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Label Element Value
Risk/Return: rr_RiskReturnAbstract  
Risk/Return [Heading] rr_RiskReturnHeading INVESTMENT CO OF AMERICA®
Objective [Heading] rr_ObjectiveHeading Investment objectives
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The fund’s investment objectives are to achieve long-term growth of capital and income.

Expense [Heading] rr_ExpenseHeading Fees and expenses of the fund
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock

This table describes the fees and expenses that you may pay if you buy and hold shares 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 $25,000 in American Funds. More information about these and other discounts is available from your financial professional and in the “Sales charge reductions and waivers” section on page 27 of the prospectus and on page 58 of the fund’s statement of additional information.

Shareholder Fees Caption [Text] rr_ShareholderFeesCaption Shareholder fees (fees paid directly from your investment)
Operating Expenses Caption [Text] rr_OperatingExpensesCaption Annual fund operating expenses (expenses that you pay each year as a percentage of the value of your investment)
Portfolio Turnover [Heading] rr_PortfolioTurnoverHeading Portfolio turnover
Portfolio Turnover [Text Block] rr_PortfolioTurnoverTextBlock

The fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s investment results. During the most recent fiscal year, the fund’s portfolio turnover rate was 29% of the average value of its portfolio.

Portfolio Turnover, Rate rr_PortfolioTurnoverRate 29.00%rr_PortfolioTurnoverRate
Expense Breakpoint Discounts [Text] rr_ExpenseBreakpointDiscounts You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in American Funds.
Expense Breakpoint, Minimum Investment Required [Amount] rr_ExpenseBreakpointMinimumInvestmentRequiredAmount $ 25,000rr_ExpenseBreakpointMinimumInvestmentRequiredAmount
Expense Example [Heading] rr_ExpenseExampleHeading Example
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock

This example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds.


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’s operating expenses remain the same.
Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Expense Example, No Redemption, By Year, Caption [Text] rr_ExpenseExampleNoRedemptionByYearCaption For the share classes listed below, you would pay the following if you did not redeem your shares:
Strategy [Heading] rr_StrategyHeading Principal investment strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

The fund invests primarily in common stocks, most of which have a history of paying dividends. The fund’s equity investments are limited to securities of companies that are included on its eligible list. Securities are added to, or deleted from, the eligible list based upon a number of factors, such as the fund’s investment objectives and policies, whether a company is deemed to be an established company of sufficient quality and a company’s dividend payment prospects. Although the fund focuses on investments in medium to larger capitalization companies, the fund’s investments are not limited to a particular capitalization size. In the selection of common stocks and other securities for investment, potential for capital appreciation and future dividends are given more weight than current yield.


The fund may invest up to 15% of its assets, at the time of purchase, in securities of issuers domiciled outside the United States.


The investment adviser uses a system of multiple portfolio managers in managing the fund’s assets. Under this approach, the portfolio of the fund is divided into segments managed by individual managers who decide how their respective segments will be invested.


The fund relies on the professional judgment of its investment adviser to make decisions about the fund’s portfolio investments. The basic investment philosophy of the investment adviser is to seek to invest in attractively valued companies that, in its opinion, represent good, long-term investment opportunities. The investment adviser believes that an important way to accomplish this is through fundamental analysis, which may include meeting with company executives and employees, suppliers, customers and competitors. Securities may be sold when the investment adviser believes that they no longer represent relatively attractive investment opportunities.

Risk [Heading] rr_RiskHeading Principal risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock

This section describes the principal risks associated with the fund’s principal investment strategies. You may lose money by investing in the fund. The likelihood of loss may be greater if you invest for a shorter period of time. Investors in the fund should have a long-term perspective and be able to tolerate potentially sharp declines in value.


Market conditions — The prices of, and the income generated by, the common stocks and other securities held by the fund may decline – sometimes rapidly or unpredictably – due to various factors, including events or conditions affecting the general economy or particular industries; overall market changes; local, regional or global political, social or economic instability; governmental or governmental agency responses to economic conditions; and currency exchange, interest rate and commodity price fluctuations.


Issuer risks — The prices of, and the income generated by, securities held by the fund may decline in response to various factors directly related to the issuers of such securities, including reduced demand for an issuer’s goods or services, poor management performance and strategic initiatives such as mergers, acquisitions or dispositions and the market response to any such initiatives.


Investing in income-oriented stocks — Income provided by the fund may be reduced by changes in the dividend policies of, and the capital resources available for dividend payments at, the companies in which the fund invests.


Investing in growth-oriented stocks — Growth-oriented common stocks and other equity-type securities (such as preferred stocks, convertible preferred stocks and convertible bonds) may involve larger price swings and greater potential for loss than other types of investments.


Investing outside the United States — Securities of issuers domiciled outside the United States, or with significant operations or revenues outside the United States, may lose value because of adverse political, social, economic or market developments (including social instability, regional conflicts, terrorism and war) in the countries or regions in which the issuers operate or generate revenue. These securities may also lose value due to changes in foreign currency exchange rates against the U.S. dollar and/or currencies of other countries. Issuers of these securities may be more susceptible to actions of foreign governments, such as the imposition of price controls or punitive taxes, that could adversely impact revenues. Securities markets in certain countries may be more volatile and/or less liquid than those in the United States. Investments outside the United States may also be subject to different accounting practices and different regulatory, legal and reporting standards and practices, and may be more difficult to value, than those in the United States. In addition, the value of investments outside the United States may be reduced by foreign taxes, including foreign withholding taxes on interest and dividends. Further, there may be increased risks of delayed settlement of securities purchased or sold by the fund. The risks of investing outside the United States may be heightened in connection with investments in emerging markets.


Management — The investment adviser to the fund actively manages the fund’s investments. Consequently, the fund is subject to the risk that the methods and analyses employed by the investment adviser in this process may not produce the desired results. This could cause the fund to lose value or its investment results to lag relevant benchmarks or other funds with similar objectives.


Your investment in the fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency, entity or person. You should consider how this fund fits into your overall investment program.

Risk Lose Money [Text] rr_RiskLoseMoney You may lose money by investing in the fund.
Risk Not Insured Depository Institution [Text] rr_RiskNotInsuredDepositoryInstitution Your investment in the fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency, entity or person.
Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading Investment results
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The following bar chart shows how the fund’s investment results have varied from year to year, and the following table shows how the fund’s average annual total returns for various periods compare with different broad measures of market results. This information provides some indication of the risks of investing in the fund. The Lipper Growth and Income Funds Index includes the fund and other funds that disclose investment objectives and/or strategies reasonably comparable to those of the fund. Past investment results (before and after taxes) are not predictive of future investment results. Updated information on the fund’s investment results can be obtained by visiting americanfunds.com.

Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The following bar chart shows how the fund’s investment results have varied from year to year, and the following table shows how the fund’s average annual total returns for various periods compare with different broad measures of market results.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress americanfunds.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture Past investment results (before and after taxes) are not predictive of future investment results.
Bar Chart [Heading] rr_BarChartHeading Calendar year total returns for Class A shares (Results do not include a sales charge; if a sales charge were included, results would be lower.)
Bar Chart Narrative [Text Block] rr_BarChartNarrativeTextBlock

The following bar chart shows how the fund’s investment results have varied from year to year, and the following table shows how the fund’s average annual total returns for various periods compare with different broad measures of market results.


Bar Chart Does Not Reflect Sales Loads [Text] rr_BarChartDoesNotReflectSalesLoads Results do not include a sales charge; if a sales charge were included, results would be lower.
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock

Highest/Lowest quarterly results during this period were:


Highest  15.30% (quarter ended June 30, 2009)


Lowest  -18.97% (quarter ended December 31, 2008)

Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Highest
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Jun. 30, 2009
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 15.30%rr_BarChartHighestQuarterlyReturn
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Lowest
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Dec. 31, 2008
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (18.97%)rr_BarChartLowestQuarterlyReturn
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate After-tax returns are calculated using the highest individual federal income tax rates in effect during each year of the periods shown and do not reflect the impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred Your actual after-tax returns depend on your individual tax situation and likely will differ from the results shown above. In addition, after-tax returns are not relevant if you hold your fund shares through a tax-favored arrangement, such as a 401(k) plan, individual retirement account (IRA) or 529 college savings plan.
Performance Table One Class of after Tax Shown [Text] rr_PerformanceTableOneClassOfAfterTaxShown After-tax returns are shown only for Class A shares; after-tax returns for other share classes will vary.
Performance Table Narrative rr_PerformanceTableNarrativeTextBlock

After-tax returns are shown only for Class A shares; after-tax returns for other share classes will vary. After-tax returns are calculated using the highest individual federal income tax rates in effect during each year of the periods shown and do not reflect the impact of state and local taxes. Your actual after-tax returns depend on your individual tax situation and likely will differ from the results shown above. In addition, after-tax returns are not relevant if you hold your fund shares through a tax-favored arrangement, such as a 401(k) plan, individual retirement account (IRA) or 529 college savings plan.

Performance Table Closing [Text Block] rr_PerformanceTableClosingTextBlock

Class A annualized 30-day yield at December 31, 2014: 1.62%
(For current yield information, please call American FundsLine® at (800) 325-3590.)

Caption rr_AverageAnnualReturnCaption Average annual total returns For the periods ended December 31, 2014 (with maximum sales charge):
S&P 500 Index (reflects no deductions for sales charges, account fees, expenses or U.S. federal income taxes)
  
Risk/Return: rr_RiskReturnAbstract  
Label rr_AverageAnnualReturnLabel S&P 500 Index (reflects no deductions for sales charges, account fees, expenses or U.S. federal income taxes)
Average Annual Returns, 1 Year rr_AverageAnnualReturnYear01 13.66%rr_AverageAnnualReturnYear01
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Average Annual Returns, 5 Years rr_AverageAnnualReturnYear05 15.44%rr_AverageAnnualReturnYear05
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Average Annual Returns, 10 Years rr_AverageAnnualReturnYear10 7.67%rr_AverageAnnualReturnYear10
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Average Annual Returns, Since Inception rr_AverageAnnualReturnSinceInception 10.90%rr_AverageAnnualReturnSinceInception
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Average Annual Returns, Inception Date rr_AverageAnnualReturnInceptionDate Jan. 01, 1934
Lipper Growth and Income Funds Index (reflects no deductions for sales charges, account fees or U.S. federal income taxes)
  
Risk/Return: rr_RiskReturnAbstract  
Label rr_AverageAnnualReturnLabel Lipper Growth and Income Funds Index (reflects no deductions for sales charges, account fees or U.S. federal income taxes)
Average Annual Returns, 1 Year rr_AverageAnnualReturnYear01 8.77%rr_AverageAnnualReturnYear01
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Average Annual Returns, 5 Years rr_AverageAnnualReturnYear05 12.30%rr_AverageAnnualReturnYear05
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Average Annual Returns, 10 Years rr_AverageAnnualReturnYear10 6.37%rr_AverageAnnualReturnYear10
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Class A
  
Risk/Return: rr_RiskReturnAbstract  
Maximum sales charge (load) imposed on purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice 5.75%rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice
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Maximum deferred sales charge (load) (as a percentage of the amount redeemed) rr_MaximumDeferredSalesChargeOverOfferingPrice 1.00%rr_MaximumDeferredSalesChargeOverOfferingPrice
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Maximum sales charge (load) imposed on reinvested dividends rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther none
Redemption or exchange fees rr_RedemptionFeeOverRedemption none
Management fees rr_ManagementFeesOverAssets 0.24%rr_ManagementFeesOverAssets
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Distribution and/or service (12b-1) fees rr_DistributionAndService12b1FeesOverAssets 0.23%rr_DistributionAndService12b1FeesOverAssets
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Other expenses rr_OtherExpensesOverAssets 0.12%rr_OtherExpensesOverAssets
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Total annual fund operating expenses rr_ExpensesOverAssets 0.59%rr_ExpensesOverAssets
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Expenses Deferred Charges [Text Block] rr_ExpensesDeferredChargesTextBlock A contingent deferred sales charge of 1.00% applies on certain redemptions within one year following purchases of $1 million or more made without an initial sales charge.
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 632rr_ExpenseExampleYear01
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Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 753rr_ExpenseExampleYear03
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Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 885rr_ExpenseExampleYear05
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Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 1,270rr_ExpenseExampleYear10
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Annual Return 2005 rr_AnnualReturn2005 6.87%rr_AnnualReturn2005
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Annual Return 2006 rr_AnnualReturn2006 15.94%rr_AnnualReturn2006
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Annual Return 2007 rr_AnnualReturn2007 5.94%rr_AnnualReturn2007
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Annual Return 2008 rr_AnnualReturn2008 (34.74%)rr_AnnualReturn2008
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Annual Return 2009 rr_AnnualReturn2009 27.18%rr_AnnualReturn2009
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Annual Return 2010 rr_AnnualReturn2010 10.86%rr_AnnualReturn2010
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Annual Return 2011 rr_AnnualReturn2011 (1.76%)rr_AnnualReturn2011
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Annual Return 2012 rr_AnnualReturn2012 15.60%rr_AnnualReturn2012
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Annual Return 2013 rr_AnnualReturn2013 32.42%rr_AnnualReturn2013
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Annual Return 2014 rr_AnnualReturn2014 12.09%rr_AnnualReturn2014
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Label rr_AverageAnnualReturnLabel A Before taxes
Average Annual Returns, 1 Year rr_AverageAnnualReturnYear01 5.64%rr_AverageAnnualReturnYear01
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Average Annual Returns, 5 Years rr_AverageAnnualReturnYear05 11.99%rr_AverageAnnualReturnYear05
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Average Annual Returns, 10 Years rr_AverageAnnualReturnYear10 6.73%rr_AverageAnnualReturnYear10
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Average Annual Returns, Since Inception rr_AverageAnnualReturnSinceInception 12.17%rr_AverageAnnualReturnSinceInception
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Average Annual Returns, Inception Date rr_AverageAnnualReturnInceptionDate Jan. 01, 1934
Thirty Day Yield Caption rr_ThirtyDayYieldCaption Class A annualized 30-day yield at December 31, 2014:
Thirty Day Yield Phone rr_ThirtyDayYieldPhone (800) 325-3590
Thirty Day Yield rr_ThirtyDayYield 1.62%rr_ThirtyDayYield
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Class A | Average Annual Returns, After Taxes on Distributions
  
Risk/Return: rr_RiskReturnAbstract  
Label rr_AverageAnnualReturnLabel A After taxes on distributions
Average Annual Returns, 1 Year rr_AverageAnnualReturnYear01 3.15%rr_AverageAnnualReturnYear01
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Average Annual Returns, 5 Years rr_AverageAnnualReturnYear05 10.75%rr_AverageAnnualReturnYear05
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Average Annual Returns, 10 Years rr_AverageAnnualReturnYear10 5.74%rr_AverageAnnualReturnYear10
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Class A | After Taxes on Distributions and Sales
  
Risk/Return: rr_RiskReturnAbstract  
Label rr_AverageAnnualReturnLabel A After taxes on distributions and sale of fund shares
Average Annual Returns, 1 Year rr_AverageAnnualReturnYear01 5.26%rr_AverageAnnualReturnYear01
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Average Annual Returns, 5 Years rr_AverageAnnualReturnYear05 9.56%rr_AverageAnnualReturnYear05
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Average Annual Returns, 10 Years rr_AverageAnnualReturnYear10 5.44%rr_AverageAnnualReturnYear10
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Class 529-A
  
Risk/Return: rr_RiskReturnAbstract  
Maximum sales charge (load) imposed on purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice 5.75%rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice
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Maximum deferred sales charge (load) (as a percentage of the amount redeemed) rr_MaximumDeferredSalesChargeOverOfferingPrice 1.00%rr_MaximumDeferredSalesChargeOverOfferingPrice
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Maximum sales charge (load) imposed on reinvested dividends rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther none
Redemption or exchange fees rr_RedemptionFeeOverRedemption none
Management fees rr_ManagementFeesOverAssets 0.24%rr_ManagementFeesOverAssets
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Distribution and/or service (12b-1) fees rr_DistributionAndService12b1FeesOverAssets 0.23%rr_DistributionAndService12b1FeesOverAssets
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Other expenses rr_OtherExpensesOverAssets 0.22%rr_OtherExpensesOverAssets
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Total annual fund operating expenses rr_ExpensesOverAssets 0.69%rr_ExpensesOverAssets
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Expenses Deferred Charges [Text Block] rr_ExpensesDeferredChargesTextBlock A contingent deferred sales charge of 1.00% applies on certain redemptions within one year following purchases of $1 million or more made without an initial sales charge.
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 641rr_ExpenseExampleYear01
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Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 783rr_ExpenseExampleYear03
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Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 937rr_ExpenseExampleYear05
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Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 1,384rr_ExpenseExampleYear10
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Label rr_AverageAnnualReturnLabel 529-A Before taxes
Average Annual Returns, 1 Year rr_AverageAnnualReturnYear01 5.51%rr_AverageAnnualReturnYear01
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Average Annual Returns, 5 Years rr_AverageAnnualReturnYear05 11.88%rr_AverageAnnualReturnYear05
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Average Annual Returns, 10 Years rr_AverageAnnualReturnYear10 6.64%rr_AverageAnnualReturnYear10
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/ rr_ProspectusShareClassAxis
= ck0000051931_C000026223Member
Average Annual Returns, Since Inception rr_AverageAnnualReturnSinceInception 6.69%rr_AverageAnnualReturnSinceInception
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026223Member
Average Annual Returns, Inception Date rr_AverageAnnualReturnInceptionDate Feb. 15, 2002
Class B
  
Risk/Return: rr_RiskReturnAbstract  
Maximum sales charge (load) imposed on purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum deferred sales charge (load) (as a percentage of the amount redeemed) rr_MaximumDeferredSalesChargeOverOfferingPrice 5.00%rr_MaximumDeferredSalesChargeOverOfferingPrice
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026220Member
Maximum sales charge (load) imposed on reinvested dividends rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther none
Redemption or exchange fees rr_RedemptionFeeOverRedemption none
Management fees rr_ManagementFeesOverAssets 0.24%rr_ManagementFeesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026220Member
Distribution and/or service (12b-1) fees rr_DistributionAndService12b1FeesOverAssets 1.00%rr_DistributionAndService12b1FeesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026220Member
Other expenses rr_OtherExpensesOverAssets 0.10%rr_OtherExpensesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026220Member
Total annual fund operating expenses rr_ExpensesOverAssets 1.34%rr_ExpensesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026220Member
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 636rr_ExpenseExampleYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026220Member
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 825rr_ExpenseExampleYear03
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026220Member
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 934rr_ExpenseExampleYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026220Member
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 1,407rr_ExpenseExampleYear10
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026220Member
Expense Example, No Redemption, 1 Year rr_ExpenseExampleNoRedemptionYear01 136rr_ExpenseExampleNoRedemptionYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026220Member
Expense Example, No Redemption, 3 Years rr_ExpenseExampleNoRedemptionYear03 425rr_ExpenseExampleNoRedemptionYear03
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026220Member
Expense Example, No Redemption, 5 Years rr_ExpenseExampleNoRedemptionYear05 734rr_ExpenseExampleNoRedemptionYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026220Member
Expense Example, No Redemption, 10 Years rr_ExpenseExampleNoRedemptionYear10 1,407rr_ExpenseExampleNoRedemptionYear10
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026220Member
Label rr_AverageAnnualReturnLabel B Before taxes
Average Annual Returns, 1 Year rr_AverageAnnualReturnYear01 6.26%rr_AverageAnnualReturnYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026220Member
Average Annual Returns, 5 Years rr_AverageAnnualReturnYear05 12.21%rr_AverageAnnualReturnYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026220Member
Average Annual Returns, 10 Years rr_AverageAnnualReturnYear10 6.71%rr_AverageAnnualReturnYear10
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026220Member
Average Annual Returns, Since Inception rr_AverageAnnualReturnSinceInception 5.81%rr_AverageAnnualReturnSinceInception
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026220Member
Average Annual Returns, Inception Date rr_AverageAnnualReturnInceptionDate Mar. 15, 2000
Class 529-B
  
Risk/Return: rr_RiskReturnAbstract  
Maximum sales charge (load) imposed on purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum deferred sales charge (load) (as a percentage of the amount redeemed) rr_MaximumDeferredSalesChargeOverOfferingPrice 5.00%rr_MaximumDeferredSalesChargeOverOfferingPrice
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026224Member
Maximum sales charge (load) imposed on reinvested dividends rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther none
Redemption or exchange fees rr_RedemptionFeeOverRedemption none
Management fees rr_ManagementFeesOverAssets 0.24%rr_ManagementFeesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026224Member
Distribution and/or service (12b-1) fees rr_DistributionAndService12b1FeesOverAssets 0.99%rr_DistributionAndService12b1FeesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026224Member
Other expenses rr_OtherExpensesOverAssets 0.24%rr_OtherExpensesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026224Member
Total annual fund operating expenses rr_ExpensesOverAssets 1.47%rr_ExpensesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026224Member
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 650rr_ExpenseExampleYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026224Member
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 865rr_ExpenseExampleYear03
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026224Member
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 1,003rr_ExpenseExampleYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026224Member
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 1,546rr_ExpenseExampleYear10
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026224Member
Expense Example, No Redemption, 1 Year rr_ExpenseExampleNoRedemptionYear01 150rr_ExpenseExampleNoRedemptionYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026224Member
Expense Example, No Redemption, 3 Years rr_ExpenseExampleNoRedemptionYear03 465rr_ExpenseExampleNoRedemptionYear03
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026224Member
Expense Example, No Redemption, 5 Years rr_ExpenseExampleNoRedemptionYear05 803rr_ExpenseExampleNoRedemptionYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026224Member
Expense Example, No Redemption, 10 Years rr_ExpenseExampleNoRedemptionYear10 1,546rr_ExpenseExampleNoRedemptionYear10
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026224Member
Label rr_AverageAnnualReturnLabel 529-B Before taxes
Average Annual Returns, 1 Year rr_AverageAnnualReturnYear01 6.10%rr_AverageAnnualReturnYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026224Member
Average Annual Returns, 5 Years rr_AverageAnnualReturnYear05 12.07%rr_AverageAnnualReturnYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026224Member
Average Annual Returns, 10 Years rr_AverageAnnualReturnYear10 6.58%rr_AverageAnnualReturnYear10
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026224Member
Average Annual Returns, Since Inception rr_AverageAnnualReturnSinceInception 6.62%rr_AverageAnnualReturnSinceInception
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026224Member
Average Annual Returns, Inception Date rr_AverageAnnualReturnInceptionDate Feb. 15, 2002
Class C
  
Risk/Return: rr_RiskReturnAbstract  
Maximum sales charge (load) imposed on purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum deferred sales charge (load) (as a percentage of the amount redeemed) rr_MaximumDeferredSalesChargeOverOfferingPrice 1.00%rr_MaximumDeferredSalesChargeOverOfferingPrice
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026221Member
Maximum sales charge (load) imposed on reinvested dividends rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther none
Redemption or exchange fees rr_RedemptionFeeOverRedemption none
Management fees rr_ManagementFeesOverAssets 0.24%rr_ManagementFeesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026221Member
Distribution and/or service (12b-1) fees rr_DistributionAndService12b1FeesOverAssets 1.00%rr_DistributionAndService12b1FeesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026221Member
Other expenses rr_OtherExpensesOverAssets 0.15%rr_OtherExpensesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026221Member
Total annual fund operating expenses rr_ExpensesOverAssets 1.39%rr_ExpensesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026221Member
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 242rr_ExpenseExampleYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026221Member
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 440rr_ExpenseExampleYear03
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026221Member
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 761rr_ExpenseExampleYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026221Member
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 1,669rr_ExpenseExampleYear10
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026221Member
Expense Example, No Redemption, 1 Year rr_ExpenseExampleNoRedemptionYear01 142rr_ExpenseExampleNoRedemptionYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026221Member
Expense Example, No Redemption, 3 Years rr_ExpenseExampleNoRedemptionYear03 440rr_ExpenseExampleNoRedemptionYear03
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026221Member
Expense Example, No Redemption, 5 Years rr_ExpenseExampleNoRedemptionYear05 761rr_ExpenseExampleNoRedemptionYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026221Member
Expense Example, No Redemption, 10 Years rr_ExpenseExampleNoRedemptionYear10 1,669rr_ExpenseExampleNoRedemptionYear10
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026221Member
Label rr_AverageAnnualReturnLabel C Before taxes
Average Annual Returns, 1 Year rr_AverageAnnualReturnYear01 10.20%rr_AverageAnnualReturnYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026221Member
Average Annual Returns, 5 Years rr_AverageAnnualReturnYear05 12.41%rr_AverageAnnualReturnYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026221Member
Average Annual Returns, 10 Years rr_AverageAnnualReturnYear10 6.50%rr_AverageAnnualReturnYear10
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026221Member
Average Annual Returns, Since Inception rr_AverageAnnualReturnSinceInception 5.98%rr_AverageAnnualReturnSinceInception
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026221Member
Average Annual Returns, Inception Date rr_AverageAnnualReturnInceptionDate Mar. 15, 2001
Class 529-C
  
Risk/Return: rr_RiskReturnAbstract  
Maximum sales charge (load) imposed on purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum deferred sales charge (load) (as a percentage of the amount redeemed) rr_MaximumDeferredSalesChargeOverOfferingPrice 1.00%rr_MaximumDeferredSalesChargeOverOfferingPrice
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026225Member
Maximum sales charge (load) imposed on reinvested dividends rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther none
Redemption or exchange fees rr_RedemptionFeeOverRedemption none
Management fees rr_ManagementFeesOverAssets 0.24%rr_ManagementFeesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026225Member
Distribution and/or service (12b-1) fees rr_DistributionAndService12b1FeesOverAssets 0.99%rr_DistributionAndService12b1FeesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026225Member
Other expenses rr_OtherExpensesOverAssets 0.23%rr_OtherExpensesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026225Member
Total annual fund operating expenses rr_ExpensesOverAssets 1.46%rr_ExpensesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026225Member
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 249rr_ExpenseExampleYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026225Member
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 462rr_ExpenseExampleYear03
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026225Member
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 797rr_ExpenseExampleYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026225Member
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 1,746rr_ExpenseExampleYear10
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026225Member
Expense Example, No Redemption, 1 Year rr_ExpenseExampleNoRedemptionYear01 149rr_ExpenseExampleNoRedemptionYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026225Member
Expense Example, No Redemption, 3 Years rr_ExpenseExampleNoRedemptionYear03 462rr_ExpenseExampleNoRedemptionYear03
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026225Member
Expense Example, No Redemption, 5 Years rr_ExpenseExampleNoRedemptionYear05 797rr_ExpenseExampleNoRedemptionYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026225Member
Expense Example, No Redemption, 10 Years rr_ExpenseExampleNoRedemptionYear10 1,746rr_ExpenseExampleNoRedemptionYear10
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026225Member
Label rr_AverageAnnualReturnLabel 529-C Before taxes
Average Annual Returns, 1 Year rr_AverageAnnualReturnYear01 10.13%rr_AverageAnnualReturnYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026225Member
Average Annual Returns, 5 Years rr_AverageAnnualReturnYear05 12.34%rr_AverageAnnualReturnYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026225Member
Average Annual Returns, 10 Years rr_AverageAnnualReturnYear10 6.43%rr_AverageAnnualReturnYear10
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026225Member
Average Annual Returns, Since Inception rr_AverageAnnualReturnSinceInception 6.45%rr_AverageAnnualReturnSinceInception
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026225Member
Average Annual Returns, Inception Date rr_AverageAnnualReturnInceptionDate Feb. 19, 2002
Class 529-E
  
Risk/Return: rr_RiskReturnAbstract  
Maximum sales charge (load) imposed on purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum deferred sales charge (load) (as a percentage of the amount redeemed) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum sales charge (load) imposed on reinvested dividends rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther none
Redemption or exchange fees rr_RedemptionFeeOverRedemption none
Management fees rr_ManagementFeesOverAssets 0.24%rr_ManagementFeesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026226Member
Distribution and/or service (12b-1) fees rr_DistributionAndService12b1FeesOverAssets 0.50%rr_DistributionAndService12b1FeesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026226Member
Other expenses rr_OtherExpensesOverAssets 0.19%rr_OtherExpensesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026226Member
Total annual fund operating expenses rr_ExpensesOverAssets 0.93%rr_ExpensesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026226Member
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 95rr_ExpenseExampleYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026226Member
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 296rr_ExpenseExampleYear03
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026226Member
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 515rr_ExpenseExampleYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026226Member
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 1,143rr_ExpenseExampleYear10
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026226Member
Label rr_AverageAnnualReturnLabel 529-E Before taxes
Average Annual Returns, 1 Year rr_AverageAnnualReturnYear01 11.70%rr_AverageAnnualReturnYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026226Member
Average Annual Returns, 5 Years rr_AverageAnnualReturnYear05 12.92%rr_AverageAnnualReturnYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026226Member
Average Annual Returns, 10 Years rr_AverageAnnualReturnYear10 6.98%rr_AverageAnnualReturnYear10
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026226Member
Average Annual Returns, Since Inception rr_AverageAnnualReturnSinceInception 6.70%rr_AverageAnnualReturnSinceInception
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026226Member
Average Annual Returns, Inception Date rr_AverageAnnualReturnInceptionDate Mar. 01, 2002
Class 529-F-1
  
Risk/Return: rr_RiskReturnAbstract  
Maximum sales charge (load) imposed on purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum deferred sales charge (load) (as a percentage of the amount redeemed) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum sales charge (load) imposed on reinvested dividends rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther none
Redemption or exchange fees rr_RedemptionFeeOverRedemption none
Management fees rr_ManagementFeesOverAssets 0.24%rr_ManagementFeesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026227Member
Distribution and/or service (12b-1) fees rr_DistributionAndService12b1FeesOverAssets none
Other expenses rr_OtherExpensesOverAssets 0.22%rr_OtherExpensesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026227Member
Total annual fund operating expenses rr_ExpensesOverAssets 0.46%rr_ExpensesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026227Member
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 47rr_ExpenseExampleYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026227Member
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 148rr_ExpenseExampleYear03
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026227Member
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 258rr_ExpenseExampleYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026227Member
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 579rr_ExpenseExampleYear10
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026227Member
Label rr_AverageAnnualReturnLabel 529-F-1 Before taxes
Average Annual Returns, 1 Year rr_AverageAnnualReturnYear01 12.23%rr_AverageAnnualReturnYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026227Member
Average Annual Returns, 5 Years rr_AverageAnnualReturnYear05 13.46%rr_AverageAnnualReturnYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026227Member
Average Annual Returns, 10 Years rr_AverageAnnualReturnYear10 7.49%rr_AverageAnnualReturnYear10
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026227Member
Average Annual Returns, Since Inception rr_AverageAnnualReturnSinceInception 8.86%rr_AverageAnnualReturnSinceInception
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026227Member
Average Annual Returns, Inception Date rr_AverageAnnualReturnInceptionDate Sep. 16, 2002
Class F-1
  
Risk/Return: rr_RiskReturnAbstract  
Maximum sales charge (load) imposed on purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum deferred sales charge (load) (as a percentage of the amount redeemed) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum sales charge (load) imposed on reinvested dividends rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther none
Redemption or exchange fees rr_RedemptionFeeOverRedemption none
Management fees rr_ManagementFeesOverAssets 0.24%rr_ManagementFeesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026222Member
Distribution and/or service (12b-1) fees rr_DistributionAndService12b1FeesOverAssets 0.25%rr_DistributionAndService12b1FeesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026222Member
Other expenses rr_OtherExpensesOverAssets 0.18%rr_OtherExpensesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026222Member
Total annual fund operating expenses rr_ExpensesOverAssets 0.67%rr_ExpensesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026222Member
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 68rr_ExpenseExampleYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026222Member
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 214rr_ExpenseExampleYear03
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026222Member
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 373rr_ExpenseExampleYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026222Member
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 835rr_ExpenseExampleYear10
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026222Member
Label rr_AverageAnnualReturnLabel F-1 Before taxes
Average Annual Returns, 1 Year rr_AverageAnnualReturnYear01 12.02%rr_AverageAnnualReturnYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026222Member
Average Annual Returns, 5 Years rr_AverageAnnualReturnYear05 13.25%rr_AverageAnnualReturnYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026222Member
Average Annual Returns, 10 Years rr_AverageAnnualReturnYear10 7.32%rr_AverageAnnualReturnYear10
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026222Member
Average Annual Returns, Since Inception rr_AverageAnnualReturnSinceInception 6.57%rr_AverageAnnualReturnSinceInception
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026222Member
Average Annual Returns, Inception Date rr_AverageAnnualReturnInceptionDate Mar. 15, 2001
Class F-2
  
Risk/Return: rr_RiskReturnAbstract  
Maximum sales charge (load) imposed on purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum deferred sales charge (load) (as a percentage of the amount redeemed) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum sales charge (load) imposed on reinvested dividends rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther none
Redemption or exchange fees rr_RedemptionFeeOverRedemption none
Management fees rr_ManagementFeesOverAssets 0.24%rr_ManagementFeesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000068572Member
Distribution and/or service (12b-1) fees rr_DistributionAndService12b1FeesOverAssets none
Other expenses rr_OtherExpensesOverAssets 0.15%rr_OtherExpensesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000068572Member
Total annual fund operating expenses rr_ExpensesOverAssets 0.39%rr_ExpensesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000068572Member
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 40rr_ExpenseExampleYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000068572Member
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 125rr_ExpenseExampleYear03
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000068572Member
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 219rr_ExpenseExampleYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000068572Member
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 493rr_ExpenseExampleYear10
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000068572Member
Label rr_AverageAnnualReturnLabel F-2 Before taxes
Average Annual Returns, 1 Year rr_AverageAnnualReturnYear01 12.31%rr_AverageAnnualReturnYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000068572Member
Average Annual Returns, 5 Years rr_AverageAnnualReturnYear05 13.56%rr_AverageAnnualReturnYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000068572Member
Average Annual Returns, Since Inception rr_AverageAnnualReturnSinceInception 9.56%rr_AverageAnnualReturnSinceInception
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000068572Member
Average Annual Returns, Inception Date rr_AverageAnnualReturnInceptionDate Aug. 01, 2008
Class R-6
  
Risk/Return: rr_RiskReturnAbstract  
Maximum sales charge (load) imposed on purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum deferred sales charge (load) (as a percentage of the amount redeemed) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum sales charge (load) imposed on reinvested dividends rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther none
Redemption or exchange fees rr_RedemptionFeeOverRedemption none
Management fees rr_ManagementFeesOverAssets 0.24%rr_ManagementFeesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000077857Member
Distribution and/or service (12b-1) fees rr_DistributionAndService12b1FeesOverAssets none
Other expenses rr_OtherExpensesOverAssets 0.06%rr_OtherExpensesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000077857Member
Total annual fund operating expenses rr_ExpensesOverAssets 0.30%rr_ExpensesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000077857Member
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 31rr_ExpenseExampleYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000077857Member
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 97rr_ExpenseExampleYear03
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000077857Member
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 169rr_ExpenseExampleYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000077857Member
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 381rr_ExpenseExampleYear10
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000077857Member
Label rr_AverageAnnualReturnLabel R-6 Before taxes
Average Annual Returns, 1 Year rr_AverageAnnualReturnYear01 12.41%rr_AverageAnnualReturnYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000077857Member
Average Annual Returns, 5 Years rr_AverageAnnualReturnYear05 13.66%rr_AverageAnnualReturnYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000077857Member
Average Annual Returns, Since Inception rr_AverageAnnualReturnSinceInception 16.91%rr_AverageAnnualReturnSinceInception
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000077857Member
Average Annual Returns, Inception Date rr_AverageAnnualReturnInceptionDate May 01, 2009
Class R-2E
  
Risk/Return: rr_RiskReturnAbstract  
Maximum sales charge (load) imposed on purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum deferred sales charge (load) (as a percentage of the amount redeemed) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum sales charge (load) imposed on reinvested dividends rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther none
Redemption or exchange fees rr_RedemptionFeeOverRedemption none
Management fees rr_ManagementFeesOverAssets 0.24%rr_ManagementFeesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000148444Member
Distribution and/or service (12b-1) fees rr_DistributionAndService12b1FeesOverAssets 0.60%rr_DistributionAndService12b1FeesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000148444Member		 [2]
Other expenses rr_OtherExpensesOverAssets 0.27%rr_OtherExpensesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000148444Member		 [2]
Total annual fund operating expenses rr_ExpensesOverAssets 1.11%rr_ExpensesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000148444Member
Other Expenses, New Fund, Based on Estimates [Text] rr_OtherExpensesNewFundBasedOnEstimates Based on estimated amounts for the current fiscal year.
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 113rr_ExpenseExampleYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000148444Member
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 353rr_ExpenseExampleYear03
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000148444Member
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 612rr_ExpenseExampleYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000148444Member
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 1,352rr_ExpenseExampleYear10
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000148444Member
Class R-2
  
Risk/Return: rr_RiskReturnAbstract  
Maximum sales charge (load) imposed on purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum deferred sales charge (load) (as a percentage of the amount redeemed) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum sales charge (load) imposed on reinvested dividends rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther none
Redemption or exchange fees rr_RedemptionFeeOverRedemption none
Management fees rr_ManagementFeesOverAssets 0.24%rr_ManagementFeesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026216Member
Distribution and/or service (12b-1) fees rr_DistributionAndService12b1FeesOverAssets 0.75%rr_DistributionAndService12b1FeesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026216Member
Other expenses rr_OtherExpensesOverAssets 0.38%rr_OtherExpensesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026216Member
Total annual fund operating expenses rr_ExpensesOverAssets 1.37%rr_ExpensesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026216Member
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 139rr_ExpenseExampleYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026216Member
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 434rr_ExpenseExampleYear03
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026216Member
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 750rr_ExpenseExampleYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026216Member
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 1,646rr_ExpenseExampleYear10
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026216Member
Label rr_AverageAnnualReturnLabel R-2 Before taxes
Average Annual Returns, 1 Year rr_AverageAnnualReturnYear01 11.20%rr_AverageAnnualReturnYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026216Member
Average Annual Returns, 5 Years rr_AverageAnnualReturnYear05 12.43%rr_AverageAnnualReturnYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026216Member
Average Annual Returns, 10 Years rr_AverageAnnualReturnYear10 6.48%rr_AverageAnnualReturnYear10
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026216Member
Average Annual Returns, Since Inception rr_AverageAnnualReturnSinceInception 6.38%rr_AverageAnnualReturnSinceInception
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026216Member
Average Annual Returns, Inception Date rr_AverageAnnualReturnInceptionDate May 21, 2002
Class R-1
  
Risk/Return: rr_RiskReturnAbstract  
Maximum sales charge (load) imposed on purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum deferred sales charge (load) (as a percentage of the amount redeemed) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum sales charge (load) imposed on reinvested dividends rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther none
Redemption or exchange fees rr_RedemptionFeeOverRedemption none
Management fees rr_ManagementFeesOverAssets 0.24%rr_ManagementFeesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026215Member
Distribution and/or service (12b-1) fees rr_DistributionAndService12b1FeesOverAssets 1.00%rr_DistributionAndService12b1FeesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026215Member
Other expenses rr_OtherExpensesOverAssets 0.16%rr_OtherExpensesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026215Member
Total annual fund operating expenses rr_ExpensesOverAssets 1.40%rr_ExpensesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026215Member
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 143rr_ExpenseExampleYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026215Member
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 443rr_ExpenseExampleYear03
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026215Member
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 766rr_ExpenseExampleYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026215Member
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 1,680rr_ExpenseExampleYear10
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026215Member
Label rr_AverageAnnualReturnLabel R-1 Before taxes
Average Annual Returns, 1 Year rr_AverageAnnualReturnYear01 11.19%rr_AverageAnnualReturnYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026215Member
Average Annual Returns, 5 Years rr_AverageAnnualReturnYear05 12.42%rr_AverageAnnualReturnYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026215Member
Average Annual Returns, 10 Years rr_AverageAnnualReturnYear10 6.50%rr_AverageAnnualReturnYear10
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026215Member
Average Annual Returns, Since Inception rr_AverageAnnualReturnSinceInception 6.70%rr_AverageAnnualReturnSinceInception
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026215Member
Average Annual Returns, Inception Date rr_AverageAnnualReturnInceptionDate Jun. 06, 2002
Class R-3
  
Risk/Return: rr_RiskReturnAbstract  
Maximum sales charge (load) imposed on purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum deferred sales charge (load) (as a percentage of the amount redeemed) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum sales charge (load) imposed on reinvested dividends rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther none
Redemption or exchange fees rr_RedemptionFeeOverRedemption none
Management fees rr_ManagementFeesOverAssets 0.24%rr_ManagementFeesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026217Member
Distribution and/or service (12b-1) fees rr_DistributionAndService12b1FeesOverAssets 0.50%rr_DistributionAndService12b1FeesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026217Member
Other expenses rr_OtherExpensesOverAssets 0.22%rr_OtherExpensesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026217Member
Total annual fund operating expenses rr_ExpensesOverAssets 0.96%rr_ExpensesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026217Member
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 98rr_ExpenseExampleYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026217Member
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 306rr_ExpenseExampleYear03
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026217Member
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 531rr_ExpenseExampleYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026217Member
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 1,178rr_ExpenseExampleYear10
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026217Member
Label rr_AverageAnnualReturnLabel R-3 Before taxes
Average Annual Returns, 1 Year rr_AverageAnnualReturnYear01 11.68%rr_AverageAnnualReturnYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026217Member
Average Annual Returns, 5 Years rr_AverageAnnualReturnYear05 12.91%rr_AverageAnnualReturnYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026217Member
Average Annual Returns, 10 Years rr_AverageAnnualReturnYear10 6.98%rr_AverageAnnualReturnYear10
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026217Member
Average Annual Returns, Since Inception rr_AverageAnnualReturnSinceInception 7.07%rr_AverageAnnualReturnSinceInception
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026217Member
Average Annual Returns, Inception Date rr_AverageAnnualReturnInceptionDate Jun. 04, 2002
Class R-4
  
Risk/Return: rr_RiskReturnAbstract  
Maximum sales charge (load) imposed on purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum deferred sales charge (load) (as a percentage of the amount redeemed) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum sales charge (load) imposed on reinvested dividends rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther none
Redemption or exchange fees rr_RedemptionFeeOverRedemption none
Management fees rr_ManagementFeesOverAssets 0.24%rr_ManagementFeesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026218Member
Distribution and/or service (12b-1) fees rr_DistributionAndService12b1FeesOverAssets 0.25%rr_DistributionAndService12b1FeesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026218Member
Other expenses rr_OtherExpensesOverAssets 0.16%rr_OtherExpensesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026218Member
Total annual fund operating expenses rr_ExpensesOverAssets 0.65%rr_ExpensesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026218Member
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 66rr_ExpenseExampleYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026218Member
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 208rr_ExpenseExampleYear03
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026218Member
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 362rr_ExpenseExampleYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026218Member
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 810rr_ExpenseExampleYear10
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026218Member
Label rr_AverageAnnualReturnLabel R-4 Before taxes
Average Annual Returns, 1 Year rr_AverageAnnualReturnYear01 12.02%rr_AverageAnnualReturnYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026218Member
Average Annual Returns, 5 Years rr_AverageAnnualReturnYear05 13.27%rr_AverageAnnualReturnYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026218Member
Average Annual Returns, 10 Years rr_AverageAnnualReturnYear10 7.31%rr_AverageAnnualReturnYear10
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026218Member
Average Annual Returns, Since Inception rr_AverageAnnualReturnSinceInception 7.21%rr_AverageAnnualReturnSinceInception
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026218Member
Average Annual Returns, Inception Date rr_AverageAnnualReturnInceptionDate May 28, 2002
Class R-5
  
Risk/Return: rr_RiskReturnAbstract  
Maximum sales charge (load) imposed on purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum deferred sales charge (load) (as a percentage of the amount redeemed) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum sales charge (load) imposed on reinvested dividends rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther none
Redemption or exchange fees rr_RedemptionFeeOverRedemption none
Management fees rr_ManagementFeesOverAssets 0.24%rr_ManagementFeesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026219Member
Distribution and/or service (12b-1) fees rr_DistributionAndService12b1FeesOverAssets none
Other expenses rr_OtherExpensesOverAssets 0.11%rr_OtherExpensesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026219Member
Total annual fund operating expenses rr_ExpensesOverAssets 0.35%rr_ExpensesOverAssets
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026219Member
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 36rr_ExpenseExampleYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026219Member
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 113rr_ExpenseExampleYear03
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026219Member
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 197rr_ExpenseExampleYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026219Member
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 443rr_ExpenseExampleYear10
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026219Member
Label rr_AverageAnnualReturnLabel R-5 Before taxes
Average Annual Returns, 1 Year rr_AverageAnnualReturnYear01 12.36%rr_AverageAnnualReturnYear01
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026219Member
Average Annual Returns, 5 Years rr_AverageAnnualReturnYear05 13.62%rr_AverageAnnualReturnYear05
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026219Member
Average Annual Returns, 10 Years rr_AverageAnnualReturnYear10 7.63%rr_AverageAnnualReturnYear10
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026219Member
Average Annual Returns, Since Inception rr_AverageAnnualReturnSinceInception 7.46%rr_AverageAnnualReturnSinceInception
/ dei_LegalEntityAxis
= ck0000051931_S000009597Member
/ rr_ProspectusShareClassAxis
= ck0000051931_C000026219Member
Average Annual Returns, Inception Date rr_AverageAnnualReturnInceptionDate May 15, 2002
[1] A contingent deferred sales charge of 1.00% applies on certain redemptions within one year following purchases of $1 million or more made without an initial sales charge.
[2] Based on estimated amounts for the current fiscal year.