equity Index Fund {Transposed}truefalsefalse1falseColumnprimaryElement*4false0rr_ExpenseExampleByYearColumnNamerrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalselabel1falsefalsefalse00InstitutionalfalsefalsefalsetruefalseOtherus-types:textBlockItemTypestringThe 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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalseExpense Example, By Year, Column [Text]falseUSDfalsefalse$2falseColumnprimaryElement*5false0rr_ExpenseExampleYear01rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue2222falsefalsefalsetruefalseMonetaryrr: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 4 -Subsection instructions falsefalse1 yearfalseUSDfalsefalse$3falseColumnprimaryElement*6false0rr_ExpenseExampleYear03rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue6868falsefalsefalsetruefalseMonetaryrr: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalse3 yearsfalseUSDfalsefalse$4falseColumnprimaryElement*7false0rr_ExpenseExampleYear05rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue118118falsefalsefalsetruefalseMonetaryrr: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalse5 yearsfalseUSDfalsefalse$5falseColumnprimaryElement*8false0rr_ExpenseExampleYear10rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsetrue268268falsefalsefalsetruefalseMonetaryrr: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 1 -Subparagraph 2 -Subsection example falsefalse10 yearsfalseUSDfalsefalse$1falseRowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2010-05-02T00:00:002011-04-29T00:00:00falsefalseAmerican Beacon International Equity Index Funddei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiabf809593_S000001829Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseInstitutional Class - American Beacon International Equity Index Fundrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldiabf809593_C000004794Memberrr_ProspectusShareClassAxisexplicitMemberAmerican Beacon International Equity Index FundInstitutional Class - American Beacon International Equity Index FundUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso421700truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00InstitutionalInstitutionalfalsefalsefalsetruefalse2truefalsetrue2222falsefalsefalsetruefalse3truefalsetrue6868falsefalsefalsetruefalse4truefalsetrue118118falsefalsefalsetruefalse5truefalsetrue268268falsefalsefalsetruefalseOthernanafalsefalseAmerican Beacon International Equity Index Fund Institutional Class - American Beacon International Equity Index Fund51Expense Example - American Beacon International Equity Index Fund (USD $)UnKnownUnKnownUnKnownUnKnownfalsetrueColumnprimaryElement*RowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to ExpenseExample.No authoritative reference available.falsefalseExpense Example, With Redemption [Table]60false0rr_PortfolioTurnoverHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Portfolio TurnoverfalsefalsefalsefalsefalseOtherxbrli: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 5 -Subsection instructions falsefalsePortfolio Turnover [Heading]61false0rr_PortfolioTurnoverTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The Fund pays transaction costs, such as commissions, when it buys and sells securities (or &#8220;turns over&#8221; 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&#8217;s performance. The Fund invests all if its investable assets in the Master International Index Series of the Quantitative Master Series LLC, therefore, the portfolio turnover rate is that of the Master International Index Series. During the most recent fiscal year, the Fund&#8217;s portfolio turnover rate was 8% of the average value of its portfolio.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringDisclose 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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 3 -Paragraph 3 -Subsection example falsefalsePortfolio Turnover [Text Block]62false0rr_StrategyHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<i>Principal Investment Strategies</i>falsefalsefalsefalsefalseOtherxbrli: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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection a falsefalseStrategy [Heading]63false0rr_StrategyNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>The Fund seeks its investment objective by investing substantially all of its investable assets in the Master International Index Series (&#8220;Portfolio&#8221;) of the Quantitative Master Series LLC (&#8220;Index Trust&#8221;). The discussion below refers to investments made by the Portfolio. For easier reading, in this Prospectus, the term &#8220;Fund&#8221; includes the Portfolio.</p><p>The Portfolio employs a &#8220;passive&#8221; management approach, attempting to invest in a portfolio of assets whose performance is expected to match approximately the performance of the MSCI EAFE Index. The MSCI EAFE Index is composed of equity securities of companies from various industrial sectors whose primary trading markets are located outside of North America. Companies included in the MSCI EAFE Index are selected from among the larger capitalization companies in these markets. The weighting of the countries in the Index is based upon each country&#8217;s relative market capitalization, and not its gross domestic product. This means that the Index contains more companies from countries with the largest capital markets (like Japan and the United Kingdom), which in turn, will have the most effect on the Index&#8217;s performance.</p><p>The Portfolio will be substantially invested in securities in the Index, and under normal circumstances will invest at least 80% of its assets in securities or other financial instruments or portions thereof, which are components of or have economic characteristics similar to the securities included in the Index. The Fund is also a non-diversified fund.</p><p>The Portfolio invests in a statistically selected sample of equity securities included in the MSCI EAFE Index and in derivative instruments linked to the MSCI EAFE Index. Equity securities include common stock, preferred stock and securities or other instruments whose price is linked to the value of common stock. The Portfolio will, under normal circumstances, invest in all of the countries represented in the MSCI EAFE Index. The Portfolio may not, however, invest in all of the companies within a country, represented in the MSCI EAFE Index, or in the same weightings as in the MSCI EAFE Index. Instead, using a statistical sampling technique, the Portfolio may invest in a sample of equity securities included in the MSCI EAFE Index and in derivative instruments that correlate with components of the MSCI EAFE Index as a whole. The Portfolio aims to create a portfolio that approximates the performance of the MSCI EAFE Index with fewer transaction costs than would be incurred through full replication.</p><p>In addition, the Portfolio may at times invest a significant portion of its assets in options or futures contracts linked to the performance of the Index. These derivatives allow the Portfolio to increase or decrease exposure to the Index quickly and at less cost than buying or selling stocks. The Portfolio may invest in options, futures and other derivative investments in order to gain market exposure quickly in the event of subscriptions, to maintain liquidity in the event of redemptions and to keep trading costs low. The Portfolio may enter into short sales in order to adjust the weightings of particular securities represented in a derivative to more accurately reflect the securities&#8217; weightings in the Index. The Portfolio may use derivatives for hedging purposes, including anticipatory hedges, and to seek to enhance returns. The Portfolio may enter into a foreign exchange transaction for purposes of hedging a specific transaction by, for example, purchasing a currency needed to settle a security transaction or selling a currency in which the Portfolio has received or anticipates receiving a dividend or distribution. The Portfolio may enter into a foreign exchange transaction for purposes of hedging a portfolio position by selling forward a currency in which a portfolio position of the Portfolio is denominated or by purchasing a currency in which the Portfolio anticipates acquiring a portfolio position in the near future. The Portfolio may also hedge portfolio positions through currency swaps, which are transactions in which one currency is simultaneously bought for a second currency on a spot basis and sold for the second currency on a forward basis.</p><p>The Portfolio is not required to use hedging and may choose not to do so. The Portfolio may lend its securities to broker-dealers and other institutions to earn additional income.</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringPrincipal 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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection a falsefalseStrategy Narrative [Text Block]64false0rr_RiskHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<i>Principal Risks</i>falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNarrative Risk Disclosure.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 1 -Subsection b falsefalseRisk [Heading]65false0rr_RiskNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>There is no assurance that the Fund will achieve its investment objective and you could lose part or all of your investment in the Fund. The Fund is not a complete investment program and may not be appropriate for all investors. Investors should carefully consider their own investment goals and risk tolerance before investing in the Fund. The principal risks of investing in the Fund are:</p><p><b>Market Risk</b></p><p>Since this Portfolio invests most of its assets in stocks, it is subject to stock market risk. Market risk involves the possibility that the value of the Portfolio&#8217;s investments in stocks of a particular country will vary from day to day in response to the activities of individual companies, as well as general market, regulatory, political and economic conditions of that country. From time to time, certain securities held by the Portfolio may have limited marketability and may be difficult to sell at favorable times or prices. If the Portfolio is forced to sell such securities to meet redemption requests or other cash needs, the Portfolio may have to sell them at a loss.</p><p><b>Foreign Investing Risk</b></p><p>Oversees investing caries potential risks not associated with domestic investments. Such risks include, but are not limited to: (1) currency exchange rate fluctuations, (2) political and financial instability, (3) less liquidity and greater volatility, (4) lack of uniform accounting, auditing and financial reporting standards, (5) increased price volatility; (6) less government regulation and supervision of foreign stock exchanges, brokers and listed companies; and (7) delays in transaction settlement in some foreign markets.</p><p><b>Tracking Error Risk</b></p><p>The Portfolio&#8217;s return may not match the return of the Index for a number of reasons. For example, the Portfolio incurs a number of operating expenses not applicable to the Index, and incurs costs in buying and selling securities. Other factors that may affect the Portfolio&#8217;s ability to match the return of the Index include a temporary lack of liquidity in the markets for the securities held by the Portfolio, the different closing times of international and U.S. markets, and different valuation methodologies employed by the Portfolio and the Index. In addition, the return on the sample of stocks purchased by the Portfolio, or futures or other derivative positions taken by the Portfolio, to replicate the performance of the Index may not correlate precisely with the return on the Index. The Portfolio may not be fully invested at times, either as a result of cash flows into the Portfolio or reserves of cash held by the Portfolio to meet redemptions.</p><p><b>Non-Diversification Risk</b></p><p>The Fund is non-diversified, which means that it may invest a high percentage of its assets in a limited number of securities. Since the Fund is non-diversified, its net asset value and total return may fluctuate more or fall greater in times of weaker markets than a diversified mutual fund.</p><p><b>Derivatives Risk</b></p><p>Derivatives may involve significant risk and have the potential for losses in excess of the principal amount invested. Derivatives may be illiquid and may be more volatile than other types of investments. The Portfolio may buy derivatives not traded on an exchange which may be subject to heightened liquidity and valuation risk. Derivative investments can increase portfolio turnover and transaction costs. Derivatives are subject to counterparty credit risk, which is the risk that a counterparty to a derivative instrument becomes bankrupt or otherwise fails to perform its obligations due to financial difficulties. As a result the Portfolio may obtain no recovery of its investment or may only obtain a limited recovery, and any recovery may be delayed. In addition, the Portfolio&#8217;s investments in derivatives are subject to the following risks:</p><ul><li><i>Futures and Forward Contracts.</i> There may be an imperfect correlation between the changes in market value of the securities held by the Portfolio and the prices of futures contracts. There may not be a liquid secondary market for the futures contracts. Forward currency transactions include the risks associated with fluctuations in currency.</li></ul><ul><li><i>Hedging Risk.</i> If the Portfolio uses a hedging instrument at the wrong time or judges the market conditions incorrectly, the hedge might be unsuccessful, reduce the Portfolio&#8217;s return, or create a loss.</li></ul><ul><li><i>Options.</i> There may be an imperfect correlation between the prices of options and movements in the price of the securities (or indices) hedged or used for cover which may cause a given hedge not to achieve its objective.</li></ul><ul><li><i>Swap Agreements.</i> Swaps are subject to counterparty risk. Credit default swaps, including credit default swaps on baskets of securities (such as the CDX indices), are subject to credit risk on the underlying investment. Equity swaps are subject to market risk. Total return swaps may be subject to credit risk and market risk. Currency swaps are subject to currency risk and also involve exchange risk on principal and therefore are subject to credit risk.</li></ul><p><b>Currency Risk</b></p><p>If the Portfolio invests directly in foreign (non-U.S.) currencies or in securities that trade in, and receive revenues in, foreign (non-U.S.) currencies, or in derivatives that provide exposure to foreign (non-U.S.) currencies, it will be subject to the risk that those currencies will decline in value relative to the U.S. dollar, or, in the case of hedging positions, that the U.S. dollar will decline in value relative to the currency being hedged. Currency rates in foreign countries may fluctuate significantly over short periods of time for a number of reasons, including changes in interest rates, intervention (or the failure to intervene) by U.S. or foreign governments, central banks or supranational entities such as the International Monetary Fund, or by the imposition of currency controls or other political developments in the United States or abroad. As a result, the Portfolio&#8217;s investments in foreign currency denominated securities may reduce the returns of the Portfolio. Currency futures, forwards, options or swaps may not always work as intended, and in specific cases the Portfolio may be worse off than if it had not used such instrument(s). There may not always be suitable hedging instruments available. Even where suitable hedging instruments are available, the Portfolio may not hedge its currency risks.</p><p><b>Equity Security Risk</b></p><p>Equity securities generally are subject to market risk. The Portfolio&#8217;s investments in equity securities may include common stock, preferred stock, securities convertible into common stock and real estate investment trusts (&#8220;REITs&#8221;). Common stock ranks bellow preferred stock and debt securities in claims for dividends and for assets of the company in a liquidation or bankruptcy. The value of a company&#8217;s common stock may fall as a result of factors directly or indirectly relating to that company. Preferred stocks and convertible securities are sensitive to movements in interest rates. In addition, preferred stock and convertible securities are subject to the risk that the credit standing of the issuer may have an effect on the convertible securities&#8217; investment value. Investments in REITs are subject to the risks associated with investing in the real estate industry such as adverse developments affecting the real estate industry and real property values.</p><p><b>Short Sale Risk</b></p><p>Short sales may involve the potential loss of more money than the actual cost of the investment. Third parties to a short sale may fail to honor the contract terms, causing a loss to the Portfolio.</p><p><b>Investment Risks</b></p><p>An investment in the Fund is not a deposit with a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. When you sell your shares of the Fund, they could be worth less than what you paid for them. Therefore, you could lose money by investing in the Fund.</p><p><b>Passive Strategy/Index Risk</b></p><p>The Portfolio is managed with a passive investment strategy, attempting to track the performance of an unmanaged index of securities. This differs from an actively managed fund, which typically seeks to outperform a benchmark index. As a result, the Portfolio may hold constituent securities of the Index regardless of the current or projected performance of a specific security or a particular industry or market sector. Maintaining investments in securities regardless of market conditions or the performance of individual securities could cause the Portfolio&#8217;s return to be lower than if the Portfolio employed an active strategy.</p><p><b>Master/Feeder Structure Risk</b></p><p>Unlike a traditional mutual fund that invests directly in securities, the Fund pursues its objective by investing substantially all of its assets in the Master Portfolio with substantially the same investment objectives, policies and restrictions. The ability of the Fund to meet its investment objective is directly related to the ability of the Portfolio to meet its objective. The ability of the Fund to meet its objective may be adversely affected by the purchase and redemption activities of other investors in the corresponding Master Portfolio. The ability of the Fund to meet redemption requests depends on its ability to redeem its interest in the Master Portfolio.</p><p><b>Securities Lending Risk</b></p><p>To the extent the Portfolio lends its securities, it may be subject to the following risk. Borrowers of the Portfolio&#8217;s securities typically provide collateral in the form of securities issued or guaranteed by the U.S. Government or cash that is reinvested in securities. The securities received as collateral or the securities in which cash collateral is invested may not perform sufficiently to cover the return collateral payments owed to borrowers. In addition, delays may occur in the recovery of securities from borrowers, which could interfere with the Portfolio&#8217;s ability to vote proxies or to settle transactions.</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringNarrative 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: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 1 -Subparagraph i -Clause instruction -Subsection b falsefalseRisk Narrative [Text Block]66false0rr_BarChartAndPerformanceTableHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<i>Fund Performance</i>falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Bar Chart and Table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subsection b falsefalseBar Chart and Performance Table [Heading]67false0rr_PerformanceNarrativeTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00The bar chart and table below provide an indication of risk by showing how the Fund&#8217;s performance has varied from year to year. The table shows how the Fund&#8217;s performance compares to a broad-based market index and the Lipper International Large-Cap Core Funds Index, a composite of mutual funds comparable to the Fund. The returns of the broad-based market index do not reflect fees, expenses or taxes. You may obtain updated performance information on the Fund&#8217;s website at www.americanbeaconfunds.com. Past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringRisk/Return Bar Chart and Table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subsection b falsefalsePerformance Narrative [Text Block]68false0rr_BarChartHeadingrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Calendar year total returns for Institutional Class sharesfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringRisk/Return Bar Chart and Table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subsection b falsefalseBar Chart [Heading]69false0rr_AnnualReturnCaptionrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse00Total Return for the Calendar Year Ended 12/31 of each YearfalsefalsefalsefalsefalseOtherxbrli:stringItemTypestringIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. Provide annual total returns beginning with the earliest calendar year. Calculate annual returns using the Instructions to Item 8(a), except that the calculations should be based on calendar years. If a Fund's shares are sold subject to a sales load or account fees, state that sales loads or account fees are not reflected in the bar chart and that, if these amounts were reflected, returns would be less than those shown. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets). When a Multiple Class Fund offering one or more Classes offers a new Class in a prospectus that does not offer the shares of any other Class, include the bar chart with annual total returns for any other existing Class for the first year that the Class is offered. Explain in a footnote that the returns are for a Class that is not offered in the prospectus that would have substantially similar annual returns because the shares are invested in the same portfolio of securities and the annual returns would differ only to the extent that the Classes do not have the same expenses. Include return information for the other Class reflected in the bar chart in the performance table.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit b -Subsection b falsefalseAnnual Return Caption [Text]70false0rr_BarChartTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div> &lt;div style="display:none;"&gt;~ http://americanbeaconfunds.com/role/AnnualTotalReturnsBarChartAmericanBeaconInternationalEquityIndexFund column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact abf809593_S000001829_Member * row dei_LegalEntityAxis compact abf809593_S000001829_Member * ~&lt;/div&gt; </div>falsefalseBarChart3.jpg<div> &lt;div style="display:none;"&gt;~ http://americanbeaconfunds.com/role/AnnualTotalReturnsBarChartAmericanBeaconInternationalEquityIndexFund column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact abf809593_S000001829_Member * row dei_LegalEntityAxis compact abf809593_S000001829_Member * ~&lt;/div&gt; </div>falsehttp://americanbeaconfunds.com/role/AnnualTotalReturnsBarChartAmericanBeaconInternationalEquityIndexFundfalsefalse0200503 - Schedule - Annual Total Returns (Bar Chart) - American Beacon International Equity Index Fundtruefalsefalse1falseColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*duration2010-05-02T00:00:002011-04-29T00:00:00falsefalseAmerican Beacon International Equity Index Funddei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiabf809593_S000001829Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseInstitutional Class - American Beacon International Equity Index Fundrr_ProspectusShareClassAxisxbrldihttp://xbrl.org/2006/xbrldiabf809593_C000004794Memberrr_ProspectusShareClassAxisexplicitMemberAmerican Beacon International Equity Index FundInstitutional Class - American Beacon International Equity Index FundUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170falseUSDfalsefalse$1falseRowprimaryElement*4false0rr_AnnualReturn2001rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse-0.2214-0.2214falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse20010rr_AnnualReturn2001truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse-0.2214-0.2214falsefalsefalsetruefalseOthernanafalsefalse20012falseRowprimaryElement*5false0rr_AnnualReturn2002rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse-0.1565-0.1565falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse20020rr_AnnualReturn2002truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse-0.1565-0.1565falsefalsefalsetruefalseOthernanafalsefalse20023falseRowprimaryElement*6false0rr_AnnualReturn2003rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse0.38870.3887falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalse20030rr_AnnualReturn2003truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.38870.3887falsefalsefalsetruefalseOthernanafalsefalse20034falseRowprimaryElement*7false0rr_AnnualReturn2004rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse0.20120.2012falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalse20040rr_AnnualReturn2004truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.20120.2012falsefalsefalsetruefalseOthernanafalsefalse20045falseRowprimaryElement*8false0rr_AnnualReturn2005rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse0.13580.1358falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse20050rr_AnnualReturn2005truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.13580.1358falsefalsefalsetruefalseOthernanafalsefalse20056falseRowprimaryElement*9false0rr_AnnualReturn2006rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse0.26520.2652falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse20060rr_AnnualReturn2006truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.26520.2652falsefalsefalsetruefalseOthernanafalsefalse20067falseRowprimaryElement*10false0rr_AnnualReturn2007rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse0.10680.1068falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalse20070rr_AnnualReturn2007truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.10680.1068falsefalsefalsetruefalseOthernanafalsefalse20078falseRowprimaryElement*11false0rr_AnnualReturn2008rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse-0.4185-0.4185falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse20080rr_AnnualReturn2008truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse-0.4185-0.4185falsefalsefalsetruefalseOthernanafalsefalse20089falseRowprimaryElement*12false0rr_AnnualReturn2009rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse0.28720.2872falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 3 -Exhibit a -Subsection b falsefalse20090rr_AnnualReturn2009truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.28720.2872falsefalsefalsetruefalseOthernanafalsefalse200910falseRowprimaryElement*13false0rr_AnnualReturn2010rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse0.07570.0757falsefalsefalsetruefalseOtherxbrli:pureItemTypepureIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalse20100rr_AnnualReturn2010truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truetruefalse0.07570.0757falsefalsefalsetruefalseOthernanafalsefalse2010110Annual Total Returns (Bar Chart) - American Beacon International Equity Index Fund UnKnownUnKnownUnKnownUnKnownfalsetrueColumnperiodPeriod*Columndei_DocumentInformationDocumentAxisAxis*Columnrr_ProspectusShareClassAxisAxis*ColumnunitUnit*RowprimaryElement*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to BarChartData.No authoritative reference available.falsefalseBar Chart [Table]71false0rr_BarChartClosingTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<p>Highest Quarterly Return: 25.20% (1/1/01 through 12/31/10) (2nd Quarter 2009)</p><p>Lowest Quarterly Return: -19.77% (1/1/01 through 12/31/10) (3rd Quarter 2002)</p>falsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringIf the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph ii -Subsection b falsefalseBar Chart Closing [Text Block]72false0rr_PerformanceTableTextBlockrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div> &lt;div style="display:none;"&gt;~ http://americanbeaconfunds.com/role/AverageAnnualTotalReturnsAmericanBeaconInternationalEquityIndexFund column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact abf809593_S000001829_Member * row dei_LegalEntityAxis compact abf809593_S000001829_Member * ~&lt;/div&gt; </div>falsefalse<div> &lt;div style="display:none;"&gt;~ http://americanbeaconfunds.com/role/AverageAnnualTotalReturnsAmericanBeaconInternationalEquityIndexFund column period compact * column rr_ProspectusShareClassAxis compact * row primary compact * row dei_DocumentInformationDocumentAxis compact abf809593_S000001829_Member * row dei_LegalEntityAxis compact abf809593_S000001829_Member * ~&lt;/div&gt; </div>truehttp://americanbeaconfunds.com/role/AverageAnnualTotalReturnsAmericanBeaconInternationalEquityIndexFundfalsefalse0200603 - Schedule - Average Annual Total Returns - American Beacon International Equity Index Fund {Transposed}truefalsefalse1falseColumnprimaryElement*4false0rr_AverageAnnualReturnCaptionrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse00falsefalsefalsetruefalse2falsetruefalse00falsefalsefalsetruefalse3falsetruefalse00falsefalsefalsetruefalse4falsetruefalse00falsefalsefalsetruefalse5falsetruefalse00falsefalsefalsetruefalse6falsetruefalse00Average Annual Total Returns For the periods ended December 31, 2010[1]falsefalsefalsetruefalseOtherxbrli:stringItemTypestringThis item represents Average Anuual Total Returns. If a Multiple Class Fund offers a Class in the prospectus that converts into another Class after a stated period, compute average annual total returns in the table by using the returns of the other Class for the period after conversion.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 5 -Subsection b falsefalseCaptionfalseUSDfalsefalse$2falseColumnprimaryElement*5false0rr_AverageAnnualReturnColumnNamerrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse00Institutional Classfalsefalsefalsetruefalse2falsetruefalse00Institutional Classfalsefalsefalsetruefalse3falsetruefalse00Institutional Classfalsefalsefalsetruefalse4falsetruefalse00falsefalsefalsetruefalse5falsetruefalse00falsefalsefalsetruefalse6falsetruefalse00falsefalsefalsetruefalseOtherus-types:textBlockItemTypestringThis item represents Average Anuual Total Returns. If a Multiple Class Fund offers a Class in the prospectus that converts into another Class after a stated period, compute average annual total returns in the table by using the returns of the other Class for the period after conversion.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 1 -Subsection b falsefalseColumnfalseUSDfalsefalse$3falseColumnprimaryElement*6false0rr_AverageAnnualReturnLabelrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse00Return Before Taxesfalsefalsefalsetruefalse2falsetruefalse00Return After Taxes on Distributionsfalsefalsefalsetruefalse3falsetruefalse00Return After Taxes on Distributions and Sale of Fund Sharesfalsefalsefalsetruefalse4falsetruefalse00MSCI EAFE Indexfalsefalsefalsetruefalse5falsetruefalse00Lipper International Large-Cap Core Funds Indexfalsefalsefalsetruefalse6falsetruefalse00falsefalsefalsetruefalseOtherxbrli:stringItemTypestringThis item represents Average Anuual Total Returns. If a Multiple Class Fund offers a Class in the prospectus that converts into another Class after a stated period, compute average annual total returns in the table by using the returns of the other Class for the period after conversion.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 2 -Subsection b falsefalseLabelfalseUSDfalsefalse$4falseColumnprimaryElement*7false0rr_IndexNoDeductionForFeesExpensesTaxesrrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsetruefalse2falsefalsefalse00falsefalsefalsetruefalse3falsefalsefalse00falsefalsefalsetruefalse4falsefalsefalse00(reflects no deduction for fees, expenses or taxes)falsefalsefalsetruefalse5falsefalsefalse00(reflects no deduction for fees, expenses or taxes)falsefalsefalsetruefalse6falsefalsefalse00falsefalsefalsetruefalseOtherxbrli:stringItemTypestringThe Performance Table includes a parenthetical, indicating that the Index "(reflects no deduction for fees, expenses or taxes)". This tag is used when this is reflected in a footnote.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 5 -Subsection b falsefalseIndex No Deduction for Fees, Expenses, Taxes [Text]falseUSDfalsefalse$5falseColumnprimaryElement*8false0rr_AverageAnnualReturnYear01rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruetrue0.07570.0757falsefalsefalsetruefalse2truetruetrue0.07210.0721falsefalsefalsetruefalse3truetruetrue0.05380.0538falsefalsefalsetruefalse4truetruetrue0.07750.0775falsefalsefalsetruefalse5truetruetrue0.08820.0882falsefalsefalsetruefalse6falsetruetrue00falsefalsefalsetruefalseOtherxbrli:pureItemTypepureReturn Before Taxes.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 2 -Subsection b falsefalse1 YearfalseUSDfalsefalse$6falseColumnprimaryElement*9false0rr_AverageAnnualReturnYear05rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruetrue0.02430.0243falsefalsefalsetruefalse2truetruetrue0.01890.0189falsefalsefalsetruefalse3truetruetrue0.02040.0204falsefalsefalsetruefalse4truetruetrue0.02460.0246falsefalsefalsetruefalse5truetruetrue0.02330.0233falsefalsefalsetruefalse6falsetruetrue00falsefalsefalsetruefalseOtherxbrli:pureItemTypepureReturn Before Taxes.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 2 -Subsection b falsefalse5 YearsfalseUSDfalsefalse$7falseColumnprimaryElement*10false0rr_AverageAnnualReturnYear10rrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruetrue0.03440.0344falsefalsefalsetruefalse2truetruetrue0.02930.0293falsefalsefalsetruefalse3truetruetrue0.02830.0283falsefalsefalsetruefalse4truetruetrue0.03500.0350falsefalsefalsetruefalse5truetruetrue0.02510.0251falsefalsefalsetruefalse6falsetruetrue00falsefalsefalsetruefalseOtherxbrli:pureItemTypepureReturn Before Taxes.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph iii -Clause 1 -Exhibit 2 -Subsection b falsefalse10 YearsfalseUSDfalsefalse$8falseColumnprimaryElement*11false0rr_AverageAnnualReturnInceptionDaterrfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsetruefalse002000-07-31falsefalsetruetruefalse2falsetruefalse002000-07-31falsefalsetruetruefalse3falsetruefalse002000-07-31falsefalsetruetruefalse4falsetruefalse00falsefalsetruetruefalse5falsetruefalse00falsefalsetruetruefalse6falsetruefalse00falsefalsetruetruefalseOtherxbrli:dateItemTypedateReturn Before Taxes.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Paragraph 2 -Subparagraph instructions -Clause 4 -Subsection b falsefalseInception Date of ClassfalseUSDfalsefalse$1falseRowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_PerformanceMeasureAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2010-05-02T00:00:002011-04-29T00:00:00falsefalseAmerican Beacon International Equity Index Funddei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiabf809593_S000001829Memberdei_DocumentInformationDocumentAxisexplicitMembertruefalsePerformance Measurerr_PerformanceMeasureAxisrr_PerformanceMeasureDomainrr_PerformanceMeasureAxisexplicitMembertruefalseShare Classesrr_ProspectusShareClassAxisrr_ShareClassDomainrr_ProspectusShareClassAxisexplicitMemberAmerican Beacon International Equity Index FundPerformance MeasureShare ClassesStandard00truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse[1]1falsetruefalse00Average Annual Total Returns For the periods ended December 31, 2010Average Annual Total Returns For the periods ended December 31, 2010falsefalsefalsetruefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsefalsefalse5falsefalsefalse00falsefalsefalsefalsefalse6falsefalsefalse00falsefalsefalsefalsefalse7falsefalsefalse00falsefalsefalsefalsefalse8falsefalsefalse00falsefalsefalsefalsefalseOthernanafalsefalseAmerican Beacon International Equity Index Fund2falseRowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_PerformanceMeasureAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2010-05-02T00:00:002011-04-29T00:00:00falsefalseAmerican Beacon International Equity Index Funddei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiabf809593_S000001829Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseReturn Before Taxesrr_PerformanceMeasureAxisxbrldihttp://xbrl.org/2006/xbrldiabf809593_ReturnBeforeTaxesMemberrr_PerformanceMeasureAxisexplicitMemberfalsefalseInstitutional Class - 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American Beacon International Equity Index Fund5falseRowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_PerformanceMeasureAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2010-05-02T00:00:002011-04-29T00:00:00falsefalseAmerican Beacon International Equity Index Funddei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiabf809593_S000001829Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseMSCI EAFE Indexrr_PerformanceMeasureAxisxbrldihttp://xbrl.org/2006/xbrldiabf809593_MsciEafeIndexMemberrr_PerformanceMeasureAxisexplicitMembertruefalseShare Classesrr_ProspectusShareClassAxisrr_ShareClassDomainrr_ProspectusShareClassAxisexplicitMemberAmerican Beacon International Equity Index FundMSCI EAFE IndexShare ClassesStandard00truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsetruefalse00MSCI EAFE IndexMSCI EAFE Indexfalsefalsefalsetruefalse4falsefalsefalse00(reflects no deduction for fees, expenses or taxes)(reflects no deduction for fees, expenses or taxes)falsefalsefalsetruefalse5truetruetrue0.07750.0775falsefalsefalsetruefalse6truetruetrue0.02460.0246falsefalsefalsetruefalse7truetruetrue0.03500.0350falsefalsefalsetruefalse8falsefalsefalse00falsefalsefalsefalsefalseOthernanafalsefalseAmerican Beacon International Equity Index Fund MSCI EAFE Index6falseRowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_PerformanceMeasureAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*duration2010-05-02T00:00:002011-04-29T00:00:00falsefalseAmerican Beacon International Equity Index Funddei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldiabf809593_S000001829Memberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalseLipper International Large-Cap Core Funds Indexrr_PerformanceMeasureAxisxbrldihttp://xbrl.org/2006/xbrldiabf809593_LipperInternationalLargeCapCoreFundsIndexMemberrr_PerformanceMeasureAxisexplicitMembertruefalseShare Classesrr_ProspectusShareClassAxisrr_ShareClassDomainrr_ProspectusShareClassAxisexplicitMemberAmerican Beacon International Equity Index FundLipper International Large-Cap Core Funds IndexShare ClassesStandard00truefalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsetruefalse00Lipper International Large-Cap Core Funds IndexLipper International Large-Cap Core Funds Indexfalsefalsefalsetruefalse4falsefalsefalse00(reflects no deduction for fees, expenses or taxes)(reflects no deduction for fees, expenses or taxes)falsefalsefalsetruefalse5truetruetrue0.08820.0882falsefalsefalsetruefalse6truetruetrue0.02330.0233falsefalsefalsetruefalse7truetruetrue0.02510.0251falsefalsefalsetruefalse8falsefalsefalse00falsefalsefalsefalsefalseOthernanafalsefalseAmerican Beacon International Equity Index Fund Lipper International Large-Cap Core Funds Index1<i>After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor's tax situation and may differ from those shown. If you hold your Fund shares through a tax-deferred arrangement, such as an IRA or a 401(k), the after-tax returns do not apply to your situation.</i>86Average Annual Total Returns - American Beacon International Equity Index Fund UnKnownUnKnownUnKnownUnKnownfalsetrueColumnprimaryElement*RowperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowrr_PerformanceMeasureAxisAxis*Rowrr_ProspectusShareClassAxisAxis*RowunitUnit*falsefalsefalseOtherus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to PerformanceTableData.No authoritative reference available.falsefalsePerformance [Table]169Risk/Return SummaryUnKnownUnKnownUnKnownUnKnownfalsetrue