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Label Element Value
Prospectus [Line Items] rr_ProspectusLineItems  
Document Type dei_DocumentType 485BPOS
Document Period End Date dei_DocumentPeriodEndDate Jul. 31, 2013
Registrant Name dei_EntityRegistrantName AMERICAN CENTURY ASSET ALLOCATION PORTFOLIOS, INC.
Central Index Key dei_EntityCentralIndexKey 0001293210
Amendment Flag dei_AmendmentFlag false
Trading Symbol dei_TradingSymbol ACAAP
Document Creation Date dei_DocumentCreationDate Nov. 27, 2013
Document Effective Date dei_DocumentEffectiveDate Dec. 01, 2013
Prospectus Date rr_ProspectusDate Dec. 01, 2013
ONE CHOICE IN RETIREMENT PORTFOLIO
  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk/Return [Heading] rr_RiskReturnHeading ONE CHOICE IN RETIREMENT PORTFOLIO
Objective [Heading] rr_ObjectiveHeading

Investment Objective
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The fund seeks current income.

Objective, Secondary [Text Block] rr_ObjectiveSecondaryTextBlock

Capital appreciation is a secondary objective.

Expense [Heading] rr_ExpenseHeading

Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock The following table describes the fees and expenses 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 $50,000 in American Century Investments funds. More information about these and other discounts is available from your financial professional and in Calculation of Sales Charges on page 60 of the fund’s prospectus and Sales Charges in Appendix B of the 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

Because the fund buys and sells shares of other American Century mutual funds (the underlying funds) directly from the issuers, the fund is not expected to incur transaction costs directly. However, as a shareholder in the underlying funds, the fund indirectly pays transaction costs, such as commissions, when the underlying funds buy and sell securities (or "turn over" their portfolios). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 11% of the average value of its portfolio.

Portfolio Turnover, Rate rr_PortfolioTurnoverRate 11.00%
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 $50,000 in American Century Investments funds. More information about these and other discounts is available from your financial professional and in Calculation of Sales Charges on page 60 of the fund's prospectus and Sales Charges in Appendix B of the statement of additional information.
Expense Breakpoint, Minimum Investment Required [Amount] rr_ExpenseBreakpointMinimumInvestmentRequiredAmount $ 50,000
Expense Example [Heading] rr_ExpenseExampleHeading

Example

Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock

The example below is intended to help you compare the costs of investing in the fund with the costs of investing in other mutual funds.
Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption

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, that you earn a 5% return each year, and that the fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading] rr_StrategyHeading

Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

One Choice In Retirement Portfolio is a "fund of funds," meaning that it seeks to achieve its objective by investing in other American Century mutual funds (the underlying funds) that represent a variety of asset classes and investment styles. The underlying stock funds draw on growth, value and quantitative investment techniques and diversify investments among small, medium and large U.S. and foreign companies. The underlying bond funds invest in fixed-income securities that vary by issuer type (corporate and government), credit quality (investment-grade and high-yield or "junk bonds") and geographic exposure (domestic and international). The following table shows the fund's target allocation for the various asset classes and underlying funds as of the date of the prospectus:

 

Equity Securities (Stock Funds)

45.00%

    

Fixed-Income Securities (Bond Funds)

45.00%

  

NT Core Equity Plus Fund

3.00%

    

High-Yield Fund

 3.80%

  

NT Equity Growth Fund

10.00%

    

Inflation-Adjusted Bond Fund

1.50%

  

NT Growth Fund

 6.50%

    

International Bond Fund

 7.00%

  

NT Heritage Fund

2.50%

    

NT Diversified Bond Fund

26.60%

  

NT International Growth Fund

 5.00%

    

Short Duration Inflation Protection Bond Fund

6.10%

  

NT Large Company Value Fund

11.00%

          

NT Mid Cap Value Fund

 4.00%

    

Cash Equivalents (Money Market Funds)

10.00%

  

NT Small Company Fund

 2.00%

    

Premium Money Market Fund

10.00%

  

Real Estate Fund

 1.00%

          

 

The target asset mix of One Choice In Retirement Portfolio is expected to remain fixed over time. The fund is generally intended for investors near to, at, or in retirement and who likely are no longer making new investments in the fund. The fund is designed for investors who plan to gradually withdraw the value of their account after retirement. The fund assumes a retirement age of 65 and may not be appropriate for an investor retiring at an age well before or after age 65.

 

The portfolio managers regularly review the fund's allocations to determine whether rebalancing is appropriate. Although we do not intend to make frequent tactical adjustments to the target asset mix or trade actively among the underlying funds, we reserve the right to modify the target allocations and underlying funds from time to time should circumstances warrant a change.
Risk [Heading] rr_RiskHeading

Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock

•

Allocation Risk – The fund's performance and risks depend in part on the managers' skill in determining the fund's asset class allocations and in selecting and weighting the underlying funds. The managers' evaluations and assumptions regarding asset classes or underlying funds may differ from actual market conditions.

•

"Growth" and "Value" Style Risks – The underlying funds represent a mix of investment styles, each of which has risks associated with it. Growth stocks can be volatile and may lack dividends that can cushion share prices during market declines. Value stocks may continue to be undervalued by the market for long periods of time.

•

Small- and Mid-Cap Stock Risks – Stocks of smaller companies may be more volatile than larger-company stocks. Smaller companies may have limited financial resources, product lines and markets, and their securities may trade less frequently and in more limited volumes than the securities of larger companies, which could lead to higher transaction costs. To the extent an underlying fund invests in these companies, it may take on more risk.

•

Interest Rate Risk – Generally, when interest rates rise, the value of an underlying fund's fixed-income securities will decline. The opposite is true when interest rates decline. Underlying funds with longer weighted average maturities are more sensitive to interest rate changes.

•

Credit Risk – The value of an underlying fund's fixed-income securities will be affected adversely by any erosion in the ability of the issuers of these securities to make interest and principal payments as they become due. Changes in the credit rating of a fixed-income security held by an underlying fund could have a similar effect.

•

Foreign Securities Risk – Some of the underlying funds invest in foreign securities, which are generally riskier than U.S. securities. Securities of foreign issuers may be less liquid, more volatile and harder to value than U.S. securities. Fluctuations in currency exchange rates also may affect an underlying fund's share price.

•

High-Yield Securities Risk – Some of the underlying funds may invest in high-yield securities, which are considered to have speculative characteristics and are more likely to be negatively affected by changes in economic conditions.

•

Tobacco Exclusion – The underlying funds do not invest in securities issued by companies assigned the Global Industry Classification Standard (GICS) for the tobacco industry. This exclusion may cause an underlying fund to forego profitable investment opportunities.

•

Market Risk – The value of the fund's shares will go up and down based on the performance of the underlying funds in which it invests. The value of the underlying funds' shares will, in turn, fluctuate based on the performance of the securities they own and other factors generally affecting the securities market.

•

Principal Loss – At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.

 

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Risk Lose Money [Text] rr_RiskLoseMoney

Principal Loss -At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.
Risk Not Insured Depository Institution [Text] rr_RiskNotInsuredDepositoryInstitution

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading

Fund Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund's performance from year to year for Investor Class shares. The table shows how the fund's average annual returns for the periods shown compared with those of a broad measure of market performance. The fund's past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future. For current performance information, including yields, please visit americancentury.com.

 

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown.
Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund's performance from year to year for Investor Class shares. The table shows how the fund's average annual returns for the periods shown compared with those of a broad measure of market performance.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress americancentury.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture The fund's past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.
Bar Chart [Heading] rr_BarChartHeading

Calendar Year Total Returns
Bar Chart Does Not Reflect Sales Loads [Text] rr_BarChartDoesNotReflectSalesLoads

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown.
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock

Highest Performance Quarter (3Q 2009): 9.30% 

Lowest Performance Quarter (4Q 2008): -9.20%

As of September 30, 2013, the most recent calendar quarter end,the fund's Investor Class year-to-date return was 6.88%.

Year to Date Return, Label rr_YearToDateReturnLabel Investor Class year-to-date
Bar Chart, Year to Date Return, Date rr_BarChartYearToDateReturnDate Sep. 30, 2013
Bar Chart, Year to Date Return rr_BarChartYearToDateReturn 6.88%
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Highest Performance Quarter
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Sep. 30, 2009
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 9.30%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Lowest Performance Quarter
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Dec. 31, 2008
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (9.20%)
Performance Table Heading rr_PerformanceTableHeading

Average Annual Total Returns For the calendar year ended December 31, 2012
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate 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.
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred Actual after-tax returns depend on an investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.
Performance Table One Class of after Tax Shown [Text] rr_PerformanceTableOneClassOfAfterTaxShown The after-tax returns are shown only for Investor Class shares. After-tax returns for other share classes will vary.
Performance Table Closing [Text Block] rr_PerformanceTableClosingTextBlock

The after-tax returns are shown only for Investor Class shares. After-tax returns for other share classes will vary. 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. After-tax returns are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.
ONE CHOICE IN RETIREMENT PORTFOLIO | Russell 3000 Index (reflects no deduction for fees, expenses or taxes)
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 16.42%
5 years rr_AverageAnnualReturnYear05 2.04%
Since Inception rr_AverageAnnualReturnSinceInception 5.79%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE IN RETIREMENT PORTFOLIO | Barclays U.S. Aggregate Bond Index (reflects no deduction for fees, expenses or taxes)
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 4.21%
5 years rr_AverageAnnualReturnYear05 5.95%
Since Inception rr_AverageAnnualReturnSinceInception 5.36%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE IN RETIREMENT PORTFOLIO | INVESTOR CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee 25
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.20%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.57%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.77%
1 year rr_ExpenseExampleYear01 79
3 years rr_ExpenseExampleYear03 246
5 years rr_ExpenseExampleYear05 428
10 years rr_ExpenseExampleYear10 955
Annual Return 2005 rr_AnnualReturn2005 2.63%
Annual Return 2006 rr_AnnualReturn2006 9.26%
Annual Return 2007 rr_AnnualReturn2007 7.18%
Annual Return 2008 rr_AnnualReturn2008 (16.57%)
Annual Return 2009 rr_AnnualReturn2009 16.42%
Annual Return 2010 rr_AnnualReturn2010 10.07%
Annual Return 2011 rr_AnnualReturn2011 3.58%
Annual Return 2012 rr_AnnualReturn2012 10.13%
1 year rr_AverageAnnualReturnYear01 10.13%
5 years rr_AverageAnnualReturnYear05 4.04%
Since Inception rr_AverageAnnualReturnSinceInception 5.44%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE IN RETIREMENT PORTFOLIO | INVESTOR CLASS | Return After Taxes on Distributions
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 9.35%
5 years rr_AverageAnnualReturnYear05 3.19%
Since Inception rr_AverageAnnualReturnSinceInception 4.41%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE IN RETIREMENT PORTFOLIO | INVESTOR CLASS | Return After Taxes on Distributions and Sale of Fund Shares
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 6.98%
5 years rr_AverageAnnualReturnYear05 3.02%
Since Inception rr_AverageAnnualReturnSinceInception 4.14%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE IN RETIREMENT PORTFOLIO | INSTITUTIONAL CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Administrative Fee rr_Component1OtherExpensesOverAssets none
Other rr_Component2OtherExpensesOverAssets none
Other Expenses rr_OtherExpensesOverAssets none
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.57%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.57%
1 year rr_ExpenseExampleYear01 58
3 years rr_ExpenseExampleYear03 183
5 years rr_ExpenseExampleYear05 319
10 years rr_ExpenseExampleYear10 714
1 year rr_AverageAnnualReturnYear01 10.35%
5 years rr_AverageAnnualReturnYear05 4.25%
Since Inception rr_AverageAnnualReturnSinceInception 5.65%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE IN RETIREMENT PORTFOLIO | A CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice 5.75%
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none [1]
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.25%
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.20%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.57%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.02%
1 year rr_ExpenseExampleYear01 673
3 years rr_ExpenseExampleYear03 882
5 years rr_ExpenseExampleYear05 1,106
10 years rr_ExpenseExampleYear10 1,751
1 year rr_AverageAnnualReturnYear01 3.53% [2]
5 years rr_AverageAnnualReturnYear05 2.56% [2]
Since Inception rr_AverageAnnualReturnSinceInception 4.43% [2]
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004 [2]
ONE CHOICE IN RETIREMENT PORTFOLIO | C CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice 1.00%
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 1.00%
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.20%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.57%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.77%
1 year rr_ExpenseExampleYear01 180
3 years rr_ExpenseExampleYear03 558
5 years rr_ExpenseExampleYear05 960
10 years rr_ExpenseExampleYear10 2,082
1 year rr_AverageAnnualReturnYear01 9.04%
5 years rr_AverageAnnualReturnYear05 3.00% [3]
Since Inception rr_AverageAnnualReturnSinceInception 4.38% [3]
Inception Date rr_AverageAnnualReturnInceptionDate Mar. 01, 2010
ONE CHOICE IN RETIREMENT PORTFOLIO | R CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.50%
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.20%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.57%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.27%
1 year rr_ExpenseExampleYear01 130
3 years rr_ExpenseExampleYear03 403
5 years rr_ExpenseExampleYear05 698
10 years rr_ExpenseExampleYear10 1,533
1 year rr_AverageAnnualReturnYear01 9.59%
5 years rr_AverageAnnualReturnYear05 3.50%
Since Inception rr_AverageAnnualReturnSinceInception 4.90%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE 2015 PORTFOLIO
  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk/Return [Heading] rr_RiskReturnHeading ONE CHOICE 2015 PORTFOLIO
Objective [Heading] rr_ObjectiveHeading

Investment Objective
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The fund seeks the highest total return consistent with its asset mix.
Expense [Heading] rr_ExpenseHeading

Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses 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 $50,000 in American Century Investments funds. More information about these and other discounts is available from your financial professional and in Calculation of Sales Charges on page 60 of the fund's prospectus and Sales Charges in Appendix B of the 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

Because the fund buys and sells shares of other American Century mutual funds (the underlying funds) directly from the issuers, the fund is not expected to incur transaction costs directly. However, as a shareholder in the underlying funds, the fund indirectly pays transaction costs, such as commissions, when the underlying funds buy and sell securities (or "turn over" their portfolios). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 6% of the average value of its portfolio.

Portfolio Turnover, Rate rr_PortfolioTurnoverRate 6.00%
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 $50,000 in American Century Investments funds. More information about these and other discounts is available from your financial professional and in Calculation of Sales Charges on page 60 of the fund's prospectus and Sales Charges in Appendix B of the statement of additional information.
Expense Breakpoint, Minimum Investment Required [Amount] rr_ExpenseBreakpointMinimumInvestmentRequiredAmount 50,000
Expense Example [Heading] rr_ExpenseExampleHeading

Example
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock

The example below is intended to help you compare the costs of investing in the fund with the costs of investing in other mutual funds.

Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption

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, that you earn a 5% return each year, and that the fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading] rr_StrategyHeading

Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

One Choice 2015 Portfolio is a "fund of funds," meaning that it seeks to achieve its objective by investing in other American Century mutual funds (the underlying funds) that represent a variety of asset classes and investment styles. The underlying stock funds draw on growth, value and quantitative investment techniques and diversify investments among small, medium and large U.S. and foreign companies. The underlying bond funds invest in fixed-income securities that vary by issuer type (corporate and government), credit quality (investment-grade and high-yield or "junk bonds") and geographic exposure (domestic and international). The following table shows the fund's target allocation for the various asset classes and underlying funds as of the date of the prospectus:

 

Equity Securities (Stock Funds)

46.05%

    

Fixed-Income Securities (Bond Funds)

44.45%

  

NT Core Equity Plus Fund

3.00%

    

High-Yield Fund

 3.75%

  

NT Emerging Markets Fund

0.25%

    

Inflation-Adjusted Bond Fund

   1.80%

  

NT Equity Growth Fund

10.00%

    

International Bond Fund

   6.80%

  

NT Growth Fund

6.75%

    

NT Diversified Bond Fund

26.40%

  

NT Heritage Fund

2.75%

    

Short Duration Inflation Protection Bond Fund

   5.70%

  

NT International Growth Fund

 5.00%

          

NT Large Company Value Fund

11.00%

    

Cash Equivalents (Money Market Funds)

   9.50%

  

NT Mid Cap Value Fund

 4.25%

    

Premium Money Market Fund

   9.50%

  

NT Small Company Fund

 2.00%

          

Real Estate Fund

 1.05%

          

 

The target date in the fund name (2015) refers to the approximate year an investor plans to retire and likely would stop making new investments in the fund. The fund assumes a retirement age of 65 and may not be appropriate for an investor who plans to retire at or near the target date, but at an age well before or after 65. As the target date approaches, the fund's asset mix will become more conservative by decreasing the allocation to stocks and increasing the allocation to bonds and cash. By the time the fund reaches its target date, the asset mix will become fixed and match that of One Choice In Retirement Portfolio, which is currently 45% stock funds, 45% bond funds and 10% money market funds. The fund is designed for investors who plan to withdraw the value of their account gradually after retirement. The following chart shows how the asset mix is expected to change over time according to a predetermined glide path.

One Choice Target Date Portfolios' Glide Path

Years to Retirement 45 44 43 42 41 40 39 38 37 36 35 34 33
Stocks 85.00% 85.00% 85.00% 85.00% 85.00% 85.00% 84.70% 83.90% 83.35% 82.80% 82.25% 81.70% 81.40%
Bonds 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.30% 16.10% 16.65% 17.20% 17.75% 18.30% 18.60%
Cash 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%
32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15
80.85% 80.40% 80.00% 78.45% 77.15% 76.35% 74.95% 73.40% 72.10% 70.80% 70.25% 68.55% 67.00% 65.85% 64.50% 63.35% 62.30% 61.00%
19.15% 19.60% 20.00% 21.05% 21.85% 22.15% 23.05% 24.10% 24.90% 25.70% 25.75% 26.95% 28.00% 29.15% 30.50% 31.65% 32.70% 34.00%
0.00% 0.00% 0.00% 0.50% 1.00% 1.50% 2.00% 2.50% 3.00% 3.50% 4.00% 4.50% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%
14 13 12 11 10 9 8 7 6 5 4 3 2 1   RETIREMENT
59.70% 58.60% 57.35% 56.30% 55.00% 54.20% 52.90% 52.10% 51.05% 50.00% 48.95% 47.90% 46.85% 46.05%   45.00%
35.30% 36.40% 37.65% 38.70% 40.00% 40.30% 41.10% 41.40% 41.95% 42.50% 43.05% 43.60% 44.15% 44.45%   45.00%
5.00% 5.00% 5.00% 5.00% 5.00% 5.50% 6.00% 6.50% 7.00% 7.50% 8.00% 8.50% 9.00% 9.50%   10.00%
Years After Retirement 1 2 3 4 5 6 7 8 9 10 11 12 13
Stocks 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Bonds 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Cash 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%

 

The portfolio managers regularly review the fund's allocations to determine whether rebalancing is appropriate. Although we do not intend to make frequent tactical adjustments to the target asset mix or trade actively among the underlying funds (other than the glide path adjustments described above), we reserve the right to modify the target allocations and underlying funds from time to time should circumstances warrant a change.
Risk [Heading] rr_RiskHeading

Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock

•

Allocation Risk – The fund's performance and risks depend in part on the managers' skill in determining the fund's asset class allocations and in selecting and weighting the underlying funds. The managers' evaluations and assumptions regarding asset classes or underlying funds may differ from actual market conditions.

•

"Growth" and "Value" Style Risks – The underlying funds represent a mix of investment styles, each of which has risks associated with it. Growth stocks can be volatile and may lack dividends that can cushion share prices during market declines. Value stocks may continue to be undervalued by the market for long periods of time.

•

Small- and Mid-Cap Stock Risks – Stocks of smaller companies may be more volatile than larger-company stocks. Smaller companies may have limited financial resources, product lines and markets, and their securities may trade less frequently and in more limited volumes than the securities of larger companies, which could lead to higher transaction costs. To the extent an underlying fund invests in these companies, it may take on more risk.

•

Interest Rate Risk – Generally, when interest rates rise, the value of an underlying fund's fixed-income securities will decline. The opposite is true when interest rates decline. Underlying funds with longer weighted average maturities are more sensitive to interest rate changes.

•

Credit Risk - The value of an underlying fund's fixed-income securities will be affected adversely by any erosion in the ability of the issuers of these securities to make interest and principal payments as they become due. Changes in the credit rating of a fixed-income security held by an underlying fund could have a similar effect.

•

Foreign Securities Risk – Some of the underlying funds invest in foreign securities, which are generally riskier than U.S. securities. Securities of foreign issuers may be less liquid, more volatile and harder to value than U.S. securities. Fluctuations in currency exchange rates also may affect an underlying fund's share price.

•

High-Yield Securities Risk – Some of the underlying funds may invest in high-yield securities, which are considered to have speculative characteristics and are more likely to be negatively affected by changes in economic conditions.

•

Tobacco Exclusion – The underlying funds do not invest in securities issued by companies assigned the Global Industry Classification Standard (GICS) for the tobacco industry. This exclusion may cause an underlying fund to forego profitable investment opportunities.

•

Market Risk – The value of the fund's shares will go up and down based on the performance of the underlying funds in which it invests. The value of the underlying funds' shares will, in turn, fluctuate based on the performance of the securities they own and other factors generally affecting the securities market.

•

Principal Loss – At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.

 

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Risk Lose Money [Text] rr_RiskLoseMoney

Principal Loss -At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.
Risk Not Insured Depository Institution [Text] rr_RiskNotInsuredDepositoryInstitution

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading

Fund Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund's performance from year to year for Investor Class shares. The table shows how the fund's average annual returns for the periods shown compared with those of a broad measure of market performance. The fund's past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future. For current performance information, including yields, please visit americancentury.com.

 

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown.
Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund's performance from year to year for Investor Class shares. The table shows how the fund's average annual returns for the periods shown compared with those of a broad measure of market performance.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress americancentury.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture The fund's past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.
Bar Chart [Heading] rr_BarChartHeading

Calendar Year Total Returns
Bar Chart Does Not Reflect Sales Loads [Text] rr_BarChartDoesNotReflectSalesLoads

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown.
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock

Highest Performance Quarter (3Q 2009): 10.20% 

Lowest Performance Quarter (4Q 2008): -11.00% 

As of September 30, 2013, the most recent calendar quarter end,the fund's Investor Class year-to-date return was 7.12%.
Year to Date Return, Label rr_YearToDateReturnLabel Investor Class year-to-date
Bar Chart, Year to Date Return, Date rr_BarChartYearToDateReturnDate Sep. 30, 2013
Bar Chart, Year to Date Return rr_BarChartYearToDateReturn 7.12%
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Highest Performance Quarter
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Sep. 30, 2009
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 10.20%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Lowest Performance Quarter
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Dec. 31, 2008
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (11.00%)
Performance Table Heading rr_PerformanceTableHeading

Average Annual Total Returns For the calendar year ended December 31, 2012
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate 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.
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred Actual after-tax returns depend on an investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.
Performance Table One Class of after Tax Shown [Text] rr_PerformanceTableOneClassOfAfterTaxShown The after-tax returns are shown only for Investor Class shares. After-tax returns for other share classes will vary.
Performance Table Closing [Text Block] rr_PerformanceTableClosingTextBlock

The after-tax returns are shown only for Investor Class shares. After-tax returns for other share classes will vary. 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. After-tax returns are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.
ONE CHOICE 2015 PORTFOLIO | Russell 3000 Index (reflects no deduction for fees, expenses or taxes)
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 16.42%
5 years rr_AverageAnnualReturnYear05 2.04%
Since Inception rr_AverageAnnualReturnSinceInception 5.79%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE 2015 PORTFOLIO | Barclays U.S. Aggregate Bond Index (reflects no deduction for fees, expenses or taxes)
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 4.21%
5 years rr_AverageAnnualReturnYear05 5.95%
Since Inception rr_AverageAnnualReturnSinceInception 5.36%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE 2015 PORTFOLIO | INVESTOR CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee 25
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.21%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.58%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.79%
1 year rr_ExpenseExampleYear01 81
3 years rr_ExpenseExampleYear03 253
5 years rr_ExpenseExampleYear05 439
10 years rr_ExpenseExampleYear10 978
Annual Return 2005 rr_AnnualReturn2005 4.70%
Annual Return 2006 rr_AnnualReturn2006 10.53%
Annual Return 2007 rr_AnnualReturn2007 8.50%
Annual Return 2008 rr_AnnualReturn2008 (20.10%)
Annual Return 2009 rr_AnnualReturn2009 18.26%
Annual Return 2010 rr_AnnualReturn2010 10.84%
Annual Return 2011 rr_AnnualReturn2011 3.16%
Annual Return 2012 rr_AnnualReturn2012 10.59%
1 year rr_AverageAnnualReturnYear01 10.59%
5 years rr_AverageAnnualReturnYear05 3.62%
Since Inception rr_AverageAnnualReturnSinceInception 5.98%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE 2015 PORTFOLIO | INVESTOR CLASS | Return After Taxes on Distributions
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 9.88%
5 years rr_AverageAnnualReturnYear05 2.82%
Since Inception rr_AverageAnnualReturnSinceInception 5.03%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE 2015 PORTFOLIO | INVESTOR CLASS | Return After Taxes on Distributions and Sale of Fund Shares
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 7.23%
5 years rr_AverageAnnualReturnYear05 2.68%
Since Inception rr_AverageAnnualReturnSinceInception 4.69%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE 2015 PORTFOLIO | INSTITUTIONAL CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Administrative Fee rr_Component1OtherExpensesOverAssets none
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.01%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.58%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.59%
1 year rr_ExpenseExampleYear01 60
3 years rr_ExpenseExampleYear03 189
5 years rr_ExpenseExampleYear05 330
10 years rr_ExpenseExampleYear10 738
1 year rr_AverageAnnualReturnYear01 10.81%
5 years rr_AverageAnnualReturnYear05 3.84%
Since Inception rr_AverageAnnualReturnSinceInception 6.20%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE 2015 PORTFOLIO | A CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice 5.75%
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none [1]
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.25%
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.21%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.58%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.04%
1 year rr_ExpenseExampleYear01 675
3 years rr_ExpenseExampleYear03 887
5 years rr_ExpenseExampleYear05 1,117
10 years rr_ExpenseExampleYear10 1,773
1 year rr_AverageAnnualReturnYear01 3.98% [2]
5 years rr_AverageAnnualReturnYear05 2.14% [2]
Since Inception rr_AverageAnnualReturnSinceInception 4.97% [2]
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004 [2]
ONE CHOICE 2015 PORTFOLIO | C CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice 1.00%
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 1.00%
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.21%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.58%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.79%
1 year rr_ExpenseExampleYear01 182
3 years rr_ExpenseExampleYear03 564
5 years rr_ExpenseExampleYear05 970
10 years rr_ExpenseExampleYear10 2,103
1 year rr_AverageAnnualReturnYear01 9.47%
5 years rr_AverageAnnualReturnYear05 2.59% [3]
Since Inception rr_AverageAnnualReturnSinceInception 4.92% [3]
Inception Date rr_AverageAnnualReturnInceptionDate Mar. 01, 2010
ONE CHOICE 2015 PORTFOLIO | R CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.50%
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.21%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.58%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.29%
1 year rr_ExpenseExampleYear01 132
3 years rr_ExpenseExampleYear03 410
5 years rr_ExpenseExampleYear05 708
10 years rr_ExpenseExampleYear10 1,556
1 year rr_AverageAnnualReturnYear01 10.04%
5 years rr_AverageAnnualReturnYear05 3.10%
Since Inception rr_AverageAnnualReturnSinceInception 5.46%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE 2020 PORTFOLIO
  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk/Return [Heading] rr_RiskReturnHeading ONE CHOICE 2020 PORTFOLIO
Objective [Heading] rr_ObjectiveHeading

Investment Objective
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The fund seeks the highest total return consistent with its asset mix.
Expense [Heading] rr_ExpenseHeading

Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses 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 $50,000 in American Century Investments funds. More information about these and other discounts is available from your financial professional and in Calculation of Sales Charges on page 60 of the fund's prospectus and Sales Charges in Appendix B of the 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

Because the fund buys and sells shares of other American Century mutual funds (the underlying funds) directly from the issuers, the fund is not expected to incur transaction costs directly. However, as a shareholder in the underlying funds, the fund indirectly pays transaction costs, such as commissions, when the underlying funds buy and sell securities (or "turn over" their portfolios). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 6% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 6.00%
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 $50,000 in American Century Investments funds. More information about these and other discounts is available from your financial professional and in Calculation of Sales Charges on page 60 of the fund's prospectus and Sales Charges in Appendix B of the statement of additional information.
Expense Breakpoint, Minimum Investment Required [Amount] rr_ExpenseBreakpointMinimumInvestmentRequiredAmount 50,000
Expense Example [Heading] rr_ExpenseExampleHeading

Example
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock

The example below is intended to help you compare the costs of investing in the fund with the costs of investing in other mutual funds.

Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption

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, that you earn a 5% return each year, and that the fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading] rr_StrategyHeading

Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

One Choice 2020 Portfolio is a "fund of funds," meaning that it seeks to achieve its objective by investing in other American Century mutual funds (the underlying funds) that represent a variety of asset classes and investment styles. The underlying stock funds draw on growth, value and quantitative investment techniques and diversify investments among small, medium and large U.S. and foreign companies. The underlying bond funds invest in fixed-income securities that vary by issuer type (corporate and government), credit quality (investment-grade and high-yield or "junk bonds") and geographic exposure (domestic and international). The following table shows the fund's target allocation for the various asset classes and underlying funds as of the date of the prospectus:

 

Equity Securities (Stock Funds)

51.05%

  

Fixed-Income Securities (Bond Funds)

41.95%

NT Core Equity Plus Fund

3.00%

  

High-Yield Fund

3.60%

NT Emerging Markets Fund

1.25%

  

Inflation-Adjusted Bond Fund

3.10%

NT Equity Growth Fund

9.50%

  

International Bond Fund

5.80%

NT Growth Fund

8.00%

  

NT Diversified Bond Fund

25.30%

NT Heritage Fund

3.75%

  

Short Duration Inflation Protection Bond Fund

4.15%

NT International Growth Fund

6.00%

      

NT Large Company Value Fund

11.25%

  

Cash Equivalents (Money Market Funds)

7.00%

NT Mid Cap Value Fund

5.00%

  

Premium Money Market Fund

7.00%

NT Small Company Fund

2.00%

      

Real Estate Fund

1.30%

      

 

The target date in the fund name (2020) refers to the approximate year an investor plans to retire and likely would stop making new investments in the fund. The fund assumes a retirement age of 65 and may not be appropriate for an investor who plans to retire at or near the target date, but at an age well before or after 65. As the target date approaches, the fund's asset mix will become more conservative by decreasing the allocation to stocks and increasing the allocation to bonds and cash. By the time the fund reaches its target date, the asset mix will become fixed and match that of One Choice In Retirement Portfolio, which is currently 45% stock funds, 45% bond funds and 10% money market funds. The fund is designed for investors who plan to withdraw the value of their account gradually after retirement. The following chart shows how the asset mix is expected to change over time according to a predetermined glide path.

 

One Choice Target Date Portfolios' Glide Path

Years to Retirement 45 44 43 42 41 40 39 38 37 36 35 34 33
Stocks 85.00% 85.00% 85.00% 85.00% 85.00% 85.00% 84.70% 83.90% 83.35% 82.80% 82.25% 81.70% 81.40%
Bonds 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.30% 16.10% 16.65% 17.20% 17.75% 18.30% 18.60%
Cash 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%
32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15
80.85% 80.40% 80.00% 78.45% 77.15% 76.35% 74.95% 73.40% 72.10% 70.80% 70.25% 68.55% 67.00% 65.85% 64.50% 63.35% 62.30% 61.00%
19.15% 19.60% 20.00% 21.05% 21.85% 22.15% 23.05% 24.10% 24.90% 25.70% 25.75% 26.95% 28.00% 29.15% 30.50% 31.65% 32.70% 34.00%
0.00% 0.00% 0.00% 0.50% 1.00% 1.50% 2.00% 2.50% 3.00% 3.50% 4.00% 4.50% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%
14 13 12 11 10 9 8 7 6 5 4 3 2 1   RETIREMENT
59.70% 58.60% 57.35% 56.30% 55.00% 54.20% 52.90% 52.10% 51.05% 50.00% 48.95% 47.90% 46.85% 46.05%   45.00%
35.30% 36.40% 37.65% 38.70% 40.00% 40.30% 41.10% 41.40% 41.95% 42.50% 43.05% 43.60% 44.15% 44.45%   45.00%
5.00% 5.00% 5.00% 5.00% 5.00% 5.50% 6.00% 6.50% 7.00% 7.50% 8.00% 8.50% 9.00% 9.50%   10.00%
Years After Retirement 1 2 3 4 5 6 7 8 9 10 11 12 13
Stocks 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Bonds 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Cash 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%

 

The portfolio managers regularly review the fund's allocations to determine whether rebalancing is appropriate. Although we do not intend to make frequent tactical adjustments to the target asset mix or trade actively among the underlying funds (other than the glide path adjustments described above), we reserve the right to modify the target allocations and underlying funds from time to time should circumstances warrant a change.
Risk [Heading] rr_RiskHeading

Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock

•

Allocation Risk – The fund's performance and risks depend in part on the managers' skill in determining the fund's asset class allocations and in selecting and weighting the underlying funds. The managers' evaluations and assumptions regarding asset classes or underlying funds may differ from actual market conditions.

•

"Growth" and "Value" Style Risks – The underlying funds represent a mix of investment styles, each of which has risks associated with it. Growth stocks can be volatile and may lack dividends that can cushion share prices during market declines. Value stocks may continue to be undervalued by the market for long periods of time.

•

Small- and Mid-Cap Stock Risks – Stocks of smaller companies may be more volatile than larger-company stocks. Smaller companies may have limited financial resources, product lines and markets, and their securities may trade less frequently and in more limited volumes than the securities of larger companies, which could lead to higher transaction costs. To the extent an underlying fund invests in these companies, it may take on more risk.

•

Interest Rate Risk – Generally, when interest rates rise, the value of an underlying fund's fixed-income securities will decline. The opposite is true when interest rates decline. Underlying funds with longer weighted average maturities are more sensitive to interest rate changes.

•

Credit Risk - The value of an underlying fund's fixed-income securities will be affected adversely by any erosion in the ability of the issuers of these securities to make interest and principal payments as they become due. Changes in the credit rating of a fixed-income security held by an underlying fund could have a similar effect.

•

Foreign Securities Risk – Some of the underlying funds invest in foreign securities, which are generally riskier than U.S. securities. Securities of foreign issuers may be less liquid, more volatile and harder to value than U.S. securities. Fluctuations in currency exchange rates also may affect an underlying fund's share price.

•

High-Yield Securities Risk – Some of the underlying funds may invest in high-yield securities, which are considered to have speculative characteristics and are more likely to be negatively affected by changes in economic conditions.

•

Tobacco Exclusion – The underlying funds do not invest in securities issued by companies assigned the Global Industry Classification Standard (GICS) for the tobacco industry. This exclusion may cause an underlying fund to forego profitable investment opportunities.

•

Market Risk – The value of the fund's shares will go up and down based on the performance of the underlying funds in which it invests. The value of the underlying funds' shares will, in turn, fluctuate based on the performance of the securities they own and other factors generally affecting the securities market.

•

Principal Loss – At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.

 

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Risk Lose Money [Text] rr_RiskLoseMoney

Principal Loss -At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.
Risk Not Insured Depository Institution [Text] rr_RiskNotInsuredDepositoryInstitution

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading

Fund Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund's performance from year to year for Investor Class shares. The table shows how the fund's average annual returns for the periods shown compared with those of a broad measure of market performance. The fund's past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future. For current performance information, including yields, please visit americancentury.com.

 

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown.
Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund's performance from year to year for Investor Class shares. The table shows how the fund's average annual returns for the periods shown compared with those of a broad measure of market performance.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress americancentury.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture The fund's past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.
Bar Chart [Heading] rr_BarChartHeading

Calendar Year Total Returns
Bar Chart Does Not Reflect Sales Loads [Text] rr_BarChartDoesNotReflectSalesLoads

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown.
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock

Highest Performance Quarter (3Q 2009): 11.07% 

Lowest Performance Quarter (3Q 2011): -8.06% 

As of September 30, 2013, the most recent calendar quarter end, the fund’s Investor Class year-to-date return was 7.79%.

Year to Date Return, Label rr_YearToDateReturnLabel Investor Class year-to-date
Bar Chart, Year to Date Return, Date rr_BarChartYearToDateReturnDate Sep. 30, 2013
Bar Chart, Year to Date Return rr_BarChartYearToDateReturn 7.79%
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Highest Performance Quarter
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Sep. 30, 2009
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 11.07%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Lowest Performance Quarter
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Sep. 30, 2011
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (8.06%)
Performance Table Heading rr_PerformanceTableHeading

Average Annual Total Returns For the calendar year ended December 31, 2012
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate 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.
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred Actual after-tax returns depend on an investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.
Performance Table One Class of after Tax Shown [Text] rr_PerformanceTableOneClassOfAfterTaxShown The after-tax returns are shown only for Investor Class shares. After-tax returns for other share classes will vary.
Performance Table Closing [Text Block] rr_PerformanceTableClosingTextBlock

The after-tax returns are shown only for Investor Class shares. After-tax returns for other share classes will vary. 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. After-tax returns are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.
ONE CHOICE 2020 PORTFOLIO | Russell 3000 Index (reflects no deduction for fees, expenses or taxes)
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 16.42%
Since Inception rr_AverageAnnualReturnSinceInception 2.93%
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008
ONE CHOICE 2020 PORTFOLIO | Barclays U.S. Aggregate Bond Index (reflects no deduction for fees, expenses or taxes)
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 4.21%
Since Inception rr_AverageAnnualReturnSinceInception 6.23%
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008
ONE CHOICE 2020 PORTFOLIO | INVESTOR CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee 25
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.21%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.61%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.82%
1 year rr_ExpenseExampleYear01 84
3 years rr_ExpenseExampleYear03 262
5 years rr_ExpenseExampleYear05 456
10 years rr_ExpenseExampleYear10 1,014
Annual Return 2009 rr_AnnualReturn2009 20.11%
Annual Return 2010 rr_AnnualReturn2010 11.70%
Annual Return 2011 rr_AnnualReturn2011 2.50%
Annual Return 2012 rr_AnnualReturn2012 11.47%
1 year rr_AverageAnnualReturnYear01 11.47%
Since Inception rr_AverageAnnualReturnSinceInception 3.99%
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008
ONE CHOICE 2020 PORTFOLIO | INVESTOR CLASS | Return After Taxes on Distributions
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 10.79%
Since Inception rr_AverageAnnualReturnSinceInception 3.36%
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008
ONE CHOICE 2020 PORTFOLIO | INVESTOR CLASS | Return After Taxes on Distributions and Sale of Fund Shares
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 7.83%
Since Inception rr_AverageAnnualReturnSinceInception 3.11%
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008
ONE CHOICE 2020 PORTFOLIO | INSTITUTIONAL CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Administrative Fee rr_Component1OtherExpensesOverAssets none
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.01%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.61%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.62%
1 year rr_ExpenseExampleYear01 63
3 years rr_ExpenseExampleYear03 199
5 years rr_ExpenseExampleYear05 346
10 years rr_ExpenseExampleYear10 775
1 year rr_AverageAnnualReturnYear01 11.59%
Since Inception rr_AverageAnnualReturnSinceInception 4.18%
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008
ONE CHOICE 2020 PORTFOLIO | A CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice 5.75%
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none [1]
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.25%
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.21%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.61%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.07%
1 year rr_ExpenseExampleYear01 678
3 years rr_ExpenseExampleYear03 896
5 years rr_ExpenseExampleYear05 1,132
10 years rr_ExpenseExampleYear10 1,805
1 year rr_AverageAnnualReturnYear01 4.67% [2]
Since Inception rr_AverageAnnualReturnSinceInception 2.38% [2]
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008 [2]
ONE CHOICE 2020 PORTFOLIO | C CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice 1.00%
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 1.00%
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.21%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.61%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.82%
1 year rr_ExpenseExampleYear01 185
3 years rr_ExpenseExampleYear03 573
5 years rr_ExpenseExampleYear05 986
10 years rr_ExpenseExampleYear10 2,135
1 year rr_AverageAnnualReturnYear01 10.22%
Since Inception rr_AverageAnnualReturnSinceInception 2.95% [3]
Inception Date rr_AverageAnnualReturnInceptionDate Mar. 01, 2010
ONE CHOICE 2020 PORTFOLIO | R CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.50%
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.21%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.61%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.32%
1 year rr_ExpenseExampleYear01 135
3 years rr_ExpenseExampleYear03 419
5 years rr_ExpenseExampleYear05 724
10 years rr_ExpenseExampleYear10 1,589
1 year rr_AverageAnnualReturnYear01 10.81%
Since Inception rr_AverageAnnualReturnSinceInception 3.45%
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008
ONE CHOICE 2025 PORTFOLIO
  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk/Return [Heading] rr_RiskReturnHeading ONE CHOICE 2025 PORTFOLIO
Objective [Heading] rr_ObjectiveHeading

Investment Objective
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The fund seeks the highest total return consistent with its asset mix.
Expense [Heading] rr_ExpenseHeading

Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses 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 $50,000 in American Century Investments funds. More information about these and other discounts is available from your financial professional and in Calculation of Sales Charges on page 60 of the fund's prospectus and Sales Charges in Appendix B of the 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

Because the fund buys and sells shares of other American Century mutual funds (the underlying funds) directly from the issuers, the fund is not expected to incur transaction costs directly. However, as a shareholder in the underlying funds, the fund indirectly pays transaction costs, such as commissions, when the underlying funds buy and sell securities (or "turn over" their portfolios). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 3% of the average value of its portfolio.

Portfolio Turnover, Rate rr_PortfolioTurnoverRate 3.00%
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 $50,000 in American Century Investments funds. More information about these and other discounts is available from your financial professional and in Calculation of Sales Charges on page 60 of the fund's prospectus and Sales Charges in Appendix B of the statement of additional information.
Expense Breakpoint, Minimum Investment Required [Amount] rr_ExpenseBreakpointMinimumInvestmentRequiredAmount 50,000
Expense Example [Heading] rr_ExpenseExampleHeading

Example
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock

The example below is intended to help you compare the costs of investing in the fund with the costs of investing in other mutual funds.
Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption

 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, that you earn a 5% return each year, and that the fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading] rr_StrategyHeading

Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

One Choice 2025 Portfolio is a "fund of funds," meaning that it seeks to achieve its objective by investing in other American Century mutual funds (the underlying funds) that represent a variety of asset classes and investment styles. The underlying stock funds draw on growth, value and quantitative investment techniques and diversify investments among small, medium and large U.S. and foreign companies. The underlying bond funds invest in fixed-income securities that vary by issuer type (corporate and government), credit quality (investment-grade and high-yield or "junk bonds") and geographic exposure (domestic and international). The following table shows the fund's target allocation for the various asset classes and underlying funds as of the date of the prospectus:

 

Equity Securities (Stock Funds)

56.30%

    

Fixed-Income Securities (Bond Funds)

38.70%

  

NT Core Equity Plus Fund

3.00%

    

High-Yield Fund

3.40%

  

NT Emerging Markets Fund

2.25%

    

Inflation-Adjusted Bond Fund

4.20%

  

NT Equity Growth Fund

9.25%

    

International Bond Fund

4.50%

  

NT Growth Fund

9.25%

    

NT Diversified Bond Fund

24.00%

  

NT Heritage Fund

4.50%

    

Short Duration Inflation Protection Bond Fund

2.60%

  

NT International Growth Fund

7.00%

          

NT Large Company Value Fund

11.50%

    

Cash Equivalents (Money Market Funds)

 5.00%

  

NT Mid Cap Value Fund

5.50%

    

Premium Money Market Fund

5.00%

  

NT Small Company Fund

2.50%

          

Real Estate Fund

1.55%

          

 

The target date in the fund name (2025) refers to the approximate year an investor plans to retire and likely would stop making new investments in the fund. The fund assumes a retirement age of 65 and may not be appropriate for an investor who plans to retire at or near the target date, but at an age well before or after 65. As the target date approaches, the fund's asset mix will become more conservative by decreasing the allocation to stocks and increasing the allocation to bonds and cash. By the time the fund reaches its target date, the asset mix will become fixed and match that of One Choice In Retirement Portfolio, which is currently 45% stock funds, 45% bond funds and 10% money market funds. The fund is designed for investors who plan to withdraw the value of their account gradually after retirement. The following chart shows how the asset mix is expected to change over time according to a predetermined glide path.

 

One Choice Target Date Portfolios' Glide Path

Years to Retirement 45 44 43 42 41 40 39 38 37 36 35 34 33
Stocks 85.00% 85.00% 85.00% 85.00% 85.00% 85.00% 84.70% 83.90% 83.35% 82.80% 82.25% 81.70% 81.40%
Bonds 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.30% 16.10% 16.65% 17.20% 17.75% 18.30% 18.60%
Cash 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%
32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15
80.85% 80.40% 80.00% 78.45% 77.15% 76.35% 74.95% 73.40% 72.10% 70.80% 70.25% 68.55% 67.00% 65.85% 64.50% 63.35% 62.30% 61.00%
19.15% 19.60% 20.00% 21.05% 21.85% 22.15% 23.05% 24.10% 24.90% 25.70% 25.75% 26.95% 28.00% 29.15% 30.50% 31.65% 32.70% 34.00%
0.00% 0.00% 0.00% 0.50% 1.00% 1.50% 2.00% 2.50% 3.00% 3.50% 4.00% 4.50% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%
14 13 12 11 10 9 8 7 6 5 4 3 2 1   RETIREMENT
59.70% 58.60% 57.35% 56.30% 55.00% 54.20% 52.90% 52.10% 51.05% 50.00% 48.95% 47.90% 46.85% 46.05%   45.00%
35.30% 36.40% 37.65% 38.70% 40.00% 40.30% 41.10% 41.40% 41.95% 42.50% 43.05% 43.60% 44.15% 44.45%   45.00%
5.00% 5.00% 5.00% 5.00% 5.00% 5.50% 6.00% 6.50% 7.00% 7.50% 8.00% 8.50% 9.00% 9.50%   10.00%
Years After Retirement 1 2 3 4 5 6 7 8 9 10 11 12 13
Stocks 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Bonds 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Cash 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%

 

The portfolio managers regularly review the fund's allocations to determine whether rebalancing is appropriate. Although we do not intend to make frequent tactical adjustments to the target asset mix or trade actively among the underlying funds (other than the glide path adjustments described above), we reserve the right to modify the target allocations and underlying funds from time to time should circumstances warrant a change.
Risk [Heading] rr_RiskHeading

Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock

•

Allocation Risk – The fund's performance and risks depend in part on the managers' skill in determining the fund's asset class allocations and in selecting and weighting the underlying funds. The managers' evaluations and assumptions regarding asset classes or underlying funds may differ from actual market conditions.

•

"Growth" and "Value" Style Risks – The underlying funds represent a mix of investment styles, each of which has risks associated with it. Growth stocks can be volatile and may lack dividends that can cushion share prices during market declines. Value stocks may continue to be undervalued by the market for long periods of time.

•

Small- and Mid-Cap Stock Risks – Stocks of smaller companies may be more volatile than larger-company stocks. Smaller companies may have limited financial resources, product lines and markets, and their securities may trade less frequently and in more limited volumes than the securities of larger companies, which could lead to higher transaction costs. To the extent an underlying fund invests in these companies, it may take on more risk.

•

Interest Rate Risk – Generally, when interest rates rise, the value of an underlying fund's fixed-income securities will decline. The opposite is true when interest rates decline. Underlying funds with longer weighted average maturities are more sensitive to interest rate changes.

•

Credit Risk - The value of an underlying fund's fixed-income securities will be affected adversely by any erosion in the ability of the issuers of these securities to make interest and principal payments as they become due. Changes in the credit rating of a fixed-income security held by an underlying fund could have a similar effect.

•

Foreign Securities Risk – Some of the underlying funds invest in foreign securities, which are generally riskier than U.S. securities. Securities of foreign issuers may be less liquid, more volatile and harder to value than U.S. securities. Fluctuations in currency exchange rates also may affect an underlying fund's share price.

•

High-Yield Securities Risk – Some of the underlying funds may invest in high-yield securities, which are considered to have speculative characteristics and are more likely to be negatively affected by changes in economic conditions.

•

Tobacco Exclusion – The underlying funds do not invest in securities issued by companies assigned the Global Industry Classification Standard (GICS) for the tobacco industry. This exclusion may cause an underlying fund to forego profitable investment opportunities.

•

Market Risk – The value of the fund's shares will go up and down based on the performance of the underlying funds in which it invests. The value of the underlying funds' shares will, in turn, fluctuate based on the performance of the securities they own and other factors generally affecting the securities market.

•

Principal Loss – At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.

 

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency. 
Risk Lose Money [Text] rr_RiskLoseMoney

Principal Loss -At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.
Risk Not Insured Depository Institution [Text] rr_RiskNotInsuredDepositoryInstitution

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading

Fund Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund's performance from year to year for Investor Class shares. The table shows how the fund's average annual returns for the periods shown compared with those of a broad measure of market performance. The fund's past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future. For current performance information, including yields, please visit americancentury.com.

 

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown.
Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund's performance from year to year for Investor Class shares. The table shows how the fund's average annual returns for the periods shown compared with those of a broad measure of market performance.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress americancentury.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture The fund's past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.
Bar Chart [Heading] rr_BarChartHeading

Calendar Year Total Returns
Bar Chart Does Not Reflect Sales Loads [Text] rr_BarChartDoesNotReflectSalesLoads

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown.
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock

Highest Performance Quarter (3Q 2009): 11.70% 

Lowest Performance Quarter (4Q 2008): -13.92% 

As of September 30, 2013, the most recent calendar quarter end, the fund’s Investor Class year-to-date return was 8.83%.
Year to Date Return, Label rr_YearToDateReturnLabel Investor Class year-to-date
Bar Chart, Year to Date Return, Date rr_BarChartYearToDateReturnDate Sep. 30, 2013
Bar Chart, Year to Date Return rr_BarChartYearToDateReturn 8.83%
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Highest Performance Quarter
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Sep. 30, 2009
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 11.70%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Lowest Performance Quarter
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Dec. 31, 2008
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (13.92%)
Performance Table Heading rr_PerformanceTableHeading

Average Annual Total Returns For the calendar year ended December 31, 2012
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate 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.
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred Actual after-tax returns depend on an investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.
Performance Table One Class of after Tax Shown [Text] rr_PerformanceTableOneClassOfAfterTaxShown The after-tax returns are shown only for Investor Class shares. After-tax returns for other share classes will vary.
Performance Table Closing [Text Block] rr_PerformanceTableClosingTextBlock

The after-tax returns are shown only for Investor Class shares. After-tax returns for other share classes will vary. 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. After-tax returns are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.
ONE CHOICE 2025 PORTFOLIO | Russell 3000 Index (reflects no deduction for fees, expenses or taxes)
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 16.42%
5 years rr_AverageAnnualReturnYear05 2.04%
Since Inception rr_AverageAnnualReturnSinceInception 5.79%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE 2025 PORTFOLIO | Barclays U.S. Aggregate Bond Index (reflects no deduction for fees, expenses or taxes)
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 4.21%
5 years rr_AverageAnnualReturnYear05 5.95%
Since Inception rr_AverageAnnualReturnSinceInception 5.36%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE 2025 PORTFOLIO | INVESTOR CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee 25
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.21%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.64%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.85%
1 year rr_ExpenseExampleYear01 87
3 years rr_ExpenseExampleYear03 272
5 years rr_ExpenseExampleYear05 472
10 years rr_ExpenseExampleYear10 1,049
Annual Return 2005 rr_AnnualReturn2005 6.42%
Annual Return 2006 rr_AnnualReturn2006 11.80%
Annual Return 2007 rr_AnnualReturn2007 9.29%
Annual Return 2008 rr_AnnualReturn2008 (25.02%)
Annual Return 2009 rr_AnnualReturn2009 21.24%
Annual Return 2010 rr_AnnualReturn2010 12.57%
Annual Return 2011 rr_AnnualReturn2011 1.77%
Annual Return 2012 rr_AnnualReturn2012 12.14%
1 year rr_AverageAnnualReturnYear01 12.14%
5 years rr_AverageAnnualReturnYear05 3.15%
Since Inception rr_AverageAnnualReturnSinceInception 6.31%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE 2025 PORTFOLIO | INVESTOR CLASS | Return After Taxes on Distributions
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 11.50%
5 years rr_AverageAnnualReturnYear05 2.45%
Since Inception rr_AverageAnnualReturnSinceInception 5.41%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE 2025 PORTFOLIO | INVESTOR CLASS | Return After Taxes on Distributions and Sale of Fund Shares
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 8.24%
5 years rr_AverageAnnualReturnYear05 2.34%
Since Inception rr_AverageAnnualReturnSinceInception 5.04%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE 2025 PORTFOLIO | INSTITUTIONAL CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Administrative Fee rr_Component1OtherExpensesOverAssets none
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.01%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.64%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.65%
1 year rr_ExpenseExampleYear01 67
3 years rr_ExpenseExampleYear03 208
5 years rr_ExpenseExampleYear05 363
10 years rr_ExpenseExampleYear10 811
1 year rr_AverageAnnualReturnYear01 12.36%
5 years rr_AverageAnnualReturnYear05 3.35%
Since Inception rr_AverageAnnualReturnSinceInception 6.52%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE 2025 PORTFOLIO | A CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice 5.75%
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none [1]
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.25%
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.21%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.64%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.10%
1 year rr_ExpenseExampleYear01 681
3 years rr_ExpenseExampleYear03 905
5 years rr_ExpenseExampleYear05 1,147
10 years rr_ExpenseExampleYear10 1,838
1 year rr_AverageAnnualReturnYear01 5.40% [2]
5 years rr_AverageAnnualReturnYear05 1.67% [2]
Since Inception rr_AverageAnnualReturnSinceInception 5.30% [2]
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004 [2]
ONE CHOICE 2025 PORTFOLIO | C CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice 1.00%
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 1.00%
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.21%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.64%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.85%
1 year rr_ExpenseExampleYear01 188
3 years rr_ExpenseExampleYear03 583
5 years rr_ExpenseExampleYear05 1,001
10 years rr_ExpenseExampleYear10 2,167
1 year rr_AverageAnnualReturnYear01 10.98%
5 years rr_AverageAnnualReturnYear05 2.13% [3]
Since Inception rr_AverageAnnualReturnSinceInception 5.26% [3]
Inception Date rr_AverageAnnualReturnInceptionDate Mar. 01, 2010
ONE CHOICE 2025 PORTFOLIO | R CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.50%
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.21%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.64%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.35%
1 year rr_ExpenseExampleYear01 138
3 years rr_ExpenseExampleYear03 428
5 years rr_ExpenseExampleYear05 740
10 years rr_ExpenseExampleYear10 1,623
1 year rr_AverageAnnualReturnYear01 11.57%
5 years rr_AverageAnnualReturnYear05 2.63%
Since Inception rr_AverageAnnualReturnSinceInception 5.78%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE 2030 PORTFOLIO
  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk/Return [Heading] rr_RiskReturnHeading ONE CHOICE 2030 PORTFOLIO
Objective [Heading] rr_ObjectiveHeading

Investment Objective
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The fund seeks the highest total return consistent with its asset mix.
Expense [Heading] rr_ExpenseHeading

Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses 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 $50,000 in American Century Investments funds. More information about these and other discounts is available from your financial professional and in Calculation of Sales Charges on page 60 of the fund's prospectus and Sales Charges in Appendix B of the 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

Because the fund buys and sells shares of other American Century mutual funds (the underlying funds) directly from the issuers, the fund is not expected to incur transaction costs directly. However, as a shareholder in the underlying funds, the fund indirectly pays transaction costs, such as commissions, when the underlying funds buy and sell securities (or "turn over" their portfolios). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 5% of the average value of its portfolio.

Portfolio Turnover, Rate rr_PortfolioTurnoverRate 5.00%
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 $50,000 in American Century Investments funds. More information about these and other discounts is available from your financial professional and in Calculation of Sales Charges on page 60 of the fund's prospectus and Sales Charges in Appendix B of the statement of additional information.
Expense Breakpoint, Minimum Investment Required [Amount] rr_ExpenseBreakpointMinimumInvestmentRequiredAmount 50,000
Expense Example [Heading] rr_ExpenseExampleHeading

Example
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock

The example below is intended to help you compare the costs of investing in the fund with the costs of investing in other mutual funds.

Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption

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, that you earn a 5% return each year, and that the fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading] rr_StrategyHeading

Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

One Choice 2030 Portfolio is a "fund of funds," meaning that it seeks to achieve its objective by investing in other American Century mutual funds (the underlying funds) that represent a variety of asset classes and investment styles. The underlying stock funds draw on growth, value and quantitative investment techniques and diversify investments among small, medium and large U.S. and foreign companies. The underlying bond funds invest in fixed-income securities that vary by issuer type (corporate and government), credit quality (investment-grade and high-yield or "junk bonds") and geographic exposure (domestic and international). The following table shows the fund's target allocation for the various asset classes and underlying funds as of the date of the prospectus:

 

Equity Securities (Stock Funds)

62.30%

    

Fixed-Income Securities (Bond Funds)

32.70%

  

NT Core Equity Plus Fund

3.25%

    

High-Yield Fund

3.00%

  

NT Emerging Markets Fund

2.75%

    

Inflation-Adjusted Bond Fund

5.00%

  

NT Equity Growth Fund

9.25%

    

International Bond Fund

2.00%

  

NT Growth Fund

11.00%

    

NT Diversified Bond Fund

21.50%

  

NT Heritage Fund

5.00%

    

Short Duration Inflation Protection Bond Fund

1.20%

  

NT International Growth Fund

8.50%

          

NT Large Company Value Fund

12.00%

    

Cash Equivalents (Money Market Funds)

 5.00%

  

NT Mid Cap Value Fund

5.25%

    

Premium Money Market Fund

5.00%

  

NT Small Company Fund

3.50%

          

Real Estate Fund

1.80%

          

 

The target date in the fund name (2030) refers to the approximate year an investor plans to retire and likely would stop making new investments in the fund. The fund assumes a retirement age of 65 and may not be appropriate for an investor who plans to retire at or near the target date, but at an age well before or after 65. As the target date approaches, the fund's asset mix will become more conservative by decreasing the allocation to stocks and increasing the allocation to bonds and cash. By the time the fund reaches its target date, the asset mix will become fixed and match that of One Choice In Retirement Portfolio, which is currently 45% stock funds, 45% bond funds and 10% money market funds. The fund is designed for investors who plan to withdraw the value of their account gradually after retirement. The following chart shows how the asset mix is expected to change over time according to a predetermined glide path.

 

One Choice Target Date Portfolios' Glide Path

Years to Retirement 45 44 43 42 41 40 39 38 37 36 35 34 33
Stocks 85.00% 85.00% 85.00% 85.00% 85.00% 85.00% 84.70% 83.90% 83.35% 82.80% 82.25% 81.70% 81.40%
Bonds 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.30% 16.10% 16.65% 17.20% 17.75% 18.30% 18.60%
Cash 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%
32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15
80.85% 80.40% 80.00% 78.45% 77.15% 76.35% 74.95% 73.40% 72.10% 70.80% 70.25% 68.55% 67.00% 65.85% 64.50% 63.35% 62.30% 61.00%
19.15% 19.60% 20.00% 21.05% 21.85% 22.15% 23.05% 24.10% 24.90% 25.70% 25.75% 26.95% 28.00% 29.15% 30.50% 31.65% 32.70% 34.00%
0.00% 0.00% 0.00% 0.50% 1.00% 1.50% 2.00% 2.50% 3.00% 3.50% 4.00% 4.50% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%
14 13 12 11 10 9 8 7 6 5 4 3 2 1   RETIREMENT
59.70% 58.60% 57.35% 56.30% 55.00% 54.20% 52.90% 52.10% 51.05% 50.00% 48.95% 47.90% 46.85% 46.05%   45.00%
35.30% 36.40% 37.65% 38.70% 40.00% 40.30% 41.10% 41.40% 41.95% 42.50% 43.05% 43.60% 44.15% 44.45%   45.00%
5.00% 5.00% 5.00% 5.00% 5.00% 5.50% 6.00% 6.50% 7.00% 7.50% 8.00% 8.50% 9.00% 9.50%   10.00%
Years After Retirement 1 2 3 4 5 6 7 8 9 10 11 12 13
Stocks 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Bonds 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Cash 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%

 

The portfolio managers regularly review the fund's allocations to determine whether rebalancing is appropriate. Although we do not intend to make frequent tactical adjustments to the target asset mix or trade actively among the underlying funds (other than the glide path adjustments described above), we reserve the right to modify the target allocations and underlying funds from time to time should circumstances warrant a change.
Risk [Heading] rr_RiskHeading

Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock

•

Allocation Risk – The fund's performance and risks depend in part on the managers' skill in determining the fund's asset class allocations and in selecting and weighting the underlying funds. The managers' evaluations and assumptions regarding asset classes or underlying funds may differ from actual market conditions.

•

"Growth" and "Value" Style Risks – The underlying funds represent a mix of investment styles, each of which has risks associated with it. Growth stocks can be volatile and may lack dividends that can cushion share prices during market declines. Value stocks may continue to be undervalued by the market for long periods of time.

•

Small- and Mid-Cap Stock Risks – Stocks of smaller companies may be more volatile than larger-company stocks. Smaller companies may have limited financial resources, product lines and markets, and their securities may trade less frequently and in more limited volumes than the securities of larger companies, which could lead to higher transaction costs. To the extent an underlying fund invests in these companies, it may take on more risk.

•

Interest Rate Risk – Generally, when interest rates rise, the value of an underlying fund's fixed-income securities will decline. The opposite is true when interest rates decline. Underlying funds with longer weighted average maturities are more sensitive to interest rate changes.

•

Credit Risk - The value of an underlying fund's fixed-income securities will be affected adversely by any erosion in the ability of the issuers of these securities to make interest and principal payments as they become due. Changes in the credit rating of a fixed-income security held by an underlying fund could have a similar effect.

•

Foreign Securities Risk – Some of the underlying funds invest in foreign securities, which are generally riskier than U.S. securities. Securities of foreign issuers may be less liquid, more volatile and harder to value than U.S. securities. Fluctuations in currency exchange rates also may affect an underlying fund's share price. Investing in securities of companies located in emerging market countries is generally riskier than investing in securities of companies located in developed foreign countries.

•

High-Yield Securities Risk – Some of the underlying funds may invest in high-yield securities, which are considered to have speculative characteristics and are more likely to be negatively affected by changes in economic conditions.

•

Tobacco Exclusion – The underlying funds do not invest in securities issued by companies assigned the Global Industry Classification Standard (GICS) for the tobacco industry. This exclusion may cause an underlying fund to forego profitable investment opportunities.

•

Market Risk – The value of the fund's shares will go up and down based on the performance of the underlying funds in which it invests. The value of the underlying funds' shares will, in turn, fluctuate based on the performance of the securities they own and other factors generally affecting the securities market.

•

Principal Loss – At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.

 

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Risk Lose Money [Text] rr_RiskLoseMoney

Principal Loss -At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.
Risk Not Insured Depository Institution [Text] rr_RiskNotInsuredDepositoryInstitution

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading

Fund Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund's performance from year to year for Investor Class shares. The table shows how the fund's average annual returns for the periods shown compared with those of a broad measure of market performance. The fund's past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future. For current performance information, including yields, please visit americancentury.com.

 

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown. 
Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund's performance from year to year for Investor Class shares. The table shows how the fund's average annual returns for the periods shown compared with those of a broad measure of market performance.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress americancentury.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture The fund's past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.
Bar Chart [Heading] rr_BarChartHeading

Calendar Year Total Returns
Bar Chart Does Not Reflect Sales Loads [Text] rr_BarChartDoesNotReflectSalesLoads

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown.
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock

Highest Performance Quarter (3Q 2009): 12.53% 

Lowest Performance Quarter (3Q 2011): -10.33% 

As of September 30, 2013, the most recent calendar quarter end, the fund's Investor Class year-to-date return was 10.07%.
Year to Date Return, Label rr_YearToDateReturnLabel Investor Class year-to-date
Bar Chart, Year to Date Return, Date rr_BarChartYearToDateReturnDate Sep. 30, 2013
Bar Chart, Year to Date Return rr_BarChartYearToDateReturn 10.07%
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Highest Performance Quarter
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Sep. 30, 2009
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 12.53%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Lowest Performance Quarter
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Sep. 30, 2011
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (10.33%)
Performance Table Heading rr_PerformanceTableHeading

Average Annual Total Returns For the calendar year ended December 31, 2012
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate 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.
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred Actual after-tax returns depend on an investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.
Performance Table One Class of after Tax Shown [Text] rr_PerformanceTableOneClassOfAfterTaxShown The after-tax returns are shown only for Investor Class shares. After-tax returns for other share classes will vary.
Performance Table Closing [Text Block] rr_PerformanceTableClosingTextBlock

The after-tax returns are shown only for Investor Class shares. After-tax returns for other share classes will vary. 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. After-tax returns are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.
ONE CHOICE 2030 PORTFOLIO | Russell 3000 Index (reflects no deduction for fees, expenses or taxes)
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 16.42%
Since Inception rr_AverageAnnualReturnSinceInception 2.93%
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008
ONE CHOICE 2030 PORTFOLIO | Barclays U.S. Aggregate Bond Index (reflects no deduction for fees, expenses or taxes)
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 4.21%
Since Inception rr_AverageAnnualReturnSinceInception 6.23%
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008
ONE CHOICE 2030 PORTFOLIO | INVESTOR CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee 25
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.21%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.66%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.87%
1 year rr_ExpenseExampleYear01 89
3 years rr_ExpenseExampleYear03 278
5 years rr_ExpenseExampleYear05 483
10 years rr_ExpenseExampleYear10 1,073
Annual Return 2009 rr_AnnualReturn2009 22.88%
Annual Return 2010 rr_AnnualReturn2010 13.39%
Annual Return 2011 rr_AnnualReturn2011 1.04%
Annual Return 2012 rr_AnnualReturn2012 12.79%
1 year rr_AverageAnnualReturnYear01 12.79%
Since Inception rr_AverageAnnualReturnSinceInception 3.33%
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008
ONE CHOICE 2030 PORTFOLIO | INVESTOR CLASS | Return After Taxes on Distributions
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 12.19%
Since Inception rr_AverageAnnualReturnSinceInception 2.84%
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008
ONE CHOICE 2030 PORTFOLIO | INVESTOR CLASS | Return After Taxes on Distributions and Sale of Fund Shares
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 8.71%
Since Inception rr_AverageAnnualReturnSinceInception 2.62%
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008
ONE CHOICE 2030 PORTFOLIO | INSTITUTIONAL CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Administrative Fee rr_Component1OtherExpensesOverAssets none
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.01%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.66%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.67%
1 year rr_ExpenseExampleYear01 69
3 years rr_ExpenseExampleYear03 215
5 years rr_ExpenseExampleYear05 374
10 years rr_ExpenseExampleYear10 835
1 year rr_AverageAnnualReturnYear01 13.13%
Since Inception rr_AverageAnnualReturnSinceInception 3.54%
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008
ONE CHOICE 2030 PORTFOLIO | A CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice 5.75%
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none [1]
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.25%
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.21%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.66%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.12%
1 year rr_ExpenseExampleYear01 683
3 years rr_ExpenseExampleYear03 911
5 years rr_ExpenseExampleYear05 1,157
10 years rr_ExpenseExampleYear10 1,860
1 year rr_AverageAnnualReturnYear01 6.04% [2]
Since Inception rr_AverageAnnualReturnSinceInception 1.74% [2]
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008 [2]
ONE CHOICE 2030 PORTFOLIO | C CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice 1.00%
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 1.00%
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.21%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.66%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.87%
1 year rr_ExpenseExampleYear01 190
3 years rr_ExpenseExampleYear03 589
5 years rr_ExpenseExampleYear05 1,012
10 years rr_ExpenseExampleYear10 2,188
1 year rr_AverageAnnualReturnYear01 11.63%
Since Inception rr_AverageAnnualReturnSinceInception 2.30% [3]
Inception Date rr_AverageAnnualReturnInceptionDate Mar. 01, 2010
ONE CHOICE 2030 PORTFOLIO | R CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.50%
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.21%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.66%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.37%
1 year rr_ExpenseExampleYear01 140
3 years rr_ExpenseExampleYear03 435
5 years rr_ExpenseExampleYear05 751
10 years rr_ExpenseExampleYear10 1,645
1 year rr_AverageAnnualReturnYear01 12.23%
Since Inception rr_AverageAnnualReturnSinceInception 2.80%
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008
ONE CHOICE 2035 PORTFOLIO
  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk/Return [Heading] rr_RiskReturnHeading ONE CHOICE 2035 PORTFOLIO
Objective [Heading] rr_ObjectiveHeading

Investment Objective
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The fund seeks the highest total return consistent with its asset mix.
Expense [Heading] rr_ExpenseHeading

Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses 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 $50,000 in American Century Investments funds. More information about these and other discounts is available from your financial professional and in Calculation of Sales Charges on page 60 of the fund's prospectus and Sales Charges in Appendix B of the 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

Because the fund buys and sells shares of other American Century mutual funds (the underlying funds) directly from the issuers, the fund is not expected to incur transaction costs directly. However, as a shareholder in the underlying funds, the fund indirectly pays transaction costs, such as commissions, when the underlying funds buy and sell securities (or "turn over" their portfolios). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 3% of the average value of its portfolio.

Portfolio Turnover, Rate rr_PortfolioTurnoverRate 3.00%
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 $50,000 in American Century Investments funds. More information about these and other discounts is available from your financial professional and in Calculation of Sales Charges on page 60 of the fund's prospectus and Sales Charges in Appendix B of the statement of additional information.
Expense Breakpoint, Minimum Investment Required [Amount] rr_ExpenseBreakpointMinimumInvestmentRequiredAmount 50,000
Expense Example [Heading] rr_ExpenseExampleHeading

Example
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock

The example below is intended to help you compare the costs of investing in the fund with the costs of investing in other mutual funds.

Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption

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, that you earn a 5% return each year, and that the fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading] rr_StrategyHeading

Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

One Choice 2035 Portfolio is a "fund of funds," meaning that it seeks to achieve its objective by investing in other American Century mutual funds (the underlying funds) that represent a variety of asset classes and investment styles. The underlying stock funds draw on growth, value and quantitative investment techniques and diversify investments among small, medium and large U.S. and foreign companies. The underlying bond funds invest in fixed-income securities that vary by issuer type (corporate and government) and credit quality (investment-grade and high-yield or "junk bonds"). The following table shows the fund's target allocation for the various asset classes and underlying funds as of the date of the prospectus:

 

Equity Securities (Stock Funds)

68.55%

    

Fixed-Income Securities (Bond Funds)

26.95%

  

NT Core Equity Plus Fund

3.25%

    

High-Yield Fund

2.65%

  

NT Emerging Markets Fund

3.50%

    

Inflation-Adjusted Bond Fund

5.40%

  

NT Equity Growth Fund

9.50%

    

NT Diversified Bond Fund

18.90%

  

NT Growth Fund

12.75%

          

NT Heritage Fund

5.50%

    

Cash Equivalents (Money Market Funds)

4.50%

  

NT International Growth Fund

9.50%

    

Premium Money Market Fund

4.50%

  

NT Large Company Value Fund

12.75%

          

NT Mid Cap Value Fund

5.50%

          

NT Small Company Fund

4.25%

          

Real Estate Fund

2.05%

          

 

The target date in the fund name (2035) refers to the approximate year an investor plans to retire and likely would stop making new investments in the fund. The fund assumes a retirement age of 65 and may not be appropriate for an investor who plans to retire at or near the target date, but at an age well before or after 65. As the target date approaches, the fund's asset mix will become more conservative by decreasing the allocation to stocks and increasing the allocation to bonds and cash. By the time the fund reaches its target date, the asset mix will become fixed and match that of One Choice In Retirement Portfolio, which is currently 45% stock funds, 45% bond funds and 10% money market funds. The fund is designed for investors who plan to withdraw the value of their account gradually after retirement. The following chart shows how the asset mix is expected to change over time according to a predetermined glide path.

 

One Choice Target Date Portfolios' Glide Path

Years to Retirement 45 44 43 42 41 40 39 38 37 36 35 34 33
Stocks 85.00% 85.00% 85.00% 85.00% 85.00% 85.00% 84.70% 83.90% 83.35% 82.80% 82.25% 81.70% 81.40%
Bonds 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.30% 16.10% 16.65% 17.20% 17.75% 18.30% 18.60%
Cash 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%
32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15
80.85% 80.40% 80.00% 78.45% 77.15% 76.35% 74.95% 73.40% 72.10% 70.80% 70.25% 68.55% 67.00% 65.85% 64.50% 63.35% 62.30% 61.00%
19.15% 19.60% 20.00% 21.05% 21.85% 22.15% 23.05% 24.10% 24.90% 25.70% 25.75% 26.95% 28.00% 29.15% 30.50% 31.65% 32.70% 34.00%
0.00% 0.00% 0.00% 0.50% 1.00% 1.50% 2.00% 2.50% 3.00% 3.50% 4.00% 4.50% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%
14 13 12 11 10 9 8 7 6 5 4 3 2 1   RETIREMENT
59.70% 58.60% 57.35% 56.30% 55.00% 54.20% 52.90% 52.10% 51.05% 50.00% 48.95% 47.90% 46.85% 46.05%   45.00%
35.30% 36.40% 37.65% 38.70% 40.00% 40.30% 41.10% 41.40% 41.95% 42.50% 43.05% 43.60% 44.15% 44.45%   45.00%
5.00% 5.00% 5.00% 5.00% 5.00% 5.50% 6.00% 6.50% 7.00% 7.50% 8.00% 8.50% 9.00% 9.50%   10.00%
Years After Retirement 1 2 3 4 5 6 7 8 9 10 11 12 13
Stocks 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Bonds 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Cash 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%

 

 

The portfolio managers regularly review the fund's allocations to determine whether rebalancing is appropriate. Although we do not intend to make frequent tactical adjustments to the target asset mix or trade actively among the underlying funds (other than the glide path adjustments described above), we reserve the right to modify the target allocations and underlying funds from time to time should circumstances warrant a change.
Risk [Heading] rr_RiskHeading

Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock

•

Allocation Risk – The fund's performance and risks depend in part on the managers' skill in determining the fund's asset class allocations and in selecting and weighting the underlying funds. The managers' evaluations and assumptions regarding asset classes or underlying funds may differ from actual market conditions.

•

"Growth" and "Value" Style Risks – The underlying funds represent a mix of investment styles, each of which has risks associated with it. Growth stocks can be volatile and may lack dividends that can cushion share prices during market declines. Value stocks may continue to be undervalued by the market for long periods of time.

•

Small- and Mid-Cap Stock Risks – Stocks of smaller companies may be more volatile than larger-company stocks. Smaller companies may have limited financial resources, product lines and markets, and their securities may trade less frequently and in more limited volumes than the securities of larger companies, which could lead to higher transaction costs. To the extent an underlying fund invests in these companies, it may take on more risk.

•

Interest Rate Risk – Generally, when interest rates rise, the value of an underlying fund's fixed-income securities will decline. The opposite is true when interest rates decline. Underlying funds with longer weighted average maturities are more sensitive to interest rate changes.

•

Credit Risk - The value of an underlying fund's fixed-income securities will be affected adversely by any erosion in the ability of the issuers of these securities to make interest and principal payments as they become due. Changes in the credit rating of a fixed-income security held by an underlying fund could have a similar effect.

•

Foreign Securities Risk – Some of the underlying funds invest in foreign securities, which are generally riskier than U.S. securities. Securities of foreign issuers may be less liquid, more volatile and harder to value than U.S. securities. Fluctuations in currency exchange rates also may affect an underlying fund's share price. Investing in securities of companies located in emerging market countries is generally riskier than investing in securities of companies located in developed foreign countries.

•

Tobacco Exclusion – The underlying funds do not invest in securities issued by companies assigned the Global Industry Classification Standard (GICS) for the tobacco industry. This exclusion may cause an underlying fund to forego profitable investment opportunities.

•

Market Risk – The value of the fund's shares will go up and down based on the performance of the underlying funds in which it invests. The value of the underlying funds' shares will, in turn, fluctuate based on the performance of the securities they own and other factors generally affecting the securities market.

•

Principal Loss – At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.

 

 

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Risk Lose Money [Text] rr_RiskLoseMoney

Principal Loss -At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.
Risk Not Insured Depository Institution [Text] rr_RiskNotInsuredDepositoryInstitution

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading

Fund Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund's performance from year to year for Investor Class shares. The table shows how the fund's average annual returns for the periods shown compared with those of a broad measure of market performance. The fund's past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future. For current performance information, including yields, please visit americancentury.com.

 

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown.
Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund's performance from year to year for Investor Class shares. The table shows how the fund's average annual returns for the periods shown compared with those of a broad measure of market performance.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress americancentury.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture The fund's past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.
Bar Chart [Heading] rr_BarChartHeading

Calendar Year Total Returns
Bar Chart Does Not Reflect Sales Loads [Text] rr_BarChartDoesNotReflectSalesLoads

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown.
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock

Highest Performance Quarter (3Q 2009): 13.46%  

Lowest Performance Quarter (4Q 2008): -17.42% 

As of September 30, 2013, the most recent calendar quarter end, the fund’s Investor Class year-to-date return was 11.42%.
Year to Date Return, Label rr_YearToDateReturnLabel Investor Class year-to-date
Bar Chart, Year to Date Return, Date rr_BarChartYearToDateReturnDate Sep. 30, 2013
Bar Chart, Year to Date Return rr_BarChartYearToDateReturn 11.42%
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Highest Performance Quarter
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Sep. 30, 2009
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 13.46%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Lowest Performance Quarter
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Dec. 31, 2008
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (17.42%)
Performance Table Heading rr_PerformanceTableHeading

Average Annual Total Returns For the calendar year ended December 31, 2012
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate 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.
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred Actual after-tax returns depend on an investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.
Performance Table One Class of after Tax Shown [Text] rr_PerformanceTableOneClassOfAfterTaxShown The after-tax returns are shown only for Investor Class shares. After-tax returns for other share classes will vary.
Performance Table Closing [Text Block] rr_PerformanceTableClosingTextBlock

The after-tax returns are shown only for Investor Class shares. After-tax returns for other share classes will vary. 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. After-tax returns are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.
ONE CHOICE 2035 PORTFOLIO | Russell 3000 Index (reflects no deduction for fees, expenses or taxes)
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 16.42%
5 years rr_AverageAnnualReturnYear05 2.04%
Since Inception rr_AverageAnnualReturnSinceInception 5.79%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE 2035 PORTFOLIO | Barclays U.S. Aggregate Bond Index (reflects no deduction for fees, expenses or taxes)
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 4.21%
5 years rr_AverageAnnualReturnYear05 5.95%
Since Inception rr_AverageAnnualReturnSinceInception 5.36%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE 2035 PORTFOLIO | INVESTOR CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee 25
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.21%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.69%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.90%
1 year rr_ExpenseExampleYear01 92
3 years rr_ExpenseExampleYear03 287
5 years rr_ExpenseExampleYear05 499
10 years rr_ExpenseExampleYear10 1,108
Annual Return 2005 rr_AnnualReturn2005 7.44%
Annual Return 2006 rr_AnnualReturn2006 13.60%
Annual Return 2007 rr_AnnualReturn2007 10.36%
Annual Return 2008 rr_AnnualReturn2008 (30.58%)
Annual Return 2009 rr_AnnualReturn2009 24.31%
Annual Return 2010 rr_AnnualReturn2010 14.28%
Annual Return 2011 rr_AnnualReturn2011 0.37%
Annual Return 2012 rr_AnnualReturn2012 13.62%
1 year rr_AverageAnnualReturnYear01 13.62%
5 years rr_AverageAnnualReturnYear05 2.38%
Since Inception rr_AverageAnnualReturnSinceInception 6.47%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE 2035 PORTFOLIO | INVESTOR CLASS | Return After Taxes on Distributions
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 13.06%
5 years rr_AverageAnnualReturnYear05 1.81%
Since Inception rr_AverageAnnualReturnSinceInception 5.69%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE 2035 PORTFOLIO | INVESTOR CLASS | Return After Taxes on Distributions and Sale of Fund Shares
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 9.28%
5 years rr_AverageAnnualReturnYear05 1.77%
Since Inception rr_AverageAnnualReturnSinceInception 5.26%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE 2035 PORTFOLIO | INSTITUTIONAL CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Administrative Fee rr_Component1OtherExpensesOverAssets none
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.01%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.69%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.70%
1 year rr_ExpenseExampleYear01 72
3 years rr_ExpenseExampleYear03 224
5 years rr_ExpenseExampleYear05 390
10 years rr_ExpenseExampleYear10 871
1 year rr_AverageAnnualReturnYear01 13.84%
5 years rr_AverageAnnualReturnYear05 2.59%
Since Inception rr_AverageAnnualReturnSinceInception 6.69%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE 2035 PORTFOLIO | A CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice 5.75%
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none [1]
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.25%
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.21%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.69%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.15%
1 year rr_ExpenseExampleYear01 686
3 years rr_ExpenseExampleYear03 920
5 years rr_ExpenseExampleYear05 1,172
10 years rr_ExpenseExampleYear10 1,892
1 year rr_AverageAnnualReturnYear01 6.85% [2]
5 years rr_AverageAnnualReturnYear05 0.92% [2]
Since Inception rr_AverageAnnualReturnSinceInception 5.45% [2]
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004 [2]
ONE CHOICE 2035 PORTFOLIO | C CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice 1.00%
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 1.00%
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.21%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.69%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.90%
1 year rr_ExpenseExampleYear01 193
3 years rr_ExpenseExampleYear03 598
5 years rr_ExpenseExampleYear05 1,027
10 years rr_ExpenseExampleYear10 2,219
1 year rr_AverageAnnualReturnYear01 12.46%
5 years rr_AverageAnnualReturnYear05 1.35% [3]
Since Inception rr_AverageAnnualReturnSinceInception 5.40% [3]
Inception Date rr_AverageAnnualReturnInceptionDate Mar. 01, 2010
ONE CHOICE 2035 PORTFOLIO | R CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.50%
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.21%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.69%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.40%
1 year rr_ExpenseExampleYear01 143
3 years rr_ExpenseExampleYear03 444
5 years rr_ExpenseExampleYear05 767
10 years rr_ExpenseExampleYear10 1,679
1 year rr_AverageAnnualReturnYear01 13.05%
5 years rr_AverageAnnualReturnYear05 1.87%
Since Inception rr_AverageAnnualReturnSinceInception 5.94%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE 2040 PORTFOLIO
  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk/Return [Heading] rr_RiskReturnHeading ONE CHOICE 2040 PORTFOLIO
Objective [Heading] rr_ObjectiveHeading

Investment Objective
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The fund seeks the highest total return consistent with its asset mix.
Expense [Heading] rr_ExpenseHeading

Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses 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 $50,000 in American Century Investments funds. More information about these and other discounts is available from your financial professional and in Calculation of Sales Charges on page 60 of the fund's prospectus and Sales Charges in Appendix B of the 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

Because the fund buys and sells shares of other American Century mutual funds (the underlying funds) directly from the issuers, the fund is not expected to incur transaction costs directly. However, as a shareholder in the underlying funds, the fund indirectly pays transaction costs, such as commissions, when the underlying funds buy and sell securities (or "turn over" their portfolios). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 5% of the average value of its portfolio.

Portfolio Turnover, Rate rr_PortfolioTurnoverRate 5.00%
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 $50,000 in American Century Investments funds. More information about these and other discounts is available from your financial professional and in Calculation of Sales Charges on page 60 of the fund's prospectus and Sales Charges in Appendix B of the statement of additional information.
Expense Breakpoint, Minimum Investment Required [Amount] rr_ExpenseBreakpointMinimumInvestmentRequiredAmount 50,000
Expense Example [Heading] rr_ExpenseExampleHeading

Example
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock

The example below is intended to help you compare the costs of investing in the fund with the costs of investing in other mutual funds.

Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption

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, that you earn a 5% return each year, and that the fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading] rr_StrategyHeading

Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

One Choice 2040 Portfolio is a "fund of funds," meaning that it seeks to achieve its objective by investing in other American Century mutual funds (the underlying funds) that represent a variety of asset classes and investment styles. The underlying stock funds draw on growth, value and quantitative investment techniques and diversify investments among small, medium and large U.S. and foreign companies. The underlying bond funds invest in fixed-income securities that vary by issuer type (corporate and government) and credit quality (investment-grade and high-yield or "junk bonds"). The following table shows the fund's target allocation for the various asset classes and underlying funds as of the date of the prospectus:

 

Equity Securities (Stock Funds)

74.95%

    

Fixed-Income Securities (Bond Funds)

23.05%

  

NT Core Equity Plus Fund

3.50%

    

High-Yield Fund

2.30%

  

NT Emerging Markets Fund

4.25%

    

Inflation-Adjusted Bond Fund

4.60%

  

NT Equity Growth Fund

10.25%

    

NT Diversified Bond Fund

16.15%

  

NT Growth Fund

13.75%

          

NT Heritage Fund

6.50%

    

Cash Equivalents (Money Market Funds)

2.00%

  

NT International Growth Fund

10.00%

    

Premium Money Market Fund

2.00%

  

NT Large Company Value Fund

13.75%

          

NT Mid Cap Value Fund

6.50%

          

NT Small Company Fund

4.15%

          

Real Estate Fund

2.30%

          

 

The target date in the fund name (2040) refers to the approximate year an investor plans to retire and likely would stop making new investments in the fund. The fund assumes a retirement age of 65 and may not be appropriate for an investor who plans to retire at or near the target date, but at an age well before or after 65. As the target date approaches, the fund's asset mix will become more conservative by decreasing the allocation to stocks and increasing the allocation to bonds and cash. By the time the fund reaches its target date, the asset mix will become fixed and match that of One Choice In Retirement Portfolio, which is currently 45% stock funds, 45% bond funds and 10% money market funds. The fund is designed for investors who plan to withdraw the value of their account gradually after retirement. The following chart shows how the asset mix is expected to change over time according to a predetermined glide path.

 One Choice Target Date Portfolios' Glide Path

Years to Retirement 45 44 43 42 41 40 39 38 37 36 35 34 33
Stocks 85.00% 85.00% 85.00% 85.00% 85.00% 85.00% 84.70% 83.90% 83.35% 82.80% 82.25% 81.70% 81.40%
Bonds 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.30% 16.10% 16.65% 17.20% 17.75% 18.30% 18.60%
Cash 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%
32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15
80.85% 80.40% 80.00% 78.45% 77.15% 76.35% 74.95% 73.40% 72.10% 70.80% 70.25% 68.55% 67.00% 65.85% 64.50% 63.35% 62.30% 61.00%
19.15% 19.60% 20.00% 21.05% 21.85% 22.15% 23.05% 24.10% 24.90% 25.70% 25.75% 26.95% 28.00% 29.15% 30.50% 31.65% 32.70% 34.00%
0.00% 0.00% 0.00% 0.50% 1.00% 1.50% 2.00% 2.50% 3.00% 3.50% 4.00% 4.50% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%
14 13 12 11 10 9 8 7 6 5 4 3 2 1   RETIREMENT
59.70% 58.60% 57.35% 56.30% 55.00% 54.20% 52.90% 52.10% 51.05% 50.00% 48.95% 47.90% 46.85% 46.05%   45.00%
35.30% 36.40% 37.65% 38.70% 40.00% 40.30% 41.10% 41.40% 41.95% 42.50% 43.05% 43.60% 44.15% 44.45%   45.00%
5.00% 5.00% 5.00% 5.00% 5.00% 5.50% 6.00% 6.50% 7.00% 7.50% 8.00% 8.50% 9.00% 9.50%   10.00%
Years After Retirement 1 2 3 4 5 6 7 8 9 10 11 12 13
Stocks 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Bonds 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Cash 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%

 

The portfolio managers regularly review the fund's allocations to determine whether rebalancing is appropriate. Although we do not intend to make frequent tactical adjustments to the target asset mix or trade actively among the underlying funds (other than the glide path adjustments described above), we reserve the right to modify the target allocations and underlying funds from time to time should circumstances warrant a change.
Risk [Heading] rr_RiskHeading

Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock

•

Allocation Risk – The fund's performance and risks depend in part on the managers' skill in determining the fund's asset class allocations and in selecting and weighting the underlying funds. The managers' evaluations and assumptions regarding asset classes or underlying funds may differ from actual market conditions.

•

"Growth" and "Value" Style Risks – The underlying funds represent a mix of investment styles, each of which has risks associated with it. Growth stocks can be volatile and may lack dividends that can cushion share prices during market declines. Value stocks may continue to be undervalued by the market for long periods of time.

•

Small- and Mid-Cap Stock Risks – Stocks of smaller companies may be more volatile than larger-company stocks. Smaller companies may have limited financial resources, product lines and markets, and their securities may trade less frequently and in more limited volumes than the securities of larger companies, which could lead to higher transaction costs. To the extent an underlying fund invests in these companies, it may take on more risk.

•

Interest Rate Risk – Generally, when interest rates rise, the value of an underlying fund's fixed-income securities will decline. The opposite is true when interest rates decline. Underlying funds with longer weighted average maturities are more sensitive to interest rate changes.

•

Credit Risk - The value of an underlying fund's fixed-income securities will be affected adversely by any erosion in the ability of the issuers of these securities to make interest and principal payments as they become due. Changes in the credit rating of a fixed-income security held by an underlying fund could have a similar effect.

•

Foreign Securities Risk – Some of the underlying funds invest in foreign securities, which are generally riskier than U.S. securities. Securities of foreign issuers may be less liquid, more volatile and harder to value than U.S. securities. Fluctuations in currency exchange rates also may affect an underlying fund's share price. Investing in securities of companies located in emerging market countries is generally riskier than investing in securities of companies located in developed foreign countries.

•

Tobacco Exclusion – The underlying funds do not invest in securities issued by companies assigned the Global Industry Classification Standard (GICS) for the tobacco industry. This exclusion may cause an underlying fund to forego profitable investment opportunities.

•

Market Risk – The value of the fund's shares will go up and down based on the performance of the underlying funds in which it invests. The value of the underlying funds' shares will, in turn, fluctuate based on the performance of the securities they own and other factors generally affecting the securities market.

•

Principal Loss – At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.

 

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Risk Lose Money [Text] rr_RiskLoseMoney

Principal Loss -At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.
Risk Not Insured Depository Institution [Text] rr_RiskNotInsuredDepositoryInstitution

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading

Fund Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund's performance from year to year for Investor Class shares. The table shows how the fund's average annual returns for the periods shown compared with those of a broad measure of market performance. The fund's past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future. For current performance information, including yields, please visit americancentury.com.

 

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown. 
Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund's performance from year to year for Investor Class shares. The table shows how the fund's average annual returns for the periods shown compared with those of a broad measure of market performance.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress americancentury.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture The fund's past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.
Bar Chart [Heading] rr_BarChartHeading

Calendar Year Total Returns
Bar Chart Does Not Reflect Sales Loads [Text] rr_BarChartDoesNotReflectSalesLoads

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown.
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock

Highest Performance Quarter (2Q 2009): 14.38% 

Lowest Performance Quarter (3Q 2011): -12.68% 

As of September 30, 2013, the most recent calendar quarter end, the fund's Investor Class year-to-date return was 12.50%.
Year to Date Return, Label rr_YearToDateReturnLabel Investor Class year-to-date
Bar Chart, Year to Date Return, Date rr_BarChartYearToDateReturnDate Sep. 30, 2013
Bar Chart, Year to Date Return rr_BarChartYearToDateReturn 12.50%
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Highest Performance Quarter
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Jun. 30, 2009
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 14.38%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Lowest Performance Quarter
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Sep. 30, 2011
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (12.68%)
Performance Table Heading rr_PerformanceTableHeading

Average Annual Total Returns For the calendar year ended December 31, 2012
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate 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.
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred Actual after-tax returns depend on an investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.
Performance Table One Class of after Tax Shown [Text] rr_PerformanceTableOneClassOfAfterTaxShown The after-tax returns are shown only for Investor Class shares. After-tax returns for other share classes will vary.
Performance Table Closing [Text Block] rr_PerformanceTableClosingTextBlock

The after-tax returns are shown only for Investor Class shares. After-tax returns for other share classes will vary. 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. After-tax returns are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.
ONE CHOICE 2040 PORTFOLIO | Russell 3000 Index (reflects no deduction for fees, expenses or taxes)
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 16.42%
Since Inception rr_AverageAnnualReturnSinceInception 2.93%
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008
ONE CHOICE 2040 PORTFOLIO | Barclays U.S. Aggregate Bond Index (reflects no deduction for fees, expenses or taxes)
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 4.21%
Since Inception rr_AverageAnnualReturnSinceInception 6.23%
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008
ONE CHOICE 2040 PORTFOLIO | INVESTOR CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee 25
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.20%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.73%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.93%
1 year rr_ExpenseExampleYear01 95
3 years rr_ExpenseExampleYear03 297
5 years rr_ExpenseExampleYear05 515
10 years rr_ExpenseExampleYear10 1,143
Annual Return 2009 rr_AnnualReturn2009 25.95%
Annual Return 2010 rr_AnnualReturn2010 14.99%
Annual Return 2011 rr_AnnualReturn2011 (0.27%)
Annual Return 2012 rr_AnnualReturn2012 14.50%
1 year rr_AverageAnnualReturnYear01 14.50%
Since Inception rr_AverageAnnualReturnSinceInception 3.17%
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008
ONE CHOICE 2040 PORTFOLIO | INVESTOR CLASS | Return After Taxes on Distributions
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 14.01%
Since Inception rr_AverageAnnualReturnSinceInception 2.76%
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008
ONE CHOICE 2040 PORTFOLIO | INVESTOR CLASS | Return After Taxes on Distributions and Sale of Fund Shares
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 9.84%
Since Inception rr_AverageAnnualReturnSinceInception 2.54%
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008
ONE CHOICE 2040 PORTFOLIO | INSTITUTIONAL CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Administrative Fee rr_Component1OtherExpensesOverAssets none
Other rr_Component2OtherExpensesOverAssets none
Other Expenses rr_OtherExpensesOverAssets none
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.73%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.73%
1 year rr_ExpenseExampleYear01 75
3 years rr_ExpenseExampleYear03 234
5 years rr_ExpenseExampleYear05 407
10 years rr_ExpenseExampleYear10 907
1 year rr_AverageAnnualReturnYear01 14.73%
Since Inception rr_AverageAnnualReturnSinceInception 3.37%
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008
ONE CHOICE 2040 PORTFOLIO | A CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice 5.75%
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none [1]
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.25%
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.20%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.73%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.18%
1 year rr_ExpenseExampleYear01 689
3 years rr_ExpenseExampleYear03 929
5 years rr_ExpenseExampleYear05 1,187
10 years rr_ExpenseExampleYear10 1,924
1 year rr_AverageAnnualReturnYear01 7.65% [2]
Since Inception rr_AverageAnnualReturnSinceInception 1.59% [2]
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008 [2]
ONE CHOICE 2040 PORTFOLIO | C CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice 1.00%
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 1.00%
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.20%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.73%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.93%
1 year rr_ExpenseExampleYear01 196
3 years rr_ExpenseExampleYear03 607
5 years rr_ExpenseExampleYear05 1,043
10 years rr_ExpenseExampleYear10 2,251
1 year rr_AverageAnnualReturnYear01 13.34%
Since Inception rr_AverageAnnualReturnSinceInception 2.11% [3]
Inception Date rr_AverageAnnualReturnInceptionDate Mar. 01, 2010
ONE CHOICE 2040 PORTFOLIO | R CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.50%
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.20%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.73%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.43%
1 year rr_ExpenseExampleYear01 146
3 years rr_ExpenseExampleYear03 453
5 years rr_ExpenseExampleYear05 782
10 years rr_ExpenseExampleYear10 1,712
1 year rr_AverageAnnualReturnYear01 13.93%
Since Inception rr_AverageAnnualReturnSinceInception 2.65%
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008
ONE CHOICE 2045 PORTFOLIO
  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk/Return [Heading] rr_RiskReturnHeading ONE CHOICE 2045 PORTFOLIO
Objective [Heading] rr_ObjectiveHeading

Investment Objective
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The fund seeks the highest total return consistent with its asset mix.
Expense [Heading] rr_ExpenseHeading

Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses 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 $50,000 in American Century Investments funds. More information about these and other discounts is available from your financial professional and in Calculation of Sales Charges on page 60 of the fund's prospectus and Sales Charges in Appendix B of the 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

Because the fund buys and sells shares of other American Century mutual funds (the underlying funds) directly from the issuers, the fund is not expected to incur transaction costs directly. However, as a shareholder in the underlying funds, the fund indirectly pays transaction costs, such as commissions, when the underlying funds buy and sell securities (or "turn over" their portfolios). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 3% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 3.00%
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 $50,000 in American Century Investments funds. More information about these and other discounts is available from your financial professional and in Calculation of Sales Charges on page 60 of the fund's prospectus and Sales Charges in Appendix B of the statement of additional information.
Expense Breakpoint, Minimum Investment Required [Amount] rr_ExpenseBreakpointMinimumInvestmentRequiredAmount 50,000
Expense Example [Heading] rr_ExpenseExampleHeading

Example
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock

The example below is intended to help you compare the costs of investing in the fund with the costs of investing in other mutual funds.

Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption

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, that you earn a 5% return each year, and that the fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading] rr_StrategyHeading

Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

One Choice 2045 Portfolio is a "fund of funds," meaning that it seeks to achieve its objective by investing in other American Century mutual funds (the underlying funds) that represent a variety of asset classes and investment styles. The underlying stock funds draw on growth, value and quantitative investment techniques and diversify investments among small, medium and large U.S. and foreign companies. The underlying bond funds invest in fixed-income securities that vary by issuer type (corporate and government) and credit quality (investment-grade and high-yield or "junk bonds"). The following table shows the fund's target allocation for the various asset classes and underlying funds as of the date of the prospectus:

 

Equity Securities (Stock Funds)

80.40%

    

Fixed-Income Securities (Bond Funds)

19.60%

  

NT Core Equity Plus Fund

4.50%

    

High-Yield Fund

1.95%

  

NT Emerging Markets Fund

5.25%

    

Inflation-Adjusted Bond Fund

3.90%

  

NT Equity Growth Fund

10.35%

    

NT Diversified Bond Fund

13.75%

  

NT Growth Fund

14.50%

          

NT Heritage Fund

7.25%

    

Cash Equivalents (Money Market Funds)

 0.00%

  

NT International Growth Fund

10.25%

          

NT Large Company Value Fund

14.50%

          

NT Mid Cap Value Fund

7.25%

          

NT Small Company Fund

4.00%

          

Real Estate Fund

2.55%

          

 

The target date in the fund name (2045) refers to the approximate year an investor plans to retire and likely would stop making new investments in the fund. The fund assumes a retirement age of 65 and may not be appropriate for an investor who plans to retire at or near the target date, but at an age well before or after 65. As the target date approaches, the fund's asset mix will become more conservative by decreasing the allocation to stocks and increasing the allocation to bonds and cash. By the time the fund reaches its target date, the asset mix will become fixed and match that of One Choice In Retirement Portfolio, which is currently 45% stock funds, 45% bond funds and 10% money market funds. The fund is designed for investors who plan to withdraw the value of their account gradually after retirement. The following chart shows how the asset mix is expected to change over time according to a predetermined glide path.

 

One Choice Target Date Portfolios' Glide Path

Years to Retirement 45 44 43 42 41 40 39 38 37 36 35 34 33
Stocks 85.00% 85.00% 85.00% 85.00% 85.00% 85.00% 84.70% 83.90% 83.35% 82.80% 82.25% 81.70% 81.40%
Bonds 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.30% 16.10% 16.65% 17.20% 17.75% 18.30% 18.60%
Cash 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%
32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15
80.85% 80.40% 80.00% 78.45% 77.15% 76.35% 74.95% 73.40% 72.10% 70.80% 70.25% 68.55% 67.00% 65.85% 64.50% 63.35% 62.30% 61.00%
19.15% 19.60% 20.00% 21.05% 21.85% 22.15% 23.05% 24.10% 24.90% 25.70% 25.75% 26.95% 28.00% 29.15% 30.50% 31.65% 32.70% 34.00%
0.00% 0.00% 0.00% 0.50% 1.00% 1.50% 2.00% 2.50% 3.00% 3.50% 4.00% 4.50% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%
14 13 12 11 10 9 8 7 6 5 4 3 2 1   RETIREMENT
59.70% 58.60% 57.35% 56.30% 55.00% 54.20% 52.90% 52.10% 51.05% 50.00% 48.95% 47.90% 46.85% 46.05%   45.00%
35.30% 36.40% 37.65% 38.70% 40.00% 40.30% 41.10% 41.40% 41.95% 42.50% 43.05% 43.60% 44.15% 44.45%   45.00%
5.00% 5.00% 5.00% 5.00% 5.00% 5.50% 6.00% 6.50% 7.00% 7.50% 8.00% 8.50% 9.00% 9.50%   10.00%
Years After Retirement 1 2 3 4 5 6 7 8 9 10 11 12 13
Stocks 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Bonds 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Cash 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%

 

 

The portfolio managers regularly review the fund's allocations to determine whether rebalancing is appropriate. Although we do not intend to make frequent tactical adjustments to the target asset mix or trade actively among the underlying funds (other than the glide path adjustments described above), we reserve the right to modify the target allocations and underlying funds from time to time should circumstances warrant a change.
Risk [Heading] rr_RiskHeading

Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock

•

Allocation Risk – The fund's performance and risks depend in part on the managers' skill in determining the fund's asset class allocations and in selecting and weighting the underlying funds. The managers' evaluations and assumptions regarding asset classes or underlying funds may differ from actual market conditions.

•

"Growth" and "Value" Style Risks – The underlying funds represent a mix of investment styles, each of which has risks associated with it. Growth stocks can be volatile and may lack dividends that can cushion share prices during market declines. Value stocks may continue to be undervalued by the market for long periods of time.

•

Small- and Mid-Cap Stock Risks – Stocks of smaller companies may be more volatile than larger-company stocks. Smaller companies may have limited financial resources, product lines and markets, and their securities may trade less frequently and in more limited volumes than the securities of larger companies, which could lead to higher transaction costs. To the extent an underlying fund invests in these companies, it may take on more risk.

•

Interest Rate Risk – Generally, when interest rates rise, the value of an underlying fund's fixed-income securities will decline. The opposite is true when interest rates decline. Underlying funds with longer weighted average maturities are more sensitive to interest rate changes.

•

Credit Risk - The value of an underlying fund's fixed-income securities will be affected adversely by any erosion in the ability of the issuers of these securities to make interest and principal payments as they become due. Changes in the credit rating of a fixed-income security held by an underlying fund could have a similar effect.

•

Foreign Securities Risk – Some of the underlying funds invest in foreign securities, which are generally riskier than U.S. securities. Securities of foreign issuers may be less liquid, more volatile and harder to value than U.S. securities. Fluctuations in currency exchange rates also may affect an underlying fund's share price. Investing in securities of companies located in emerging market countries is generally riskier than investing in securities of companies located in developed foreign countries.

•

Tobacco Exclusion – The underlying funds do not invest in securities issued by companies assigned the Global Industry Classification Standard (GICS) for the tobacco industry. This exclusion may cause an underlying fund to forego profitable investment opportunities.

•

Market Risk – The value of the fund's shares will go up and down based on the performance of the underlying funds in which it invests. The value of the underlying funds' shares will, in turn, fluctuate based on the performance of the securities they own and other factors generally affecting the securities market.

•

Principal Loss – At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.

  

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Risk Lose Money [Text] rr_RiskLoseMoney

Principal Loss -At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.
Risk Not Insured Depository Institution [Text] rr_RiskNotInsuredDepositoryInstitution

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading

Fund Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund's performance from year to year for Investor Class shares. The table shows how the fund's average annual returns for the periods shown compared with those of a broad measure of market performance. The fund's past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future. For current performance information, including yields, please visit americancentury.com.

 

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown.
Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund's performance from year to year for Investor Class shares. The table shows how the fund's average annual returns for the periods shown compared with those of a broad measure of market performance.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress americancentury.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture The fund's past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.
Bar Chart [Heading] rr_BarChartHeading

Calendar Year Total Returns
Bar Chart Does Not Reflect Sales Loads [Text] rr_BarChartDoesNotReflectSalesLoads

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown.
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock

Highest Performance Quarter (2Q 2009): 14.89% 

Lowest Performance Quarter (4Q 2008): -19.49% 

As of September 30, 2013, the most recent calendar quarter end, the fund's Investor Class year-to-date return was 13.33%.
Year to Date Return, Label rr_YearToDateReturnLabel Investor Class year-to-date
Bar Chart, Year to Date Return, Date rr_BarChartYearToDateReturnDate Sep. 30, 2013
Bar Chart, Year to Date Return rr_BarChartYearToDateReturn 13.33%
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Highest Performance Quarter
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Jun. 30, 2009
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 14.89%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Lowest Performance Quarter
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Dec. 31, 2008
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (19.49%)
Performance Table Heading rr_PerformanceTableHeading

Average Annual Total Returns For the calendar year ended December 31, 2012
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate 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.
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred Actual after-tax returns depend on an investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.
Performance Table One Class of after Tax Shown [Text] rr_PerformanceTableOneClassOfAfterTaxShown The after-tax returns are shown only for Investor Class shares. After-tax returns for other share classes will vary.
Performance Table Closing [Text Block] rr_PerformanceTableClosingTextBlock

The after-tax returns are shown only for Investor Class shares. After-tax returns for other share classes will vary. 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. After-tax returns are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.
ONE CHOICE 2045 PORTFOLIO | Russell 3000 Index (reflects no deduction for fees, expenses or taxes)
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 16.42%
5 years rr_AverageAnnualReturnYear05 2.04%
Since Inception rr_AverageAnnualReturnSinceInception 5.79%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE 2045 PORTFOLIO | Barclays U.S. Aggregate Bond Index (reflects no deduction for fees, expenses or taxes)
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 4.21%
5 years rr_AverageAnnualReturnYear05 5.95%
Since Inception rr_AverageAnnualReturnSinceInception 5.36%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE 2045 PORTFOLIO | INVESTOR CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee 25
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.21%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.76%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.97%
1 year rr_ExpenseExampleYear01 99
3 years rr_ExpenseExampleYear03 310
5 years rr_ExpenseExampleYear05 537
10 years rr_ExpenseExampleYear10 1,190
Annual Return 2005 rr_AnnualReturn2005 7.85%
Annual Return 2006 rr_AnnualReturn2006 14.53%
Annual Return 2007 rr_AnnualReturn2007 10.74%
Annual Return 2008 rr_AnnualReturn2008 (33.64%)
Annual Return 2009 rr_AnnualReturn2009 26.36%
Annual Return 2010 rr_AnnualReturn2010 15.50%
Annual Return 2011 rr_AnnualReturn2011 (0.78%)
Annual Return 2012 rr_AnnualReturn2012 15.00%
1 year rr_AverageAnnualReturnYear01 15.00%
5 years rr_AverageAnnualReturnYear05 2.02%
Since Inception rr_AverageAnnualReturnSinceInception 6.54%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE 2045 PORTFOLIO | INVESTOR CLASS | Return After Taxes on Distributions
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 14.52%
5 years rr_AverageAnnualReturnYear05 1.52%
Since Inception rr_AverageAnnualReturnSinceInception 5.81%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE 2045 PORTFOLIO | INVESTOR CLASS | Return After Taxes on Distributions and Sale of Fund Shares
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 10.18%
5 years rr_AverageAnnualReturnYear05 1.50%
Since Inception rr_AverageAnnualReturnSinceInception 5.37%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE 2045 PORTFOLIO | INSTITUTIONAL CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Administrative Fee rr_Component1OtherExpensesOverAssets none
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.01%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.76%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.77%
1 year rr_ExpenseExampleYear01 79
3 years rr_ExpenseExampleYear03 246
5 years rr_ExpenseExampleYear05 428
10 years rr_ExpenseExampleYear10 955
1 year rr_AverageAnnualReturnYear01 15.32%
5 years rr_AverageAnnualReturnYear05 2.22%
Since Inception rr_AverageAnnualReturnSinceInception 6.76%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE 2045 PORTFOLIO | A CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice 5.75%
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none [1]
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.25%
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.21%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.76%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.22%
1 year rr_ExpenseExampleYear01 692
3 years rr_ExpenseExampleYear03 941
5 years rr_ExpenseExampleYear05 1,207
10 years rr_ExpenseExampleYear10 1,967
1 year rr_AverageAnnualReturnYear01 8.12% [2]
5 years rr_AverageAnnualReturnYear05 0.57% [2]
Since Inception rr_AverageAnnualReturnSinceInception 5.52% [2]
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004 [2]
ONE CHOICE 2045 PORTFOLIO | C CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice 1.00%
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 1.00%
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.21%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.76%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.97%
1 year rr_ExpenseExampleYear01 200
3 years rr_ExpenseExampleYear03 619
5 years rr_ExpenseExampleYear05 1,063
10 years rr_ExpenseExampleYear10 2,293
1 year rr_AverageAnnualReturnYear01 13.90%
5 years rr_AverageAnnualReturnYear05 1.00% [3]
Since Inception rr_AverageAnnualReturnSinceInception 5.48% [3]
Inception Date rr_AverageAnnualReturnInceptionDate Mar. 01, 2010
ONE CHOICE 2045 PORTFOLIO | R CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.50%
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.21%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.76%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.47%
1 year rr_ExpenseExampleYear01 150
3 years rr_ExpenseExampleYear03 466
5 years rr_ExpenseExampleYear05 803
10 years rr_ExpenseExampleYear10 1,756
1 year rr_AverageAnnualReturnYear01 14.42%
5 years rr_AverageAnnualReturnYear05 1.49%
Since Inception rr_AverageAnnualReturnSinceInception 6.01%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 2004
ONE CHOICE 2050 PORTFOLIO
  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk/Return [Heading] rr_RiskReturnHeading ONE CHOICE 2050 PORTFOLIO
Objective [Heading] rr_ObjectiveHeading

Investment Objective
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The fund seeks the highest total return consistent with its asset mix.
Expense [Heading] rr_ExpenseHeading

Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses 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 $50,000 in American Century Investments funds. More information about these and other discounts is available from your financial professional and in Calculation of Sales Charges on page 60 of the fund's prospectus and Sales Charges in Appendix B of the 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

Because the fund buys and sells shares of other American Century mutual funds (the underlying funds) directly from the issuers, the fund is not expected to incur transaction costs directly. However, as a shareholder in the underlying funds, the fund indirectly pays transaction costs, such as commissions, when the underlying funds buy and sell securities (or "turn over" their portfolios). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 4% of the average value of its portfolio.

Portfolio Turnover, Rate rr_PortfolioTurnoverRate 4.00%
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 $50,000 in American Century Investments funds. More information about these and other discounts is available from your financial professional and in Calculation of Sales Charges on page 60 of the fund's prospectus and Sales Charges in Appendix B of the statement of additional information.
Expense Breakpoint, Minimum Investment Required [Amount] rr_ExpenseBreakpointMinimumInvestmentRequiredAmount 50,000
Expense Example [Heading] rr_ExpenseExampleHeading

Example
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock

The example below is intended to help you compare the costs of investing in the fund with the costs of investing in other mutual funds.

Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption

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, that you earn a 5% return each year, and that the fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading] rr_StrategyHeading

Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

One Choice 2050 Portfolio is a "fund of funds," meaning that it seeks to achieve its objective by investing in other American Century mutual funds (the underlying funds) that represent a variety of asset classes and investment styles. The underlying stock funds draw on growth, value and quantitative investment techniques and diversify investments among small, medium and large U.S. and foreign companies. The underlying bond funds invest in fixed-income securities that vary by issuer type (corporate and government) and credit quality (investment-grade and high-yield or "junk bonds"). The following table shows the fund's target allocation for the various asset classes and underlying funds as of the date of the prospectus:

 

Equity Securities (Stock Funds)

82.80%

    

Fixed-Income Securities (Bond Funds)

17.20%

  

NT Core Equity Plus Fund

4.50%

    

High-Yield Fund

1.70%

  

NT Emerging Markets Fund

6.25%

    

Inflation-Adjusted Bond Fund

3.40%

  

NT Equity Growth Fund

10.25%

    

NT Diversified Bond Fund

12.10%

  

NT Growth Fund

14.75%

          

NT Heritage Fund

7.25%

    

Cash Equivalents (Money Market Funds)

 0.00%

  

NT International Growth Fund

10.00%

          

NT Large Company Value Fund

15.00%

          

NT Mid Cap Value Fund

7.25%

          

NT Small Company Fund

4.75%

          

Real Estate Fund

2.80%

          

 

The target date in the fund name (2050) refers to the approximate year an investor plans to retire and likely would stop making new investments in the fund. The fund assumes a retirement age of 65 and may not be appropriate for an investor who plans to retire at or near the target date, but at an age well before or after 65. As the target date approaches, the fund's asset mix will become more conservative by decreasing the allocation to stocks and increasing the allocation to bonds and cash. By the time the fund reaches its target date, the asset mix will become fixed and match that of One Choice In Retirement Portfolio, which is currently 45% stock funds, 45% bond funds and 10% money market funds. The fund is designed for investors who plan to withdraw the value of their account gradually after retirement. The following chart shows how the asset mix is expected to change over time according to a predetermined glide path. 

 

One Choice Target Date Portfolios' Glide Path

Years to Retirement 45 44 43 42 41 40 39 38 37 36 35 34 33
Stocks 85.00% 85.00% 85.00% 85.00% 85.00% 85.00% 84.70% 83.90% 83.35% 82.80% 82.25% 81.70% 81.40%
Bonds 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.30% 16.10% 16.65% 17.20% 17.75% 18.30% 18.60%
Cash 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%
32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15
80.85% 80.40% 80.00% 78.45% 77.15% 76.35% 74.95% 73.40% 72.10% 70.80% 70.25% 68.55% 67.00% 65.85% 64.50% 63.35% 62.30% 61.00%
19.15% 19.60% 20.00% 21.05% 21.85% 22.15% 23.05% 24.10% 24.90% 25.70% 25.75% 26.95% 28.00% 29.15% 30.50% 31.65% 32.70% 34.00%
0.00% 0.00% 0.00% 0.50% 1.00% 1.50% 2.00% 2.50% 3.00% 3.50% 4.00% 4.50% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%
14 13 12 11 10 9 8 7 6 5 4 3 2 1   RETIREMENT
59.70% 58.60% 57.35% 56.30% 55.00% 54.20% 52.90% 52.10% 51.05% 50.00% 48.95% 47.90% 46.85% 46.05%   45.00%
35.30% 36.40% 37.65% 38.70% 40.00% 40.30% 41.10% 41.40% 41.95% 42.50% 43.05% 43.60% 44.15% 44.45%   45.00%
5.00% 5.00% 5.00% 5.00% 5.00% 5.50% 6.00% 6.50% 7.00% 7.50% 8.00% 8.50% 9.00% 9.50%   10.00%
Years After Retirement 1 2 3 4 5 6 7 8 9 10 11 12 13
Stocks 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Bonds 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Cash 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%

 

The portfolio managers regularly review the fund's allocations to determine whether rebalancing is appropriate. Although we do not intend to make frequent tactical adjustments to the target asset mix or trade actively among the underlying funds (other than the glide path adjustments described above), we reserve the right to modify the target allocations and underlying funds from time to time should circumstances warrant a change.
Risk [Heading] rr_RiskHeading

Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock

•

Allocation Risk – The fund's performance and risks depend in part on the managers' skill in determining the fund's asset class allocations and in selecting and weighting the underlying funds. The managers' evaluations and assumptions regarding asset classes or underlying funds may differ from actual market conditions.

•

"Growth" and "Value" Style Risks – The underlying funds represent a mix of investment styles, each of which has risks associated with it. Growth stocks can be volatile and may lack dividends that can cushion share prices during market declines. Value stocks may continue to be undervalued by the market for long periods of time.

•

Small- and Mid-Cap Stock Risks – Stocks of smaller companies may be more volatile than larger-company stocks. Smaller companies may have limited financial resources, product lines and markets, and their securities may trade less frequently and in more limited volumes than the securities of larger companies, which could lead to higher transaction costs. To the extent an underlying fund invests in these companies, it may take on more risk.

•

Interest Rate Risk – Generally, when interest rates rise, the value of an underlying fund's fixed-income securities will decline. The opposite is true when interest rates decline. Underlying funds with longer weighted average maturities are more sensitive to interest rate changes.

•

Credit Risk - The value of an underlying fund's fixed-income securities will be affected adversely by any erosion in the ability of the issuers of these securities to make interest and principal payments as they become due. Changes in the credit rating of a fixed-income security held by an underlying fund could have a similar effect.

•

Foreign Securities Risk – Some of the underlying funds invest in foreign securities, which are generally riskier than U.S. securities. Securities of foreign issuers may be less liquid, more volatile and harder to value than U.S. securities. Fluctuations in currency exchange rates also may affect an underlying fund's share price. Investing in securities of companies located in emerging market countries is generally riskier than investing in securities of companies located in developed foreign countries.

•

Tobacco Exclusion – The underlying funds do not invest in securities issued by companies assigned the Global Industry Classification Standard (GICS) for the tobacco industry. This exclusion may cause an underlying fund to forego profitable investment opportunities.

•

Market Risk – The value of the fund's shares will go up and down based on the performance of the underlying funds in which it invests. The value of the underlying funds' shares will, in turn, fluctuate based on the performance of the securities they own and other factors generally affecting the securities market.

•

Principal Loss – At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.

 

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Risk Lose Money [Text] rr_RiskLoseMoney

Principal Loss -At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.
Risk Not Insured Depository Institution [Text] rr_RiskNotInsuredDepositoryInstitution

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading

Fund Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund's performance from year to year for Investor Class shares. The table shows how the fund's average annual returns for the periods shown compared with those of a broad measure of market performance. The fund's past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future. For current performance information, including yields, please visit americancentury.com.

 

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown. 
Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund's performance from year to year for Investor Class shares. The table shows how the fund's average annual returns for the periods shown compared with those of a broad measure of market performance.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress americancentury.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture The fund's past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.
Bar Chart [Heading] rr_BarChartHeading

Calendar Year Total Returns
Bar Chart Does Not Reflect Sales Loads [Text] rr_BarChartDoesNotReflectSalesLoads

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown.
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock

Highest Performance Quarter (2Q 2009): 15.07%

Lowest Performance Quarter (3Q 2011): -14.04% 

As of September 30, 2013, the most recent calendar quarter end, the fund's Investor Class year-to-date return was 13.59%.

Year to Date Return, Label rr_YearToDateReturnLabel Investor Class year-to-date
Bar Chart, Year to Date Return, Date rr_BarChartYearToDateReturnDate Sep. 30, 2013
Bar Chart, Year to Date Return rr_BarChartYearToDateReturn 13.59%
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Highest Performance Quarter
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Jun. 30, 2009
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 15.07%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Lowest Performance Quarter
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Sep. 30, 2011
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (14.04%)
Performance Table Heading rr_PerformanceTableHeading

Average Annual Total Returns For the calendar year ended December 31, 2012
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate 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.
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred Actual after-tax returns depend on an investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.
Performance Table One Class of after Tax Shown [Text] rr_PerformanceTableOneClassOfAfterTaxShown The after-tax returns are shown only for Investor Class shares. After-tax returns for other share classes will vary.
Performance Table Closing [Text Block] rr_PerformanceTableClosingTextBlock

The after-tax returns are shown only for Investor Class shares. After-tax returns for other share classes will vary. 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. After-tax returns are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.
ONE CHOICE 2050 PORTFOLIO | Russell 3000 Index (reflects no deduction for fees, expenses or taxes)
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 16.42%
Since Inception rr_AverageAnnualReturnSinceInception 2.93%
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008
ONE CHOICE 2050 PORTFOLIO | Barclays U.S. Aggregate Bond Index (reflects no deduction for fees, expenses or taxes)
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 4.21%
Since Inception rr_AverageAnnualReturnSinceInception 6.23%
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008
ONE CHOICE 2050 PORTFOLIO | INVESTOR CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee 25
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.20%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.78%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.98%
1 year rr_ExpenseExampleYear01 100
3 years rr_ExpenseExampleYear03 313
5 years rr_ExpenseExampleYear05 542
10 years rr_ExpenseExampleYear10 1,201
Annual Return 2009 rr_AnnualReturn2009 26.66%
Annual Return 2010 rr_AnnualReturn2010 15.70%
Annual Return 2011 rr_AnnualReturn2011 (0.96%)
Annual Return 2012 rr_AnnualReturn2012 15.39%
1 year rr_AverageAnnualReturnYear01 15.39%
Since Inception rr_AverageAnnualReturnSinceInception 2.55%
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008
ONE CHOICE 2050 PORTFOLIO | INVESTOR CLASS | Return After Taxes on Distributions
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 14.94%
Since Inception rr_AverageAnnualReturnSinceInception 2.21%
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008
ONE CHOICE 2050 PORTFOLIO | INVESTOR CLASS | Return After Taxes on Distributions and Sale of Fund Shares
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 10.43%
Since Inception rr_AverageAnnualReturnSinceInception 2.05%
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008
ONE CHOICE 2050 PORTFOLIO | INSTITUTIONAL CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Administrative Fee rr_Component1OtherExpensesOverAssets none
Other rr_Component2OtherExpensesOverAssets none
Other Expenses rr_OtherExpensesOverAssets none
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.78%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.78%
1 year rr_ExpenseExampleYear01 80
3 years rr_ExpenseExampleYear03 250
5 years rr_ExpenseExampleYear05 434
10 years rr_ExpenseExampleYear10 966
1 year rr_AverageAnnualReturnYear01 15.50%
Since Inception rr_AverageAnnualReturnSinceInception 2.75%
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008
ONE CHOICE 2050 PORTFOLIO | A CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice 5.75%
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none [1]
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.25%
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.20%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.78%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.23%
1 year rr_ExpenseExampleYear01 693
3 years rr_ExpenseExampleYear03 943
5 years rr_ExpenseExampleYear05 1,212
10 years rr_ExpenseExampleYear10 1,978
1 year rr_AverageAnnualReturnYear01 8.54% [2]
Since Inception rr_AverageAnnualReturnSinceInception 0.98% [2]
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008 [2]
ONE CHOICE 2050 PORTFOLIO | C CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice 1.00%
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 1.00%
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.20%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.78%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.98%
1 year rr_ExpenseExampleYear01 201
3 years rr_ExpenseExampleYear03 622
5 years rr_ExpenseExampleYear05 1,068
10 years rr_ExpenseExampleYear10 2,303
1 year rr_AverageAnnualReturnYear01 14.20%
Since Inception rr_AverageAnnualReturnSinceInception 1.52% [3]
Inception Date rr_AverageAnnualReturnInceptionDate Mar. 01, 2010
ONE CHOICE 2050 PORTFOLIO | R CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.50%
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.20%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.78%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.48%
1 year rr_ExpenseExampleYear01 151
3 years rr_ExpenseExampleYear03 469
5 years rr_ExpenseExampleYear05 809
10 years rr_ExpenseExampleYear10 1,767
1 year rr_AverageAnnualReturnYear01 14.68%
Since Inception rr_AverageAnnualReturnSinceInception 2.04%
Inception Date rr_AverageAnnualReturnInceptionDate May 30, 2008
ONE CHOICE 2055 PORTFOLIO
  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk/Return [Heading] rr_RiskReturnHeading ONE CHOICE 2055 PORTFOLIO
Objective [Heading] rr_ObjectiveHeading

Investment Objective
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The fund seeks the highest total return consistent with its asset mix.
Expense [Heading] rr_ExpenseHeading

Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses 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 $50,000 in American Century Investments funds. More information about these and other discounts is available from your financial professional and in Calculation of Sales Charges on page 60 of the fund's prospectus and Sales Charges in Appendix B of the 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

Because the fund buys and sells shares of other American Century mutual funds (the underlying funds) directly from the issuers, the fund is not expected to incur transaction costs directly. However, as a shareholder in the underlying funds, the fund indirectly pays transaction costs, such as commissions, when the underlying funds buy and sell securities (or "turn over" their portfolios). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 13% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 13.00%
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 $50,000 in American Century Investments funds. More information about these and other discounts is available from your financial professional and in Calculation of Sales Charges on page 60 of the fund's prospectus and Sales Charges in Appendix B of the statement of additional information.
Expense Breakpoint, Minimum Investment Required [Amount] rr_ExpenseBreakpointMinimumInvestmentRequiredAmount 50,000
Expense Example [Heading] rr_ExpenseExampleHeading

Example
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock

The example below is intended to help you compare the costs of investing in the fund with the costs of investing in other mutual funds.

Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption

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, that you earn a 5% return each year, and that the fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading] rr_StrategyHeading

Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

One Choice 2055 Portfolio is a "fund of funds," meaning that it seeks to achieve its objective by investing in other American Century mutual funds (the underlying funds) that represent a variety of asset classes and investment styles. The underlying stock funds draw on growth, value and quantitative investment techniques and diversify investments among small, medium and large U.S. and foreign companies. The underlying bond funds invest in fixed-income securities that vary by issuer type (corporate and government) and credit quality (investment-grade and high-yield or "junk bonds"). The following table shows the fund's target allocation for the various asset classes and underlying funds as of the date of the prospectus:

 

Equity Securities (Stock Funds)

85.00%

    

Fixed-Income Securities (Bond Funds)

15.00%

  

NT Core Equity Plus Fund

4.50%

    

High-Yield Fund

1.50%

  

NT Emerging Markets Fund

6.50%

    

Inflation-Adjusted Bond Fund

3.00%

  

NT Equity Growth Fund

10.75%

    

NT Diversified Bond Fund

10.50%

  

NT Growth Fund

15.25%

          

NT Heritage Fund

7.50%

    

Cash Equivalents (Money Market Funds)

 0.00%

  

NT International Growth Fund

9.50%

          

NT Large Company Value Fund

15.50%

          

NT Mid Cap Value Fund

7.50%

          

NT Small Company Fund

5.00%

          

Real Estate Fund

3.00%

          

 

The target date in the fund name (2055) refers to the approximate year an investor plans to retire and likely would stop making new investments in the fund. The fund assumes a retirement age of 65 and may not be appropriate for an investor who plans to retire at or near the target date, but at an age well before or after 65. As the target date approaches, the fund's asset mix will become more conservative by decreasing the allocation to stocks and increasing the allocation to bonds and cash. By the time the fund reaches its target date, the asset mix will become fixed and match that of One Choice In Retirement Portfolio, which is currently 45% stock funds, 45% bond funds and 10% money market funds. The fund is designed for investors who plan to withdraw the value of their account gradually after retirement. The following chart shows how the asset mix is expected to change over time according to a predetermined glide path.

 

One Choice Target Date Portfolios' Glide Path

Years to Retirement 45 44 43 42 41 40 39 38 37 36 35 34 33
Stocks 85.00% 85.00% 85.00% 85.00% 85.00% 85.00% 84.70% 83.90% 83.35% 82.80% 82.25% 81.70% 81.40%
Bonds 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.30% 16.10% 16.65% 17.20% 17.75% 18.30% 18.60%
Cash 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%
32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15
80.85% 80.40% 80.00% 78.45% 77.15% 76.35% 74.95% 73.40% 72.10% 70.80% 70.25% 68.55% 67.00% 65.85% 64.50% 63.35% 62.30% 61.00%
19.15% 19.60% 20.00% 21.05% 21.85% 22.15% 23.05% 24.10% 24.90% 25.70% 25.75% 26.95% 28.00% 29.15% 30.50% 31.65% 32.70% 34.00%
0.00% 0.00% 0.00% 0.50% 1.00% 1.50% 2.00% 2.50% 3.00% 3.50% 4.00% 4.50% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%
14 13 12 11 10 9 8 7 6 5 4 3 2 1   RETIREMENT
59.70% 58.60% 57.35% 56.30% 55.00% 54.20% 52.90% 52.10% 51.05% 50.00% 48.95% 47.90% 46.85% 46.05%   45.00%
35.30% 36.40% 37.65% 38.70% 40.00% 40.30% 41.10% 41.40% 41.95% 42.50% 43.05% 43.60% 44.15% 44.45%   45.00%
5.00% 5.00% 5.00% 5.00% 5.00% 5.50% 6.00% 6.50% 7.00% 7.50% 8.00% 8.50% 9.00% 9.50%   10.00%
Years After Retirement 1 2 3 4 5 6 7 8 9 10 11 12 13
Stocks 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Bonds 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Cash 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%

 

The portfolio managers regularly review the fund's allocations to determine whether rebalancing is appropriate. Although we do not intend to make frequent tactical adjustments to the target asset mix or trade actively among the underlying funds (other than the glide path adjustments described above), we reserve the right to modify the target allocations and underlying funds from time to time should circumstances warrant a change.
Risk [Heading] rr_RiskHeading

Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock

•

Allocation Risk – The fund's performance and risks depend in part on the managers' skill in determining the fund's asset class allocations and in selecting and weighting the underlying funds. The managers' evaluations and assumptions regarding asset classes or underlying funds may differ from actual market conditions.

•

"Growth" and "Value" Style Risks – The underlying funds represent a mix of investment styles, each of which has risks associated with it. Growth stocks can be volatile and may lack dividends that can cushion share prices during market declines. Value stocks may continue to be undervalued by the market for long periods of time.

•

Small- and Mid-Cap Stock Risks – Stocks of smaller companies may be more volatile than larger-company stocks. Smaller companies may have limited financial resources, product lines and markets, and their securities may trade less frequently and in more limited volumes than the securities of larger companies, which could lead to higher transaction costs. To the extent an underlying fund invests in these companies, it may take on more risk.

•

Interest Rate Risk – Generally, when interest rates rise, the value of an underlying fund's fixed-income securities will decline. The opposite is true when interest rates decline. Underlying funds with longer weighted average maturities are more sensitive to interest rate changes.

•

Credit Risk - The value of an underlying fund's fixed-income securities will be affected adversely by any erosion in the ability of the issuers of these securities to make interest and principal payments as they become due. Changes in the credit rating of a fixed-income security held by an underlying fund could have a similar effect.

•

Foreign Securities Risk – Some of the underlying funds invest in foreign securities, which are generally riskier than U.S. securities. Securities of foreign issuers may be less liquid, more volatile and harder to value than U.S. securities. Fluctuations in currency exchange rates also may affect an underlying fund's share price. Investing in securities of companies located in emerging market countries is generally riskier than investing in securities of companies located in developed foreign countries.

•

Tobacco Exclusion – The underlying funds do not invest in securities issued by companies assigned the Global Industry Classification Standard (GICS) for the tobacco industry. This exclusion may cause an underlying fund to forego profitable investment opportunities.

•

Market Risk – The value of the fund's shares will go up and down based on the performance of the underlying funds in which it invests. The value of the underlying funds' shares will, in turn, fluctuate based on the performance of the securities they own and other factors generally affecting the securities market.

•

Principal Loss – At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.

 

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Risk Lose Money [Text] rr_RiskLoseMoney

Principal Loss -At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.
Risk Not Insured Depository Institution [Text] rr_RiskNotInsuredDepositoryInstitution

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading

Fund Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund's performance from year to year for Investor Class shares. The table shows how the fund's average annual returns for the periods shown compared with those of a broad measure of market performance. The fund's past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future. For current performance information, including yields, please visit americancentury.com.

 

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown. 
Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund's performance from year to year for Investor Class shares. The table shows how the fund's average annual returns for the periods shown compared with those of a broad measure of market performance.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress americancentury.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture The fund's past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.
Bar Chart [Heading] rr_BarChartHeading

Calendar Year Total Returns
Bar Chart Does Not Reflect Sales Loads [Text] rr_BarChartDoesNotReflectSalesLoads

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown.
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock

Highest Performance Quarter (1Q 2012): 11.54% 

Lowest Performance Quarter (2Q 2012): -3.16% 

As of September 30, 2013, the most recent calendar quarter end, the fund's Investor Class year-to-date return was 14.00%.

Year to Date Return, Label rr_YearToDateReturnLabel Investor Class year-to-date
Bar Chart, Year to Date Return, Date rr_BarChartYearToDateReturnDate Sep. 30, 2013
Bar Chart, Year to Date Return rr_BarChartYearToDateReturn 14.00%
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Highest Performance Quarter
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Mar. 31, 2012
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 11.54%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Lowest Performance Quarter
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Jun. 30, 2012
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (3.16%)
Performance Table Heading rr_PerformanceTableHeading

Average Annual Total Returns For the calendar year ended December 31, 2012
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate 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.
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred Actual after-tax returns depend on an investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.
Performance Table One Class of after Tax Shown [Text] rr_PerformanceTableOneClassOfAfterTaxShown The after-tax returns are shown only for Investor Class shares. After-tax returns for other share classes will vary.
Performance Table Closing [Text Block] rr_PerformanceTableClosingTextBlock

The after-tax returns are shown only for Investor Class shares. After-tax returns for other share classes will vary. 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. After-tax returns are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.
ONE CHOICE 2055 PORTFOLIO | Russell 3000 Index (reflects no deduction for fees, expenses or taxes)
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 16.42%
Since Inception rr_AverageAnnualReturnSinceInception 5.90%
Inception Date rr_AverageAnnualReturnInceptionDate Mar. 31, 2011
ONE CHOICE 2055 PORTFOLIO | Barclays U.S. Aggregate Bond Index (reflects no deduction for fees, expenses or taxes)
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 4.21%
Since Inception rr_AverageAnnualReturnSinceInception 6.64%
Inception Date rr_AverageAnnualReturnInceptionDate Mar. 31, 2011
ONE CHOICE 2055 PORTFOLIO | INVESTOR CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee 25
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.21%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.78%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.99%
1 year rr_ExpenseExampleYear01 101
3 years rr_ExpenseExampleYear03 316
5 years rr_ExpenseExampleYear05 548
10 years rr_ExpenseExampleYear10 1,213
Annual Return 2012 rr_AnnualReturn2012 15.51%
1 year rr_AverageAnnualReturnYear01 15.51%
Since Inception rr_AverageAnnualReturnSinceInception 5.15%
Inception Date rr_AverageAnnualReturnInceptionDate Mar. 31, 2011
ONE CHOICE 2055 PORTFOLIO | INVESTOR CLASS | Return After Taxes on Distributions
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 15.17%
Since Inception rr_AverageAnnualReturnSinceInception 4.83%
Inception Date rr_AverageAnnualReturnInceptionDate Mar. 31, 2011
ONE CHOICE 2055 PORTFOLIO | INVESTOR CLASS | Return After Taxes on Distributions and Sale of Fund Shares
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 10.38%
Since Inception rr_AverageAnnualReturnSinceInception 4.29%
Inception Date rr_AverageAnnualReturnInceptionDate Mar. 31, 2011
ONE CHOICE 2055 PORTFOLIO | INSTITUTIONAL CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Administrative Fee rr_Component1OtherExpensesOverAssets none
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.01%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.78%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.79%
1 year rr_ExpenseExampleYear01 81
3 years rr_ExpenseExampleYear03 253
5 years rr_ExpenseExampleYear05 439
10 years rr_ExpenseExampleYear10 978
1 year rr_AverageAnnualReturnYear01 15.63%
Since Inception rr_AverageAnnualReturnSinceInception 5.31%
Inception Date rr_AverageAnnualReturnInceptionDate Mar. 31, 2011
ONE CHOICE 2055 PORTFOLIO | A CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice 5.75%
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none [1]
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.25%
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.21%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.78%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.24%
1 year rr_ExpenseExampleYear01 694
3 years rr_ExpenseExampleYear03 946
5 years rr_ExpenseExampleYear05 1,218
10 years rr_ExpenseExampleYear10 1,988
1 year rr_AverageAnnualReturnYear01 8.61%
Since Inception rr_AverageAnnualReturnSinceInception 1.36%
Inception Date rr_AverageAnnualReturnInceptionDate Mar. 31, 2011
ONE CHOICE 2055 PORTFOLIO | C CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice 1.00%
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 1.00%
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.21%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.78%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.99%
1 year rr_ExpenseExampleYear01 202
3 years rr_ExpenseExampleYear03 625
5 years rr_ExpenseExampleYear05 1,073
10 years rr_ExpenseExampleYear10 2,314
1 year rr_AverageAnnualReturnYear01 14.34%
Since Inception rr_AverageAnnualReturnSinceInception 4.10%
Inception Date rr_AverageAnnualReturnInceptionDate Mar. 31, 2011
ONE CHOICE 2055 PORTFOLIO | R CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
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 lower of the original offering price or redemption proceeds when redeemed within one year of purchase) rr_MaximumDeferredSalesChargeOverOfferingPrice none
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee none
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets 0.50%
Administrative Fee rr_Component1OtherExpensesOverAssets 0.20%
Other rr_Component2OtherExpensesOverAssets 0.01%
Other Expenses rr_OtherExpensesOverAssets 0.21%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.78%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.49%
1 year rr_ExpenseExampleYear01 152
3 years rr_ExpenseExampleYear03 472
5 years rr_ExpenseExampleYear05 814
10 years rr_ExpenseExampleYear10 1,778
1 year rr_AverageAnnualReturnYear01 14.93%
Since Inception rr_AverageAnnualReturnSinceInception 4.63%
Inception Date rr_AverageAnnualReturnInceptionDate Mar. 31, 2011
ONE CHOICE PORTFOLIO: VERY CONSERVATIVE
  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk/Return [Heading] rr_RiskReturnHeading ONE CHOICE PORTFOLIO: VERY CONSERVATIVE
Objective [Heading] rr_ObjectiveHeading

Investment Objective
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The fund seeks the highest total return consistent with its asset mix.

Expense [Heading] rr_ExpenseHeading

Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the fund.
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

Because the fund buys and sells shares of other American Century mutual funds (the underlying funds) directly from the issuers, the fund is not expected to incur transaction costs directly. However, as a shareholder in the underlying funds, the fund indirectly pays transaction costs, such as commissions, when the underlying funds buy and sell securities (or "turn over" their portfolios). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 28% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 28.00%
Expense Example [Heading] rr_ExpenseExampleHeading

Example
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock

The example below is intended to help you compare the costs of investing in the fund with the costs of investing in other mutual funds.

Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption

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, that you earn a 5% return each year, and that the fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading] rr_StrategyHeading

Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

One Choice Portfolio: Very Conservative is a "fund of funds," meaning that it seeks to achieve its objective by investing in other American Century Investments mutual funds (the underlying funds) that represent a variety of asset classes and investment styles. The fund's asset allocation is intended to diversify investments among stocks, bonds and cash equivalents.

  

The following table indicates the fund's neutral mix; that is, how the fund's investments generally will be allocated among the major asset classes over the long term.

 

Equity Securities (Stock Funds)

25.00%

  

Fixed-Income Securities (Bond Funds)

  52.00%

Core Equity Plus Fund

1.00%

  

Diversified Bond Fund

32.00%

Equity Growth Fund

4.00%

  

Inflation-Adjusted Bond Fund

10.00%

Growth Fund

2.50%

  

International Bond Fund

10.00%

Heritage Fund*

1.50%

      

Large Company Value Fund

8.00%

  

Cash Equivalents (Money Market Funds)

23.00%

Mid Cap Value Fund

5.00%

  

Prime Money Market Fund

23.00%

Real Estate Fund

2.00%

      

Small Company Fund

1.00%

      

 

The managers regularly review the fund and may make changes to the fund's asset class allocations that deviate from the neutral mix to emphasize investments that they believe will provide the most favorable outlook for achieving the fund's objective. The fund also may deviate from the neutral mix due to differences in asset class performance or prevailing market conditions. The following table shows the operating ranges within which the fund's asset class allocations generally will vary over short-term periods.

 

 

Equity Securities (Stock Funds)

Fixed-Income Securities (Bond Funds)

Cash Equivalents (Money Market Funds)

Operating Ranges

20-30%

45-55%

15-35%

 

However, in light of the current extreme low interest rate environment for cash equivalent (money market) securities, the managers have reallocated a portion of the fund's assets from money market funds to short-term bond funds. This shift will cause the fund to temporarily deviate from the neutral mix and operating ranges listed above. During this period, the fund's investments generally will be allocated as indicated in the following table, subject to any further adjustments deemed appropriate by the managers in light of changing market conditions. Over the long term, the managers expect to reallocate the fund's assets back toward the neutral mix.

 

Equity Securities (Stock Funds)

25.00%

  

Fixed-Income Securities (Bond Funds)

67.00%

Core Equity Plus Fund

1.00%

  

Diversified Bond Fund

 32.00%

Equity Growth Fund

4.00%

  

Inflation-Adjusted Bond Fund

 10.00%

Growth Fund

2.50%

  

International Bond Fund

 10.00%

Heritage Fund*

1.50%

  

Short Duration Fund

   7.00%

Large Company Value Fund

8.00%

  

Short Duration Inflation Protection Bond Fund

   8.00%

Mid Cap Value Fund

5.00%

      

Real Estate Fund

2.00%

  

Cash Equivalents (Money Market Funds)

   8.00%

Small Company Fund

1.00%

  

Prime Money Market Fund

   8.00%

 

 

*

As of December 1, 2013, the fund owns shares of the Vista Fund. However, Vista's Board of Directors has approved an agreement and plan of reorganization, whereby the net assets of the Vista Fund will be transferred to the Heritage Fund in exchange for shares of Heritage Fund, effective as of the close of the New York Stock Exchange on December 6, 2013.
Risk [Heading] rr_RiskHeading

Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock

•

Allocation Risk – The fund's ability to achieve its investment objective depends in part on the managers' skill in determining the funds' asset class allocations and in selecting and weighting the underlying funds. The managers' evaluations and assumptions regarding asset classes and underlying funds may differ from actual market conditions.

•

Market Risk – The value of the fund's shares will go up and down based on the performance of the underlying funds in which it invests. The value of the underlying funds' shares will, in turn, fluctuate based on the performance of the securities they own and other factors generally affecting the securities market.

•

"Growth" and "Value" Style Risks – The underlying funds represent a mix of investment styles, each of which has risks associated with it. Growth stocks can be volatile and may lack dividends that can cushion share prices during market declines. Value stocks may continue to be undervalued by the market for long periods of time.

•

Interest Rate Risk – Generally, when interest rates rise, the value of an underlying fund's fixed-income securities will decline. The opposite is true when interest rates decline. Underlying funds with longer weighted average maturities are more sensitive to interest rate changes.

•

Credit Risk – The value of an underlying fund's fixed-income securities will be affected adversely by the inability or perceived inability of the issuers of these securities to make interest and principal payments as they become due. Changes in the credit rating of a fixed-income security held by an underlying fund could have a similar effect.

•

Foreign Risk – Some of the underlying funds invest in foreign securities, which are generally riskier than U.S. securities. Securities of foreign issuers may be less liquid, more volatile and harder to value than U.S. securities. Fluctuations in currency exchange rates also may affect an underlying fund's share price.

•

Principal Loss – At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund.

 

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Risk Lose Money [Text] rr_RiskLoseMoney

Principal Loss -At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund.
Risk Not Insured Depository Institution [Text] rr_RiskNotInsuredDepositoryInstitution

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading

Fund Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund's performance from year to year for Investor Class shares. The table shows how the fund's average annual returns for the periods shown compared with those of a broad measure of market performance. The fund's past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future. For current performance information, including yields, please visit americancentury.com.

 

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown.
Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund's performance from year to year for Investor Class shares. The table shows how the fund's average annual returns for the periods shown compared with those of a broad measure of market performance.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress americancentury.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture The fund's past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.
Bar Chart [Heading] rr_BarChartHeading

Calendar Year Total Returns
Bar Chart Does Not Reflect Sales Loads [Text] rr_BarChartDoesNotReflectSalesLoads

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown.
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock

Highest Performance Quarter (3Q 2009): 6.20%

Lowest Performance Quarter (4Q 2008): -3.97% 

As of September 30, 2013, the most recent calendar quarter end, the fund's Investor Class year-to-date return was 2.34%.
Year to Date Return, Label rr_YearToDateReturnLabel Investor Class year-to-date
Bar Chart, Year to Date Return, Date rr_BarChartYearToDateReturnDate Sep. 30, 2013
Bar Chart, Year to Date Return rr_BarChartYearToDateReturn 2.34%
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Highest Performance Quarter
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Sep. 30, 2009
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 6.20%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Lowest Performance Quarter
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Dec. 31, 2008
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (3.97%)
Performance Table Heading rr_PerformanceTableHeading

Average Annual Total Returns For the calendar year ended December 31, 2012
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate 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.
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred Actual after-tax returns depend on an investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.
Performance Table Closing [Text Block] rr_PerformanceTableClosingTextBlock

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. After-tax returns are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.
ONE CHOICE PORTFOLIO: VERY CONSERVATIVE | Russell 3000 Index (reflects no deduction for fees, expenses or taxes)
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 16.42%
5 years rr_AverageAnnualReturnYear05 2.04%
Since Inception rr_AverageAnnualReturnSinceInception 5.65%
Inception Date rr_AverageAnnualReturnInceptionDate Sep. 30, 2004
ONE CHOICE PORTFOLIO: VERY CONSERVATIVE | Barclays U.S. Aggregate Bond Index (reflects no deduction for fees, expenses or taxes)
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 4.21%
5 years rr_AverageAnnualReturnYear05 5.95%
Since Inception rr_AverageAnnualReturnSinceInception 5.38%
Inception Date rr_AverageAnnualReturnInceptionDate Sep. 30, 2004
ONE CHOICE PORTFOLIO: VERY CONSERVATIVE | INVESTOR CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee 25
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses rr_OtherExpensesOverAssets none
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.64%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.64%
1 year rr_ExpenseExampleYear01 66
3 years rr_ExpenseExampleYear03 205
5 years rr_ExpenseExampleYear05 357
10 years rr_ExpenseExampleYear10 799
Annual Return 2005 rr_AnnualReturn2005 2.40%
Annual Return 2006 rr_AnnualReturn2006 7.50%
Annual Return 2007 rr_AnnualReturn2007 5.77%
Annual Return 2008 rr_AnnualReturn2008 (6.66%)
Annual Return 2009 rr_AnnualReturn2009 10.59%
Annual Return 2010 rr_AnnualReturn2010 6.84%
Annual Return 2011 rr_AnnualReturn2011 4.88%
Annual Return 2012 rr_AnnualReturn2012 6.78%
1 year rr_AverageAnnualReturnYear01 6.78%
5 years rr_AverageAnnualReturnYear05 4.31%
Since Inception rr_AverageAnnualReturnSinceInception 4.98%
Inception Date rr_AverageAnnualReturnInceptionDate Sep. 30, 2004
ONE CHOICE PORTFOLIO: VERY CONSERVATIVE | INVESTOR CLASS | Return After Taxes on Distributions
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 6.06%
5 years rr_AverageAnnualReturnYear05 3.45%
Since Inception rr_AverageAnnualReturnSinceInception 3.90%
Inception Date rr_AverageAnnualReturnInceptionDate Sep. 30, 2004
ONE CHOICE PORTFOLIO: VERY CONSERVATIVE | INVESTOR CLASS | Return After Taxes on Distributions and Sale of Fund Shares
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 4.61%
5 years rr_AverageAnnualReturnYear05 3.22%
Since Inception rr_AverageAnnualReturnSinceInception 3.68%
Inception Date rr_AverageAnnualReturnInceptionDate Sep. 30, 2004
ONE CHOICE PORTFOLIO: CONSERVATIVE
  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk/Return [Heading] rr_RiskReturnHeading ONE CHOICE PORTFOLIO: CONSERVATIVE
Objective [Heading] rr_ObjectiveHeading

Investment Objective
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The fund seeks the highest total return consistent with its asset mix.

Expense [Heading] rr_ExpenseHeading

Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the fund.
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

Because the fund buys and sells shares of other American Century mutual funds (the underlying funds) directly from the issuers, the fund is not expected to incur transaction costs directly. However, as a shareholder in the underlying funds, the fund indirectly pays transaction costs, such as commissions, when the underlying funds buy and sell securities (or "turn over" their portfolios). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 3% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 3.00%
Expense Example [Heading] rr_ExpenseExampleHeading

Example
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock

The example below is intended to help you compare the costs of investing in the fund with the costs of investing in other mutual funds.

Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption

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, that you earn a 5% return each year, and that the fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading] rr_StrategyHeading

Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

One Choice Portfolio: Conservative is a "fund of funds," meaning that it seeks to achieve its objective by investing in other American Century Investments mutual funds (the underlying funds) that represent a variety of asset classes and investment styles. The fund's asset allocation is intended to diversify investments among stocks, bonds and cash equivalents.

 

The following table indicates the fund's neutral mix; that is, how the fund's investments generally will be allocated among the major asset classes over the long term. The table also shows the neutral weightings of each underlying fund currently being used within the various asset classes. This information is as of the date of this prospectus.

 

Equity Securities (Stock Funds)

 45.00%

  

Fixed-Income Securities (Bond Funds)

  47.00%

Core Equity Plus Fund

 2.00%

  

Diversified Bond Fund

30.00%

Equity Growth Fund

 7.00%

  

Inflation-Adjusted Bond Fund

  9.00%

Growth Fund

 4.75%

  

International Bond Fund

  8.00%

Heritage Fund*

 4.00%

      

International Growth Fund

 6.00%

  

Cash Equivalents (Money Market Funds)

  8.00%

Large Company Value Fund

  11.00%

  

Prime Money Market Fund

  8.00%

Mid Cap Value Fund

 6.75%

      

Real Estate Fund

 2.00%

      

Small Company Fund

 1.50%

      

 

*

As of December 1, 2013, the fund owns shares of the Vista Fund. However, Vista's Board of Directors has approved an agreement and plan of reorganization, whereby the net assets of the Vista Fund will be transferred to the Heritage Fund in exchange for shares of Heritage Fund, effective as of the close of the New York Stock Exchange on December 6, 2013.

 

The managers regularly review the fund and may make changes to the fund's asset class allocations that deviate from the neutral mix to emphasize investments that they believe will provide the most favorable outlook for achieving the fund's objective. The fund also may deviate from the neutral mix due to differences in asset class performance or prevailing market conditions. The following table shows the operating ranges within which the fund's asset class allocations generally will vary over short-term periods.

 

 

Equity Securities (Stock Funds)

Fixed-Income Securities (Bond Funds)

Cash Equivalents (Money Market Funds)

Operating Ranges

39-51%

38-52%

5-20%
Risk [Heading] rr_RiskHeading

Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock

•

Allocation Risk – The fund's ability to achieve its investment objective depends in part on the managers' skill in determining the funds' asset class allocations and in selecting and weighting the underlying funds. The managers' evaluations and assumptions regarding asset classes and underlying funds may differ from actual market conditions.

•

Market Risk – The value of the fund's shares will go up and down based on the performance of the underlying funds in which it invests. The value of the underlying funds' shares will, in turn, fluctuate based on the performance of the securities they own and other factors generally affecting the securities market.

•

Small- and Mid-Cap Stock Risks – Stocks of smaller companies may be more volatile than larger-company stocks. Smaller companies may have limited financial resources, product lines and markets, and their securities may trade less frequently and in more limited volumes than the securities of larger companies, which could lead to higher transaction costs. To the extent an underlying fund invests in these companies, it may take on more risk.

•

"Growth" and "Value" Style Risks – The underlying funds represent a mix of investment styles, each of which has risks associated with it. Growth stocks can be volatile and may lack dividends that can cushion share prices during market declines. Value stocks may continue to be undervalued by the market for long periods of time.

•

Interest Rate Risk – Generally, when interest rates rise, the value of an underlying fund's fixed-income securities will decline. The opposite is true when interest rates decline. Underlying funds with longer weighted average maturities are more sensitive to interest rate changes.

•

Credit Risk – The value of an underlying fund's fixed-income securities will be affected adversely by the inability or perceived inability of the issuers of these securities to make interest and principal payments as they become due. Changes in the credit rating of a fixed-income security held by an underlying fund could have a similar effect. 

•

Foreign Risk – Some of the underlying funds invest in foreign securities, which are generally riskier than U.S. securities. Securities of foreign issuers may be less liquid, more volatile and harder to value than U.S. securities. Fluctuations in currency exchange rates also may affect an underlying fund's share price.

•

Principal Loss – At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund.

 

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Risk Lose Money [Text] rr_RiskLoseMoney

Principal Loss -At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund.
Risk Not Insured Depository Institution [Text] rr_RiskNotInsuredDepositoryInstitution

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading

Fund Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund's performance from year to year for Investor Class shares. The table shows how the fund's average annual returns for the periods shown compared with those of a broad measure of market performance. The fund's past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future. For current performance information, including yields, please visit americancentury.com.

 

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown.
Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund's performance from year to year for Investor Class shares. The table shows how the fund's average annual returns for the periods shown compared with those of a broad measure of market performance.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress americancentury.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture The fund's past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.
Bar Chart [Heading] rr_BarChartHeading

Calendar Year Total Returns
Bar Chart Does Not Reflect Sales Loads [Text] rr_BarChartDoesNotReflectSalesLoads

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown.
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock

Highest Performance Quarter (3Q 2009): 9.27% 

Lowest Performance Quarter (4Q 2008): -8.82% 

As of September 30, 2013, the most recent calendar quarter end, the fund's Investor Class year-to-date return was 6.36%.
Year to Date Return, Label rr_YearToDateReturnLabel Investor Class year-to-date
Bar Chart, Year to Date Return, Date rr_BarChartYearToDateReturnDate Sep. 30, 2013
Bar Chart, Year to Date Return rr_BarChartYearToDateReturn 6.36%
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Highest Performance Quarter
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Sep. 30, 2009
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 9.27%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Lowest Performance Quarter
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Dec. 31, 2008
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (8.82%)
Performance Table Heading rr_PerformanceTableHeading

Average Annual Total Returns For the calendar year ended December 31, 2012
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate 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.
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred Actual after-tax returns depend on an investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.
Performance Table Closing [Text Block] rr_PerformanceTableClosingTextBlock

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. After-tax returns are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.
ONE CHOICE PORTFOLIO: CONSERVATIVE | Russell 3000 Index (reflects no deduction for fees, expenses or taxes)
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 16.42%
5 years rr_AverageAnnualReturnYear05 2.04%
Since Inception rr_AverageAnnualReturnSinceInception 5.65%
Inception Date rr_AverageAnnualReturnInceptionDate Sep. 30, 2004
ONE CHOICE PORTFOLIO: CONSERVATIVE | Barclays U.S. Aggregate Bond Index (reflects no deduction for fees, expenses or taxes)
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 4.21%
5 years rr_AverageAnnualReturnYear05 5.95%
Since Inception rr_AverageAnnualReturnSinceInception 5.38%
Inception Date rr_AverageAnnualReturnInceptionDate Sep. 30, 2004
ONE CHOICE PORTFOLIO: CONSERVATIVE | INVESTOR CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee 25
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses rr_OtherExpensesOverAssets none
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.75%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.75%
1 year rr_ExpenseExampleYear01 77
3 years rr_ExpenseExampleYear03 240
5 years rr_ExpenseExampleYear05 417
10 years rr_ExpenseExampleYear10 931
Annual Return 2005 rr_AnnualReturn2005 3.79%
Annual Return 2006 rr_AnnualReturn2006 10.05%
Annual Return 2007 rr_AnnualReturn2007 7.05%
Annual Return 2008 rr_AnnualReturn2008 (16.03%)
Annual Return 2009 rr_AnnualReturn2009 15.81%
Annual Return 2010 rr_AnnualReturn2010 9.86%
Annual Return 2011 rr_AnnualReturn2011 3.76%
Annual Return 2012 rr_AnnualReturn2012 10.05%
1 year rr_AverageAnnualReturnYear01 10.05%
5 years rr_AverageAnnualReturnYear05 4.05%
Since Inception rr_AverageAnnualReturnSinceInception 5.68%
Inception Date rr_AverageAnnualReturnInceptionDate Sep. 30, 2004
ONE CHOICE PORTFOLIO: CONSERVATIVE | INVESTOR CLASS | Return After Taxes on Distributions
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 9.42%
5 years rr_AverageAnnualReturnYear05 3.21%
Since Inception rr_AverageAnnualReturnSinceInception 4.68%
Inception Date rr_AverageAnnualReturnInceptionDate Sep. 30, 2004
ONE CHOICE PORTFOLIO: CONSERVATIVE | INVESTOR CLASS | Return After Taxes on Distributions and Sale of Fund Shares
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 6.69%
5 years rr_AverageAnnualReturnYear05 3.02%
Since Inception rr_AverageAnnualReturnSinceInception 4.37%
Inception Date rr_AverageAnnualReturnInceptionDate Sep. 30, 2004
ONE CHOICE PORTFOLIO: MODERATE
  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk/Return [Heading] rr_RiskReturnHeading ONE CHOICE PORTFOLIO: MODERATE
Objective [Heading] rr_ObjectiveHeading

Investment Objective
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The fund seeks the highest total return consistent with its asset mix.

Expense [Heading] rr_ExpenseHeading

Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the fund.
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

Because the fund buys and sells shares of other American Century mutual funds (the underlying funds) directly from the issuers, the fund is not expected to incur transaction costs directly. However, as a shareholder in the underlying funds, the fund indirectly pays transaction costs, such as commissions, when the underlying funds buy and sell securities (or "turn over" their portfolios). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 3% of the average value of its portfolio.

Portfolio Turnover, Rate rr_PortfolioTurnoverRate 3.00%
Expense Example [Heading] rr_ExpenseExampleHeading

Example
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock

The example below is intended to help you compare the costs of investing in the fund with the costs of investing in other mutual funds.

Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption

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, that you earn a 5% return each year, and that the fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading] rr_StrategyHeading

Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

One Choice Portfolio: Moderate is a "fund of funds," meaning that it seeks to achieve its objective by investing in other American Century Investments mutual funds (the underlying funds) that represent a variety of asset classes and investment styles. The fund's asset allocation is intended to diversify investments among stocks, bonds and cash equivalents.

 

The following table indicates the fund's neutral mix; that is, how the fund's investments generally will be allocated among the major asset classes over the long term. The table also shows the neutral weightings of each underlying fund currently being used within the various asset classes. This information is as of the date of this prospectus.

  

Equity Securities (Stock Funds)

 64.00%

  

Fixed-Income Securities (Bond Funds)

  31.00%

Core Equity Plus Fund

 4.00%

  

Diversified Bond Fund

19.00%

Emerging Markets Fund

 4.00%

  

High-Yield Fund

  3.00%

Equity Growth Fund

  12.00%

  

Inflation-Adjusted Bond Fund

  6.00%

Growth Fund

 8.00%

  

International Bond Fund

  3.00%

Heritage Fund*

 7.00%

      

International Growth Fund

  10.00%

  

Cash Equivalents (Money Market Funds)

  5.00%

Large Company Value Fund

 9.50%

  

Prime Money Market Fund

  5.00%

Mid Cap Value Fund

 5.50%

      

Real Estate Fund

 2.00%

      

Small Company Fund

 2.00%

      

 

*

As of December 1, 2013, the fund owns shares of the Vista Fund. However, Vista's Board of Directors has approved an agreement and plan of reorganization, whereby the net assets of the Vista Fund will be transferred to the Heritage Fund in exchange for shares of Heritage Fund, effective as of the close of the New York Stock Exchange on December 6, 2013.

 

The managers regularly review the fund and may make changes to the fund's asset class allocations that deviate from the neutral mix to emphasize investments that they believe will provide the most favorable outlook for achieving the fund's objective. The fund also may deviate from the neutral mix due to differences in asset class performance or prevailing market conditions. The following table shows the operating ranges within which the fund's asset class allocations generally will vary over short-term periods.

 

 

Equity Securities (Stock Funds)

Fixed-Income Securities (Bond Funds)

Cash Equivalents (Money Market Funds)

Operating Ranges

53-73%

21-41%

0-15%
Risk [Heading] rr_RiskHeading

Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock

•

Allocation Risk – The fund's ability to achieve its investment objective depends in part on the managers' skill in determining the funds' asset class allocations and in selecting and weighting the underlying funds. The managers' evaluations and assumptions regarding asset classes and underlying funds may differ from actual market conditions.

•

Market Risk – The value of the fund's shares will go up and down based on the performance of the underlying funds in which it invests. The value of the underlying funds' shares will, in turn, fluctuate based on the performance of the securities they own and other factors generally affecting the securities market.

•

Small- and Mid-Cap Stock Risks – Stocks of smaller companies may be more volatile than larger-company stocks. Smaller companies may have limited financial resources, product lines and markets, and their securities may trade less frequently and in more limited volumes than the securities of larger companies, which could lead to higher transaction costs. To the extent an underlying fund invests in these companies, it may take on more risk.

•

"Growth" and "Value" Style Risks – The underlying funds represent a mix of investment styles, each of which has risks associated with it. Growth stocks can be volatile and may lack dividends that can cushion share prices during market declines. Value stocks may continue to be undervalued by the market for long periods of time.

•

Interest Rate Risk – Generally, when interest rates rise, the value of an underlying fund's fixed-income securities will decline. The opposite is true when interest rates decline. Underlying funds with longer weighted average maturities are more sensitive to interest rate changes.

•

Credit Risk – The value of an underlying fund's fixed-income securities will be affected adversely by the inability or perceived inability of the issuers of these securities to make interest and principal payments as they become due. Changes in the credit rating of a fixed-income security held by an underlying fund could have a similar effect.

•

Foreign Risk – Some of the underlying funds invest in foreign securities, which are generally riskier than U.S. securities. Securities of foreign issuers may be less liquid, more volatile and harder to value than U.S. securities. Fluctuations in currency exchange rates also may affect an underlying fund's share price. Investing in securities of companies located in emerging market countries is generally riskier than investing in securities of companies located in developed foreign countries.

•

Principal Loss – At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund.

 

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Risk Lose Money [Text] rr_RiskLoseMoney

Principal Loss -At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund.
Risk Not Insured Depository Institution [Text] rr_RiskNotInsuredDepositoryInstitution

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading

Fund Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund's performance from year to year for Investor Class shares. The table shows how the fund's average annual returns for the periods shown compared with those of a broad measure of market performance. The fund's past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future. For current performance information, including yields, please visit americancentury.com.

 

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown.
Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund's performance from year to year for Investor Class shares. The table shows how the fund's average annual returns for the periods shown compared with those of a broad measure of market performance.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress americancentury.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture The fund's past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.
Bar Chart [Heading] rr_BarChartHeading

Calendar Year Total Returns
Bar Chart Does Not Reflect Sales Loads [Text] rr_BarChartDoesNotReflectSalesLoads

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown.
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock

Highest Performance Quarter (3Q 2009): 11.86% 

Lowest Performance Quarter (4Q 2008): -14.20% 

As of September 30, 2013, the most recent calendar quarter end, the fund's Investor Class year-to-date return was 9.89%
Year to Date Return, Label rr_YearToDateReturnLabel Investor Class year-to-date
Bar Chart, Year to Date Return, Date rr_BarChartYearToDateReturnDate Sep. 30, 2013
Bar Chart, Year to Date Return rr_BarChartYearToDateReturn 9.89%
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Highest Performance Quarter
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Sep. 30, 2009
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 11.86%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Lowest Performance Quarter
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Dec. 31, 2008
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (14.20%)
Performance Table Heading rr_PerformanceTableHeading

Average Annual Total Returns For the calendar year ended December 31, 2012
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate 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.
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred Actual after-tax returns depend on an investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.
Performance Table Closing [Text Block] rr_PerformanceTableClosingTextBlock

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. After-tax returns are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.
ONE CHOICE PORTFOLIO: MODERATE | Russell 3000 Index (reflects no deduction for fees, expenses or taxes)
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 16.42%
5 years rr_AverageAnnualReturnYear05 2.04%
Since Inception rr_AverageAnnualReturnSinceInception 5.65%
Inception Date rr_AverageAnnualReturnInceptionDate Sep. 30, 2004
ONE CHOICE PORTFOLIO: MODERATE | Barclays U.S. Aggregate Bond Index (reflects no deduction for fees, expenses or taxes)
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 4.21%
5 years rr_AverageAnnualReturnYear05 5.95%
Since Inception rr_AverageAnnualReturnSinceInception 5.38%
Inception Date rr_AverageAnnualReturnInceptionDate Sep. 30, 2004
ONE CHOICE PORTFOLIO: MODERATE | INVESTOR CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee 25
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses rr_OtherExpensesOverAssets none
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.88%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.88%
1 year rr_ExpenseExampleYear01 90
3 years rr_ExpenseExampleYear03 281
5 years rr_ExpenseExampleYear05 488
10 years rr_ExpenseExampleYear10 1,085
Annual Return 2005 rr_AnnualReturn2005 6.59%
Annual Return 2006 rr_AnnualReturn2006 12.90%
Annual Return 2007 rr_AnnualReturn2007 9.82%
Annual Return 2008 rr_AnnualReturn2008 (25.92%)
Annual Return 2009 rr_AnnualReturn2009 21.76%
Annual Return 2010 rr_AnnualReturn2010 12.74%
Annual Return 2011 rr_AnnualReturn2011 0.88%
Annual Return 2012 rr_AnnualReturn2012 13.23%
1 year rr_AverageAnnualReturnYear01 13.23%
5 years rr_AverageAnnualReturnYear05 3.04%
Since Inception rr_AverageAnnualReturnSinceInception 6.31%
Inception Date rr_AverageAnnualReturnInceptionDate Sep. 30, 2004
ONE CHOICE PORTFOLIO: MODERATE | INVESTOR CLASS | Return After Taxes on Distributions
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 12.66%
5 years rr_AverageAnnualReturnYear05 2.31%
Since Inception rr_AverageAnnualReturnSinceInception 5.43%
Inception Date rr_AverageAnnualReturnInceptionDate Sep. 30, 2004
ONE CHOICE PORTFOLIO: MODERATE | INVESTOR CLASS | Return After Taxes on Distributions and Sale of Fund Shares
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 8.80%
5 years rr_AverageAnnualReturnYear05 2.24%
Since Inception rr_AverageAnnualReturnSinceInception 5.03%
Inception Date rr_AverageAnnualReturnInceptionDate Sep. 30, 2004
ONE CHOICE PORTFOLIO: AGGRESSIVE
  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk/Return [Heading] rr_RiskReturnHeading ONE CHOICE PORTFOLIO: AGGRESSIVE
Objective [Heading] rr_ObjectiveHeading

Investment Objective
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The fund seeks the highest total return consistent with its asset mix.

Expense [Heading] rr_ExpenseHeading

Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the fund.
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

Because the fund buys and sells shares of other American Century mutual funds (the underlying funds) directly from the issuers, the fund is not expected to incur transaction costs directly. However, as a shareholder in the underlying funds, the fund indirectly pays transaction costs, such as commissions, when the underlying funds buy and sell securities (or "turn over" their portfolios). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 5% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 5.00%
Expense Example [Heading] rr_ExpenseExampleHeading

Example
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock

The example below is intended to help you compare the costs of investing in the fund with the costs of investing in other mutual funds.

Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption

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, that you earn a 5% return each year, and that the fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading] rr_StrategyHeading

Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

One Choice Portfolio: Aggressive is a "fund of funds," meaning that it seeks to achieve its objective by investing in other American Century Investments mutual funds (the underlying funds) that represent a variety of asset classes and investment styles. The fund's asset allocation is intended to diversify investments among stocks, bonds and cash equivalents.

 

The following table indicates the fund's neutral mix; that is, how the fund's investments generally will be allocated among the major asset classes over the long term. The table also shows the neutral weightings of each underlying fund currently being used within the various asset classes. This information is as of the date of this prospectus.

 

Equity Securities (Stock Funds)

 79.00%

  

Fixed-Income Securities (Bond Funds)

  20.00%

Core Equity Plus Fund

 4.50%

  

Diversified Bond Fund

11.00%

Emerging Markets Fund

 6.50%

  

High-Yield Fund

  5.00%

Equity Growth Fund

  10.00%

  

Inflation-Adjusted Bond Fund

  4.00%

Growth Fund

  14.50%

      

Heritage Fund*

  13.50%

  

Cash Equivalents (Money Market Funds)

  1.00%

International Growth Fund

  12.50%

  

Prime Money Market Fund

   1.00%

Large Company Value Fund

 8.50%

      

Mid Cap Value Fund

 4.75%

      

Real Estate Fund

 2.00%

      

Small Company Fund

 2.25%

      

 

*

As of December 1, 2013, the fund owns shares of the Vista Fund. However, Vista's Board of Directors has approved an agreement and plan of reorganization, whereby the net assets of the Vista Fund will be transferred to the Heritage Fund in exchange for shares of Heritage Fund, effective as of the close of the New York Stock Exchange on December 6, 2013.

 

The managers regularly review the fund and may make changes to the fund's asset class allocations that deviate from the neutral mix to emphasize investments that they believe will provide the most favorable outlook for achieving the fund's objective. The fund also may deviate from the neutral mix due to differences in asset class performance or prevailing market conditions. The following table shows the operating ranges within which the fund's asset class allocations generally will vary over short-term periods.

 

 

Equity Securities (Stock Funds)

Fixed-Income Securities (Bond Funds)

Cash Equivalents (Money Market Funds)

Operating Ranges

60-90%

10-30%

0-15%
Risk [Heading] rr_RiskHeading

Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock

•

Allocation Risk – The fund's ability to achieve its investment objective depends in part on the managers' skill in determining the funds' asset class allocations and in selecting and weighting the underlying funds. The managers' evaluations and assumptions regarding asset classes and underlying funds may differ from actual market conditions.

•

Market Risk – The value of the fund's shares will go up and down based on the performance of the underlying funds in which it invests. The value of the underlying funds' shares will, in turn, fluctuate based on the performance of the securities they own and other factors generally affecting the securities market.

•

Small- and Mid-Cap Stock Risks – Stocks of smaller companies may be more volatile than larger-company stocks. Smaller companies may have limited financial resources, product lines and markets, and their securities may trade less frequently and in more limited volumes than the securities of larger companies, which could lead to higher transaction costs. To the extent an underlying fund invests in these companies, it may take on more risk.

•

"Growth" and "Value" Style Risks – The underlying funds represent a mix of investment styles, each of which has risks associated with it. Growth stocks can be volatile and may lack dividends that can cushion share prices during market declines. Value stocks may continue to be undervalued by the market for long periods of time.

•

Interest Rate Risk – Generally, when interest rates rise, the value of an underlying fund's fixed-income securities will decline. The opposite is true when interest rates decline. Underlying funds with longer weighted average maturities are more sensitive to interest rate changes.

•

Credit Risk – The value of an underlying fund's fixed-income securities will be affected adversely by the inability or perceived inability of the issuers of these securities to make interest and principal payments as they become due. Changes in the credit rating of a fixed-income security held by an underlying fund could have a similar effect.

•

Foreign Risk – Some of the underlying funds invest in foreign securities, which are generally riskier than U.S. securities. Securities of foreign issuers may be less liquid, more volatile and harder to value than U.S. securities. Fluctuations in currency exchange rates also may affect an underlying fund's share price. Investing in securities of companies located in emerging market countries is generally riskier than investing in securities of companies located in developed foreign countries.

•

Principal Loss – At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund.

 

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
Risk Lose Money [Text] rr_RiskLoseMoney

Principal Loss -At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund.
Risk Not Insured Depository Institution [Text] rr_RiskNotInsuredDepositoryInstitution

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading

Fund Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund's performance from year to year for Investor Class shares. The table shows how the fund's average annual returns for the periods shown compared with those of a broad measure of market performance. The fund's past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future. For current performance information, including yields, please visit americancentury.com.

 

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown.
Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund's performance from year to year for Investor Class shares. The table shows how the fund's average annual returns for the periods shown compared with those of a broad measure of market performance.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress americancentury.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture The fund's past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.
Bar Chart [Heading] rr_BarChartHeading

Calendar Year Total Returns
Bar Chart Does Not Reflect Sales Loads [Text] rr_BarChartDoesNotReflectSalesLoads

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown.
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock

Highest Performance Quarter (3Q 2009): 13.90% 

Lowest Performance Quarter (4Q 2008): -18.80% 

As of September 30, 2013, the most recent calendar quarter end, the fund's Investor Class year-to-date return was 12.83%.
Year to Date Return, Label rr_YearToDateReturnLabel Investor Class year-to-date
Bar Chart, Year to Date Return, Date rr_BarChartYearToDateReturnDate Sep. 30, 2013
Bar Chart, Year to Date Return rr_BarChartYearToDateReturn 12.83%
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Highest Performance Quarter
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Sep. 30, 2009
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 13.90%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Lowest Performance Quarter
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Dec. 31, 2008
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (18.80%)
Performance Table Heading rr_PerformanceTableHeading

Average Annual Total Returns For the calendar year ended December 31, 2012
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate 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.
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred Actual after-tax returns depend on an investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.
Performance Table Closing [Text Block] rr_PerformanceTableClosingTextBlock

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. After-tax returns are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.
ONE CHOICE PORTFOLIO: AGGRESSIVE | Russell 3000 Index (reflects no deduction for fees, expenses or taxes)
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 16.42%
5 years rr_AverageAnnualReturnYear05 2.04%
Since Inception rr_AverageAnnualReturnSinceInception 5.65%
Inception Date rr_AverageAnnualReturnInceptionDate Sep. 30, 2004
ONE CHOICE PORTFOLIO: AGGRESSIVE | Barclays U.S. Aggregate Bond Index (reflects no deduction for fees, expenses or taxes)
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 4.21%
5 years rr_AverageAnnualReturnYear05 5.95%
Since Inception rr_AverageAnnualReturnSinceInception 5.38%
Inception Date rr_AverageAnnualReturnInceptionDate Sep. 30, 2004
ONE CHOICE PORTFOLIO: AGGRESSIVE | INVESTOR CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee 25
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses rr_OtherExpensesOverAssets none
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.98%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.98%
1 year rr_ExpenseExampleYear01 100
3 years rr_ExpenseExampleYear03 313
5 years rr_ExpenseExampleYear05 542
10 years rr_ExpenseExampleYear10 1,201
Annual Return 2005 rr_AnnualReturn2005 8.54%
Annual Return 2006 rr_AnnualReturn2006 14.41%
Annual Return 2007 rr_AnnualReturn2007 13.65%
Annual Return 2008 rr_AnnualReturn2008 (33.87%)
Annual Return 2009 rr_AnnualReturn2009 26.68%
Annual Return 2010 rr_AnnualReturn2010 15.59%
Annual Return 2011 rr_AnnualReturn2011 (1.68%)
Annual Return 2012 rr_AnnualReturn2012 15.42%
1 year rr_AverageAnnualReturnYear01 15.42%
5 years rr_AverageAnnualReturnYear05 1.90%
Since Inception rr_AverageAnnualReturnSinceInception 6.57%
Inception Date rr_AverageAnnualReturnInceptionDate Sep. 30, 2004
ONE CHOICE PORTFOLIO: AGGRESSIVE | INVESTOR CLASS | Return After Taxes on Distributions
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 15.01%
5 years rr_AverageAnnualReturnYear05 1.28%
Since Inception rr_AverageAnnualReturnSinceInception 5.81%
Inception Date rr_AverageAnnualReturnInceptionDate Sep. 30, 2004
ONE CHOICE PORTFOLIO: AGGRESSIVE | INVESTOR CLASS | Return After Taxes on Distributions and Sale of Fund Shares
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 10.24%
5 years rr_AverageAnnualReturnYear05 1.33%
Since Inception rr_AverageAnnualReturnSinceInception 5.36%
Inception Date rr_AverageAnnualReturnInceptionDate Sep. 30, 2004
ONE CHOICE PORTFOLIO: VERY AGGRESSIVE
  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk/Return [Heading] rr_RiskReturnHeading ONE CHOICE PORTFOLIO: VERY AGGRESSIVE
Objective [Heading] rr_ObjectiveHeading

Investment Objective
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The fund seeks the highest total return consistent with its asset mix.

Expense [Heading] rr_ExpenseHeading

Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock

The following table describes the fees and expenses you may pay if you buy and hold shares of the fund.
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

Because the fund buys and sells shares of other American Century mutual funds (the underlying funds) directly from the issuers, the fund is not expected to incur transaction costs directly. However, as a shareholder in the underlying funds, the fund indirectly pays transaction costs, such as commissions, when the underlying funds buy and sell securities (or "turn over" their portfolios). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 16% of the average value of its portfolio.

Portfolio Turnover, Rate rr_PortfolioTurnoverRate 16.00%
Expense Example [Heading] rr_ExpenseExampleHeading

Example
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock

The example below is intended to help you compare the costs of investing in the fund with the costs of investing in other mutual funds.

Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption

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, that you earn a 5% return each year, and that the fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading] rr_StrategyHeading

Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

One Choice Portfolio: Very Aggressive is a "fund of funds," meaning that it seeks to achieve its objective by investing in other American Century Investments mutual funds (the underlying funds) that represent a variety of asset classes and investment styles. The fund's asset allocation is intended to diversify investments among stocks, bonds and cash equivalents.

 

The following table indicates the fund's neutral mix; that is, how the fund's investments generally will be allocated among the major asset classes over the long term. The table also shows the neutral weightings of each underlying fund currently being used within the various asset classes. This information is as of the date of this prospectus.

 

Equity Securities (Stock Funds)

96.00%

  

Fixed-Income Securities (Bond Funds)

3.00%

Core Equity Plus Fund

4.75%

  

Diversified Bond Fund

3.00%

Emerging Markets Fund

7.50%

      

Equity Growth Fund

 13.00%

  

Cash Equivalents (Money Market Funds)

1.00%

Growth Fund

 17.75%

  

Prime Money Market Fund

1.00%

Heritage Fund*

 16.50%

    

International Growth Fund

 15.50%

      

Large Company Value Fund

 10.50%

      

Mid Cap Value Fund

6.00%

      

Real Estate Fund

2.00%

      

Small Company Fund

2.50%

      

 

*

As of December 1, 2013, the fund owns shares of the Vista Fund. However, Vista's Board of Directors has approved an agreement and plan of reorganization, whereby the net assets of the Vista Fund will be transferred to the Heritage Fund in exchange for shares of Heritage Fund, effective as of the close of the New York Stock Exchange on December 6, 2013.

 

The managers regularly review the fund and may make changes to the fund's asset class allocations that deviate from the neutral mix to emphasize investments that they believe will provide the most favorable outlook for achieving the fund's objective. The fund also may deviate from the neutral mix due to differences in asset class performance or prevailing market conditions. The following table shows the operating ranges within which the fund's asset class allocations generally will vary over short-term periods.

 

 

Equity Securities (Stock Funds)

Fixed-Income Securities (Bond Funds)

Cash Equivalents (Money Market Funds)

Operating Ranges

75-100%

0-10%

0-15%
Risk [Heading] rr_RiskHeading

Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock

•

Allocation Risk – The fund's ability to achieve its investment objective depends in part on the managers' skill in determining the funds' asset class allocations and in selecting and weighting the underlying funds. The managers' evaluations and assumptions regarding asset classes and underlying funds may differ from actual market conditions.

•

Market Risk – The value of the fund's shares will go up and down based on the performance of the underlying funds in which it invests. The value of the underlying funds' shares will, in turn, fluctuate based on the performance of the securities they own and other factors generally affecting the securities market.

•

Small- and Mid-Cap Stock Risks – Stocks of smaller companies may be more volatile than larger-company stocks. Smaller companies may have limited financial resources, product lines and markets, and their securities may trade less frequently and in more limited volumes than the securities of larger companies, which could lead to higher transaction costs. To the extent an underlying fund invests in these companies, it may take on more risk.

•

"Growth" and "Value" Style Risks – The underlying funds represent a mix of investment styles, each of which has risks associated with it. Growth stocks can be volatile and may lack dividends that can cushion share prices during market declines. Value stocks may continue to be undervalued by the market for long periods of time.

•

Foreign Risk – Some of the underlying funds invest in foreign securities, which are generally riskier than U.S. securities. Securities of foreign issuers may be less liquid, more volatile and harder to value than U.S. securities. Fluctuations in currency exchange rates also may affect an underlying fund's share price. Investing in securities of companies located in emerging market countries is generally riskier than investing in securities of companies located in developed foreign countries.

•

Principal Loss – At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund.

 

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Risk Lose Money [Text] rr_RiskLoseMoney

Principal Loss -At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund.
Risk Not Insured Depository Institution [Text] rr_RiskNotInsuredDepositoryInstitution

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading

Fund Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund's performance from year to year for Investor Class shares. The table shows how the fund's average annual returns for the periods shown compared with those of a broad measure of market performance. The fund's past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future. For current performance information, including yields, please visit americancentury.com.

 

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown.
Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund's performance from year to year for Investor Class shares. The table shows how the fund's average annual returns for the periods shown compared with those of a broad measure of market performance.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress americancentury.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture The fund's past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future.
Bar Chart [Heading] rr_BarChartHeading

Calendar Year Total Returns
Bar Chart Does Not Reflect Sales Loads [Text] rr_BarChartDoesNotReflectSalesLoads

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown.
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock

Highest Performance Quarter (3Q 2009): 15.67%  

Lowest Performance Quarter (4Q 2008): -22.24% 

As of September 30, 2013, the most recent calendar quarter end, the fund's Investor Class year-to-date return was 16.31%.

Year to Date Return, Label rr_YearToDateReturnLabel Investor Class year-to-date
Bar Chart, Year to Date Return, Date rr_BarChartYearToDateReturnDate Sep. 30, 2013
Bar Chart, Year to Date Return rr_BarChartYearToDateReturn 16.31%
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Highest Performance Quarter
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Sep. 30, 2009
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 15.67%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Lowest Performance Quarter
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Dec. 31, 2008
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (22.24%)
Performance Table Heading rr_PerformanceTableHeading

Average Annual Total Returns For the calendar year ended December 31, 2012
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate 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.
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred Actual after-tax returns depend on an investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.
Performance Table Closing [Text Block] rr_PerformanceTableClosingTextBlock

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. After-tax returns are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.
ONE CHOICE PORTFOLIO: VERY AGGRESSIVE | Russell 3000 Index (reflects no deduction for fees, expenses or taxes)
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 16.42%
5 years rr_AverageAnnualReturnYear05 2.04%
Since Inception rr_AverageAnnualReturnSinceInception 5.65%
Inception Date rr_AverageAnnualReturnInceptionDate Sep. 30, 2004
ONE CHOICE PORTFOLIO: VERY AGGRESSIVE | Barclays U.S. Aggregate Bond Index (reflects no deduction for fees, expenses or taxes)
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 4.21%
5 years rr_AverageAnnualReturnYear05 5.95%
Since Inception rr_AverageAnnualReturnSinceInception 5.38%
Inception Date rr_AverageAnnualReturnInceptionDate Sep. 30, 2004
ONE CHOICE PORTFOLIO: VERY AGGRESSIVE | INVESTOR CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000) rr_MaximumAccountFee 25
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.01%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 1.05%
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 1.06%
1 year rr_ExpenseExampleYear01 108
3 years rr_ExpenseExampleYear03 338
5 years rr_ExpenseExampleYear05 585
10 years rr_ExpenseExampleYear10 1,294
Annual Return 2005 rr_AnnualReturn2005 9.58%
Annual Return 2006 rr_AnnualReturn2006 16.40%
Annual Return 2007 rr_AnnualReturn2007 15.08%
Annual Return 2008 rr_AnnualReturn2008 (39.69%)
Annual Return 2009 rr_AnnualReturn2009 28.59%
Annual Return 2010 rr_AnnualReturn2010 16.70%
Annual Return 2011 rr_AnnualReturn2011 (3.78%)
Annual Return 2012 rr_AnnualReturn2012 16.79%
1 year rr_AverageAnnualReturnYear01 16.79%
5 years rr_AverageAnnualReturnYear05 0.34%
Since Inception rr_AverageAnnualReturnSinceInception 6.28%
Inception Date rr_AverageAnnualReturnInceptionDate Sep. 30, 2004
ONE CHOICE PORTFOLIO: VERY AGGRESSIVE | INVESTOR CLASS | Return After Taxes on Distributions
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 16.65%
5 years rr_AverageAnnualReturnYear05 (0.04%)
Since Inception rr_AverageAnnualReturnSinceInception 5.73%
Inception Date rr_AverageAnnualReturnInceptionDate Sep. 30, 2004
ONE CHOICE PORTFOLIO: VERY AGGRESSIVE | INVESTOR CLASS | Return After Taxes on Distributions and Sale of Fund Shares
  
Prospectus [Line Items] rr_ProspectusLineItems  
1 year rr_AverageAnnualReturnYear01 11.17%
5 years rr_AverageAnnualReturnYear05 0.17%
Since Inception rr_AverageAnnualReturnSinceInception 5.26%
Inception Date rr_AverageAnnualReturnInceptionDate Sep. 30, 2004
ONE CHOICE IN RETIREMENT PORTFOLIO R6
  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk/Return [Heading] rr_RiskReturnHeading ONE CHOICE IN RETIREMENT PORTFOLIO R6
Objective [Heading] rr_ObjectiveHeading

Investment Objective
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The fund seeks current income.

Objective, Secondary [Text Block] rr_ObjectiveSecondaryTextBlock

Capital appreciation is a secondary objective.

Expense [Heading] rr_ExpenseHeading

Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock The following table describes the fees and expenses you may pay if you buy and hold shares of the fund.
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

Because the fund buys and sells shares of other American Century mutual funds (the underlying funds) directly from the issuers, the fund is not expected to incur transaction costs directly. However, as a shareholder in the underlying funds, the fund indirectly pays transaction costs, such as commissions, when the underlying funds buy and sell securities (or “turn over” their portfolios). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. During the one day period from the fund’s inception through its most recent fiscal year end, the fund’s portfolio turnover rate was 0% of the average value of its portfolio.

Portfolio Turnover, Rate rr_PortfolioTurnoverRate 0.00%
Other Expenses, New Fund, Based on Estimates [Text] rr_OtherExpensesNewFundBasedOnEstimates Other Expenses and Acquired Fund Fees and Expenses are based on estimated amounts for the current fiscal year.
Acquired Fund Fees and Expenses, Based on Estimates [Text] rr_AcquiredFundFeesAndExpensesBasedOnEstimates Other Expenses and Acquired Fund Fees and Expenses are based on estimated amounts for the current fiscal year.
Expense Example [Heading] rr_ExpenseExampleHeading

Example
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock

The example below is intended to help you compare the costs of investing in the fund with the costs of investing in other mutual funds.
Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption

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, that you earn a 5% return each year, and that the fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading] rr_StrategyHeading

Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

One Choice In Retirement Portfolio R6 is a “fund of funds,” meaning that it seeks to achieve its objective by investing in other American Century mutual funds (the underlying funds) that represent a variety of asset classes and investment styles. The underlying stock funds draw on growth, value and quantitative investment techniques and diversify investments among small, medium and large U.S. and foreign companies. The underlying bond funds invest in fixed-income securities that vary by issuer type (corporate and government), credit quality (investment-grade and high-yield or "junk bonds") and geographic exposure (domestic and international). The following table shows the fund’s target allocation for the various asset classes and underlying funds as of the date of the prospectus:

 

Equity Securities (Stock Funds)

45.00%

  

Fixed-Income Securities (Bond Funds)

45.00%

  

NT Core Equity Plus Fund

3.00%

  

High-Yield Fund

3.80%

NT Equity Growth Fund

10.00%

  

Inflation-Adjusted Bond Fund

1.50%

NT Growth Fund

6.50%

    

International Bond Fund

7.00%

NT Heritage Fund

2.50%

  

NT Diversified Bond Fund

26.60%

NT International Growth Fund

5.00%

  

Short Duration Inflation Protection Bond Fund

6.10%

NT Large Company Value Fund

11.00%

  

NT Mid Cap Value Fund

4.00%

  

Cash Equivalents (Money Market Funds)

10.00%

NT Small Company Fund

2.00%

  

Premium Money Market Fund

10.00

  %

Real Estate Fund

1.00%

    

 

The target asset mix of One Choice In Retirement Portfolio R6 is expected to remain fixed over time. The fund is generally intended for investors near to, at, or in retirement and who likely are no longer making new investments in the fund. The fund is designed for investors who plan to gradually withdraw the value of their account after retirement. The fund assumes a retirement age of 65 and may not be appropriate for an investor retiring at an age well before or after age 65.

 

The portfolio managers regularly review the fund’s allocations to determine whether rebalancing is appropriate. Although we do not intend to make frequent tactical adjustments to the target asset mix or trade actively among the underlying funds, we reserve the right to modify the target allocations and underlying funds from time to time should circumstances warrant a change.
Risk [Heading] rr_RiskHeading

Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock

 

•

Allocation Risk - The fund’s performance and risks depend in part on the managers’ skill in determining the fund’s asset class allocations and in selecting and weighting the underlying funds. The managers’ evaluations and assumptions regarding asset classes or underlying funds may differ from actual market conditions.

•

“Growth” and “Value” Style Risks - The underlying funds represent a mix of investment styles, each of which has risks associated with it. Growth stocks can be volatile and may lack dividends that can cushion share prices during market declines. Value stocks may continue to be undervalued by the market for long periods of time.

•

Small- and Mid-Cap Stock Risks - Stocks of smaller companies may be more volatile than larger-company stocks. Smaller companies may have limited financial resources, product lines and markets, and their securities may trade less frequently and in more limited volumes than the securities of larger companies, which could lead to higher transaction costs. To the extent an underlying fund invests in these companies, it may take on more risk.

•

Interest Rate Risk - Generally, when interest rates rise, the value of an underlying fund’s fixed-income securities will decline. The opposite is true when interest rates decline. Underlying funds with longer weighted average maturities are more sensitive to interest rate changes.

•

Credit Risk -The value of an underlying fund’s fixed-income securities will be affected adversely by any erosion in the ability of the issuers of these securities to make interest and principal payments as they become due. Changes in the credit rating of a fixed-income security held by an underlying fund could have a similar effect.

•

Foreign Securities Risk - Some of the underlying funds invest in foreign securities, which are generally riskier than U.S. securities. Securities of foreign issuers may be less liquid, more volatile and harder to value than U.S. securities. Fluctuations in currency exchange rates also may affect an underlying fund’s share price.

•

High-Yield Securities Risk - Some of the underlying funds may invest in high-yield securities, which are considered to have speculative characteristics and are more likely to be negatively affected by changes in economic conditions.

•

Tobacco Exclusion - The underlying funds do not invest in securities issued by companies assigned the Global Industry Classification Standard (GICS) for the tobacco industry. This exclusion may cause an underlying fund to forego profitable investment opportunities.

•

Market Risk - The value of the fund’s shares will go up and down based on the performance of the underlying funds in which it invests. The value of the underlying funds’ shares will, in turn, fluctuate based on the performance of the securities they own and other factors generally affecting the securities market.

•

Principal Loss - At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.

 

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Risk Lose Money [Text] rr_RiskLoseMoney

Principal Loss -At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.
Risk Not Insured Depository Institution [Text] rr_RiskNotInsuredDepositoryInstitution

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading

Fund Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The fund’s performance history is not available as of the date of this prospectus. When the fund has investment results for a full calendar year, this section will feature charts that show annual total returns, highest and lowest quarterly returns and average annual total returns for the fund. This information indicates the volatility of the fund’s historical returns from year to year.

 

Performance information is designed to help you see how fund returns can vary. Keep in mind that past performance (before and after taxes) does not predict how the fund will perform in the future.

 

For current performance information, please visit ipro.americancentury.com.
Performance One Year or Less [Text] rr_PerformanceOneYearOrLess The fund’s performance history is not available as of the date of this prospectus. When the fund has investment results for a full calendar year, this section will feature charts that show annual total returns, highest and lowest quarterly returns and average annual total returns for the fund. This information indicates the volatility of the fund’s historical returns from year to year.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress ipro.americancentury.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture Keep in mind that past performance (before and after taxes) does not predict how the fund will perform in the future.
ONE CHOICE IN RETIREMENT PORTFOLIO R6 | R6 CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.01% [4]
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.51% [4]
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.52%
1 year rr_ExpenseExampleYear01 53
3 years rr_ExpenseExampleYear03 167
ONE CHOICE 2015 PORTFOLIO R6
  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk/Return [Heading] rr_RiskReturnHeading ONE CHOICE 2015 PORTFOLIO R6
Objective [Heading] rr_ObjectiveHeading

Investment Objective
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The fund seeks the highest total return consistent with its asset mix.
Expense [Heading] rr_ExpenseHeading

Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock The following table describes the fees and expenses you may pay if you buy and hold shares of the fund.
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

Because the fund buys and sells shares of other American Century mutual funds (the underlying funds) directly from the issuers, the fund is not expected to incur transaction costs directly. However, as a shareholder in the underlying funds, the fund indirectly pays transaction costs, such as commissions, when the underlying funds buy and sell securities (or “turn over” their portfolios). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. During the one day period from the fund’s inception through its most recent fiscal year end, the fund’s portfolio turnover rate was 0% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 0.00%
Other Expenses, New Fund, Based on Estimates [Text] rr_OtherExpensesNewFundBasedOnEstimates Other Expenses and Acquired Fund Fees and Expenses are based on estimated amounts for the current fiscal year.
Acquired Fund Fees and Expenses, Based on Estimates [Text] rr_AcquiredFundFeesAndExpensesBasedOnEstimates Other Expenses and Acquired Fund Fees and Expenses are based on estimated amounts for the current fiscal year.
Expense Example [Heading] rr_ExpenseExampleHeading

Example
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock

The example below is intended to help you compare the costs of investing in the fund with the costs of investing in other mutual funds.
Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption

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, that you earn a 5% return each year, and that the fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading] rr_StrategyHeading

Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

One Choice 2015 Portfolio R6 is a “fund of funds” meaning that it seeks to achieve its objective by investing in other American Century mutual funds (the underlying funds) that represent a variety of asset classes and investment styles. The underlying stock funds draw on growth, value and quantitative investment techniques and diversify investments among small, medium and large U.S. and foreign companies. The underlying bond funds invest in fixed-income securities that vary by issuer type (corporate and government), credit quality (investment-grade and high-yield or "junk bonds") and geographic exposure (domestic and international). The following table shows the fund’s target allocation for the various asset classes and underlying funds as of the date of the prospectus:

 

Equity Securities (Stock Funds)

46.05%

    

Fixed-Income Securities (Bond Funds)

44.45%

  

NT Core Equity Plus Fund

3.00%

    

High-Yield Fund

 3.75%

  

NT Emerging Markets Fund

0.25%

    

Inflation-Adjusted Bond Fund

   1.80%

  

NT Equity Growth Fund

10.00%

    

International Bond Fund

   6.80%

  

NT Growth Fund

6.75%

    

NT Diversified Bond Fund

26.40%

  

NT Heritage Fund

2.75%

    

Short Duration Inflation Protection Bond Fund

   5.70%

  

NT International Growth Fund

 5.00%

          

NT Large Company Value Fund

11.00%

    

Cash Equivalents (Money Market Funds)

   9.50%

  

NT Mid Cap Value Fund

 4.25%

    

Premium Money Market Fund

   9.50%

  

NT Small Company Fund

 2.00%

          

Real Estate Fund

 1.05%

          

 

 

The target date in the fund name (2015) refers to the approximate year an investor plans to retire and likely would stop making new investments in the fund. The fund assumes a retirement age of 65 and may not be appropriate for an investor who plans to retire at or near the target date, but at an age well before or after 65. As the target date approaches, the fund’s asset mix will become more conservative by decreasing the allocation to stocks and increasing the allocation to bonds and cash. By the time the fund reaches its target date, the asset mix will become fixed and match that of One Choice In Retirement Portfolio R6, which is currently 45% stock funds, 45% bond funds and 10% money market funds. The fund is designed for investors who plan to withdraw the value of their account gradually after retirement. The following chart shows how the asset mix is expected to change over time according to a predetermined glide path.

 

One Choice Target Date Portfolios' Glide Path

Years to Retirement 45 44 43 42 41 40 39 38 37 36 35 34 33
Stocks 85.00% 85.00% 85.00% 85.00% 85.00% 85.00% 84.70% 83.90% 83.35% 82.80% 82.25% 81.70% 81.40%
Bonds 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.30% 16.10% 16.65% 17.20% 17.75% 18.30% 18.60%
Cash 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%
32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15
80.85% 80.40% 80.00% 78.45% 77.15% 76.35% 74.95% 73.40% 72.10% 70.80% 70.25% 68.55% 67.00% 65.85% 64.50% 63.35% 62.30% 61.00%
19.15% 19.60% 20.00% 21.05% 21.85% 22.15% 23.05% 24.10% 24.90% 25.70% 25.75% 26.95% 28.00% 29.15% 30.50% 31.65% 32.70% 34.00%
0.00% 0.00% 0.00% 0.50% 1.00% 1.50% 2.00% 2.50% 3.00% 3.50% 4.00% 4.50% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%
14 13 12 11 10 9 8 7 6 5 4 3 2 1   RETIREMENT
59.70% 58.60% 57.35% 56.30% 55.00% 54.20% 52.90% 52.10% 51.05% 50.00% 48.95% 47.90% 46.85% 46.05%   45.00%
35.30% 36.40% 37.65% 38.70% 40.00% 40.30% 41.10% 41.40% 41.95% 42.50% 43.05% 43.60% 44.15% 44.45%   45.00%
5.00% 5.00% 5.00% 5.00% 5.00% 5.50% 6.00% 6.50% 7.00% 7.50% 8.00% 8.50% 9.00% 9.50%   10.00%
Years After Retirement 1 2 3 4 5 6 7 8 9 10 11 12 13
Stocks 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Bonds 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Cash 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%

 

The portfolio managers regularly review the fund’s allocations to determine whether rebalancing is appropriate. Although we do not intend to make frequent tactical adjustments to the target asset mix or trade actively among the underlying funds (other than the glide path adjustments described above), we reserve the right to modify the target allocations and underlying funds from time to time should circumstances warrant a change.
Risk [Heading] rr_RiskHeading

Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock

 

•

Allocation Risk - The fund's performance and risks depend in part on the managers’ skill in determining the fund’s asset class allocations and in selecting and weighting the underlying funds. The managers’ evaluations and assumptions regarding asset classes or underlying funds may differ from actual market conditions.

•

“Growth” and “Value” Style Risks - The underlying funds represent a mix of investment styles, each of which has risks associated with it. Growth stocks can be volatile and may lack dividends that can cushion share prices during market declines. Value stocks may continue to be undervalued by the market for long periods of time.

•

Small- and Mid-Cap Stock Risks - Stocks of smaller companies may be more volatile than larger-company stocks. Smaller companies may have limited financial resources, product lines and markets, and their securities may trade less frequently and in more limited volumes than the securities of larger companies, which could lead to higher transaction costs. To the extent an underlying fund invests in these companies, it may take on more risk.

•

Interest Rate Risk - Generally, when interest rates rise, the value of an underlying fund’s fixed-income securities will decline. The opposite is true when interest rates decline. Underlying funds with longer weighted average maturities are more sensitive to interest rate changes.

•

Credit Risk - The value of an underlying fund’s fixed-income securities will be affected adversely by any erosion in the ability of the issuers of these securities to make interest and principal payments as they become due. Changes in the credit rating of a fixed-income security held by an underlying fund could have a similar effect.

•

Foreign Securities Risk - Some of the underlying funds invest in foreign securities, which are generally riskier than U.S. securities. Securities of foreign issuers may be less liquid, more volatile and harder to value than U.S. securities. Fluctuations in currency exchange rates also may affect an underlying fund’s share price.

•

High-Yield Securities Risk - Some of the underlying funds may invest in high-yield securities, which are considered to have speculative characteristics and are more likely to be negatively affected by changes in economic conditions.

•

Tobacco Exclusion - The underlying funds do not invest in securities issued by companies assigned the Global Industry Classification Standard (GICS) for the tobacco industry. This exclusion may cause an underlying fund to forego profitable investment opportunities.

•

Market Risk -The value of the fund’s shares will go up and down based on the performance of the underlying funds in which it invests. The value of the underlying funds’ shares will, in turn, fluctuate based on the performance of the securities they own and other factors generally affecting the securities market.

•

Principal Loss - At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.

 

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

 
Risk Lose Money [Text] rr_RiskLoseMoney

Principal Loss -At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.
Risk Not Insured Depository Institution [Text] rr_RiskNotInsuredDepositoryInstitution

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading

Fund Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The fund’s performance history is not available as of the date of this prospectus. When the fund has investment results for a full calendar year, this section will feature charts that show annual total returns, highest and lowest quarterly returns and average annual total returns for the fund. This information indicates the volatility of the fund’s historical returns from year to year.

 

Performance information is designed to help you see how fund returns can vary. Keep in mind that past performance (before and after taxes) does not predict how the fund will perform in the future.

 

For current performance information, please visit ipro.americancentury.com.
Performance One Year or Less [Text] rr_PerformanceOneYearOrLess The fund’s performance history is not available as of the date of this prospectus. When the fund has investment results for a full calendar year, this section will feature charts that show annual total returns, highest and lowest quarterly returns and average annual total returns for the fund. This information indicates the volatility of the fund’s historical returns from year to year.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress ipro.americancentury.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture Keep in mind that past performance (before and after taxes) does not predict how the fund will perform in the future.
ONE CHOICE 2015 PORTFOLIO R6 | R6 CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.01% [4]
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.52% [4]
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.53%
1 year rr_ExpenseExampleYear01 54
3 years rr_ExpenseExampleYear03 170
ONE CHOICE 2020 PORTFOLIO R6
  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk/Return [Heading] rr_RiskReturnHeading ONE CHOICE 2020 PORTFOLIO R6
Objective [Heading] rr_ObjectiveHeading

Investment Objective
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The fund seeks the highest total return consistent with its asset mix.
Expense [Heading] rr_ExpenseHeading

Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock The following table describes the fees and expenses you may pay if you buy and hold shares of the fund.
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 Because the fund buys and sells shares of other American Century mutual funds (the underlying funds) directly from the issuers, the fund is not expected to incur transaction costs directly. However, as a shareholder in the underlying funds, the fund indirectly pays transaction costs, such as commissions, when the underlying funds buy and sell securities (or “turn over” their portfolios). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. During the one day period from the fund’s inception through its most recent fiscal year end, the fund’s portfolio turnover rate was 0% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 0.00%
Other Expenses, New Fund, Based on Estimates [Text] rr_OtherExpensesNewFundBasedOnEstimates Other Expenses and Acquired Fund Fees and Expenses are based on estimated amounts for the current fiscal year.
Acquired Fund Fees and Expenses, Based on Estimates [Text] rr_AcquiredFundFeesAndExpensesBasedOnEstimates Other Expenses and Acquired Fund Fees and Expenses are based on estimated amounts for the current fiscal year.
Expense Example [Heading] rr_ExpenseExampleHeading

Example
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock

The example below is intended to help you compare the costs of investing in the fund with the costs of investing in other mutual funds.
Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption

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, that you earn a 5% return each year, and that the fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading] rr_StrategyHeading

Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

One Choice 2020 Portfolio R6 is a “fund of funds” meaning that it seeks to achieve its objective by investing in other American Century mutual funds (the underlying funds) that represent a variety of asset classes and investment styles. The underlying stock funds draw on growth, value and quantitative investment techniques and diversify investments among small, medium and large U.S. and foreign companies. The underlying bond funds invest in fixed-income securities that vary by issuer type (corporate and government), credit quality (investment-grade and high-yield or "junk bonds") and geographic exposure (domestic and international). The following table shows the fund’s target allocation for the various asset classes and underlying funds as of the date of the prospectus:

 

Equity Securities (Stock Funds)

51.05%

  

Fixed-Income Securities (Bond Funds)

41.95%

NT Core Equity Plus Fund

3.00%

  

High-Yield Fund

3.60%

NT Emerging Markets Fund

1.25%

  

Inflation-Adjusted Bond Fund

3.10%

NT Equity Growth Fund

9.50%

  

International Bond Fund

5.80%

NT Growth Fund

8.00%

  

NT Diversified Bond Fund

25.30%

NT Heritage Fund

3.75%

  

Short Duration Inflation Protection Bond Fund

4.15%

NT International Growth Fund

6.00%

    

NT Large Company Value Fund

11.25%

  

Cash Equivalents (Money Market Funds)

7.00%

NT Mid Cap Value Fund

5.00%

  

Premium Money Market Fund

7.00%

NT Small Company Fund

2.00%

    

Real Estate Fund

1.30%

  

 

 

The target date in the fund name (2020) refers to the approximate year an investor plans to retire and likely would stop making new investments in the fund. The fund assumes a retirement age of 65 and may not be appropriate for an investor who plans to retire at or near the target date, but at an age well before or after 65. As the target date approaches, the fund’s asset mix will become more conservative by decreasing the allocation to stocks and increasing the allocation to bonds and cash. By the time the fund reaches its target date, the asset mix will become fixed and match that of One Choice In Retirement Portfolio R6, which is currently 45% stock funds, 45% bond funds and 10% money market funds. The fund is designed for investors who plan to withdraw the value of their account gradually after retirement. The following chart shows how the asset mix is expected to change over time according to a predetermined glide path.

 

One Choice Target Date Portfolios' Glide Path

Years to Retirement 45 44 43 42 41 40 39 38 37 36 35 34 33
Stocks 85.00% 85.00% 85.00% 85.00% 85.00% 85.00% 84.70% 83.90% 83.35% 82.80% 82.25% 81.70% 81.40%
Bonds 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.30% 16.10% 16.65% 17.20% 17.75% 18.30% 18.60%
Cash 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%
32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15
80.85% 80.40% 80.00% 78.45% 77.15% 76.35% 74.95% 73.40% 72.10% 70.80% 70.25% 68.55% 67.00% 65.85% 64.50% 63.35% 62.30% 61.00%
19.15% 19.60% 20.00% 21.05% 21.85% 22.15% 23.05% 24.10% 24.90% 25.70% 25.75% 26.95% 28.00% 29.15% 30.50% 31.65% 32.70% 34.00%
0.00% 0.00% 0.00% 0.50% 1.00% 1.50% 2.00% 2.50% 3.00% 3.50% 4.00% 4.50% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%
14 13 12 11 10 9 8 7 6 5 4 3 2 1   RETIREMENT
59.70% 58.60% 57.35% 56.30% 55.00% 54.20% 52.90% 52.10% 51.05% 50.00% 48.95% 47.90% 46.85% 46.05%   45.00%
35.30% 36.40% 37.65% 38.70% 40.00% 40.30% 41.10% 41.40% 41.95% 42.50% 43.05% 43.60% 44.15% 44.45%   45.00%
5.00% 5.00% 5.00% 5.00% 5.00% 5.50% 6.00% 6.50% 7.00% 7.50% 8.00% 8.50% 9.00% 9.50%   10.00%
Years After Retirement 1 2 3 4 5 6 7 8 9 10 11 12 13
Stocks 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Bonds 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Cash 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%

 

The portfolio managers regularly review the fund’s allocations to determine whether rebalancing is appropriate. Although we do not intend to make frequent tactical adjustments to the target asset mix or trade actively among the underlying funds (other than the glide path adjustments described above), we reserve the right to modify the target allocations and underlying funds from time to time should circumstances warrant a change.
Risk [Heading] rr_RiskHeading

Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock

•

Allocation Risk -The fund’s performance and risks depend in part on the managers’ skill in determining the fund’s asset class allocations and in selecting and weighting the underlying funds. The managers’ evaluations and assumptions regarding asset classes or underlying funds may differ from actual market conditions.

•

“Growth” and “Value” Style Risks - The underlying funds represent a mix of investment styles, each of which has risks associated with it. Growth stocks can be volatile and may lack dividends that can cushion share prices during market declines. Value stocks may continue to be undervalued by the market for long periods of time.

•

Small- and Mid-Cap Stock Risks - Stocks of smaller companies may be more volatile than larger-company stocks. Smaller companies may have limited financial resources, product lines and markets, and their securities may trade less frequently and in more limited volumes than the securities of larger companies, which could lead to higher transaction costs. To the extent an underlying fund invests in these companies, it may take on more risk.

•

Interest Rate Risk - Generally, when interest rates rise, the value of an underlying fund’s fixed-income securities will decline. The opposite is true when interest rates decline. Underlying funds with longer weighted average maturities are more sensitive to interest rate changes.

•

Credit Risk - The value of an underlying fund’s fixed-income securities will be affected adversely by any erosion in the ability of the issuers of these securities to make interest and principal payments as they become due. Changes in the credit rating of a fixed-income security held by an underlying fund could have a similar effect.

•

Foreign Securities Risk - Some of the underlying funds invest in foreign securities, which are generally riskier than U.S. securities. Securities of foreign issuers may be less liquid, more volatile and harder to value than U.S. securities. Fluctuations in currency exchange rates also may affect an underlying fund’s share price.

•

High-Yield Securities Risk - Some of the underlying funds may invest in high-yield securities, which are considered to have speculative characteristics and are more likely to be negatively affected by changes in economic conditions.

•

Tobacco Exclusion - The underlying funds do not invest in securities issued by companies assigned the Global Industry Classification Standard (GICS) for the tobacco industry. This exclusion may cause an underlying fund to forego profitable investment opportunities.

•

Market Risk - The value of the fund’s shares will go up and down based on the performance of the underlying funds in which it invests. The value of the underlying funds’ shares will, in turn, fluctuate based on the performance of the securities they own and other factors generally affecting the securities market.

•

Principal Loss - At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.

 

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Risk Lose Money [Text] rr_RiskLoseMoney

Principal Loss -At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.
Risk Not Insured Depository Institution [Text] rr_RiskNotInsuredDepositoryInstitution

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading

Fund Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The fund’s performance history is not available as of the date of this prospectus. When the fund has investment results for a full calendar year, this section will feature charts that show annual total returns, highest and lowest quarterly returns and average annual total returns for the fund. This information indicates the volatility of the fund’s historical returns from year to year.

 

Performance information is designed to help you see how fund returns can vary. Keep in mind that past performance (before and after taxes) does not predict how the fund will perform in the future.

 

For current performance information, please visit ipro.americancentury.com.
Performance One Year or Less [Text] rr_PerformanceOneYearOrLess The fund’s performance history is not available as of the date of this prospectus. When the fund has investment results for a full calendar year, this section will feature charts that show annual total returns, highest and lowest quarterly returns and average annual total returns for the fund. This information indicates the volatility of the fund’s historical returns from year to year.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress ipro.americancentury.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture Keep in mind that past performance (before and after taxes) does not predict how the fund will perform in the future.
ONE CHOICE 2020 PORTFOLIO R6 | R6 CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.01% [4]
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.54% [4]
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.55%
1 year rr_ExpenseExampleYear01 56
3 years rr_ExpenseExampleYear03 177
ONE CHOICE 2025 PORTFOLIO R6
  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk/Return [Heading] rr_RiskReturnHeading ONE CHOICE 2025 PORTFOLIO R6
Objective [Heading] rr_ObjectiveHeading

Investment Objective
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The fund seeks the highest total return consistent with its asset mix.
Expense [Heading] rr_ExpenseHeading

Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock The following table describes the fees and expenses you may pay if you buy and hold shares of the fund.
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 Because the fund buys and sells shares of other American Century mutual funds (the underlying funds) directly from the issuers, the fund is not expected to incur transaction costs directly. However, as a shareholder in the underlying funds, the fund indirectly pays transaction costs, such as commissions, when the underlying funds buy and sell securities (or ‘turn over’ their portfolios). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. During the one day period from the fund’s inception through its most recent fiscal year end, the fund’s portfolio turnover rate was 0% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 0.00%
Other Expenses, New Fund, Based on Estimates [Text] rr_OtherExpensesNewFundBasedOnEstimates Other Expenses and Acquired Fund Fees and Expenses are based on estimated amounts for the current fiscal year.
Acquired Fund Fees and Expenses, Based on Estimates [Text] rr_AcquiredFundFeesAndExpensesBasedOnEstimates Other Expenses and Acquired Fund Fees and Expenses are based on estimated amounts for the current fiscal year.
Expense Example [Heading] rr_ExpenseExampleHeading

Example
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock

The example below is intended to help you compare the costs of investing in the fund with the costs of investing in other mutual funds.
Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption

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, that you earn a 5% return each year, and that the fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading] rr_StrategyHeading

Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

One Choice 2025 Portfolio R6 is a ‘fund of funds’ meaning that it seeks to achieve its objective by investing in other American Century mutual funds (the underlying funds) that represent a variety of asset classes and investment styles. The underlying stock funds draw on growth, value and quantitative investment techniques and diversify investments among small, medium and large U.S. and foreign companies. The underlying bond funds invest in fixed-income securities that vary by issuer type (corporate and government), credit quality (investment-grade and high-yield or "junk bonds") and geographic exposure (domestic and international). The following table shows the fund’s target allocation for the various asset classes and underlying funds as of the date of the prospectus:

 

Equity Securities (Stock Funds)

56.30%

  

Fixed-Income Securities (Bond Funds)

38.70%

NT Core Equity Plus Fund

3.00%

High-Yield Fund

3.40%

NT Emerging Markets Fund

2.25%

  

Inflation-Adjusted Bond Fund

  4.20%

NT Equity Growth Fund

9.25%

  

International Bond Fund

  4.50%

NT Growth Fund

9.25%

NT Diversified Bond Fund

24.00%

NT Heritage Fund

4.50%

  

Short Duration Inflation Protection Bond Fund

 

2.60%

NT International Growth Fund

7.00%

  

NT Large Company Value Fund

11.50%

  

Cash Equivalents (Money Market Funds)

5.00%

NT Mid Cap Value Fund

5.50%

Premium Money Market Fund

5.00%

NT Small Company Fund

2.50%

Real Estate Fund

1.55%

 

The target date in the fund name (2025) refers to the approximate year an investor plans to retire and likely would stop making new investments in the fund. The fund assumes a retirement age of 65 and may not be appropriate for an investor who plans to retire at or near the target date, but at an age well before or after 65. As the target date approaches, the fund’s asset mix will become more conservative by decreasing the allocation to stocks and increasing the allocation to bonds and cash. By the time the fund reaches its target date, the asset mix will become fixed and match that of One Choice In Retirement Portfolio R6, which is currently 45% stock funds, 45% bond funds and 10% money market funds. The fund is designed for investors who plan to withdraw the value of their account gradually after retirement. The following chart shows how the asset mix is expected to change over time according to a predetermined glide path.

 

One Choice Target Date Portfolios' Glide Path

Years to Retirement 45 44 43 42 41 40 39 38 37 36 35 34 33
Stocks 85.00% 85.00% 85.00% 85.00% 85.00% 85.00% 84.70% 83.90% 83.35% 82.80% 82.25% 81.70% 81.40%
Bonds 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.30% 16.10% 16.65% 17.20% 17.75% 18.30% 18.60%
Cash 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%
32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15
80.85% 80.40% 80.00% 78.45% 77.15% 76.35% 74.95% 73.40% 72.10% 70.80% 70.25% 68.55% 67.00% 65.85% 64.50% 63.35% 62.30% 61.00%
19.15% 19.60% 20.00% 21.05% 21.85% 22.15% 23.05% 24.10% 24.90% 25.70% 25.75% 26.95% 28.00% 29.15% 30.50% 31.65% 32.70% 34.00%
0.00% 0.00% 0.00% 0.50% 1.00% 1.50% 2.00% 2.50% 3.00% 3.50% 4.00% 4.50% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%
14 13 12 11 10 9 8 7 6 5 4 3 2 1   RETIREMENT
59.70% 58.60% 57.35% 56.30% 55.00% 54.20% 52.90% 52.10% 51.05% 50.00% 48.95% 47.90% 46.85% 46.05%   45.00%
35.30% 36.40% 37.65% 38.70% 40.00% 40.30% 41.10% 41.40% 41.95% 42.50% 43.05% 43.60% 44.15% 44.45%   45.00%
5.00% 5.00% 5.00% 5.00% 5.00% 5.50% 6.00% 6.50% 7.00% 7.50% 8.00% 8.50% 9.00% 9.50%   10.00%
Years After Retirement 1 2 3 4 5 6 7 8 9 10 11 12 13
Stocks 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Bonds 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Cash 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%

 

The portfolio managers regularly review the fund’s allocations to determine whether rebalancing is appropriate. Although we do not intend to make frequent tactical adjustments to the target asset mix or trade actively among the underlying funds (other than the glide path adjustments described above), we reserve the right to modify the target allocations and underlying funds from time to time should circumstances warrant a change.
Risk [Heading] rr_RiskHeading

Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock

•

Allocation Risk - The fund’s performance and risks depend in part on the managers’ skill in determining the fund’s asset class allocations and in selecting and weighting the underlying funds. The managers’ evaluations and assumptions regarding asset classes or underlying funds may differ from actual market conditions.

•

“Growth” and “Value” Style Risks -The underlying funds represent a mix of investment styles, each of which has risks associated with it. Growth stocks can be volatile and may lack dividends that can cushion share prices during market declines. Value stocks may continue to be undervalued by the market for long periods of time.

•

Small- and Mid-Cap Stock Risks - Stocks of smaller companies may be more volatile than larger-company stocks. Smaller companies may have limited financial resources, product lines and markets, and their securities may trade less frequently and in more limited volumes than the securities of larger companies, which could lead to higher transaction costs. To the extent an underlying fund invests in these companies, it may take on more risk.

•

Interest Rate Risk - Generally, when interest rates rise, the value of an underlying fund’s fixed-income securities will decline. The opposite is true when interest rates decline. Underlying funds with longer weighted average maturities are more sensitive to interest rate changes.

•

Credit Risk - The value of an underlying fund’s fixed-income securities will be affected adversely by any erosion in the ability of the issuers of these securities to make interest and principal payments as they become due. Changes in the credit rating of a fixed-income security held by an underlying fund could have a similar effect.

•

Foreign Securities Risk - Some of the underlying funds invest in foreign securities, which are generally riskier than U.S. securities. Securities of foreign issuers may be less liquid, more volatile and harder to value than U.S. securities. Fluctuations in currency exchange rates also may affect an underlying fund’s share price.

•

High-Yield Securities Risk - Some of the underlying funds may invest in high-yield securities, which are considered to have speculative characteristics and are more likely to be negatively affected by changes in economic conditions.

•

Tobacco Exclusion - The underlying funds do not invest in securities issued by companies assigned the Global Industry Classification Standard (GICS) for the tobacco industry. This exclusion may cause an underlying fund to forego profitable investment opportunities.

•

Market Risk - The value of the fund’s shares will go up and down based on the performance of the underlying funds in which it invests. The value of the underlying funds’ shares will, in turn, fluctuate based on the performance of the securities they own and other factors generally affecting the securities market.

•

Principal Loss - At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.

 

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
Risk Lose Money [Text] rr_RiskLoseMoney

Principal Loss -At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.
Risk Not Insured Depository Institution [Text] rr_RiskNotInsuredDepositoryInstitution

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading

Fund Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The fund’s performance history is not available as of the date of this prospectus. When the fund has investment results for a full calendar year, this section will feature charts that show annual total returns, highest and lowest quarterly returns and average annual total returns for the fund. This information indicates the volatility of the fund’s historical returns from year to year.

 

Performance information is designed to help you see how fund returns can vary. Keep in mind that past performance (before and after taxes) does not predict how the fund will perform in the future.

 

For current performance information, please visit ipro.americancentury.com.
Performance One Year or Less [Text] rr_PerformanceOneYearOrLess The fund’s performance history is not available as of the date of this prospectus. When the fund has investment results for a full calendar year, this section will feature charts that show annual total returns, highest and lowest quarterly returns and average annual total returns for the fund. This information indicates the volatility of the fund’s historical returns from year to year.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress ipro.americancentury.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture Keep in mind that past performance (before and after taxes) does not predict how the fund will perform in the future.
ONE CHOICE 2025 PORTFOLIO R6 | R6 CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.01% [4]
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.56% [4]
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.57%
1 year rr_ExpenseExampleYear01 58
3 years rr_ExpenseExampleYear03 183
ONE CHOICE 2030 PORTFOLIO R6
  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk/Return [Heading] rr_RiskReturnHeading ONE CHOICE 2030 PORTFOLIO R6
Objective [Heading] rr_ObjectiveHeading

Investment Objective
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The fund seeks the highest total return consistent with its asset mix.
Expense [Heading] rr_ExpenseHeading

Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock The following table describes the fees and expenses you may pay if you buy and hold shares of the fund.
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 Because the fund buys and sells shares of other American Century mutual funds (the underlying funds) directly from the issuers, the fund is not expected to incur transaction costs directly. However, as a shareholder in the underlying funds, the fund indirectly pays transaction costs, such as commissions, when the underlying funds buy and sell securities (or “turn over” their portfolios). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. During the one day period from the fund’s inception through its most recent fiscal year end, the fund’s portfolio turnover rate was 0% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 0.00%
Other Expenses, New Fund, Based on Estimates [Text] rr_OtherExpensesNewFundBasedOnEstimates Other Expenses and Acquired Fund Fees and Expenses are based on estimated amounts for the current fiscal year.
Acquired Fund Fees and Expenses, Based on Estimates [Text] rr_AcquiredFundFeesAndExpensesBasedOnEstimates Other Expenses and Acquired Fund Fees and Expenses are based on estimated amounts for the current fiscal year.
Expense Example [Heading] rr_ExpenseExampleHeading

Example
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock

The example below is intended to help you compare the costs of investing in the fund with the costs of investing in other mutual funds.
Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption

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, that you earn a 5% return each year, and that the fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading] rr_StrategyHeading

Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

One Choice 2030 Portfolio R6 is a “fund of funds” meaning that it seeks to achieve its objective by investing in other American Century mutual funds (the underlying funds) that represent a variety of asset classes and investment styles. The underlying stock funds draw on growth, value and quantitative investment techniques and diversify investments among small, medium and large U.S. and foreign companies. The underlying bond funds invest in fixed-income securities that vary by issuer type (corporate and government), credit quality (investment-grade and high-yield or "junk bonds") and geographic exposure (domestic and international). The following table shows the fund’s target allocation for the various asset classes and underlying funds as of the date of the prospectus:

 

Equity Securities (Stock Funds)

62.30%

    

Fixed-Income Securities (Bond Funds)

32.70%

  

NT Core Equity Plus Fund

3.25%

    

High-Yield Fund

3.00%

  

NT Emerging Markets Fund

2.75%

    

Inflation-Adjusted Bond Fund

5.00%

  

NT Equity Growth Fund

9.25%

    

International Bond Fund

2.00%

  

NT Growth Fund

11.00%

    

NT Diversified Bond Fund

21.50%

  

NT Heritage Fund

5.00%

    

Short Duration Inflation Protection Bond Fund

1.20%

  

NT International Growth Fund

8.50%

          

NT Large Company Value Fund

12.00%

    

Cash Equivalents (Money Market Funds)

 5.00%

  

NT Mid Cap Value Fund

5.25%

    

Premium Money Market Fund

5.00%

  

NT Small Company Fund

3.50%

          

Real Estate Fund

1.80%

          

 

The target date in the fund name (2030) refers to the approximate year an investor plans to retire and likely would stop making new investments in the fund. The fund assumes a retirement age of 65 and may not be appropriate for an investor who plans to retire at or near the target date, but at an age well before or after 65. As the target date approaches, the fund’s asset mix will become more conservative by decreasing the allocation to stocks and increasing the allocation to bonds and cash. By the time the fund reaches its target date, the asset mix will become fixed and match that of One Choice In Retirement Portfolio R6, which is currently 45% stock funds, 45% bond funds and 10% money market funds. The fund is designed for investors who plan to withdraw the value of their account gradually after retirement. The following chart shows how the asset mix is expected to change over time according to a predetermined glide path.

 

One Choice Target Date Portfolios' Glide Path

Years to Retirement 45 44 43 42 41 40 39 38 37 36 35 34 33
Stocks 85.00% 85.00% 85.00% 85.00% 85.00% 85.00% 84.70% 83.90% 83.35% 82.80% 82.25% 81.70% 81.40%
Bonds 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.30% 16.10% 16.65% 17.20% 17.75% 18.30% 18.60%
Cash 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%
32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15
80.85% 80.40% 80.00% 78.45% 77.15% 76.35% 74.95% 73.40% 72.10% 70.80% 70.25% 68.55% 67.00% 65.85% 64.50% 63.35% 62.30% 61.00%
19.15% 19.60% 20.00% 21.05% 21.85% 22.15% 23.05% 24.10% 24.90% 25.70% 25.75% 26.95% 28.00% 29.15% 30.50% 31.65% 32.70% 34.00%
0.00% 0.00% 0.00% 0.50% 1.00% 1.50% 2.00% 2.50% 3.00% 3.50% 4.00% 4.50% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%
14 13 12 11 10 9 8 7 6 5 4 3 2 1   RETIREMENT
59.70% 58.60% 57.35% 56.30% 55.00% 54.20% 52.90% 52.10% 51.05% 50.00% 48.95% 47.90% 46.85% 46.05%   45.00%
35.30% 36.40% 37.65% 38.70% 40.00% 40.30% 41.10% 41.40% 41.95% 42.50% 43.05% 43.60% 44.15% 44.45%   45.00%
5.00% 5.00% 5.00% 5.00% 5.00% 5.50% 6.00% 6.50% 7.00% 7.50% 8.00% 8.50% 9.00% 9.50%   10.00%
Years After Retirement 1 2 3 4 5 6 7 8 9 10 11 12 13
Stocks 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Bonds 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Cash 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%

 

The portfolio managers regularly review the fund’s allocations to determine whether rebalancing is appropriate. Although we do not intend to make frequent tactical adjustments to the target asset mix or trade actively among the underlying funds (other than the glide path adjustments described above), we reserve the right to modify the target allocations and underlying funds from time to time should circumstances warrant a change.
Risk [Heading] rr_RiskHeading

Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock

•

Allocation Risk -The fund’s performance and risks depend in part on the managers’ skill in determining the fund’s asset class allocations and in selecting and weighting the underlying funds. The managers’ evaluations and assumptions regarding asset classes or underlying funds may differ from actual market conditions.

•

“Growth” and “Value” Style Risks - The underlying funds represent a mix of investment styles, each of which has risks associated with it. Growth stocks can be volatile and may lack dividends that can cushion share prices during market declines. Value stocks may continue to be undervalued by the market for long periods of time.

•

Small- and Mid-Cap Stock Risks - Stocks of smaller companies may be more volatile than larger-company stocks. Smaller companies may have limited financial resources, product lines and markets, and their securities may trade less frequently and in more limited volumes than the securities of larger companies, which could lead to higher transaction costs. To the extent an underlying fund invests in these companies, it may take on more risk.

•

Interest Rate Risk - Generally, when interest rates rise, the value of an underlying fund’s fixed-income securities will decline. The opposite is true when interest rates decline. Underlying funds with longer weighted average maturities are more sensitive to interest rate changes.

•

Credit Risk - The value of an underlying fund’s fixed-income securities will be affected adversely by any erosion in the ability of the issuers of these securities to make interest and principal payments as they become due. Changes in the credit rating of a fixed-income security held by an underlying fund could have a similar effect.

•

Foreign Securities Risk - Some of the underlying funds invest in foreign securities, which are generally riskier than U.S. securities. Securities of foreign issuers may be less liquid, more volatile and harder to value than U.S. securities. Fluctuations in currency exchange rates also may affect an underlying fund’s share price. Investing in securities of companies located in emerging market countries is generally riskier than investing in securities of companies located in developed foreign countries.

•

High-Yield Securities Risk - Some of the underlying funds may invest in high-yield securities, which are considered to have speculative characteristics and are more likely to be negatively affected by changes in economic conditions.

•

Tobacco Exclusion -The underlying funds do not invest in securities issued by companies assigned the Global Industry Classification Standard (GICS) for the tobacco industry. This exclusion may cause an underlying fund to forego profitable investment opportunities.

•

Market Risk -The value of the fund’s shares will go up and down based on the performance of the underlying funds in which it invests. The value of the underlying funds’ shares will, in turn, fluctuate based on the performance of the securities they own and other factors generally affecting the securities market.

•

Principal Loss -At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.

 

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

 
Risk Lose Money [Text] rr_RiskLoseMoney

Principal Loss -At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.
Risk Not Insured Depository Institution [Text] rr_RiskNotInsuredDepositoryInstitution

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading

Fund Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The fund’s performance history is not available as of the date of this prospectus. When the fund has investment results for a full calendar year, this section will feature charts that show annual total returns, highest and lowest quarterly returns and average annual total returns for the fund. This information indicates the volatility of the fund’s historical returns from year to year.

 

Performance information is designed to help you see how fund returns can vary. Keep in mind that past performance (before and after taxes) does not predict how the fund will perform in the future.

 

For current performance information, please visit ipro.americancentury.com.
Performance One Year or Less [Text] rr_PerformanceOneYearOrLess The fund’s performance history is not available as of the date of this prospectus. When the fund has investment results for a full calendar year, this section will feature charts that show annual total returns, highest and lowest quarterly returns and average annual total returns for the fund. This information indicates the volatility of the fund’s historical returns from year to year.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress ipro.americancentury.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture Keep in mind that past performance (before and after taxes) does not predict how the fund will perform in the future.
ONE CHOICE 2030 PORTFOLIO R6 | R6 CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.01% [4]
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.58% [4]
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.59%
1 year rr_ExpenseExampleYear01 60
3 years rr_ExpenseExampleYear03 189
ONE CHOICE 2035 PORTFOLIO R6
  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk/Return [Heading] rr_RiskReturnHeading ONE CHOICE 2035 PORTFOLIO R6
Objective [Heading] rr_ObjectiveHeading

Investment Objective
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The fund seeks the highest total return consistent with its asset mix.
Expense [Heading] rr_ExpenseHeading

Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock The following table describes the fees and expenses you may pay if you buy and hold shares of the fund.
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 Because the fund buys and sells shares of other American Century mutual funds (the underlying funds) directly from the issuers, the fund is not expected to incur transaction costs directly. However, as a shareholder in the underlying funds, the fund indirectly pays transaction costs, such as commissions, when the underlying funds buy and sell securities (or “turn over” their portfolios). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. During the one day period from the fund’s inception through its most recent fiscal year end, the fund’s portfolio turnover rate was 0% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 0.00%
Other Expenses, New Fund, Based on Estimates [Text] rr_OtherExpensesNewFundBasedOnEstimates Other Expenses and Acquired Fund Fees and Expenses are based on estimated amounts for the current fiscal year.
Acquired Fund Fees and Expenses, Based on Estimates [Text] rr_AcquiredFundFeesAndExpensesBasedOnEstimates Other Expenses and Acquired Fund Fees and Expenses are based on estimated amounts for the current fiscal year.
Expense Example [Heading] rr_ExpenseExampleHeading

Example
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock

The example below is intended to help you compare the costs of investing in the fund with the costs of investing in other mutual funds.
Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption

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, that you earn a 5% return each year, and that the fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading] rr_StrategyHeading

Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

One Choice 2035 Portfolio R6 is a “fund of funds” meaning that it seeks to achieve its objective by investing in other American Century mutual funds (the underlying funds) that represent a variety of asset classes and investment styles. The underlying stock funds draw on growth, value and quantitative investment techniques and diversify investments among small, medium and large U.S. and foreign companies. The underlying bond funds invest in fixed-income securities that vary by issuer type (corporate and government) and credit quality (investment-grade and high-yield or "junk bonds"). The following table shows the fund’s target allocation for the various asset classes and underlying funds as of the date of the prospectus:

 

Equity Securities (Stock Funds)

68.55%

  

Fixed-Income Securities (Bond Funds)

26.95%

NT Core Equity Plus Fund

3.25%

  

High-Yield Fund

2.65%

NT Emerging Markets Fund

3.50%

  

Inflation-Adjusted Bond Fund

5.40%

NT Equity Growth Fund

9.50%

  

NT Diversified Bond Fund

18.90%

NT Growth Fund

12.75%

  

NT Heritage Fund

5.50%

  

Cash Equivalents (Money Market Funds)

 

4.50%

NT International Growth Fund

9.50%

  

Premium Money Market Fund

4.50%

NT Large Company Value Fund

12.75%

      

NT Mid Cap Value Fund

5.50%

    

NT Small Company Fund

4.25%

    

Real Estate Fund

2.05%

    

 

The target date in the fund name (2035) refers to the approximate year an investor plans to retire and likely would stop making new investments in the fund. The fund assumes a retirement age of 65 and may not be appropriate for an investor who plans to retire at or near the target date, but at an age well before or after 65. As the target date approaches, the fund’s asset mix will become more conservative by decreasing the allocation to stocks and increasing the allocation to bonds and cash. By the time the fund reaches its target date, the asset mix will become fixed and match that of One Choice In Retirement Portfolio R6, which is currently 45% stock funds, 45% bond funds and 10% money market funds. The fund is designed for investors who plan to withdraw the value of their account gradually after retirement. The following chart shows how the asset mix is expected to change over time according to a predetermined glide path.

 

One Choice Target Date Portfolios' Glide Path

Years to Retirement 45 44 43 42 41 40 39 38 37 36 35 34 33
Stocks 85.00% 85.00% 85.00% 85.00% 85.00% 85.00% 84.70% 83.90% 83.35% 82.80% 82.25% 81.70% 81.40%
Bonds 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.30% 16.10% 16.65% 17.20% 17.75% 18.30% 18.60%
Cash 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%
32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15
80.85% 80.40% 80.00% 78.45% 77.15% 76.35% 74.95% 73.40% 72.10% 70.80% 70.25% 68.55% 67.00% 65.85% 64.50% 63.35% 62.30% 61.00%
19.15% 19.60% 20.00% 21.05% 21.85% 22.15% 23.05% 24.10% 24.90% 25.70% 25.75% 26.95% 28.00% 29.15% 30.50% 31.65% 32.70% 34.00%
0.00% 0.00% 0.00% 0.50% 1.00% 1.50% 2.00% 2.50% 3.00% 3.50% 4.00% 4.50% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%
14 13 12 11 10 9 8 7 6 5 4 3 2 1   RETIREMENT
59.70% 58.60% 57.35% 56.30% 55.00% 54.20% 52.90% 52.10% 51.05% 50.00% 48.95% 47.90% 46.85% 46.05%   45.00%
35.30% 36.40% 37.65% 38.70% 40.00% 40.30% 41.10% 41.40% 41.95% 42.50% 43.05% 43.60% 44.15% 44.45%   45.00%
5.00% 5.00% 5.00% 5.00% 5.00% 5.50% 6.00% 6.50% 7.00% 7.50% 8.00% 8.50% 9.00% 9.50%   10.00%
Years After Retirement 1 2 3 4 5 6 7 8 9 10 11 12 13
Stocks 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Bonds 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Cash 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%

 

 

The portfolio managers regularly review the fund’s allocations to determine whether rebalancing is appropriate. Although we do not intend to make frequent tactical adjustments to the target asset mix or trade actively among the underlying funds (other than the glide path adjustments described above), we reserve the right to modify the target allocations and underlying funds from time to time should circumstances warrant a change.
Risk [Heading] rr_RiskHeading

Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock

•

Allocation Risk - The fund’s performance and risks depend in part on the managers’ skill in determining the fund’s asset class allocations and in selecting and weighting the underlying funds. The managers’ evaluations and assumptions regarding asset classes or underlying funds may differ from actual market conditions.

•

“Growth” and “Value” Style Risks - The underlying funds represent a mix of investment styles, each of which has risks associated with it. Growth stocks can be volatile and may lack dividends that can cushion share prices during market declines. Value stocks may continue to be undervalued by the market for long periods of time.

•

Small- and Mid-Cap Stock Risks - Stocks of smaller companies may be more volatile than larger-company stocks. Smaller companies may have limited financial resources, product lines and markets, and their securities may trade less frequently and in more limited volumes than the securities of larger companies, which could lead to higher transaction costs. To the extent an underlying fund invests in these companies, it may take on more risk.

•

Interest Rate Risk - Generally, when interest rates rise, the value of an underlying fund’s fixed-income securities will decline. The opposite is true when interest rates decline. Underlying funds with longer weighted average maturities are more sensitive to interest rate changes.

•

Credit Risk - The value of an underlying fund’s fixed-income securities will be affected adversely by any erosion in the ability of the issuers of these securities to make interest and principal payments as they become due. Changes in the credit rating of a fixed-income security held by an underlying fund could have a similar effect.

•

Foreign Securities Risk - Some of the underlying funds invest in foreign securities, which are generally riskier than U.S. securities. Securities of foreign issuers may be less liquid, more volatile and harder to value than U.S. securities. Fluctuations in currency exchange rates also may affect an underlying fund’s share price. Investing in securities of companies located in emerging market countries is generally riskier than investing in securities of companies located in developed foreign countries.

•

Tobacco Exclusion - The underlying funds do not invest in securities issued by companies assigned the Global Industry Classification Standard (GICS) for the tobacco industry. This exclusion may cause an underlying fund to forego profitable investment opportunities.

•

Market Risk - The value of the fund’s shares will go up and down based on the performance of the underlying funds in which it invests. The value of the underlying funds’ shares will, in turn, fluctuate based on the performance of the securities they own and other factors generally affecting the securities market.

•

Principal Loss - At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.

 

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Risk Lose Money [Text] rr_RiskLoseMoney

Principal Loss -At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.
Risk Not Insured Depository Institution [Text] rr_RiskNotInsuredDepositoryInstitution

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading

Fund Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The fund’s performance history is not available as of the date of this prospectus. When the fund has investment results for a full calendar year, this section will feature charts that show annual total returns, highest and lowest quarterly returns and average annual total returns for the fund. This information indicates the volatility of the fund’s historical returns from year to year.

 

Performance information is designed to help you see how fund returns can vary. Keep in mind that past performance (before and after taxes) does not predict how the fund will perform in the future.

 

For current performance information, please visit ipro.americancentury.com.
Performance One Year or Less [Text] rr_PerformanceOneYearOrLess The fund’s performance history is not available as of the date of this prospectus. When the fund has investment results for a full calendar year, this section will feature charts that show annual total returns, highest and lowest quarterly returns and average annual total returns for the fund. This information indicates the volatility of the fund’s historical returns from year to year.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress ipro.americancentury.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture Keep in mind that past performance (before and after taxes) does not predict how the fund will perform in the future.
ONE CHOICE 2035 PORTFOLIO R6 | R6 CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.01% [4]
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.60% [4]
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.61%
1 year rr_ExpenseExampleYear01 62
3 years rr_ExpenseExampleYear03 196
ONE CHOICE 2040 PORTFOLIO R6
  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk/Return [Heading] rr_RiskReturnHeading ONE CHOICE 2040 PORTFOLIO R6
Objective [Heading] rr_ObjectiveHeading

Investment Objective
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The fund seeks the highest total return consistent with its asset mix.
Expense [Heading] rr_ExpenseHeading

Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock The following table describes the fees and expenses you may pay if you buy and hold shares of the fund.
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 Because the fund buys and sells shares of other American Century mutual funds (the underlying funds) directly from the issuers, the fund is not expected to incur transaction costs directly. However, as a shareholder in the underlying funds, the fund indirectly pays transaction costs, such as commissions, when the underlying funds buy and sell securities (or “turn over” their portfolios). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. During the one day period from the fund’s inception through its most recent fiscal year end, the fund’s portfolio turnover rate was 0% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 0.00%
Other Expenses, New Fund, Based on Estimates [Text] rr_OtherExpensesNewFundBasedOnEstimates Other Expenses and Acquired Fund Fees and Expenses are based on estimated amounts for the current fiscal year.
Acquired Fund Fees and Expenses, Based on Estimates [Text] rr_AcquiredFundFeesAndExpensesBasedOnEstimates Other Expenses and Acquired Fund Fees and Expenses are based on estimated amounts for the current fiscal year.
Expense Example [Heading] rr_ExpenseExampleHeading

Example
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock

The example below is intended to help you compare the costs of investing in the fund with the costs of investing in other mutual funds.
Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption

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, that you earn a 5% return each year, and that the fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading] rr_StrategyHeading

Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

One Choice 2040 Portfolio R6 is a “fund of funds” meaning that it seeks to achieve its objective by investing in other American Century mutual funds (the underlying funds) that represent a variety of asset classes and investment styles. The underlying stock funds draw on growth, value and quantitative investment techniques and diversify investments among small, medium and large U.S. and foreign companies. The underlying bond funds invest in fixed-income securities that vary by issuer type (corporate and government) and credit quality (investment-grade and high-yield or "junk bonds"). The following table shows the fund’s target allocation for the various asset classes and underlying funds as of the date of the prospectus:

 

Equity Securities (Stock Funds)

74.95%

  

Fixed-Income Securities (Bond Funds)

23.05%

NT Core Equity Plus Fund

3.50%

  

High-Yield Fund

2.30%

NT Emerging Markets Fund

4.25%

  

Inflation-Adjusted Bond Fund

4.60%

NT Equity Growth Fund

10.25%

  

NT Diversified Bond Fund

16.15%

NT Growth Fund

13.75%

  

NT Heritage Fund

6.50%

  

Cash Equivalents (Money Market Funds)

 

2.00%

NT International Growth Fund

10.00%

  

Premium Money Market Fund

2.00%

NT Large Company Value Fund

13.75%

  

NT Mid Cap Value Fund

6.50%

    

NT Small Company Fund

4.15%

    

Real Estate Fund

2.30%

      

 

The target date in the fund name (2040) refers to the approximate year an investor plans to retire and likely would stop making new investments in the fund. The fund assumes a retirement age of 65 and may not be appropriate for an investor who plans to retire at or near the target date, but at an age well before or after 65. As the target date approaches, the fund’s asset mix will become more conservative by decreasing the allocation to stocks and increasing the allocation to bonds and cash. By the time the fund reaches its target date, the asset mix will become fixed and match that of One Choice In Retirement Portfolio R6, which is currently 45% stock funds, 45% bond funds and 10% money market funds. The fund is designed for investors who plan to withdraw the value of their account gradually after retirement. The following chart shows how the asset mix is expected to change over time according to a predetermined glide path.

 

One Choice Target Date Portfolios' Glide Path

Years to Retirement 45 44 43 42 41 40 39 38 37 36 35 34 33
Stocks 85.00% 85.00% 85.00% 85.00% 85.00% 85.00% 84.70% 83.90% 83.35% 82.80% 82.25% 81.70% 81.40%
Bonds 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.30% 16.10% 16.65% 17.20% 17.75% 18.30% 18.60%
Cash 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%
32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15
80.85% 80.40% 80.00% 78.45% 77.15% 76.35% 74.95% 73.40% 72.10% 70.80% 70.25% 68.55% 67.00% 65.85% 64.50% 63.35% 62.30% 61.00%
19.15% 19.60% 20.00% 21.05% 21.85% 22.15% 23.05% 24.10% 24.90% 25.70% 25.75% 26.95% 28.00% 29.15% 30.50% 31.65% 32.70% 34.00%
0.00% 0.00% 0.00% 0.50% 1.00% 1.50% 2.00% 2.50% 3.00% 3.50% 4.00% 4.50% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%
14 13 12 11 10 9 8 7 6 5 4 3 2 1   RETIREMENT
59.70% 58.60% 57.35% 56.30% 55.00% 54.20% 52.90% 52.10% 51.05% 50.00% 48.95% 47.90% 46.85% 46.05%   45.00%
35.30% 36.40% 37.65% 38.70% 40.00% 40.30% 41.10% 41.40% 41.95% 42.50% 43.05% 43.60% 44.15% 44.45%   45.00%
5.00% 5.00% 5.00% 5.00% 5.00% 5.50% 6.00% 6.50% 7.00% 7.50% 8.00% 8.50% 9.00% 9.50%   10.00%
Years After Retirement 1 2 3 4 5 6 7 8 9 10 11 12 13
Stocks 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Bonds 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Cash 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%

 

The portfolio managers regularly review the fund’s allocations to determine whether rebalancing is appropriate. Although we do not intend to make frequent tactical adjustments to the target asset mix or trade actively among the underlying funds (other than the glide path adjustments described above), we reserve the right to modify the target allocations and underlying funds from time to time should circumstances warrant a change.
Risk [Heading] rr_RiskHeading

Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock

•

Allocation Risk -The fund’s performance and risks depend in part on the managers’ skill in determining the fund’s asset class allocations and in selecting and weighting the underlying funds. The managers’ evaluations and assumptions regarding asset classes or underlying funds may differ from actual market conditions.

•

“Growth” and “Value” Style Risks - The underlying funds represent a mix of investment styles, each of which has risks associated with it. Growth stocks can be volatile and may lack dividends that can cushion share prices during market declines. Value stocks may continue to be undervalued by the market for long periods of time.

•

Small- and Mid-Cap Stock Risks - Stocks of smaller companies may be more volatile than larger-company stocks. Smaller companies may have limited financial resources, product lines and markets, and their securities may trade less frequently and in more limited volumes than the securities of larger companies, which could lead to higher transaction costs. To the extent an underlying fund invests in these companies, it may take on more risk.

•

Interest Rate Risk - Generally, when interest rates rise, the value of an underlying fund’s fixed-income securities will decline. The opposite is true when interest rates decline. Underlying funds with longer weighted average maturities are more sensitive to interest rate changes.

•

Credit Risk - The value of an underlying fund’s fixed-income securities will be affected adversely by any erosion in the ability of the issuers of these securities to make interest and principal payments as they become due. Changes in the credit rating of a fixed-income security held by an underlying fund could have a similar effect.

•

Foreign Securities Risk - Some of the underlying funds invest in foreign securities, which are generally riskier than U.S. securities. Securities of foreign issuers may be less liquid, more volatile and harder to value than U.S. securities. Fluctuations in currency exchange rates also may affect an underlying fund’s share price. Investing in securities of companies located in emerging market countries is generally riskier than investing in securities of companies located in developed foreign countries.

•

Tobacco Exclusion - The underlying funds do not invest in securities issued by companies assigned the Global Industry Classification Standard (GICS) for the tobacco industry. This exclusion may cause an underlying fund to forego profitable investment opportunities.

•

Market Risk - The value of the fund’s shares will go up and down based on the performance of the underlying funds in which it invests. The value of the underlying funds’ shares will, in turn, fluctuate based on the performance of the securities they own and other factors generally affecting the securities market.

•

Principal Loss - At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.

 

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Risk Lose Money [Text] rr_RiskLoseMoney

Principal Loss -At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.
Risk Not Insured Depository Institution [Text] rr_RiskNotInsuredDepositoryInstitution

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading

Fund Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The fund’s performance history is not available as of the date of this prospectus. When the fund has investment results for a full calendar year, this section will feature charts that show annual total returns, highest and lowest quarterly returns and average annual total returns for the fund. This information indicates the volatility of the fund’s historical returns from year to year.

 

Performance information is designed to help you see how fund returns can vary. Keep in mind that past performance (before and after taxes) does not predict how the fund will perform in the future.

 

For current performance information, please visit ipro.americancentury.com.

Performance One Year or Less [Text] rr_PerformanceOneYearOrLess The fund’s performance history is not available as of the date of this prospectus. When the fund has investment results for a full calendar year, this section will feature charts that show annual total returns, highest and lowest quarterly returns and average annual total returns for the fund. This information indicates the volatility of the fund’s historical returns from year to year.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress ipro.americancentury.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture Keep in mind that past performance (before and after taxes) does not predict how the fund will perform in the future.
ONE CHOICE 2040 PORTFOLIO R6 | R6 CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.01% [4]
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.63% [4]
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.64%
1 year rr_ExpenseExampleYear01 66
3 years rr_ExpenseExampleYear03 205
ONE CHOICE 2045 PORTFOLIO R6
  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk/Return [Heading] rr_RiskReturnHeading ONE CHOICE 2045 PORTFOLIO R6
Objective [Heading] rr_ObjectiveHeading

Investment Objective
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The fund seeks the highest total return consistent with its asset mix.
Expense [Heading] rr_ExpenseHeading

Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock The following table describes the fees and expenses you may pay if you buy and hold shares of the fund.
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

Because the fund buys and sells shares of other American Century mutual funds (the underlying funds) directly from the issuers, the fund is not expected to incur transaction costs directly. However, as a shareholder in the underlying funds, the fund indirectly pays transaction costs, such as commissions, when the underlying funds buy and sell securities (or “turn over” their portfolios). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. During the one day period from the fund’s inception through its most recent fiscal year end, the fund’s portfolio turnover rate was 0% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 0.00%
Other Expenses, New Fund, Based on Estimates [Text] rr_OtherExpensesNewFundBasedOnEstimates Other Expenses and Acquired Fund Fees and Expenses are based on estimated amounts for the current fiscal year.
Acquired Fund Fees and Expenses, Based on Estimates [Text] rr_AcquiredFundFeesAndExpensesBasedOnEstimates Other Expenses and Acquired Fund Fees and Expenses are based on estimated amounts for the current fiscal year.
Expense Example [Heading] rr_ExpenseExampleHeading

Example
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock

The example below is intended to help you compare the costs of investing in the fund with the costs of investing in other mutual funds.
Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption

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, that you earn a 5% return each year, and that the fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading] rr_StrategyHeading

Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

One Choice 2045 Portfolio R6 is a “fund of funds” meaning that it seeks to achieve its objective by investing in other American Century mutual funds (the underlying funds) that represent a variety of asset classes and investment styles. The underlying stock funds draw on growth, value and quantitative investment techniques and diversify investments among small, medium and large U.S. and foreign companies. The underlying bond funds invest in fixed-income securities that vary by issuer type (corporate and government) and credit quality (investment-grade and high-yield or "junk bonds"). The following table shows the fund’s target allocation for the various asset classes and underlying funds as of the date of the prospectus:

 

Equity Securities (Stock Funds)

80.40%

  

Fixed-Income Securities (Bond Funds)

19.60%

NT Core Equity Plus Fund

4.50%

  

High-Yield Fund

1.95%

NT Emerging Markets Fund

5.25%

  

Inflation-Adjusted Bond Fund

3.90%

NT Equity Growth Fund

10.35%

  

NT Diversified Bond Fund

13.75%

NT Growth Fund

14.50%

  

NT Heritage Fund

7.25%

  

Cash Equivalents (Money Market Funds)

0.00%

NT International Growth Fund

10.25%

    

NT Large Company Value Fund

14.50%

  

NT Mid Cap Value Fund

7.25%

  

NT Small Company Fund

4.00%

  

Real Estate Fund

2.55%

  

  

The target date in the fund name (2045) refers to the approximate year an investor plans to retire and likely would stop making new investments in the fund. The fund assumes a retirement age of 65 and may not be appropriate for an investor who plans to retire at or near the target date, but at an age well before or after 65. As the target date approaches, the fund’s asset mix will become more conservative by decreasing the allocation to stocks and increasing the allocation to bonds and cash. By the time the fund reaches its target date, the asset mix will become fixed and match that of One Choice In Retirement Portfolio R6, which is currently 45% stock funds, 45% bond funds and 10% money market funds. The fund is designed for investors who plan to withdraw the value of their account gradually after retirement. The following chart shows how the asset mix is expected to change over time according to a predetermined glide path.

 

One Choice Target Date Portfolios' Glide Path

Years to Retirement 45 44 43 42 41 40 39 38 37 36 35 34 33
Stocks 85.00% 85.00% 85.00% 85.00% 85.00% 85.00% 84.70% 83.90% 83.35% 82.80% 82.25% 81.70% 81.40%
Bonds 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.30% 16.10% 16.65% 17.20% 17.75% 18.30% 18.60%
Cash 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%
32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15
80.85% 80.40% 80.00% 78.45% 77.15% 76.35% 74.95% 73.40% 72.10% 70.80% 70.25% 68.55% 67.00% 65.85% 64.50% 63.35% 62.30% 61.00%
19.15% 19.60% 20.00% 21.05% 21.85% 22.15% 23.05% 24.10% 24.90% 25.70% 25.75% 26.95% 28.00% 29.15% 30.50% 31.65% 32.70% 34.00%
0.00% 0.00% 0.00% 0.50% 1.00% 1.50% 2.00% 2.50% 3.00% 3.50% 4.00% 4.50% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%
14 13 12 11 10 9 8 7 6 5 4 3 2 1   RETIREMENT
59.70% 58.60% 57.35% 56.30% 55.00% 54.20% 52.90% 52.10% 51.05% 50.00% 48.95% 47.90% 46.85% 46.05%   45.00%
35.30% 36.40% 37.65% 38.70% 40.00% 40.30% 41.10% 41.40% 41.95% 42.50% 43.05% 43.60% 44.15% 44.45%   45.00%
5.00% 5.00% 5.00% 5.00% 5.00% 5.50% 6.00% 6.50% 7.00% 7.50% 8.00% 8.50% 9.00% 9.50%   10.00%
Years After Retirement 1 2 3 4 5 6 7 8 9 10 11 12 13
Stocks 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Bonds 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Cash 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%

 

The portfolio managers regularly review the fund’s allocations to determine whether rebalancing is appropriate. Although we do not intend to make frequent tactical adjustments to the target asset mix or trade actively among the underlying funds (other than the glide path adjustments described above), we reserve the right to modify the target allocations and underlying funds from time to time should circumstances warrant a change.
Risk [Heading] rr_RiskHeading

Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock

•

Allocation Risk - The fund’s performance and risks depend in part on the managers’ skill in determining the fund’s asset class allocations and in selecting and weighting the underlying funds. The managers’ evaluations and assumptions regarding asset classes or underlying funds may differ from actual market conditions.

•

“Growth” and “Value” Style Risks - The underlying funds represent a mix of investment styles, each of which has risks associated with it. Growth stocks can be volatile and may lack dividends that can cushion share prices during market declines. Value stocks may continue to be undervalued by the market for long periods of time.

•

Small- and Mid-Cap Stock Risks - Stocks of smaller companies may be more volatile than larger-company stocks. Smaller companies may have limited financial resources, product lines and markets, and their securities may trade less frequently and in more limited volumes than the securities of larger companies, which could lead to higher transaction costs. To the extent an underlying fund invests in these companies, it may take on more risk.

•

Interest Rate Risk - Generally, when interest rates rise, the value of an underlying fund’s fixed-income securities will decline. The opposite is true when interest rates decline. Underlying funds with longer weighted average maturities are more sensitive to interest rate changes.

•

Credit Risk - The value of an underlying fund’s fixed-income securities will be affected adversely by any erosion in the ability of the issuers of these securities to make interest and principal payments as they become due. Changes in the credit rating of a fixed-income security held by an underlying fund could have a similar effect.

•

Foreign Securities Risk - Some of the underlying funds invest in foreign securities, which are generally riskier than U.S. securities. Securities of foreign issuers may be less liquid, more volatile and harder to value than U.S. securities. Fluctuations in currency exchange rates also may affect an underlying fund’s share price. Investing in securities of companies located in emerging market countries is generally riskier than investing in securities of companies located in developed foreign countries.

•

Tobacco Exclusion - The underlying funds do not invest in securities issued by companies assigned the Global Industry Classification Standard (GICS) for the tobacco industry. This exclusion may cause an underlying fund to forego profitable investment opportunities.

•

Market Risk - The value of the fund’s shares will go up and down based on the performance of the underlying funds in which it invests. The value of the underlying funds’ shares will, in turn, fluctuate based on the performance of the securities they own and other factors generally affecting the securities market.

•

Principal Loss - At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.

 

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Risk Lose Money [Text] rr_RiskLoseMoney

Principal Loss -At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.
Risk Not Insured Depository Institution [Text] rr_RiskNotInsuredDepositoryInstitution

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading

Fund Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The fund’s performance history is not available as of the date of this prospectus. When the fund has investment results for a full calendar year, this section will feature charts that show annual total returns, highest and lowest quarterly returns and average annual total returns for the fund. This information indicates the volatility of the fund’s historical returns from year to year.

 

Performance information is designed to help you see how fund returns can vary. Keep in mind that past performance (before and after taxes) does not predict how the fund will perform in the future.

 

For current performance information, please visit ipro.americancentury.com.
Performance One Year or Less [Text] rr_PerformanceOneYearOrLess The fund’s performance history is not available as of the date of this prospectus. When the fund has investment results for a full calendar year, this section will feature charts that show annual total returns, highest and lowest quarterly returns and average annual total returns for the fund. This information indicates the volatility of the fund’s historical returns from year to year.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress ipro.americancentury.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture Keep in mind that past performance (before and after taxes) does not predict how the fund will perform in the future.
ONE CHOICE 2045 PORTFOLIO R6 | R6 CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.01% [4]
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.66% [4]
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.67%
1 year rr_ExpenseExampleYear01 69
3 years rr_ExpenseExampleYear03 215
ONE CHOICE 2050 PORTFOLIO R6
  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk/Return [Heading] rr_RiskReturnHeading ONE CHOICE 2050 PORTFOLIO R6
Objective [Heading] rr_ObjectiveHeading

Investment Objective
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The fund seeks the highest total return consistent with its asset mix.
Expense [Heading] rr_ExpenseHeading

Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock The following table describes the fees and expenses you may pay if you buy and hold shares of the fund.
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

Because the fund buys and sells shares of other American Century mutual funds (the underlying funds) directly from the issuers, the fund is not expected to incur transaction costs directly. However, as a shareholder in the underlying funds, the fund indirectly pays transaction costs, such as commissions, when the underlying funds buy and sell securities (or “turn over” their portfolios). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. During the one day period from the fund’s inception through its most recent fiscal year end, the fund’s portfolio turnover rate was 0% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 0.00%
Other Expenses, New Fund, Based on Estimates [Text] rr_OtherExpensesNewFundBasedOnEstimates Other Expenses and Acquired Fund Fees and Expenses are based on estimated amounts for the current fiscal year.
Acquired Fund Fees and Expenses, Based on Estimates [Text] rr_AcquiredFundFeesAndExpensesBasedOnEstimates Other Expenses and Acquired Fund Fees and Expenses are based on estimated amounts for the current fiscal year.
Expense Example [Heading] rr_ExpenseExampleHeading

Example
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock

The example below is intended to help you compare the costs of investing in the fund with the costs of investing in other mutual funds.
Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption

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, that you earn a 5% return each year, and that the fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading] rr_StrategyHeading

Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

One Choice 2050 Portfolio R6 is a “fund of funds” meaning that it seeks to achieve its objective by investing in other American Century mutual funds (the underlying funds) that represent a variety of asset classes and investment styles. The underlying stock funds draw on growth, value and quantitative investment techniques and diversify investments among small, medium and large U.S. and foreign companies. The underlying bond funds invest in fixed-income securities that vary by issuer type (corporate and government) and credit quality (investment-grade and high-yield or "junk bonds"). The following table shows the fund’s target allocation for the various asset classes and underlying funds as of the date of the prospectus:

 

Equity Securities (Stock Funds)

82.80%

  

Fixed-Income Securities (Bond Funds)

17.20%

NT Core Equity Plus Fund

4.50%

  

High-Yield Fund

1.70%

NT Emerging Markets Fund

6.25%

  

Inflation-Adjusted Bond Fund

  3.40%

NT Equity Growth Fund

10.25%

  

NT Diversified Bond Fund

12.10%

NT Growth Fund

14.75%

  

NT Heritage Fund

7.25%

  

Cash Equivalents (Money Market Funds)

0.00%

NT International Growth Fund

10.00%

  

NT Large Company Value Fund

15.00%

  

NT Mid Cap Value Fund

7.25%

  

NT Small Company Fund

4.75%

    

Real Estate Fund

2.80%

    

  

The target date in the fund name (2050) refers to the approximate year an investor plans to retire and likely would stop making new investments in the fund. The fund assumes a retirement age of 65 and may not be appropriate for an investor who plans to retire at or near the target date, but at an age well before or after 65. As the target date approaches, the fund’s asset mix will become more conservative by decreasing the allocation to stocks and increasing the allocation to bonds and cash. By the time the fund reaches its target date, the asset mix will become fixed and match that of One Choice In Retirement Portfolio R6, which is currently 45% stock funds, 45% bond funds and 10% money market funds. The fund is designed for investors who plan to withdraw the value of their account gradually after retirement. The following chart shows how the asset mix is expected to change over time according to a predetermined glide path.

 

One Choice Target Date Portfolios' Glide Path

Years to Retirement 45 44 43 42 41 40 39 38 37 36 35 34 33
Stocks 85.00% 85.00% 85.00% 85.00% 85.00% 85.00% 84.70% 83.90% 83.35% 82.80% 82.25% 81.70% 81.40%
Bonds 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.30% 16.10% 16.65% 17.20% 17.75% 18.30% 18.60%
Cash 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%
32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15
80.85% 80.40% 80.00% 78.45% 77.15% 76.35% 74.95% 73.40% 72.10% 70.80% 70.25% 68.55% 67.00% 65.85% 64.50% 63.35% 62.30% 61.00%
19.15% 19.60% 20.00% 21.05% 21.85% 22.15% 23.05% 24.10% 24.90% 25.70% 25.75% 26.95% 28.00% 29.15% 30.50% 31.65% 32.70% 34.00%
0.00% 0.00% 0.00% 0.50% 1.00% 1.50% 2.00% 2.50% 3.00% 3.50% 4.00% 4.50% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%
14 13 12 11 10 9 8 7 6 5 4 3 2 1   RETIREMENT
59.70% 58.60% 57.35% 56.30% 55.00% 54.20% 52.90% 52.10% 51.05% 50.00% 48.95% 47.90% 46.85% 46.05%   45.00%
35.30% 36.40% 37.65% 38.70% 40.00% 40.30% 41.10% 41.40% 41.95% 42.50% 43.05% 43.60% 44.15% 44.45%   45.00%
5.00% 5.00% 5.00% 5.00% 5.00% 5.50% 6.00% 6.50% 7.00% 7.50% 8.00% 8.50% 9.00% 9.50%   10.00%
Years After Retirement 1 2 3 4 5 6 7 8 9 10 11 12 13
Stocks 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Bonds 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Cash 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%

 

The portfolio managers regularly review the fund’s allocations to determine whether rebalancing is appropriate. Although we do not intend to make frequent tactical adjustments to the target asset mix or trade actively among the underlying funds (other than the glide path adjustments described above), we reserve the right to modify the target allocations and underlying funds from time to time should circumstances warrant a change.
Risk [Heading] rr_RiskHeading

Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock

 

•

Allocation Risk - The fund’s performance and risks depend in part on the managers’ skill in determining the fund’s asset class allocations and in selecting and weighting the underlying funds. The managers’ evaluations and assumptions regarding asset classes or underlying funds may differ from actual market conditions.

•

“Growth” and “Value” Style Risks - The underlying funds represent a mix of investment styles, each of which has risks associated with it. Growth stocks can be volatile and may lack dividends that can cushion share prices during market declines. Value stocks may continue to be undervalued by the market for long periods of time.

•

Small- and Mid-Cap Stock Risks - Stocks of smaller companies may be more volatile than larger-company stocks. Smaller companies may have limited financial resources, product lines and markets, and their securities may trade less frequently and in more limited volumes than the securities of larger companies, which could lead to higher transaction costs. To the extent an underlying fund invests in these companies, it may take on more risk.

•

Interest Rate Risk - Generally, when interest rates rise, the value of an underlying fund’s fixed-income securities will decline. The opposite is true when interest rates decline. Underlying funds with longer weighted average maturities are more sensitive to interest rate changes.

•

Credit Risk - The value of an underlying fund’s fixed-income securities will be affected adversely by any erosion in the ability of the issuers of these securities to make interest and principal payments as they become due. Changes in the credit rating of a fixed-income security held by an underlying fund could have a similar effect.

•

Foreign Securities Risk - Some of the underlying funds invest in foreign securities, which are generally riskier than U.S. securities. Securities of foreign issuers may be less liquid, more volatile and harder to value than U.S. securities. Fluctuations in currency exchange rates also may affect an underlying fund’s share price. Investing in securities of companies located in emerging market countries is generally riskier than investing in securities of companies located in developed foreign countries.

•

Tobacco Exclusion - The underlying funds do not invest in securities issued by companies assigned the Global Industry Classification Standard (GICS) for the tobacco industry. This exclusion may cause an underlying fund to forego profitable investment opportunities.

•

Market Risk - The value of the fund’s shares will go up and down based on the performance of the underlying funds in which it invests. The value of the underlying funds’ shares will, in turn, fluctuate based on the performance of the securities they own and other factors generally affecting the securities market.

•

Principal Loss - At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.

 

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Risk Lose Money [Text] rr_RiskLoseMoney

Principal Loss -At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.
Risk Not Insured Depository Institution [Text] rr_RiskNotInsuredDepositoryInstitution

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading

Fund Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The fund’s performance history is not available as of the date of this prospectus. When the fund has investment results for a full calendar year, this section will feature charts that show annual total returns, highest and lowest quarterly returns and average annual total returns for the fund. This information indicates the volatility of the fund’s historical returns from year to year.

 

Performance information is designed to help you see how fund returns can vary. Keep in mind that past performance (before and after taxes) does not predict how the fund will perform in the future.

 

For current performance information, please visit ipro.americancentury.com.

Performance One Year or Less [Text] rr_PerformanceOneYearOrLess The fund’s performance history is not available as of the date of this prospectus. When the fund has investment results for a full calendar year, this section will feature charts that show annual total returns, highest and lowest quarterly returns and average annual total returns for the fund. This information indicates the volatility of the fund’s historical returns from year to year.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress ipro.americancentury.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture Keep in mind that past performance (before and after taxes) does not predict how the fund will perform in the future.
ONE CHOICE 2050 PORTFOLIO R6 | R6 CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.01% [4]
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.67% [4]
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.68%
1 year rr_ExpenseExampleYear01 70
3 years rr_ExpenseExampleYear03 218
ONE CHOICE 2055 PORTFOLIO R6
  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk/Return [Heading] rr_RiskReturnHeading ONE CHOICE 2055 PORTFOLIO R6
Objective [Heading] rr_ObjectiveHeading

Investment Objective
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The fund seeks the highest total return consistent with its asset mix.
Expense [Heading] rr_ExpenseHeading

Fees and Expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock The following table describes the fees and expenses you may pay if you buy and hold shares of the fund.
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

Because the fund buys and sells shares of other American Century mutual funds (the underlying funds) directly from the issuers, the fund is not expected to incur transaction costs directly. However, as a shareholder in the underlying funds, the fund indirectly pays transaction costs, such as commissions, when the underlying funds buy and sell securities (or “turn over” their portfolios). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund’s performance. During the one day period from the fund’s inception through its most recent fiscal year end, the fund’s portfolio turnover rate was 0% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 0.00%
Other Expenses, New Fund, Based on Estimates [Text] rr_OtherExpensesNewFundBasedOnEstimates Other Expenses and Acquired Fund Fees and Expenses are based on estimated amounts for the current fiscal year.
Acquired Fund Fees and Expenses, Based on Estimates [Text] rr_AcquiredFundFeesAndExpensesBasedOnEstimates Other Expenses and Acquired Fund Fees and Expenses are based on estimated amounts for the current fiscal year.
Expense Example [Heading] rr_ExpenseExampleHeading

Example
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock

The example below is intended to help you compare the costs of investing in the fund with the costs of investing in other mutual funds.
Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption

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, that you earn a 5% return each year, and that the fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading] rr_StrategyHeading

Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

One Choice 2055 Portfolio R6 is a “fund of funds” meaning that it seeks to achieve its objective by investing in other American Century mutual funds (the underlying funds) that represent a variety of asset classes and investment styles. The underlying stock funds draw on growth, value and quantitative investment techniques and diversify investments among small, medium and large U.S. and foreign companies. The underlying bond funds invest in fixed-income securities that vary by issuer type (corporate and government) and credit quality (investment-grade and high-yield or "junk bonds"). The following table shows the fund’s target allocation for the various asset classes and underlying funds as of the date of the prospectus:

 

Equity Securities (Stock Funds)

85.00%

 

Fixed-Income Securities (Bond Funds)

15.00%

NT Core Equity Plus Fund

4.50%

  

High-Yield Fund

  1.50%

NT Emerging Markets Fund

6.50%

  

Inflation-Adjusted Bond Fund

3.00%

NT Equity Growth Fund

10.75%

    

NT Diversified Bond Fund

10.50%

NT Growth Fund

15.25%

    

NT Heritage Fund

7.50%

    

Cash Equivalents (Money Market Funds)

 

0.00%

NT International Growth Fund

9.50%

      

NT Large Company Value Fund

15.50%

    

NT Mid Cap Value Fund

7.50%

      

NT Small Company Fund

5.00%

        

Real Estate Fund

3.00%

      

 

The target date in the fund name (2055) refers to the approximate year an investor plans to retire and likely would stop making new investments in the fund. The fund assumes a retirement age of 65 and may not be appropriate for an investor who plans to retire at or near the target date, but at an age well before or after 65. As the target date approaches, the fund’s asset mix will become more conservative by decreasing the allocation to stocks and increasing the allocation to bonds and cash. By the time the fund reaches its target date, the asset mix will become fixed and match that of One Choice In Retirement Portfolio R6, which is currently 45% stock funds, 45% bond funds and 10% money market funds. The fund is designed for investors who plan to withdraw the value of their account gradually after retirement. The following chart shows how the asset mix is expected to change over time according to a predetermined glide path.

 

One Choice Target Date Portfolios' Glide Path

Years to Retirement 45 44 43 42 41 40 39 38 37 36 35 34 33
Stocks 85.00% 85.00% 85.00% 85.00% 85.00% 85.00% 84.70% 83.90% 83.35% 82.80% 82.25% 81.70% 81.40%
Bonds 15.00% 15.00% 15.00% 15.00% 15.00% 15.00% 15.30% 16.10% 16.65% 17.20% 17.75% 18.30% 18.60%
Cash 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%
32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15
80.85% 80.40% 80.00% 78.45% 77.15% 76.35% 74.95% 73.40% 72.10% 70.80% 70.25% 68.55% 67.00% 65.85% 64.50% 63.35% 62.30% 61.00%
19.15% 19.60% 20.00% 21.05% 21.85% 22.15% 23.05% 24.10% 24.90% 25.70% 25.75% 26.95% 28.00% 29.15% 30.50% 31.65% 32.70% 34.00%
0.00% 0.00% 0.00% 0.50% 1.00% 1.50% 2.00% 2.50% 3.00% 3.50% 4.00% 4.50% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%
14 13 12 11 10 9 8 7 6 5 4 3 2 1   RETIREMENT
59.70% 58.60% 57.35% 56.30% 55.00% 54.20% 52.90% 52.10% 51.05% 50.00% 48.95% 47.90% 46.85% 46.05%   45.00%
35.30% 36.40% 37.65% 38.70% 40.00% 40.30% 41.10% 41.40% 41.95% 42.50% 43.05% 43.60% 44.15% 44.45%   45.00%
5.00% 5.00% 5.00% 5.00% 5.00% 5.50% 6.00% 6.50% 7.00% 7.50% 8.00% 8.50% 9.00% 9.50%   10.00%
Years After Retirement 1 2 3 4 5 6 7 8 9 10 11 12 13
Stocks 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Bonds 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
Cash 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00% 45.00%
10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%

 

The portfolio managers regularly review the fund’s allocations to determine whether rebalancing is appropriate. Although we do not intend to make frequent tactical adjustments to the target asset mix or trade actively among the underlying funds (other than the glide path adjustments described above), we reserve the right to modify the target allocations and underlying funds from time to time should circumstances warrant a change.
Risk [Heading] rr_RiskHeading

Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock

•

Allocation Risk - The fund’s performance and risks depend in part on the managers’ skill in determining the fund’s asset class allocations and in selecting and weighting the underlying funds. The managers’ evaluations and assumptions regarding asset classes or underlying funds may differ from actual market conditions.

•

“Growth” and “Value” Style Risks - The underlying funds represent a mix of investment styles, each of which has risks associated with it. Growth stocks can be volatile and may lack dividends that can cushion share prices during market declines. Value stocks may continue to be undervalued by the market for long periods of time.

•

Small- and Mid-Cap Stock Risks - Stocks of smaller companies may be more volatile than larger-company stocks. Smaller companies may have limited financial resources, product lines and markets, and their securities may trade less frequently and in more limited volumes than the securities of larger companies, which could lead to higher transaction costs. To the extent an underlying fund invests in these companies, it may take on more risk.

•

Interest Rate Risk - Generally, when interest rates rise, the value of an underlying fund’s fixed-income securities will decline. The opposite is true when interest rates decline. Underlying funds with longer weighted average maturities are more sensitive to interest rate changes.

•

Credit Risk - The value of an underlying fund’s fixed-income securities will be affected adversely by any erosion in the ability of the issuers of these securities to make interest and principal payments as they become due. Changes in the credit rating of a fixed-income security held by an underlying fund could have a similar effect.

•

Foreign Securities Risk - Some of the underlying funds invest in foreign securities, which are generally riskier than U.S. securities. Securities of foreign issuers may be less liquid, more volatile and harder to value than U.S. securities. Fluctuations in currency exchange rates also may affect an underlying fund’s share price. Investing in securities of companies located in emerging market countries is generally riskier than investing in securities of companies located in developed foreign countries.

•

Tobacco Exclusion -The underlying funds do not invest in securities issued by companies assigned the Global Industry Classification Standard (GICS) for the tobacco industry. This exclusion may cause an underlying fund to forego profitable investment opportunities.

•

Market Risk - The value of the fund’s shares will go up and down based on the performance of the underlying funds in which it invests. The value of the underlying funds’ shares will, in turn, fluctuate based on the performance of the securities they own and other factors generally affecting the securities market.

•

Principal Loss - At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.

 

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Risk Lose Money [Text] rr_RiskLoseMoney

Principal Loss -At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund, including losses near to, at, or after retirement. There is no guarantee that the fund will provide adequate income at or through your retirement.
Risk Not Insured Depository Institution [Text] rr_RiskNotInsuredDepositoryInstitution

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading

Fund Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The fund’s performance history is not available as of the date of this prospectus. When the fund has investment results for a full calendar year, this section will feature charts that show annual total returns, highest and lowest quarterly returns and average annual total returns for the fund. This information indicates the volatility of the fund’s historical returns from year to year.

 

Performance information is designed to help you see how fund returns can vary. Keep in mind that past performance (before and after taxes) does not predict how the fund will perform in the future.

 

For current performance information, please visit ipro.americancentury.com.
Performance One Year or Less [Text] rr_PerformanceOneYearOrLess The fund’s performance history is not available as of the date of this prospectus. When the fund has investment results for a full calendar year, this section will feature charts that show annual total returns, highest and lowest quarterly returns and average annual total returns for the fund. This information indicates the volatility of the fund’s historical returns from year to year.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress ipro.americancentury.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture Keep in mind that past performance (before and after taxes) does not predict how the fund will perform in the future.
ONE CHOICE 2055 PORTFOLIO R6 | R6 CLASS
  
Prospectus [Line Items] rr_ProspectusLineItems  
Management Fee rr_ManagementFeesOverAssets none
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.01% [4]
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.68% [4]
Total Annual Fund Operating Expenses rr_ExpensesOverAssets 0.69%
1 year rr_ExpenseExampleYear01 71
3 years rr_ExpenseExampleYear03 $ 221
[1] Investments of $1 million or more may be subject to a contingent deferred sales charge of 1.00% if the shares are redeemed within one year of the date of the purchase.
[2] Prior to March 1, 2010, the A Class was referred to as the Advisor Class and did not have a front-end sales charge. Performance prior to that date has been restated to reflect this charge.
[3] Historical performance for C Class prior to its inception is based on the performance of Investor Class shares. C Class performance has been adjusted to reflect differences in sales charges, if applicable, and expenses between classes.
[4] Other Expenses and Acquired Fund Fees and Expenses are based on estimated amounts for the current fiscal year.