v3.26.3
Shareholder Report
 12 Months Ended 112 Months Ended
Jul. 31, 2026
USD ($)
holding
Jul. 31, 2026
USD ($)
holding
Shareholder Report [Line Items]    
Document Type N-CSR  
Amendment Flag false  
Registrant Name AMERICAN CENTURY STRATEGIC ASSET ALLOCATIONS, INC.  
Entity Central Index Key 0000924211  
Entity Investment Company Type N-1A  
Document Period End Date Jul. 31, 2026  
Shareholder Report Annual or Semi-Annual Annual Shareholder Report  
C000016333 [Member]    
Shareholder Report [Line Items]    
Fund Name Strategic Allocation: Conservative Fund  
Class Name Investor Class  
Trading Symbol TWSCX  
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Strategic Allocation: Conservative Fund for the period of August 1, 2025 to July 31, 2026.  
Shareholder Report Annual or Semi-Annual annual shareholder report  
Additional Information [Text Block] You can find additional information about the fund at americancentury.com/docs. You can also request this information by contacting us at 1-800-345-2021.  
Additional Information Phone Number 1-800-345-2021  
Additional Information Website americancentury.com/docs  
Expenses [Text Block]
What were the fund costs for the last year? (based on a hypothetical $10,000 investment)
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Investor Class$720.69%
  
Expenses Paid, Amount $ 72  
Expense Ratio, Percent 0.69%  
Factors Affecting Performance [Text Block]
What were the key factors that affected the fund’s performance?
Strategic Allocation: Conservative Fund Investor Class returned 8.50% for the reporting period ended July 31, 2026.
The fund is an asset allocation fund. That is, it diversifies its assets among various classes of investments such as equity securities, bonds and money market instruments. The fund seeks the highest level of total return consistent with its asset mix. See the Fund Holdings for the portfolio’s asset weights. Below, we discuss the factors that affected these asset classes.
•
The portfolio's U.S. stock holdings generally did well, with mid- and large-cap equities lagging small-cap stocks, while value stocks beat growth. This reflects uncertainty around spending on artificial intelligence (AI), which weighed most on mid- and large-cap growth stocks. Smaller and more value-oriented companies benefited from broad economic and earnings strength.
•
The portfolio's non-U.S. equity holdings generally outperformed U.S. stock holdings. That's because non-U.S. stocks benefited from attractive relative valuations as investors looked beyond the most expensive U.S. growth stocks. Nevertheless, some notable non-U.S. stocks did benefit from the broadening of the AI trade beyond U.S. borders.
•
The global bond allocation produced positive total returns and diversification benefits even as some of the world's leading central banks raised rates amid elevated inflation. For example, the European Central Bank and the Bank of Japan raised rates during the period, mindful of having left rates too low for too long ahead of the 2022 inflation shock.
•
The portfolio's cash allocation produced strong returns despite rate cuts by the Federal Reserve (Fed). Even as cash yields fell in line with the Fed rate changes, short-term yields remained in excess of inflation, and total returns exceeded those of intermediate- and long-term bonds.
  
Line Graph [Table Text Block]
Cumulative Performance (based on an initial $10,000 investment)
July 31, 2016 through July 31, 2026
10
  
Average Annual Return [Table Text Block]
Average Annual Total Returns
1 Year5 Year10 Year
Investor Class8.50%3.85%6.02%
MSCI ACWI IMI22.27%10.40%12.02%
Bloomberg U.S. Aggregate Bond2.71%-0.40%1.35%
  
No Deduction of Taxes [Text Block] The opinions expressed are those of American Century Investments and are no guarantee of the future performance of any American Century Investments fund. This information is for educational purposes only and is not intended as investment advice. Data reflects past performance, assumes reinvestment of dividends and capital gains and is no guarantee of future results. Current performance may be higher or lower than data shown. Investment return and principal value will fluctuate and redemption value may be more or less than original cost, and none of the charts reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares.  
Updated Performance Information Location [Text Block] Visit americancentury.com for more recent performance information.  
Net Assets $ 276,173,910 $ 276,173,910
Holdings Count | holding 1,042 1,042
Advisory Fees Paid, Amount $ 1,662,839  
Investment Company, Portfolio Turnover 74.00%  
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds41.4%
Common Stocks18.5%
U.S. Treasury Securities14.5%
U.S. Government Agency Mortgage-Backed Securities6.0%
Corporate Bonds5.6%
Sovereign Governments and Agencies4.7%
Collateralized Mortgage Obligations1.8%
Asset-Backed Securities1.1%
Commercial Mortgage-Backed Securities0.6%
Municipal Securities0.3%
Exchange-Traded Funds0.1%
Preferred Securities0.0%
Rights0.0%
Short-Term Investments8.2%
Other Assets and Liabilities(2.8)%
  
C000016335 [Member]    
Shareholder Report [Line Items]    
Fund Name Strategic Allocation: Conservative Fund  
Class Name I Class  
Trading Symbol ACCIX  
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Strategic Allocation: Conservative Fund for the period of August 1, 2025 to July 31, 2026.  
Shareholder Report Annual or Semi-Annual annual shareholder report  
Additional Information [Text Block] You can find additional information about the fund at americancentury.com/docs. You can also request this information by contacting us at 1-800-345-2021.  
Additional Information Phone Number 1-800-345-2021  
Additional Information Website americancentury.com/docs  
Expenses [Text Block]
What were the fund costs for the last year? (based on a hypothetical $10,000 investment)
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
I Class$510.49%
  
Expenses Paid, Amount $ 51  
Expense Ratio, Percent 0.49%  
Factors Affecting Performance [Text Block]
What were the key factors that affected the fund’s performance?
Strategic Allocation: Conservative Fund I Class returned 8.51% for the reporting period ended July 31, 2026.
The fund is an asset allocation fund. That is, it diversifies its assets among various classes of investments such as equity securities, bonds and money market instruments. The fund seeks the highest level of total return consistent with its asset mix. See the Fund Holdings for the portfolio’s asset weights. Below, we discuss the factors that affected these asset classes.
•
The portfolio's U.S. stock holdings generally did well, with mid- and large-cap equities lagging small-cap stocks, while value stocks beat growth. This reflects uncertainty around spending on artificial intelligence (AI), which weighed most on mid- and large-cap growth stocks. Smaller and more value-oriented companies benefited from broad economic and earnings strength.
•
The portfolio's non-U.S. equity holdings generally outperformed U.S. stock holdings. That's because non-U.S. stocks benefited from attractive relative valuations as investors looked beyond the most expensive U.S. growth stocks. Nevertheless, some notable non-U.S. stocks did benefit from the broadening of the AI trade beyond U.S. borders.
•
The global bond allocation produced positive total returns and diversification benefits even as some of the world's leading central banks raised rates amid elevated inflation. For example, the European Central Bank and the Bank of Japan raised rates during the period, mindful of having left rates too low for too long ahead of the 2022 inflation shock.
•
The portfolio's cash allocation produced strong returns despite rate cuts by the Federal Reserve (Fed). Even as cash yields fell in line with the Fed rate changes, short-term yields remained in excess of inflation, and total returns exceeded those of intermediate- and long-term bonds.
  
Line Graph [Table Text Block]
Cumulative Performance (based on an initial $10,000 investment)
July 31, 2016 through July 31, 2026

10
  
Average Annual Return [Table Text Block]
Average Annual Total Returns
1 Year5 Year10 Year
I Class8.51%4.02%6.23%
MSCI ACWI IMI22.27%10.40%12.02%
Bloomberg U.S. Aggregate Bond2.71%-0.40%1.35%
  
No Deduction of Taxes [Text Block] The opinions expressed are those of American Century Investments and are no guarantee of the future performance of any American Century Investments fund. This information is for educational purposes only and is not intended as investment advice. Data reflects past performance, assumes reinvestment of dividends and capital gains and is no guarantee of future results. Current performance may be higher or lower than data shown. Investment return and principal value will fluctuate and redemption value may be more or less than original cost, and none of the charts reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares.  
Updated Performance Information Location [Text Block] Visit americancentury.com for more recent performance information.  
Net Assets $ 276,173,910 $ 276,173,910
Holdings Count | holding 1,042 1,042
Advisory Fees Paid, Amount $ 1,662,839  
Investment Company, Portfolio Turnover 74.00%  
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds41.4%
Common Stocks18.5%
U.S. Treasury Securities14.5%
U.S. Government Agency Mortgage-Backed Securities6.0%
Corporate Bonds5.6%
Sovereign Governments and Agencies4.7%
Collateralized Mortgage Obligations1.8%
Asset-Backed Securities1.1%
Commercial Mortgage-Backed Securities0.6%
Municipal Securities0.3%
Exchange-Traded Funds0.1%
Preferred Securities0.0%
Rights0.0%
Short-Term Investments8.2%
Other Assets and Liabilities(2.8)%
  
C000016334 [Member]    
Shareholder Report [Line Items]    
Fund Name Strategic Allocation: Conservative Fund  
Class Name A Class  
Trading Symbol ACCAX  
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Strategic Allocation: Conservative Fund for the period of August 1, 2025 to July 31, 2026.  
Shareholder Report Annual or Semi-Annual annual shareholder report  
Additional Information [Text Block] You can find additional information about the fund at americancentury.com/docs. You can also request this information by contacting us at 1-800-345-2021.  
Additional Information Phone Number 1-800-345-2021  
Additional Information Website americancentury.com/docs  
Expenses [Text Block]
What were the fund costs for the last year? (based on a hypothetical $10,000 investment)
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
A Class$980.94%
  
Expenses Paid, Amount $ 98  
Expense Ratio, Percent 0.94%  
Factors Affecting Performance [Text Block]
What were the key factors that affected the fund’s performance?
Strategic Allocation: Conservative Fund A Class returned 8.06% for the reporting period ended July 31, 2026.
The fund is an asset allocation fund. That is, it diversifies its assets among various classes of investments such as equity securities, bonds and money market instruments. The fund seeks the highest level of total return consistent with its asset mix. See the Fund Holdings for the portfolio’s asset weights. Below, we discuss the factors that affected these asset classes.
•
The portfolio's U.S. stock holdings generally did well, with mid- and large-cap equities lagging small-cap stocks, while value stocks beat growth. This reflects uncertainty around spending on artificial intelligence (AI), which weighed most on mid- and large-cap growth stocks. Smaller and more value-oriented companies benefited from broad economic and earnings strength.
•
The portfolio's non-U.S. equity holdings generally outperformed U.S. stock holdings. That's because non-U.S. stocks benefited from attractive relative valuations as investors looked beyond the most expensive U.S. growth stocks. Nevertheless, some notable non-U.S. stocks did benefit from the broadening of the AI trade beyond U.S. borders.
•
The global bond allocation produced positive total returns and diversification benefits even as some of the world's leading central banks raised rates amid elevated inflation. For example, the European Central Bank and the Bank of Japan raised rates during the period, mindful of having left rates too low for too long ahead of the 2022 inflation shock.
•
The portfolio's cash allocation produced strong returns despite rate cuts by the Federal Reserve (Fed). Even as cash yields fell in line with the Fed rate changes, short-term yields remained in excess of inflation, and total returns exceeded those of intermediate- and long-term bonds.
  
Line Graph [Table Text Block]
Cumulative Performance (based on an initial $10,000 investment)
July 31, 2016 through July 31, 2026
The initial investment is adjusted to reflect the maximum initial sales charge.
10
  
Average Annual Return [Table Text Block]
Average Annual Total Returns
1 Year5 Year10 Year
A Class8.06%3.56%5.76%
A Class - with sales charge1.84%2.34%5.13%
MSCI ACWI IMI22.27%10.40%12.02%
Bloomberg U.S. Aggregate Bond2.71%-0.40%1.35%
  
No Deduction of Taxes [Text Block] The opinions expressed are those of American Century Investments and are no guarantee of the future performance of any American Century Investments fund. This information is for educational purposes only and is not intended as investment advice. Data reflects past performance, assumes reinvestment of dividends and capital gains and is no guarantee of future results. Current performance may be higher or lower than data shown. Investment return and principal value will fluctuate and redemption value may be more or less than original cost, and none of the charts reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares.  
Updated Performance Information Location [Text Block] Visit americancentury.com for more recent performance information.  
Net Assets $ 276,173,910 $ 276,173,910
Holdings Count | holding 1,042 1,042
Advisory Fees Paid, Amount $ 1,662,839  
Investment Company, Portfolio Turnover 74.00%  
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds41.4%
Common Stocks18.5%
U.S. Treasury Securities14.5%
U.S. Government Agency Mortgage-Backed Securities6.0%
Corporate Bonds5.6%
Sovereign Governments and Agencies4.7%
Collateralized Mortgage Obligations1.8%
Asset-Backed Securities1.1%
Commercial Mortgage-Backed Securities0.6%
Municipal Securities0.3%
Exchange-Traded Funds0.1%
Preferred Securities0.0%
Rights0.0%
Short-Term Investments8.2%
Other Assets and Liabilities(2.8)%
  
C000016338 [Member]    
Shareholder Report [Line Items]    
Fund Name Strategic Allocation: Conservative Fund  
Class Name C Class  
Trading Symbol AACCX  
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Strategic Allocation: Conservative Fund for the period of August 1, 2025 to July 31, 2026.  
Shareholder Report Annual or Semi-Annual annual shareholder report  
Additional Information [Text Block] You can find additional information about the fund at americancentury.com/docs. You can also request this information by contacting us at 1-800-345-2021.  
Additional Information Phone Number 1-800-345-2021  
Additional Information Website americancentury.com/docs  
Expenses [Text Block]
What were the fund costs for the last year? (based on a hypothetical $10,000 investment)
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
C Class$1751.69%
  
Expenses Paid, Amount $ 175  
Expense Ratio, Percent 1.69%  
Factors Affecting Performance [Text Block]
What were the key factors that affected the fund’s performance?
Strategic Allocation: Conservative Fund C Class returned 7.26% for the reporting period ended July 31, 2026.
The fund is an asset allocation fund. That is, it diversifies its assets among various classes of investments such as equity securities, bonds and money market instruments. The fund seeks the highest level of total return consistent with its asset mix. See the Fund Holdings for the portfolio’s asset weights. Below, we discuss the factors that affected these asset classes.
•
The portfolio's U.S. stock holdings generally did well, with mid- and large-cap equities lagging small-cap stocks, while value stocks beat growth. This reflects uncertainty around spending on artificial intelligence (AI), which weighed most on mid- and large-cap growth stocks. Smaller and more value-oriented companies benefited from broad economic and earnings strength.
•
The portfolio's non-U.S. equity holdings generally outperformed U.S. stock holdings. That's because non-U.S. stocks benefited from attractive relative valuations as investors looked beyond the most expensive U.S. growth stocks. Nevertheless, some notable non-U.S. stocks did benefit from the broadening of the AI trade beyond U.S. borders.
•
The global bond allocation produced positive total returns and diversification benefits even as some of the world's leading central banks raised rates amid elevated inflation. For example, the European Central Bank and the Bank of Japan raised rates during the period, mindful of having left rates too low for too long ahead of the 2022 inflation shock.
•
The portfolio's cash allocation produced strong returns despite rate cuts by the Federal Reserve (Fed). Even as cash yields fell in line with the Fed rate changes, short-term yields remained in excess of inflation, and total returns exceeded those of intermediate- and long-term bonds.
  
Line Graph [Table Text Block]
Cumulative Performance (based on an initial $10,000 investment)
July 31, 2016 through July 31, 2026

10
  
Average Annual Return [Table Text Block]
Average Annual Total Returns
1 Year5 Year10 Year
C Class7.26%2.80%4.96%
MSCI ACWI IMI22.27%10.40%12.02%
Bloomberg U.S. Aggregate Bond2.71%-0.40%1.35%
  
No Deduction of Taxes [Text Block] The opinions expressed are those of American Century Investments and are no guarantee of the future performance of any American Century Investments fund. This information is for educational purposes only and is not intended as investment advice. Data reflects past performance, assumes reinvestment of dividends and capital gains and is no guarantee of future results. Current performance may be higher or lower than data shown. Investment return and principal value will fluctuate and redemption value may be more or less than original cost, and none of the charts reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares.  
Updated Performance Information Location [Text Block] Visit americancentury.com for more recent performance information.  
Net Assets $ 276,173,910 $ 276,173,910
Holdings Count | holding 1,042 1,042
Advisory Fees Paid, Amount $ 1,662,839  
Investment Company, Portfolio Turnover 74.00%  
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds41.4%
Common Stocks18.5%
U.S. Treasury Securities14.5%
U.S. Government Agency Mortgage-Backed Securities6.0%
Corporate Bonds5.6%
Sovereign Governments and Agencies4.7%
Collateralized Mortgage Obligations1.8%
Asset-Backed Securities1.1%
Commercial Mortgage-Backed Securities0.6%
Municipal Securities0.3%
Exchange-Traded Funds0.1%
Preferred Securities0.0%
Rights0.0%
Short-Term Investments8.2%
Other Assets and Liabilities(2.8)%
  
C000016332 [Member]    
Shareholder Report [Line Items]    
Fund Name Strategic Allocation: Conservative Fund  
Class Name R Class  
Trading Symbol AACRX  
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Strategic Allocation: Conservative Fund for the period of August 1, 2025 to July 31, 2026.  
Shareholder Report Annual or Semi-Annual annual shareholder report  
Additional Information [Text Block] You can find additional information about the fund at americancentury.com/docs. You can also request this information by contacting us at 1-800-345-2021.  
Additional Information Phone Number 1-800-345-2021  
Additional Information Website americancentury.com/docs  
Expenses [Text Block]
What were the fund costs for the last year? (based on a hypothetical $10,000 investment)
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
R Class$1241.19%
  
Expenses Paid, Amount $ 124  
Expense Ratio, Percent 1.19%  
Factors Affecting Performance [Text Block]
What were the key factors that affected the fund’s performance?
Strategic Allocation: Conservative Fund R Class returned 7.67% for the reporting period ended July 31, 2026.
The fund is an asset allocation fund. That is, it diversifies its assets among various classes of investments such as equity securities, bonds and money market instruments. The fund seeks the highest level of total return consistent with its asset mix. See the Fund Holdings for the portfolio’s asset weights. Below, we discuss the factors that affected these asset classes.
•
The portfolio's U.S. stock holdings generally did well, with mid- and large-cap equities lagging small-cap stocks, while value stocks beat growth. This reflects uncertainty around spending on artificial intelligence (AI), which weighed most on mid- and large-cap growth stocks. Smaller and more value-oriented companies benefited from broad economic and earnings strength.
•
The portfolio's non-U.S. equity holdings generally outperformed U.S. stock holdings. That's because non-U.S. stocks benefited from attractive relative valuations as investors looked beyond the most expensive U.S. growth stocks. Nevertheless, some notable non-U.S. stocks did benefit from the broadening of the AI trade beyond U.S. borders.
•
The global bond allocation produced positive total returns and diversification benefits even as some of the world's leading central banks raised rates amid elevated inflation. For example, the European Central Bank and the Bank of Japan raised rates during the period, mindful of having left rates too low for too long ahead of the 2022 inflation shock.
•
The portfolio's cash allocation produced strong returns despite rate cuts by the Federal Reserve (Fed). Even as cash yields fell in line with the Fed rate changes, short-term yields remained in excess of inflation, and total returns exceeded those of intermediate- and long-term bonds.
  
Line Graph [Table Text Block]
Cumulative Performance (based on an initial $10,000 investment)
July 31, 2016 through July 31, 2026

10
  
Average Annual Return [Table Text Block]
Average Annual Total Returns
1 Year5 Year10 Year
R Class7.67%3.29%5.48%
MSCI ACWI IMI22.27%10.40%12.02%
Bloomberg U.S. Aggregate Bond2.71%-0.40%1.35%
  
No Deduction of Taxes [Text Block] The opinions expressed are those of American Century Investments and are no guarantee of the future performance of any American Century Investments fund. This information is for educational purposes only and is not intended as investment advice. Data reflects past performance, assumes reinvestment of dividends and capital gains and is no guarantee of future results. Current performance may be higher or lower than data shown. Investment return and principal value will fluctuate and redemption value may be more or less than original cost, and none of the charts reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares.  
Updated Performance Information Location [Text Block] Visit americancentury.com for more recent performance information.  
Net Assets $ 276,173,910 $ 276,173,910
Holdings Count | holding 1,042 1,042
Advisory Fees Paid, Amount $ 1,662,839  
Investment Company, Portfolio Turnover 74.00%  
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds41.4%
Common Stocks18.5%
U.S. Treasury Securities14.5%
U.S. Government Agency Mortgage-Backed Securities6.0%
Corporate Bonds5.6%
Sovereign Governments and Agencies4.7%
Collateralized Mortgage Obligations1.8%
Asset-Backed Securities1.1%
Commercial Mortgage-Backed Securities0.6%
Municipal Securities0.3%
Exchange-Traded Funds0.1%
Preferred Securities0.0%
Rights0.0%
Short-Term Investments8.2%
Other Assets and Liabilities(2.8)%
  
C000189656 [Member]    
Shareholder Report [Line Items]    
Fund Name Strategic Allocation: Conservative Fund  
Class Name R5 Class  
Trading Symbol AACGX  
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Strategic Allocation: Conservative Fund for the period of August 1, 2025 to July 31, 2026.  
Shareholder Report Annual or Semi-Annual annual shareholder report  
Additional Information [Text Block] You can find additional information about the fund at americancentury.com/docs. You can also request this information by contacting us at 1-800-345-2021.  
Additional Information Phone Number 1-800-345-2021  
Additional Information Website americancentury.com/docs  
Expenses [Text Block]
What were the fund costs for the last year? (based on a hypothetical $10,000 investment)
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
R5 Class$510.49%
  
Expenses Paid, Amount $ 51  
Expense Ratio, Percent 0.49%  
Factors Affecting Performance [Text Block]
What were the key factors that affected the fund’s performance?
Strategic Allocation: Conservative Fund R5 Class returned 8.51% for the reporting period ended July 31, 2026.
The fund is an asset allocation fund. That is, it diversifies its assets among various classes of investments such as equity securities, bonds and money market instruments. The fund seeks the highest level of total return consistent with its asset mix. See the Fund Holdings for the portfolio’s asset weights. Below, we discuss the factors that affected these asset classes.
•
The portfolio's U.S. stock holdings generally did well, with mid- and large-cap equities lagging small-cap stocks, while value stocks beat growth. This reflects uncertainty around spending on artificial intelligence (AI), which weighed most on mid- and large-cap growth stocks. Smaller and more value-oriented companies benefited from broad economic and earnings strength.
•
The portfolio's non-U.S. equity holdings generally outperformed U.S. stock holdings. That's because non-U.S. stocks benefited from attractive relative valuations as investors looked beyond the most expensive U.S. growth stocks. Nevertheless, some notable non-U.S. stocks did benefit from the broadening of the AI trade beyond U.S. borders.
•
The global bond allocation produced positive total returns and diversification benefits even as some of the world's leading central banks raised rates amid elevated inflation. For example, the European Central Bank and the Bank of Japan raised rates during the period, mindful of having left rates too low for too long ahead of the 2022 inflation shock.
•
The portfolio's cash allocation produced strong returns despite rate cuts by the Federal Reserve (Fed). Even as cash yields fell in line with the Fed rate changes, short-term yields remained in excess of inflation, and total returns exceeded those of intermediate- and long-term bonds.
  
Line Graph [Table Text Block]
Cumulative Performance (based on an initial $10,000 investment)
April 10, 2017 through July 31, 2026

10
  
Average Annual Return [Table Text Block]
Average Annual Total Returns
1 Year5 YearSince InceptionInception Date
R5 Class8.51%3.98%6.38%4/10/17
MSCI ACWI IMI22.27%10.40%11.93%—
Bloomberg U.S. Aggregate Bond2.71%-0.40%1.68%—
  
Performance Inception Date   Apr. 10, 2017
No Deduction of Taxes [Text Block] The opinions expressed are those of American Century Investments and are no guarantee of the future performance of any American Century Investments fund. This information is for educational purposes only and is not intended as investment advice. Data reflects past performance, assumes reinvestment of dividends and capital gains and is no guarantee of future results. Current performance may be higher or lower than data shown. Investment return and principal value will fluctuate and redemption value may be more or less than original cost, and none of the charts reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares.  
Updated Performance Information Location [Text Block] Visit americancentury.com for more recent performance information.  
Net Assets $ 276,173,910 $ 276,173,910
Holdings Count | holding 1,042 1,042
Advisory Fees Paid, Amount $ 1,662,839  
Investment Company, Portfolio Turnover 74.00%  
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds41.4%
Common Stocks18.5%
U.S. Treasury Securities14.5%
U.S. Government Agency Mortgage-Backed Securities6.0%
Corporate Bonds5.6%
Sovereign Governments and Agencies4.7%
Collateralized Mortgage Obligations1.8%
Asset-Backed Securities1.1%
Commercial Mortgage-Backed Securities0.6%
Municipal Securities0.3%
Exchange-Traded Funds0.1%
Preferred Securities0.0%
Rights0.0%
Short-Term Investments8.2%
Other Assets and Liabilities(2.8)%
  
C000131621 [Member]    
Shareholder Report [Line Items]    
Fund Name Strategic Allocation: Conservative Fund  
Class Name R6 Class  
Trading Symbol AACDX  
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Strategic Allocation: Conservative Fund for the period of August 1, 2025 to July 31, 2026.  
Shareholder Report Annual or Semi-Annual annual shareholder report  
Additional Information [Text Block] You can find additional information about the fund at americancentury.com/docs. You can also request this information by contacting us at 1-800-345-2021.  
Additional Information Phone Number 1-800-345-2021  
Additional Information Website americancentury.com/docs  
Expenses [Text Block]
What were the fund costs for the last year? (based on a hypothetical $10,000 investment)
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
R6 Class$350.34%
  
Expenses Paid, Amount $ 35  
Expense Ratio, Percent 0.34%  
Factors Affecting Performance [Text Block]
What were the key factors that affected the fund’s performance?
Strategic Allocation: Conservative Fund R6 Class returned 8.67% for the reporting period ended July 31, 2026.
The fund is an asset allocation fund. That is, it diversifies its assets among various classes of investments such as equity securities, bonds and money market instruments. The fund seeks the highest level of total return consistent with its asset mix. See the Fund Holdings for the portfolio’s asset weights. Below, we discuss the factors that affected these asset classes.
•
The portfolio's U.S. stock holdings generally did well, with mid- and large-cap equities lagging small-cap stocks, while value stocks beat growth. This reflects uncertainty around spending on artificial intelligence (AI), which weighed most on mid- and large-cap growth stocks. Smaller and more value-oriented companies benefited from broad economic and earnings strength.
•
The portfolio's non-U.S. equity holdings generally outperformed U.S. stock holdings. That's because non-U.S. stocks benefited from attractive relative valuations as investors looked beyond the most expensive U.S. growth stocks. Nevertheless, some notable non-U.S. stocks did benefit from the broadening of the AI trade beyond U.S. borders.
•
The global bond allocation produced positive total returns and diversification benefits even as some of the world's leading central banks raised rates amid elevated inflation. For example, the European Central Bank and the Bank of Japan raised rates during the period, mindful of having left rates too low for too long ahead of the 2022 inflation shock.
•
The portfolio's cash allocation produced strong returns despite rate cuts by the Federal Reserve (Fed). Even as cash yields fell in line with the Fed rate changes, short-term yields remained in excess of inflation, and total returns exceeded those of intermediate- and long-term bonds.
  
Line Graph [Table Text Block]
Cumulative Performance (based on an initial $10,000 investment)
July 31, 2016 through July 31, 2026

10
  
Average Annual Return [Table Text Block]
Average Annual Total Returns
1 Year5 Year10 Year
R6 Class8.67%4.18%6.39%
MSCI ACWI IMI22.27%10.40%12.02%
Bloomberg U.S. Aggregate Bond2.71%-0.40%1.35%
  
No Deduction of Taxes [Text Block] The opinions expressed are those of American Century Investments and are no guarantee of the future performance of any American Century Investments fund. This information is for educational purposes only and is not intended as investment advice. Data reflects past performance, assumes reinvestment of dividends and capital gains and is no guarantee of future results. Current performance may be higher or lower than data shown. Investment return and principal value will fluctuate and redemption value may be more or less than original cost, and none of the charts reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares.  
Updated Performance Information Location [Text Block] Visit americancentury.com for more recent performance information.  
Net Assets $ 276,173,910 $ 276,173,910
Holdings Count | holding 1,042 1,042
Advisory Fees Paid, Amount $ 1,662,839  
Investment Company, Portfolio Turnover 74.00%  
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds41.4%
Common Stocks18.5%
U.S. Treasury Securities14.5%
U.S. Government Agency Mortgage-Backed Securities6.0%
Corporate Bonds5.6%
Sovereign Governments and Agencies4.7%
Collateralized Mortgage Obligations1.8%
Asset-Backed Securities1.1%
Commercial Mortgage-Backed Securities0.6%
Municipal Securities0.3%
Exchange-Traded Funds0.1%
Preferred Securities0.0%
Rights0.0%
Short-Term Investments8.2%
Other Assets and Liabilities(2.8)%
  
C000016325 [Member]    
Shareholder Report [Line Items]    
Fund Name Strategic Allocation: Moderate Fund  
Class Name Investor Class  
Trading Symbol TWSMX  
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Strategic Allocation: Moderate Fund for the period of August 1, 2025 to July 31, 2026.  
Shareholder Report Annual or Semi-Annual annual shareholder report  
Additional Information [Text Block] You can find additional information about the fund at americancentury.com/docs. You can also request this information by contacting us at 1-800-345-2021.  
Additional Information Phone Number 1-800-345-2021  
Additional Information Website americancentury.com/docs  
Expenses [Text Block]
What were the fund costs for the last year? (based on a hypothetical $10,000 investment)
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Investor Class$710.67%
  
Expenses Paid, Amount $ 71  
Expense Ratio, Percent 0.67%  
Factors Affecting Performance [Text Block]
What were the key factors that affected the fund’s performance?
Strategic Allocation: Moderate Fund Investor Class returned 11.60% for the reporting period ended July 31, 2026.
The fund is an asset allocation fund. That is, it diversifies its assets among various classes of investments such as equity securities, bonds and money market instruments. The fund seeks the highest level of total return consistent with its asset mix. See the Fund Holdings for the portfolio’s asset weights. Below, we discuss the factors that affected these asset classes.
•
Global financial markets produced strong returns amid significant volatility related to inflation, interest rates and geopolitical trade tensions and war. Nevertheless, stocks rose because corporate earnings growth remained remarkably strong. The Federal Reserve cut interest rates three times during the period, but persistently high inflation meant that long-term bond yields actually rose.
•
The portfolio's U.S. stock holdings generally did well, with mid- and large-cap equities lagging small-cap stocks, while value stocks beat growth. This reflects uncertainty around spending on artificial intelligence (AI), which weighed most on mid- and large-cap growth stocks. Smaller and more value-oriented companies benefited from broad economic and earnings strength.
•
The portfolio's non-U.S. equity holdings generally outperformed U.S. stock holdings. That's because non-U.S. stocks benefited from attractive relative valuations as investors looked beyond the most expensive U.S. growth stocks. Emerging markets stocks also did very well, but this reflects the broadening of the AI trade beyond U.S. borders.
•
The global bond allocation produced positive total returns and diversification benefits even as some of the world's leading central banks raised rates amid elevated inflation. For example, the European Central Bank and the Bank of Japan raised rates during the period, mindful of having left rates too low for too long ahead of the 2022 inflation shock.
  
Line Graph [Table Text Block]
Cumulative Performance (based on an initial $10,000 investment)
July 31, 2016 through July 31, 2026

10
  
Average Annual Return [Table Text Block]
Average Annual Total Returns
1 Year5 Year10 Year
Investor Class11.60%5.47%8.10%
MSCI ACWI IMI22.27%10.40%12.02%
Bloomberg U.S. Aggregate Bond2.71%-0.40%1.35%
  
No Deduction of Taxes [Text Block] The opinions expressed are those of American Century Investments and are no guarantee of the future performance of any American Century Investments fund. This information is for educational purposes only and is not intended as investment advice. Data reflects past performance, assumes reinvestment of dividends and capital gains and is no guarantee of future results. Current performance may be higher or lower than data shown. Investment return and principal value will fluctuate and redemption value may be more or less than original cost, and none of the charts reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares.  
Updated Performance Information Location [Text Block] Visit americancentury.com for more recent performance information.  
Net Assets $ 767,443,964 $ 767,443,964
Holdings Count | holding 1,042 1,042
Advisory Fees Paid, Amount $ 4,344,851  
Investment Company, Portfolio Turnover 67.00%  
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds49.9%
Common Stocks24.4%
U.S. Treasury Securities8.5%
U.S. Government Agency Mortgage-Backed Securities4.3%
Sovereign Governments and Agencies3.3%
Corporate Bonds3.0%
Collateralized Mortgage Obligations1.1%
Asset-Backed Securities0.7%
Commercial Mortgage-Backed Securities0.4%
Municipal Securities0.3%
Exchange-Traded Funds0.2%
Convertible Preferred Securities0.2%
Collateralized Loan Obligations0.1%
Preferred Securities0.0%
Rights0.0%
Short-Term Investments10.4%
Other Assets and Liabilities(6.8)%
  
C000016327 [Member]    
Shareholder Report [Line Items]    
Fund Name Strategic Allocation: Moderate Fund  
Class Name I Class  
Trading Symbol ASAMX  
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Strategic Allocation: Moderate Fund for the period of August 1, 2025 to July 31, 2026.  
Shareholder Report Annual or Semi-Annual annual shareholder report  
Additional Information [Text Block] You can find additional information about the fund at americancentury.com/docs. You can also request this information by contacting us at 1-800-345-2021.  
Additional Information Phone Number 1-800-345-2021  
Additional Information Website americancentury.com/docs  
Expenses [Text Block]
What were the fund costs for the last year? (based on a hypothetical $10,000 investment)
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
I Class$500.47%
  
Expenses Paid, Amount $ 50  
Expense Ratio, Percent 0.47%  
Factors Affecting Performance [Text Block]
What were the key factors that affected the fund’s performance?
Strategic Allocation: Moderate Fund I Class returned 11.81% for the reporting period ended July 31, 2026.
The fund is an asset allocation fund. That is, it diversifies its assets among various classes of investments such as equity securities, bonds and money market instruments. The fund seeks the highest level of total return consistent with its asset mix. See the Fund Holdings for the portfolio’s asset weights. Below, we discuss the factors that affected these asset classes.
•
Global financial markets produced strong returns amid significant volatility related to inflation, interest rates and geopolitical trade tensions and war. Nevertheless, stocks rose because corporate earnings growth remained remarkably strong. The Federal Reserve cut interest rates three times during the period, but persistently high inflation meant that long-term bond yields actually rose.
•
The portfolio's U.S. stock holdings generally did well, with mid- and large-cap equities lagging small-cap stocks, while value stocks beat growth. This reflects uncertainty around spending on artificial intelligence (AI), which weighed most on mid- and large-cap growth stocks. Smaller and more value-oriented companies benefited from broad economic and earnings strength.
•
The portfolio's non-U.S. equity holdings generally outperformed U.S. stock holdings. That's because non-U.S. stocks benefited from attractive relative valuations as investors looked beyond the most expensive U.S. growth stocks. Emerging markets stocks also did very well, but this reflects the broadening of the AI trade beyond U.S. borders.
•
The global bond allocation produced positive total returns and diversification benefits even as some of the world's leading central banks raised rates amid elevated inflation. For example, the European Central Bank and the Bank of Japan raised rates during the period, mindful of having left rates too low for too long ahead of the 2022 inflation shock.
  
Line Graph [Table Text Block]
Cumulative Performance (based on an initial $10,000 investment)
July 31, 2016 through July 31, 2026

10
  
Average Annual Return [Table Text Block]
Average Annual Total Returns
1 Year5 Year10 Year
I Class11.81%5.70%8.34%
MSCI ACWI IMI22.27%10.40%12.02%
Bloomberg U.S. Aggregate Bond2.71%-0.40%1.35%
  
No Deduction of Taxes [Text Block] The opinions expressed are those of American Century Investments and are no guarantee of the future performance of any American Century Investments fund. This information is for educational purposes only and is not intended as investment advice. Data reflects past performance, assumes reinvestment of dividends and capital gains and is no guarantee of future results. Current performance may be higher or lower than data shown. Investment return and principal value will fluctuate and redemption value may be more or less than original cost, and none of the charts reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares.  
Updated Performance Information Location [Text Block] Visit americancentury.com for more recent performance information.  
Net Assets $ 767,443,964 $ 767,443,964
Holdings Count | holding 1,042 1,042
Advisory Fees Paid, Amount $ 4,344,851  
Investment Company, Portfolio Turnover 67.00%  
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds49.9%
Common Stocks24.4%
U.S. Treasury Securities8.5%
U.S. Government Agency Mortgage-Backed Securities4.3%
Sovereign Governments and Agencies3.3%
Corporate Bonds3.0%
Collateralized Mortgage Obligations1.1%
Asset-Backed Securities0.7%
Commercial Mortgage-Backed Securities0.4%
Municipal Securities0.3%
Exchange-Traded Funds0.2%
Convertible Preferred Securities0.2%
Collateralized Loan Obligations0.1%
Preferred Securities0.0%
Rights0.0%
Short-Term Investments10.4%
Other Assets and Liabilities(6.8)%
  
C000016326 [Member]    
Shareholder Report [Line Items]    
Fund Name Strategic Allocation: Moderate Fund  
Class Name A Class  
Trading Symbol ACOAX  
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Strategic Allocation: Moderate Fund for the period of August 1, 2025 to July 31, 2026.  
Shareholder Report Annual or Semi-Annual annual shareholder report  
Additional Information [Text Block] You can find additional information about the fund at americancentury.com/docs. You can also request this information by contacting us at 1-800-345-2021.  
Additional Information Phone Number 1-800-345-2021  
Additional Information Website americancentury.com/docs  
Expenses [Text Block]
What were the fund costs for the last year? (based on a hypothetical $10,000 investment)
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
A Class$970.92%
  
Expenses Paid, Amount $ 97  
Expense Ratio, Percent 0.92%  
Factors Affecting Performance [Text Block]
What were the key factors that affected the fund’s performance?
Strategic Allocation: Moderate Fund A Class returned 11.40% for the reporting period ended July 31, 2026.
The fund is an asset allocation fund. That is, it diversifies its assets among various classes of investments such as equity securities, bonds and money market instruments. The fund seeks the highest level of total return consistent with its asset mix. See the Fund Holdings for the portfolio’s asset weights. Below, we discuss the factors that affected these asset classes.
•
Global financial markets produced strong returns amid significant volatility related to inflation, interest rates and geopolitical trade tensions and war. Nevertheless, stocks rose because corporate earnings growth remained remarkably strong. The Federal Reserve cut interest rates three times during the period, but persistently high inflation meant that long-term bond yields actually rose.
•
The portfolio's U.S. stock holdings generally did well, with mid- and large-cap equities lagging small-cap stocks, while value stocks beat growth. This reflects uncertainty around spending on artificial intelligence (AI), which weighed most on mid- and large-cap growth stocks. Smaller and more value-oriented companies benefited from broad economic and earnings strength.
•
The portfolio's non-U.S. equity holdings generally outperformed U.S. stock holdings. That's because non-U.S. stocks benefited from attractive relative valuations as investors looked beyond the most expensive U.S. growth stocks. Emerging markets stocks also did very well, but this reflects the broadening of the AI trade beyond U.S. borders.
•
The global bond allocation produced positive total returns and diversification benefits even as some of the world's leading central banks raised rates amid elevated inflation. For example, the European Central Bank and the Bank of Japan raised rates during the period, mindful of having left rates too low for too long ahead of the 2022 inflation shock.
  
Line Graph [Table Text Block]
Cumulative Performance (based on an initial $10,000 investment)
July 31, 2016 through July 31, 2026
The initial investment is adjusted to reflect the maximum initial sales charge.
10
  
Average Annual Return [Table Text Block]
Average Annual Total Returns
1 Year5 Year10 Year
A Class11.40%5.23%7.85%
A Class - with sales charge4.99%3.99%7.21%
MSCI ACWI IMI22.27%10.40%12.02%
Bloomberg U.S. Aggregate Bond2.71%-0.40%1.35%
  
No Deduction of Taxes [Text Block] The opinions expressed are those of American Century Investments and are no guarantee of the future performance of any American Century Investments fund. This information is for educational purposes only and is not intended as investment advice. Data reflects past performance, assumes reinvestment of dividends and capital gains and is no guarantee of future results. Current performance may be higher or lower than data shown. Investment return and principal value will fluctuate and redemption value may be more or less than original cost, and none of the charts reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares.  
Updated Performance Information Location [Text Block] Visit americancentury.com for more recent performance information.  
Net Assets $ 767,443,964 $ 767,443,964
Holdings Count | holding 1,042 1,042
Advisory Fees Paid, Amount $ 4,344,851  
Investment Company, Portfolio Turnover 67.00%  
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds49.9%
Common Stocks24.4%
U.S. Treasury Securities8.5%
U.S. Government Agency Mortgage-Backed Securities4.3%
Sovereign Governments and Agencies3.3%
Corporate Bonds3.0%
Collateralized Mortgage Obligations1.1%
Asset-Backed Securities0.7%
Commercial Mortgage-Backed Securities0.4%
Municipal Securities0.3%
Exchange-Traded Funds0.2%
Convertible Preferred Securities0.2%
Collateralized Loan Obligations0.1%
Preferred Securities0.0%
Rights0.0%
Short-Term Investments10.4%
Other Assets and Liabilities(6.8)%
  
C000016330 [Member]    
Shareholder Report [Line Items]    
Fund Name Strategic Allocation: Moderate Fund  
Class Name C Class  
Trading Symbol ASTCX  
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Strategic Allocation: Moderate Fund for the period of August 1, 2025 to July 31, 2026.  
Shareholder Report Annual or Semi-Annual annual shareholder report  
Additional Information [Text Block] You can find additional information about the fund at americancentury.com/docs. You can also request this information by contacting us at 1-800-345-2021.  
Additional Information Phone Number 1-800-345-2021  
Additional Information Website americancentury.com/docs  
Expenses [Text Block]
What were the fund costs for the last year? (based on a hypothetical $10,000 investment)
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
C Class$1761.67%
  
Expenses Paid, Amount $ 176  
Expense Ratio, Percent 1.67%  
Factors Affecting Performance [Text Block]
What were the key factors that affected the fund’s performance?
Strategic Allocation: Moderate Fund C Class returned 10.52% for the reporting period ended July 31, 2026.
The fund is an asset allocation fund. That is, it diversifies its assets among various classes of investments such as equity securities, bonds and money market instruments. The fund seeks the highest level of total return consistent with its asset mix. See the Fund Holdings for the portfolio’s asset weights. Below, we discuss the factors that affected these asset classes.
•
Global financial markets produced strong returns amid significant volatility related to inflation, interest rates and geopolitical trade tensions and war. Nevertheless, stocks rose because corporate earnings growth remained remarkably strong. The Federal Reserve cut interest rates three times during the period, but persistently high inflation meant that long-term bond yields actually rose.
•
The portfolio's U.S. stock holdings generally did well, with mid- and large-cap equities lagging small-cap stocks, while value stocks beat growth. This reflects uncertainty around spending on artificial intelligence (AI), which weighed most on mid- and large-cap growth stocks. Smaller and more value-oriented companies benefited from broad economic and earnings strength.
•
The portfolio's non-U.S. equity holdings generally outperformed U.S. stock holdings. That's because non-U.S. stocks benefited from attractive relative valuations as investors looked beyond the most expensive U.S. growth stocks. Emerging markets stocks also did very well, but this reflects the broadening of the AI trade beyond U.S. borders.
•
The global bond allocation produced positive total returns and diversification benefits even as some of the world's leading central banks raised rates amid elevated inflation. For example, the European Central Bank and the Bank of Japan raised rates during the period, mindful of having left rates too low for too long ahead of the 2022 inflation shock.
  
Line Graph [Table Text Block]
Cumulative Performance (based on an initial $10,000 investment)
July 31, 2016 through July 31, 2026

10
  
Average Annual Return [Table Text Block]
Average Annual Total Returns
1 Year5 Year10 Year
C Class10.52%4.46%7.06%
MSCI ACWI IMI22.27%10.40%12.02%
Bloomberg U.S. Aggregate Bond2.71%-0.40%1.35%
  
No Deduction of Taxes [Text Block] The opinions expressed are those of American Century Investments and are no guarantee of the future performance of any American Century Investments fund. This information is for educational purposes only and is not intended as investment advice. Data reflects past performance, assumes reinvestment of dividends and capital gains and is no guarantee of future results. Current performance may be higher or lower than data shown. Investment return and principal value will fluctuate and redemption value may be more or less than original cost, and none of the charts reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares.  
Updated Performance Information Location [Text Block] Visit americancentury.com for more recent performance information.  
Net Assets $ 767,443,964 $ 767,443,964
Holdings Count | holding 1,042 1,042
Advisory Fees Paid, Amount $ 4,344,851  
Investment Company, Portfolio Turnover 67.00%  
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds49.9%
Common Stocks24.4%
U.S. Treasury Securities8.5%
U.S. Government Agency Mortgage-Backed Securities4.3%
Sovereign Governments and Agencies3.3%
Corporate Bonds3.0%
Collateralized Mortgage Obligations1.1%
Asset-Backed Securities0.7%
Commercial Mortgage-Backed Securities0.4%
Municipal Securities0.3%
Exchange-Traded Funds0.2%
Convertible Preferred Securities0.2%
Collateralized Loan Obligations0.1%
Preferred Securities0.0%
Rights0.0%
Short-Term Investments10.4%
Other Assets and Liabilities(6.8)%
  
C000016331 [Member]    
Shareholder Report [Line Items]    
Fund Name Strategic Allocation: Moderate Fund  
Class Name R Class  
Trading Symbol ASMRX  
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Strategic Allocation: Moderate Fund for the period of August 1, 2025 to July 31, 2026.  
Shareholder Report Annual or Semi-Annual annual shareholder report  
Additional Information [Text Block] You can find additional information about the fund at americancentury.com/docs. You can also request this information by contacting us at 1-800-345-2021.  
Additional Information Phone Number 1-800-345-2021  
Additional Information Website americancentury.com/docs  
Expenses [Text Block]
What were the fund costs for the last year? (based on a hypothetical $10,000 investment)
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
R Class$1231.17%
  
Expenses Paid, Amount $ 123  
Expense Ratio, Percent 1.17%  
Factors Affecting Performance [Text Block]
What were the key factors that affected the fund’s performance?
Strategic Allocation: Moderate Fund R Class returned 11.11% for the reporting period ended July 31, 2026.
The fund is an asset allocation fund. That is, it diversifies its assets among various classes of investments such as equity securities, bonds and money market instruments. The fund seeks the highest level of total return consistent with its asset mix. See the Fund Holdings for the portfolio’s asset weights. Below, we discuss the factors that affected these asset classes.
•
Global financial markets produced strong returns amid significant volatility related to inflation, interest rates and geopolitical trade tensions and war. Nevertheless, stocks rose because corporate earnings growth remained remarkably strong. The Federal Reserve cut interest rates three times during the period, but persistently high inflation meant that long-term bond yields actually rose.
•
The portfolio's U.S. stock holdings generally did well, with mid- and large-cap equities lagging small-cap stocks, while value stocks beat growth. This reflects uncertainty around spending on artificial intelligence (AI), which weighed most on mid- and large-cap growth stocks. Smaller and more value-oriented companies benefited from broad economic and earnings strength.
•
The portfolio's non-U.S. equity holdings generally outperformed U.S. stock holdings. That's because non-U.S. stocks benefited from attractive relative valuations as investors looked beyond the most expensive U.S. growth stocks. Emerging markets stocks also did very well, but this reflects the broadening of the AI trade beyond U.S. borders.
•
The global bond allocation produced positive total returns and diversification benefits even as some of the world's leading central banks raised rates amid elevated inflation. For example, the European Central Bank and the Bank of Japan raised rates during the period, mindful of having left rates too low for too long ahead of the 2022 inflation shock.
  
Line Graph [Table Text Block]
Cumulative Performance (based on an initial $10,000 investment)
July 31, 2016 through July 31, 2026

10
  
Average Annual Return [Table Text Block]
Average Annual Total Returns
1 Year5 Year10 Year
R Class11.11%4.95%7.58%
MSCI ACWI IMI22.27%10.40%12.02%
Bloomberg U.S. Aggregate Bond2.71%-0.40%1.35%
  
No Deduction of Taxes [Text Block] The opinions expressed are those of American Century Investments and are no guarantee of the future performance of any American Century Investments fund. This information is for educational purposes only and is not intended as investment advice. Data reflects past performance, assumes reinvestment of dividends and capital gains and is no guarantee of future results. Current performance may be higher or lower than data shown. Investment return and principal value will fluctuate and redemption value may be more or less than original cost, and none of the charts reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares.  
Updated Performance Information Location [Text Block] Visit americancentury.com for more recent performance information.  
Net Assets $ 767,443,964 $ 767,443,964
Holdings Count | holding 1,042 1,042
Advisory Fees Paid, Amount $ 4,344,851  
Investment Company, Portfolio Turnover 67.00%  
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds49.9%
Common Stocks24.4%
U.S. Treasury Securities8.5%
U.S. Government Agency Mortgage-Backed Securities4.3%
Sovereign Governments and Agencies3.3%
Corporate Bonds3.0%
Collateralized Mortgage Obligations1.1%
Asset-Backed Securities0.7%
Commercial Mortgage-Backed Securities0.4%
Municipal Securities0.3%
Exchange-Traded Funds0.2%
Convertible Preferred Securities0.2%
Collateralized Loan Obligations0.1%
Preferred Securities0.0%
Rights0.0%
Short-Term Investments10.4%
Other Assets and Liabilities(6.8)%
  
C000189655 [Member]    
Shareholder Report [Line Items]    
Fund Name Strategic Allocation: Moderate Fund  
Class Name R5 Class  
Trading Symbol ASMUX  
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Strategic Allocation: Moderate Fund for the period of August 1, 2025 to July 31, 2026.  
Shareholder Report Annual or Semi-Annual annual shareholder report  
Additional Information [Text Block] You can find additional information about the fund at americancentury.com/docs. You can also request this information by contacting us at 1-800-345-2021.  
Additional Information Phone Number 1-800-345-2021  
Additional Information Website americancentury.com/docs  
Expenses [Text Block]
What were the fund costs for the last year? (based on a hypothetical $10,000 investment)
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
R5 Class$500.47%
  
Expenses Paid, Amount $ 50  
Expense Ratio, Percent 0.47%  
Factors Affecting Performance [Text Block]
What were the key factors that affected the fund’s performance?
Strategic Allocation: Moderate Fund R5 Class returned 11.63% for the reporting period ended July 31, 2026.
The fund is an asset allocation fund. That is, it diversifies its assets among various classes of investments such as equity securities, bonds and money market instruments. The fund seeks the highest level of total return consistent with its asset mix. See the Fund Holdings for the portfolio’s asset weights. Below, we discuss the factors that affected these asset classes.
•
Global financial markets produced strong returns amid significant volatility related to inflation, interest rates and geopolitical trade tensions and war. Nevertheless, stocks rose because corporate earnings growth remained remarkably strong. The Federal Reserve cut interest rates three times during the period, but persistently high inflation meant that long-term bond yields actually rose.
•
The portfolio's U.S. stock holdings generally did well, with mid- and large-cap equities lagging small-cap stocks, while value stocks beat growth. This reflects uncertainty around spending on artificial intelligence (AI), which weighed most on mid- and large-cap growth stocks. Smaller and more value-oriented companies benefited from broad economic and earnings strength.
•
The portfolio's non-U.S. equity holdings generally outperformed U.S. stock holdings. That's because non-U.S. stocks benefited from attractive relative valuations as investors looked beyond the most expensive U.S. growth stocks. Emerging markets stocks also did very well, but this reflects the broadening of the AI trade beyond U.S. borders.
•
The global bond allocation produced positive total returns and diversification benefits even as some of the world's leading central banks raised rates amid elevated inflation. For example, the European Central Bank and the Bank of Japan raised rates during the period, mindful of having left rates too low for too long ahead of the 2022 inflation shock.
  
Line Graph [Table Text Block]
Cumulative Performance (based on an initial $10,000 investment)
April 10, 2017 through July 31, 2026

10
  
Average Annual Return [Table Text Block]
Average Annual Total Returns
1 Year5 YearSince InceptionInception Date
R5 Class11.63%5.67%8.37%4/10/17
MSCI ACWI IMI22.27%10.40%11.93%—
Bloomberg U.S. Aggregate Bond2.71%-0.40%1.68%—
  
Performance Inception Date   Apr. 10, 2017
No Deduction of Taxes [Text Block] The opinions expressed are those of American Century Investments and are no guarantee of the future performance of any American Century Investments fund. This information is for educational purposes only and is not intended as investment advice. Data reflects past performance, assumes reinvestment of dividends and capital gains and is no guarantee of future results. Current performance may be higher or lower than data shown. Investment return and principal value will fluctuate and redemption value may be more or less than original cost, and none of the charts reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares.  
Updated Performance Information Location [Text Block] Visit americancentury.com for more recent performance information.  
Net Assets $ 767,443,964 $ 767,443,964
Holdings Count | holding 1,042 1,042
Advisory Fees Paid, Amount $ 4,344,851  
Investment Company, Portfolio Turnover 67.00%  
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds49.9%
Common Stocks24.4%
U.S. Treasury Securities8.5%
U.S. Government Agency Mortgage-Backed Securities4.3%
Sovereign Governments and Agencies3.3%
Corporate Bonds3.0%
Collateralized Mortgage Obligations1.1%
Asset-Backed Securities0.7%
Commercial Mortgage-Backed Securities0.4%
Municipal Securities0.3%
Exchange-Traded Funds0.2%
Convertible Preferred Securities0.2%
Collateralized Loan Obligations0.1%
Preferred Securities0.0%
Rights0.0%
Short-Term Investments10.4%
Other Assets and Liabilities(6.8)%
  
C000131620 [Member]    
Shareholder Report [Line Items]    
Fund Name Strategic Allocation: Moderate Fund  
Class Name R6 Class  
Trading Symbol ASMDX  
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Strategic Allocation: Moderate Fund for the period of August 1, 2025 to July 31, 2026.  
Shareholder Report Annual or Semi-Annual annual shareholder report  
Additional Information [Text Block] You can find additional information about the fund at americancentury.com/docs. You can also request this information by contacting us at 1-800-345-2021.  
Additional Information Phone Number 1-800-345-2021  
Additional Information Website americancentury.com/docs  
Expenses [Text Block]
What were the fund costs for the last year? (based on a hypothetical $10,000 investment)
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
R6 Class$340.32%
  
Expenses Paid, Amount $ 34  
Expense Ratio, Percent 0.32%  
Factors Affecting Performance [Text Block]
What were the key factors that affected the fund’s performance?
Strategic Allocation: Moderate Fund R6 Class returned 12.00% for the reporting period ended July 31, 2026.
The fund is an asset allocation fund. That is, it diversifies its assets among various classes of investments such as equity securities, bonds and money market instruments. The fund seeks the highest level of total return consistent with its asset mix. See the Fund Holdings for the portfolio’s asset weights. Below, we discuss the factors that affected these asset classes.
•
Global financial markets produced strong returns amid significant volatility related to inflation, interest rates and geopolitical trade tensions and war. Nevertheless, stocks rose because corporate earnings growth remained remarkably strong. The Federal Reserve cut interest rates three times during the period, but persistently high inflation meant that long-term bond yields actually rose.
•
The portfolio's U.S. stock holdings generally did well, with mid- and large-cap equities lagging small-cap stocks, while value stocks beat growth. This reflects uncertainty around spending on artificial intelligence (AI), which weighed most on mid- and large-cap growth stocks. Smaller and more value-oriented companies benefited from broad economic and earnings strength.
•
The portfolio's non-U.S. equity holdings generally outperformed U.S. stock holdings. That's because non-U.S. stocks benefited from attractive relative valuations as investors looked beyond the most expensive U.S. growth stocks. Emerging markets stocks also did very well, but this reflects the broadening of the AI trade beyond U.S. borders.
•
The global bond allocation produced positive total returns and diversification benefits even as some of the world's leading central banks raised rates amid elevated inflation. For example, the European Central Bank and the Bank of Japan raised rates during the period, mindful of having left rates too low for too long ahead of the 2022 inflation shock.
  
Line Graph [Table Text Block]
Cumulative Performance (based on an initial $10,000 investment)
July 31, 2016 through July 31, 2026

10
  
Average Annual Return [Table Text Block]
Average Annual Total Returns
1 Year5 Year10 Year
R6 Class12.00%5.85%8.49%
MSCI ACWI IMI22.27%10.40%12.02%
Bloomberg U.S. Aggregate Bond2.71%-0.40%1.35%
  
No Deduction of Taxes [Text Block] The opinions expressed are those of American Century Investments and are no guarantee of the future performance of any American Century Investments fund. This information is for educational purposes only and is not intended as investment advice. Data reflects past performance, assumes reinvestment of dividends and capital gains and is no guarantee of future results. Current performance may be higher or lower than data shown. Investment return and principal value will fluctuate and redemption value may be more or less than original cost, and none of the charts reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares.  
Updated Performance Information Location [Text Block] Visit americancentury.com for more recent performance information.  
Net Assets $ 767,443,964 $ 767,443,964
Holdings Count | holding 1,042 1,042
Advisory Fees Paid, Amount $ 4,344,851  
Investment Company, Portfolio Turnover 67.00%  
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds49.9%
Common Stocks24.4%
U.S. Treasury Securities8.5%
U.S. Government Agency Mortgage-Backed Securities4.3%
Sovereign Governments and Agencies3.3%
Corporate Bonds3.0%
Collateralized Mortgage Obligations1.1%
Asset-Backed Securities0.7%
Commercial Mortgage-Backed Securities0.4%
Municipal Securities0.3%
Exchange-Traded Funds0.2%
Convertible Preferred Securities0.2%
Collateralized Loan Obligations0.1%
Preferred Securities0.0%
Rights0.0%
Short-Term Investments10.4%
Other Assets and Liabilities(6.8)%
  
C000016319 [Member]    
Shareholder Report [Line Items]    
Fund Name Strategic Allocation: Aggressive Fund  
Class Name Investor Class  
Trading Symbol TWSAX  
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Strategic Allocation: Aggressive Fund for the period of August 1, 2025 to July 31, 2026.  
Shareholder Report Annual or Semi-Annual annual shareholder report  
Additional Information [Text Block] You can find additional information about the fund at americancentury.com/docs. You can also request this information by contacting us at 1-800-345-2021.  
Additional Information Phone Number 1-800-345-2021  
Additional Information Website americancentury.com/docs  
Expenses [Text Block]
What were the fund costs for the last year? (based on a hypothetical $10,000 investment)
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
Investor Class$640.60%
  
Expenses Paid, Amount $ 64  
Expense Ratio, Percent 0.60%  
Factors Affecting Performance [Text Block]
What were the key factors that affected the fund’s performance?
Strategic Allocation: Aggressive Fund Investor Class returned 14.49% for the reporting period ended July 31, 2026.
The fund is an asset allocation fund. That is, it diversifies its assets among various classes of investments such as equity securities, bonds and money market instruments. The fund seeks the highest level of total return consistent with its asset mix. See the Fund Holdings for the portfolio’s asset weights. Below, we discuss the factors that affected these asset classes.
•
Global financial markets produced strong returns amid significant volatility related to inflation, interest rates and geopolitical trade tensions and war. Nevertheless, stocks rose because corporate earnings growth remained remarkably strong. The Federal Reserve cut interest rates three times during the period, but persistently high inflation meant that long-term bond yields actually rose.
•
The portfolio's U.S. stock holdings generally did well, with mid- and large-cap equities lagging small-cap stocks, while value stocks beat growth. This reflects uncertainty around spending on artificial intelligence (AI), which weighed most on mid- and large-cap growth stocks. Smaller and more value-oriented companies benefited from broad economic and earnings strength.
•
The portfolio's non-U.S. equity holdings generally outperformed U.S. stock holdings. That's because non-U.S. stocks benefited from attractive relative valuations as investors looked beyond the most expensive U.S. growth stocks. Emerging markets stocks also did very well, but this reflects the broadening of the AI trade beyond U.S. borders.
•
The global bond allocation produced positive total returns and diversification benefits even as some of the world's leading central banks raised rates amid elevated inflation. For example, the European Central Bank and the Bank of Japan raised rates during the period, mindful of having left rates too low for too long ahead of the 2022 inflation shock.
  
Line Graph [Table Text Block]
Cumulative Performance (based on an initial $10,000 investment)
July 31, 2016 through July 31, 2026
2199023255567
  
Average Annual Return [Table Text Block]
Average Annual Total Returns
1 Year5 Year10 Year
Investor Class14.49%7.10%9.90%
MSCI ACWI IMI22.27%10.40%12.02%
Bloomberg U.S. Aggregate Bond2.71%-0.40%1.35%
  
No Deduction of Taxes [Text Block] The opinions expressed are those of American Century Investments and are no guarantee of the future performance of any American Century Investments fund. This information is for educational purposes only and is not intended as investment advice. Data reflects past performance, assumes reinvestment of dividends and capital gains and is no guarantee of future results. Current performance may be higher or lower than data shown. Investment return and principal value will fluctuate and redemption value may be more or less than original cost, and none of the charts reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares.  
Updated Performance Information Location [Text Block] Visit americancentury.com for more recent performance information.  
Net Assets $ 733,691,260 $ 733,691,260
Holdings Count | holding 974 974
Advisory Fees Paid, Amount $ 3,356,230  
Investment Company, Portfolio Turnover 62.00%  
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds58.5%
Common Stocks29.9%
Corporate Bonds2.8%
U.S. Government Agency Mortgage-Backed Securities2.3%
Sovereign Governments and Agencies1.6%
U.S. Treasury Securities1.0%
Collateralized Mortgage Obligations0.7%
Convertible Preferred Securities0.6%
Asset-Backed Securities0.4%
Preferred Securities0.4%
Exchange-Traded Funds0.4%
Bank Loan Obligations0.2%
Commercial Mortgage-Backed Securities0.2%
Municipal Securities0.0%
Rights0.0%
Short-Term Investments8.1%
Other Assets and Liabilities(7.1)%
  
C000016321 [Member]    
Shareholder Report [Line Items]    
Fund Name Strategic Allocation: Aggressive Fund  
Class Name I Class  
Trading Symbol AAAIX  
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Strategic Allocation: Aggressive Fund for the period of August 1, 2025 to July 31, 2026.  
Shareholder Report Annual or Semi-Annual annual shareholder report  
Additional Information [Text Block] You can find additional information about the fund at americancentury.com/docs. You can also request this information by contacting us at 1-800-345-2021.  
Additional Information Phone Number 1-800-345-2021  
Additional Information Website americancentury.com/docs  
Expenses [Text Block]
What were the fund costs for the last year? (based on a hypothetical $10,000 investment)
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
I Class$430.40%
  
Expenses Paid, Amount $ 43  
Expense Ratio, Percent 0.40%  
Factors Affecting Performance [Text Block]
What were the key factors that affected the fund’s performance?
Strategic Allocation: Aggressive Fund I Class returned 14.78% for the reporting period ended July 31, 2026.
The fund is an asset allocation fund. That is, it diversifies its assets among various classes of investments such as equity securities, bonds and money market instruments. The fund seeks the highest level of total return consistent with its asset mix. See the Fund Holdings for the portfolio’s asset weights. Below, we discuss the factors that affected these asset classes.
•
Global financial markets produced strong returns amid significant volatility related to inflation, interest rates and geopolitical trade tensions and war. Nevertheless, stocks rose because corporate earnings growth remained remarkably strong. The Federal Reserve cut interest rates three times during the period, but persistently high inflation meant that long-term bond yields actually rose.
•
The portfolio's U.S. stock holdings generally did well, with mid- and large-cap equities lagging small-cap stocks, while value stocks beat growth. This reflects uncertainty around spending on artificial intelligence (AI), which weighed most on mid- and large-cap growth stocks. Smaller and more value-oriented companies benefited from broad economic and earnings strength.
•
The portfolio's non-U.S. equity holdings generally outperformed U.S. stock holdings. That's because non-U.S. stocks benefited from attractive relative valuations as investors looked beyond the most expensive U.S. growth stocks. Emerging markets stocks also did very well, but this reflects the broadening of the AI trade beyond U.S. borders.
•
The global bond allocation produced positive total returns and diversification benefits even as some of the world's leading central banks raised rates amid elevated inflation. For example, the European Central Bank and the Bank of Japan raised rates during the period, mindful of having left rates too low for too long ahead of the 2022 inflation shock.
  
Line Graph [Table Text Block]
Cumulative Performance (based on an initial $10,000 investment)
July 31, 2016 through July 31, 2026
10
  
Average Annual Return [Table Text Block]
Average Annual Total Returns
1 Year5 Year10 Year
I Class14.78%7.31%10.12%
MSCI ACWI IMI22.27%10.40%12.02%
Bloomberg U.S. Aggregate Bond2.71%-0.40%1.35%
  
No Deduction of Taxes [Text Block] The opinions expressed are those of American Century Investments and are no guarantee of the future performance of any American Century Investments fund. This information is for educational purposes only and is not intended as investment advice. Data reflects past performance, assumes reinvestment of dividends and capital gains and is no guarantee of future results. Current performance may be higher or lower than data shown. Investment return and principal value will fluctuate and redemption value may be more or less than original cost, and none of the charts reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares.  
Updated Performance Information Location [Text Block] Visit americancentury.com for more recent performance information.  
Net Assets $ 733,691,260 $ 733,691,260
Holdings Count | holding 974 974
Advisory Fees Paid, Amount $ 3,356,230  
Investment Company, Portfolio Turnover 62.00%  
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds58.5%
Common Stocks29.9%
Corporate Bonds2.8%
U.S. Government Agency Mortgage-Backed Securities2.3%
Sovereign Governments and Agencies1.6%
U.S. Treasury Securities1.0%
Collateralized Mortgage Obligations0.7%
Convertible Preferred Securities0.6%
Asset-Backed Securities0.4%
Preferred Securities0.4%
Exchange-Traded Funds0.4%
Bank Loan Obligations0.2%
Commercial Mortgage-Backed Securities0.2%
Municipal Securities0.0%
Rights0.0%
Short-Term Investments8.1%
Other Assets and Liabilities(7.1)%
  
C000016320 [Member]    
Shareholder Report [Line Items]    
Fund Name Strategic Allocation: Aggressive Fund  
Class Name A Class  
Trading Symbol ACVAX  
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Strategic Allocation: Aggressive Fund for the period of August 1, 2025 to July 31, 2026.  
Shareholder Report Annual or Semi-Annual annual shareholder report  
Additional Information [Text Block] You can find additional information about the fund at americancentury.com/docs. You can also request this information by contacting us at 1-800-345-2021.  
Additional Information Phone Number 1-800-345-2021  
Additional Information Website americancentury.com/docs  
Expenses [Text Block]
What were the fund costs for the last year? (based on a hypothetical $10,000 investment)
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
A Class$910.85%
  
Expenses Paid, Amount $ 91  
Expense Ratio, Percent 0.85%  
Factors Affecting Performance [Text Block]
What were the key factors that affected the fund’s performance?
Strategic Allocation: Aggressive Fund A Class returned 14.25% for the reporting period ended July 31, 2026.
The fund is an asset allocation fund. That is, it diversifies its assets among various classes of investments such as equity securities, bonds and money market instruments. The fund seeks the highest level of total return consistent with its asset mix. See the Fund Holdings for the portfolio’s asset weights. Below, we discuss the factors that affected these asset classes.
•
Global financial markets produced strong returns amid significant volatility related to inflation, interest rates and geopolitical trade tensions and war. Nevertheless, stocks rose because corporate earnings growth remained remarkably strong. The Federal Reserve cut interest rates three times during the period, but persistently high inflation meant that long-term bond yields actually rose.
•
The portfolio's U.S. stock holdings generally did well, with mid- and large-cap equities lagging small-cap stocks, while value stocks beat growth. This reflects uncertainty around spending on artificial intelligence (AI), which weighed most on mid- and large-cap growth stocks. Smaller and more value-oriented companies benefited from broad economic and earnings strength.
•
The portfolio's non-U.S. equity holdings generally outperformed U.S. stock holdings. That's because non-U.S. stocks benefited from attractive relative valuations as investors looked beyond the most expensive U.S. growth stocks. Emerging markets stocks also did very well, but this reflects the broadening of the AI trade beyond U.S. borders.
•
The global bond allocation produced positive total returns and diversification benefits even as some of the world's leading central banks raised rates amid elevated inflation. For example, the European Central Bank and the Bank of Japan raised rates during the period, mindful of having left rates too low for too long ahead of the 2022 inflation shock.
  
Line Graph [Table Text Block]
Cumulative Performance (based on an initial $10,000 investment)
July 31, 2016 through July 31, 2026
The initial investment is adjusted to reflect the maximum initial sales charge.
10
  
Average Annual Return [Table Text Block]
Average Annual Total Returns
1 Year5 Year10 Year
A Class14.25%6.84%9.62%
A Class - with sales charge7.68%5.58%8.97%
MSCI ACWI IMI22.27%10.40%12.02%
Bloomberg U.S. Aggregate Bond2.71%-0.40%1.35%
  
No Deduction of Taxes [Text Block] The opinions expressed are those of American Century Investments and are no guarantee of the future performance of any American Century Investments fund. This information is for educational purposes only and is not intended as investment advice. Data reflects past performance, assumes reinvestment of dividends and capital gains and is no guarantee of future results. Current performance may be higher or lower than data shown. Investment return and principal value will fluctuate and redemption value may be more or less than original cost, and none of the charts reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares.  
Updated Performance Information Location [Text Block] Visit americancentury.com for more recent performance information.  
Net Assets $ 733,691,260 $ 733,691,260
Holdings Count | holding 974 974
Advisory Fees Paid, Amount $ 3,356,230  
Investment Company, Portfolio Turnover 62.00%  
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds58.5%
Common Stocks29.9%
Corporate Bonds2.8%
U.S. Government Agency Mortgage-Backed Securities2.3%
Sovereign Governments and Agencies1.6%
U.S. Treasury Securities1.0%
Collateralized Mortgage Obligations0.7%
Convertible Preferred Securities0.6%
Asset-Backed Securities0.4%
Preferred Securities0.4%
Exchange-Traded Funds0.4%
Bank Loan Obligations0.2%
Commercial Mortgage-Backed Securities0.2%
Municipal Securities0.0%
Rights0.0%
Short-Term Investments8.1%
Other Assets and Liabilities(7.1)%
  
C000016324 [Member]    
Shareholder Report [Line Items]    
Fund Name Strategic Allocation: Aggressive Fund  
Class Name C Class  
Trading Symbol ASTAX  
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Strategic Allocation: Aggressive Fund for the period of August 1, 2025 to July 31, 2026.  
Shareholder Report Annual or Semi-Annual annual shareholder report  
Additional Information [Text Block] You can find additional information about the fund at americancentury.com/docs. You can also request this information by contacting us at 1-800-345-2021.  
Additional Information Phone Number 1-800-345-2021  
Additional Information Website americancentury.com/docs  
Expenses [Text Block]
What were the fund costs for the last year? (based on a hypothetical $10,000 investment)
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
C Class$1711.60%
  
Expenses Paid, Amount $ 171  
Expense Ratio, Percent 1.60%  
Factors Affecting Performance [Text Block]
What were the key factors that affected the fund’s performance?
Strategic Allocation: Aggressive Fund C Class returned 13.37% for the reporting period ended July 31, 2026.
The fund is an asset allocation fund. That is, it diversifies its assets among various classes of investments such as equity securities, bonds and money market instruments. The fund seeks the highest level of total return consistent with its asset mix. See the Fund Holdings for the portfolio’s asset weights. Below, we discuss the factors that affected these asset classes.
•
Global financial markets produced strong returns amid significant volatility related to inflation, interest rates and geopolitical trade tensions and war. Nevertheless, stocks rose because corporate earnings growth remained remarkably strong. The Federal Reserve cut interest rates three times during the period, but persistently high inflation meant that long-term bond yields actually rose.
•
The portfolio's U.S. stock holdings generally did well, with mid- and large-cap equities lagging small-cap stocks, while value stocks beat growth. This reflects uncertainty around spending on artificial intelligence (AI), which weighed most on mid- and large-cap growth stocks. Smaller and more value-oriented companies benefited from broad economic and earnings strength.
•
The portfolio's non-U.S. equity holdings generally outperformed U.S. stock holdings. That's because non-U.S. stocks benefited from attractive relative valuations as investors looked beyond the most expensive U.S. growth stocks. Emerging markets stocks also did very well, but this reflects the broadening of the AI trade beyond U.S. borders.
•
The global bond allocation produced positive total returns and diversification benefits even as some of the world's leading central banks raised rates amid elevated inflation. For example, the European Central Bank and the Bank of Japan raised rates during the period, mindful of having left rates too low for too long ahead of the 2022 inflation shock.
  
Line Graph [Table Text Block]
Cumulative Performance (based on an initial $10,000 investment)
July 31, 2016 through July 31, 2026
10
  
Average Annual Return [Table Text Block]
Average Annual Total Returns
1 Year5 Year10 Year
C Class13.37%6.04%8.80%
MSCI ACWI IMI22.27%10.40%12.02%
Bloomberg U.S. Aggregate Bond2.71%-0.40%1.35%
  
No Deduction of Taxes [Text Block] The opinions expressed are those of American Century Investments and are no guarantee of the future performance of any American Century Investments fund. This information is for educational purposes only and is not intended as investment advice. Data reflects past performance, assumes reinvestment of dividends and capital gains and is no guarantee of future results. Current performance may be higher or lower than data shown. Investment return and principal value will fluctuate and redemption value may be more or less than original cost, and none of the charts reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares.  
Updated Performance Information Location [Text Block] Visit americancentury.com for more recent performance information.  
Net Assets $ 733,691,260 $ 733,691,260
Holdings Count | holding 974 974
Advisory Fees Paid, Amount $ 3,356,230  
Investment Company, Portfolio Turnover 62.00%  
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds58.5%
Common Stocks29.9%
Corporate Bonds2.8%
U.S. Government Agency Mortgage-Backed Securities2.3%
Sovereign Governments and Agencies1.6%
U.S. Treasury Securities1.0%
Collateralized Mortgage Obligations0.7%
Convertible Preferred Securities0.6%
Asset-Backed Securities0.4%
Preferred Securities0.4%
Exchange-Traded Funds0.4%
Bank Loan Obligations0.2%
Commercial Mortgage-Backed Securities0.2%
Municipal Securities0.0%
Rights0.0%
Short-Term Investments8.1%
Other Assets and Liabilities(7.1)%
  
C000016318 [Member]    
Shareholder Report [Line Items]    
Fund Name Strategic Allocation: Aggressive Fund  
Class Name R Class  
Trading Symbol AAARX  
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Strategic Allocation: Aggressive Fund for the period of August 1, 2025 to July 31, 2026.  
Shareholder Report Annual or Semi-Annual annual shareholder report  
Additional Information [Text Block] You can find additional information about the fund at americancentury.com/docs. You can also request this information by contacting us at 1-800-345-2021.  
Additional Information Phone Number 1-800-345-2021  
Additional Information Website americancentury.com/docs  
Expenses [Text Block]
What were the fund costs for the last year? (based on a hypothetical $10,000 investment)
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
R Class$1181.10%
  
Expenses Paid, Amount $ 118  
Expense Ratio, Percent 1.10%  
Factors Affecting Performance [Text Block]
What were the key factors that affected the fund’s performance?
Strategic Allocation: Aggressive Fund R Class returned 13.98% for the reporting period ended July 31, 2026.
The fund is an asset allocation fund. That is, it diversifies its assets among various classes of investments such as equity securities, bonds and money market instruments. The fund seeks the highest level of total return consistent with its asset mix. See the Fund Holdings for the portfolio’s asset weights. Below, we discuss the factors that affected these asset classes.
•
Global financial markets produced strong returns amid significant volatility related to inflation, interest rates and geopolitical trade tensions and war. Nevertheless, stocks rose because corporate earnings growth remained remarkably strong. The Federal Reserve cut interest rates three times during the period, but persistently high inflation meant that long-term bond yields actually rose.
•
The portfolio's U.S. stock holdings generally did well, with mid- and large-cap equities lagging small-cap stocks, while value stocks beat growth. This reflects uncertainty around spending on artificial intelligence (AI), which weighed most on mid- and large-cap growth stocks. Smaller and more value-oriented companies benefited from broad economic and earnings strength.
•
The portfolio's non-U.S. equity holdings generally outperformed U.S. stock holdings. That's because non-U.S. stocks benefited from attractive relative valuations as investors looked beyond the most expensive U.S. growth stocks. Emerging markets stocks also did very well, but this reflects the broadening of the AI trade beyond U.S. borders.
•
The global bond allocation produced positive total returns and diversification benefits even as some of the world's leading central banks raised rates amid elevated inflation. For example, the European Central Bank and the Bank of Japan raised rates during the period, mindful of having left rates too low for too long ahead of the 2022 inflation shock.
  
Line Graph [Table Text Block]
Cumulative Performance (based on an initial $10,000 investment)
July 31, 2016 through July 31, 2026
10
  
Average Annual Return [Table Text Block]
Average Annual Total Returns
1 Year5 Year10 Year
R Class13.98%6.55%9.35%
MSCI ACWI IMI22.27%10.40%12.02%
Bloomberg U.S. Aggregate Bond2.71%-0.40%1.35%
  
No Deduction of Taxes [Text Block] The opinions expressed are those of American Century Investments and are no guarantee of the future performance of any American Century Investments fund. This information is for educational purposes only and is not intended as investment advice. Data reflects past performance, assumes reinvestment of dividends and capital gains and is no guarantee of future results. Current performance may be higher or lower than data shown. Investment return and principal value will fluctuate and redemption value may be more or less than original cost, and none of the charts reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares.  
Updated Performance Information Location [Text Block] Visit americancentury.com for more recent performance information.  
Net Assets $ 733,691,260 $ 733,691,260
Holdings Count | holding 974 974
Advisory Fees Paid, Amount $ 3,356,230  
Investment Company, Portfolio Turnover 62.00%  
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds58.5%
Common Stocks29.9%
Corporate Bonds2.8%
U.S. Government Agency Mortgage-Backed Securities2.3%
Sovereign Governments and Agencies1.6%
U.S. Treasury Securities1.0%
Collateralized Mortgage Obligations0.7%
Convertible Preferred Securities0.6%
Asset-Backed Securities0.4%
Preferred Securities0.4%
Exchange-Traded Funds0.4%
Bank Loan Obligations0.2%
Commercial Mortgage-Backed Securities0.2%
Municipal Securities0.0%
Rights0.0%
Short-Term Investments8.1%
Other Assets and Liabilities(7.1)%
  
C000189654 [Member]    
Shareholder Report [Line Items]    
Fund Name Strategic Allocation: Aggressive Fund  
Class Name R5 Class  
Trading Symbol ASAUX  
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Strategic Allocation: Aggressive Fund for the period of August 1, 2025 to July 31, 2026.  
Shareholder Report Annual or Semi-Annual annual shareholder report  
Additional Information [Text Block] You can find additional information about the fund at americancentury.com/docs. You can also request this information by contacting us at 1-800-345-2021.  
Additional Information Phone Number 1-800-345-2021  
Additional Information Website americancentury.com/docs  
Expenses [Text Block]
What were the fund costs for the last year? (based on a hypothetical $10,000 investment)
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
R5 Class$430.40%
  
Expenses Paid, Amount $ 43  
Expense Ratio, Percent 0.40%  
Factors Affecting Performance [Text Block]
What were the key factors that affected the fund’s performance?
Strategic Allocation: Aggressive Fund R5 Class returned 14.77% for the reporting period ended July 31, 2026.
The fund is an asset allocation fund. That is, it diversifies its assets among various classes of investments such as equity securities, bonds and money market instruments. The fund seeks the highest level of total return consistent with its asset mix. See the Fund Holdings for the portfolio’s asset weights. Below, we discuss the factors that affected these asset classes.
•
Global financial markets produced strong returns amid significant volatility related to inflation, interest rates and geopolitical trade tensions and war. Nevertheless, stocks rose because corporate earnings growth remained remarkably strong. The Federal Reserve cut interest rates three times during the period, but persistently high inflation meant that long-term bond yields actually rose.
•
The portfolio's U.S. stock holdings generally did well, with mid- and large-cap equities lagging small-cap stocks, while value stocks beat growth. This reflects uncertainty around spending on artificial intelligence (AI), which weighed most on mid- and large-cap growth stocks. Smaller and more value-oriented companies benefited from broad economic and earnings strength.
•
The portfolio's non-U.S. equity holdings generally outperformed U.S. stock holdings. That's because non-U.S. stocks benefited from attractive relative valuations as investors looked beyond the most expensive U.S. growth stocks. Emerging markets stocks also did very well, but this reflects the broadening of the AI trade beyond U.S. borders.
•
The global bond allocation produced positive total returns and diversification benefits even as some of the world's leading central banks raised rates amid elevated inflation. For example, the European Central Bank and the Bank of Japan raised rates during the period, mindful of having left rates too low for too long ahead of the 2022 inflation shock.
  
Line Graph [Table Text Block]
Cumulative Performance (based on an initial $10,000 investment)
April 10, 2017 through July 31, 2026
10
  
Average Annual Return [Table Text Block]
Average Annual Total Returns
1 Year5 YearSince InceptionInception Date
R5 Class14.77%7.33%10.12%4/10/17
MSCI ACWI IMI22.27%10.40%11.93%—
Bloomberg U.S. Aggregate Bond2.71%-0.40%1.68%—
  
Performance Inception Date   Apr. 10, 2017
No Deduction of Taxes [Text Block] The opinions expressed are those of American Century Investments and are no guarantee of the future performance of any American Century Investments fund. This information is for educational purposes only and is not intended as investment advice. Data reflects past performance, assumes reinvestment of dividends and capital gains and is no guarantee of future results. Current performance may be higher or lower than data shown. Investment return and principal value will fluctuate and redemption value may be more or less than original cost, and none of the charts reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares.  
Updated Performance Information Location [Text Block] Visit americancentury.com for more recent performance information.  
Net Assets $ 733,691,260 $ 733,691,260
Holdings Count | holding 974 974
Advisory Fees Paid, Amount $ 3,356,230  
Investment Company, Portfolio Turnover 62.00%  
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds58.5%
Common Stocks29.9%
Corporate Bonds2.8%
U.S. Government Agency Mortgage-Backed Securities2.3%
Sovereign Governments and Agencies1.6%
U.S. Treasury Securities1.0%
Collateralized Mortgage Obligations0.7%
Convertible Preferred Securities0.6%
Asset-Backed Securities0.4%
Preferred Securities0.4%
Exchange-Traded Funds0.4%
Bank Loan Obligations0.2%
Commercial Mortgage-Backed Securities0.2%
Municipal Securities0.0%
Rights0.0%
Short-Term Investments8.1%
Other Assets and Liabilities(7.1)%
  
C000131619 [Member]    
Shareholder Report [Line Items]    
Fund Name Strategic Allocation: Aggressive Fund  
Class Name R6 Class  
Trading Symbol AAAUX  
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Strategic Allocation: Aggressive Fund for the period of August 1, 2025 to July 31, 2026.  
Shareholder Report Annual or Semi-Annual annual shareholder report  
Additional Information [Text Block] You can find additional information about the fund at americancentury.com/docs. You can also request this information by contacting us at 1-800-345-2021.  
Additional Information Phone Number 1-800-345-2021  
Additional Information Website americancentury.com/docs  
Expenses [Text Block]
What were the fund costs for the last year? (based on a hypothetical $10,000 investment)
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
R6 Class$270.25%
  
Expenses Paid, Amount $ 27  
Expense Ratio, Percent 0.25%  
Factors Affecting Performance [Text Block]
What were the key factors that affected the fund’s performance?
Strategic Allocation: Aggressive Fund R6 Class returned 15.04% for the reporting period ended July 31, 2026.
The fund is an asset allocation fund. That is, it diversifies its assets among various classes of investments such as equity securities, bonds and money market instruments. The fund seeks the highest level of total return consistent with its asset mix. See the Fund Holdings for the portfolio’s asset weights. Below, we discuss the factors that affected these asset classes.
•
Global financial markets produced strong returns amid significant volatility related to inflation, interest rates and geopolitical trade tensions and war. Nevertheless, stocks rose because corporate earnings growth remained remarkably strong. The Federal Reserve cut interest rates three times during the period, but persistently high inflation meant that long-term bond yields actually rose.
•
The portfolio's U.S. stock holdings generally did well, with mid- and large-cap equities lagging small-cap stocks, while value stocks beat growth. This reflects uncertainty around spending on artificial intelligence (AI), which weighed most on mid- and large-cap growth stocks. Smaller and more value-oriented companies benefited from broad economic and earnings strength.
•
The portfolio's non-U.S. equity holdings generally outperformed U.S. stock holdings. That's because non-U.S. stocks benefited from attractive relative valuations as investors looked beyond the most expensive U.S. growth stocks. Emerging markets stocks also did very well, but this reflects the broadening of the AI trade beyond U.S. borders.
•
The global bond allocation produced positive total returns and diversification benefits even as some of the world's leading central banks raised rates amid elevated inflation. For example, the European Central Bank and the Bank of Japan raised rates during the period, mindful of having left rates too low for too long ahead of the 2022 inflation shock.
  
Line Graph [Table Text Block]
Cumulative Performance (based on an initial $10,000 investment)
July 31, 2016 through July 31, 2026
10
  
Average Annual Return [Table Text Block]
Average Annual Total Returns
1 Year5 Year10 Year
R6 Class15.04%7.48%10.29%
MSCI ACWI IMI22.27%10.40%12.02%
Bloomberg U.S. Aggregate Bond2.71%-0.40%1.35%
  
No Deduction of Taxes [Text Block] The opinions expressed are those of American Century Investments and are no guarantee of the future performance of any American Century Investments fund. This information is for educational purposes only and is not intended as investment advice. Data reflects past performance, assumes reinvestment of dividends and capital gains and is no guarantee of future results. Current performance may be higher or lower than data shown. Investment return and principal value will fluctuate and redemption value may be more or less than original cost, and none of the charts reflect the deduction of taxes that a shareholder would pay on fund distributions or the redemption of fund shares.  
Updated Performance Information Location [Text Block] Visit americancentury.com for more recent performance information.  
Net Assets $ 733,691,260 $ 733,691,260
Holdings Count | holding 974 974
Advisory Fees Paid, Amount $ 3,356,230  
Investment Company, Portfolio Turnover 62.00%  
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds58.5%
Common Stocks29.9%
Corporate Bonds2.8%
U.S. Government Agency Mortgage-Backed Securities2.3%
Sovereign Governments and Agencies1.6%
U.S. Treasury Securities1.0%
Collateralized Mortgage Obligations0.7%
Convertible Preferred Securities0.6%
Asset-Backed Securities0.4%
Preferred Securities0.4%
Exchange-Traded Funds0.4%
Bank Loan Obligations0.2%
Commercial Mortgage-Backed Securities0.2%
Municipal Securities0.0%
Rights0.0%
Short-Term Investments8.1%
Other Assets and Liabilities(7.1)%