v3.26.1
Shareholder Report
 6 Months Ended
Jan. 31, 2026
USD ($)
holding
Shareholder Report [Line Items]  
Document Type N-CSRS
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 Jan. 31, 2026
Shareholder Report Annual or Semi-Annual Semi-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 semi-annual shareholder report contains important information about Strategic Allocation: Conservative Fund for the period of August 1, 2025 to January 31, 2026.
Shareholder Report Annual or Semi-Annual semi-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 six months? (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$360.70%
Expenses Paid, Amount $ 36
Expense Ratio, Percent 0.70%
Net Assets $ 285,200,120
Holdings Count | holding 986
Advisory Fees Paid, Amount $ 852,295
Investment Company, Portfolio Turnover 41.00%
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds41.7%
Common Stocks18.2%
U.S. Treasury Securities13.5%
Corporate Bonds5.4%
U.S. Government Agency Mortgage-Backed Securities5.4%
Sovereign Governments and Agencies4.3%
Collateralized Mortgage Obligations2.6%
Asset-Backed Securities1.1%
Commercial Mortgage-Backed Securities0.7%
Municipal Securities0.4%
Exchange-Traded Funds0.1%
Preferred Securities0.0%
Rights0.0%
Short-Term Investments7.8%
Other Assets and Liabilities(1.2)%
 
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 semi-annual shareholder report contains important information about Strategic Allocation: Conservative Fund for the period of August 1, 2025 to January 31, 2026.
Shareholder Report Annual or Semi-Annual semi-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 six months? (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$260.50%
Expenses Paid, Amount $ 26
Expense Ratio, Percent 0.50%
Net Assets $ 285,200,120
Holdings Count | holding 986
Advisory Fees Paid, Amount $ 852,295
Investment Company, Portfolio Turnover 41.00%
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds41.7%
Common Stocks18.2%
U.S. Treasury Securities13.5%
Corporate Bonds5.4%
U.S. Government Agency Mortgage-Backed Securities5.4%
Sovereign Governments and Agencies4.3%
Collateralized Mortgage Obligations2.6%
Asset-Backed Securities1.1%
Commercial Mortgage-Backed Securities0.7%
Municipal Securities0.4%
Exchange-Traded Funds0.1%
Preferred Securities0.0%
Rights0.0%
Short-Term Investments7.8%
Other Assets and Liabilities(1.2)%
 
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 semi-annual shareholder report contains important information about Strategic Allocation: Conservative Fund for the period of August 1, 2025 to January 31, 2026.
Shareholder Report Annual or Semi-Annual semi-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 six months? (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$490.95%
Expenses Paid, Amount $ 49
Expense Ratio, Percent 0.95%
Net Assets $ 285,200,120
Holdings Count | holding 986
Advisory Fees Paid, Amount $ 852,295
Investment Company, Portfolio Turnover 41.00%
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds41.7%
Common Stocks18.2%
U.S. Treasury Securities13.5%
Corporate Bonds5.4%
U.S. Government Agency Mortgage-Backed Securities5.4%
Sovereign Governments and Agencies4.3%
Collateralized Mortgage Obligations2.6%
Asset-Backed Securities1.1%
Commercial Mortgage-Backed Securities0.7%
Municipal Securities0.4%
Exchange-Traded Funds0.1%
Preferred Securities0.0%
Rights0.0%
Short-Term Investments7.8%
Other Assets and Liabilities(1.2)%
 
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 semi-annual shareholder report contains important information about Strategic Allocation: Conservative Fund for the period of August 1, 2025 to January 31, 2026.
Shareholder Report Annual or Semi-Annual semi-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 six months? (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$881.70%
Expenses Paid, Amount $ 88
Expense Ratio, Percent 1.70%
Net Assets $ 285,200,120
Holdings Count | holding 986
Advisory Fees Paid, Amount $ 852,295
Investment Company, Portfolio Turnover 41.00%
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds41.7%
Common Stocks18.2%
U.S. Treasury Securities13.5%
Corporate Bonds5.4%
U.S. Government Agency Mortgage-Backed Securities5.4%
Sovereign Governments and Agencies4.3%
Collateralized Mortgage Obligations2.6%
Asset-Backed Securities1.1%
Commercial Mortgage-Backed Securities0.7%
Municipal Securities0.4%
Exchange-Traded Funds0.1%
Preferred Securities0.0%
Rights0.0%
Short-Term Investments7.8%
Other Assets and Liabilities(1.2)%
 
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 semi-annual shareholder report contains important information about Strategic Allocation: Conservative Fund for the period of August 1, 2025 to January 31, 2026.
Shareholder Report Annual or Semi-Annual semi-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 six months? (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$621.20%
Expenses Paid, Amount $ 62
Expense Ratio, Percent 1.20%
Net Assets $ 285,200,120
Holdings Count | holding 986
Advisory Fees Paid, Amount $ 852,295
Investment Company, Portfolio Turnover 41.00%
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds41.7%
Common Stocks18.2%
U.S. Treasury Securities13.5%
Corporate Bonds5.4%
U.S. Government Agency Mortgage-Backed Securities5.4%
Sovereign Governments and Agencies4.3%
Collateralized Mortgage Obligations2.6%
Asset-Backed Securities1.1%
Commercial Mortgage-Backed Securities0.7%
Municipal Securities0.4%
Exchange-Traded Funds0.1%
Preferred Securities0.0%
Rights0.0%
Short-Term Investments7.8%
Other Assets and Liabilities(1.2)%
 
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 semi-annual shareholder report contains important information about Strategic Allocation: Conservative Fund for the period of August 1, 2025 to January 31, 2026.
Shareholder Report Annual or Semi-Annual semi-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 six months? (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$260.50%
Expenses Paid, Amount $ 26
Expense Ratio, Percent 0.50%
Net Assets $ 285,200,120
Holdings Count | holding 986
Advisory Fees Paid, Amount $ 852,295
Investment Company, Portfolio Turnover 41.00%
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds41.7%
Common Stocks18.2%
U.S. Treasury Securities13.5%
Corporate Bonds5.4%
U.S. Government Agency Mortgage-Backed Securities5.4%
Sovereign Governments and Agencies4.3%
Collateralized Mortgage Obligations2.6%
Asset-Backed Securities1.1%
Commercial Mortgage-Backed Securities0.7%
Municipal Securities0.4%
Exchange-Traded Funds0.1%
Preferred Securities0.0%
Rights0.0%
Short-Term Investments7.8%
Other Assets and Liabilities(1.2)%
 
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 semi-annual shareholder report contains important information about Strategic Allocation: Conservative Fund for the period of August 1, 2025 to January 31, 2026.
Shareholder Report Annual or Semi-Annual semi-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 six months? (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$180.35%
Expenses Paid, Amount $ 18
Expense Ratio, Percent 0.35%
Net Assets $ 285,200,120
Holdings Count | holding 986
Advisory Fees Paid, Amount $ 852,295
Investment Company, Portfolio Turnover 41.00%
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds41.7%
Common Stocks18.2%
U.S. Treasury Securities13.5%
Corporate Bonds5.4%
U.S. Government Agency Mortgage-Backed Securities5.4%
Sovereign Governments and Agencies4.3%
Collateralized Mortgage Obligations2.6%
Asset-Backed Securities1.1%
Commercial Mortgage-Backed Securities0.7%
Municipal Securities0.4%
Exchange-Traded Funds0.1%
Preferred Securities0.0%
Rights0.0%
Short-Term Investments7.8%
Other Assets and Liabilities(1.2)%
 
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 semi-annual shareholder report contains important information about Strategic Allocation: Moderate Fund for the period of August 1, 2025 to January 31, 2026.
Shareholder Report Annual or Semi-Annual semi-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 six months? (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$350.67%
Expenses Paid, Amount $ 35
Expense Ratio, Percent 0.67%
Net Assets $ 777,601,702
Holdings Count | holding 997
Advisory Fees Paid, Amount $ 2,217,191
Investment Company, Portfolio Turnover 36.00%
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds50.1%
Common Stocks24.5%
U.S. Treasury Securities8.0%
U.S. Government Agency Mortgage-Backed Securities3.3%
Sovereign Governments and Agencies3.2%
Corporate Bonds3.2%
Collateralized Mortgage Obligations1.7%
Asset-Backed Securities0.7%
Commercial Mortgage-Backed Securities0.4%
Municipal Securities0.3%
Exchange-Traded Funds0.1%
Preferred Securities0.0%
Rights0.0%
Short-Term Investments6.6%
Other Assets and Liabilities(2.1)%
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 semi-annual shareholder report contains important information about Strategic Allocation: Moderate Fund for the period of August 1, 2025 to January 31, 2026.
Shareholder Report Annual or Semi-Annual semi-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 six months? (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$250.47%
Expenses Paid, Amount $ 25
Expense Ratio, Percent 0.47%
Net Assets $ 777,601,702
Holdings Count | holding 997
Advisory Fees Paid, Amount $ 2,217,191
Investment Company, Portfolio Turnover 36.00%
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds50.1%
Common Stocks24.5%
U.S. Treasury Securities8.0%
U.S. Government Agency Mortgage-Backed Securities3.3%
Sovereign Governments and Agencies3.2%
Corporate Bonds3.2%
Collateralized Mortgage Obligations1.7%
Asset-Backed Securities0.7%
Commercial Mortgage-Backed Securities0.4%
Municipal Securities0.3%
Exchange-Traded Funds0.1%
Preferred Securities0.0%
Rights0.0%
Short-Term Investments6.6%
Other Assets and Liabilities(2.1)%
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 semi-annual shareholder report contains important information about Strategic Allocation: Moderate Fund for the period of August 1, 2025 to January 31, 2026.
Shareholder Report Annual or Semi-Annual semi-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 six months? (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$480.92%
Expenses Paid, Amount $ 48
Expense Ratio, Percent 0.92%
Net Assets $ 777,601,702
Holdings Count | holding 997
Advisory Fees Paid, Amount $ 2,217,191
Investment Company, Portfolio Turnover 36.00%
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds50.1%
Common Stocks24.5%
U.S. Treasury Securities8.0%
U.S. Government Agency Mortgage-Backed Securities3.3%
Sovereign Governments and Agencies3.2%
Corporate Bonds3.2%
Collateralized Mortgage Obligations1.7%
Asset-Backed Securities0.7%
Commercial Mortgage-Backed Securities0.4%
Municipal Securities0.3%
Exchange-Traded Funds0.1%
Preferred Securities0.0%
Rights0.0%
Short-Term Investments6.6%
Other Assets and Liabilities(2.1)%
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 semi-annual shareholder report contains important information about Strategic Allocation: Moderate Fund for the period of August 1, 2025 to January 31, 2026.
Shareholder Report Annual or Semi-Annual semi-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 six months? (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$871.67%
Expenses Paid, Amount $ 87
Expense Ratio, Percent 1.67%
Net Assets $ 777,601,702
Holdings Count | holding 997
Advisory Fees Paid, Amount $ 2,217,191
Investment Company, Portfolio Turnover 36.00%
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds50.1%
Common Stocks24.5%
U.S. Treasury Securities8.0%
U.S. Government Agency Mortgage-Backed Securities3.3%
Sovereign Governments and Agencies3.2%
Corporate Bonds3.2%
Collateralized Mortgage Obligations1.7%
Asset-Backed Securities0.7%
Commercial Mortgage-Backed Securities0.4%
Municipal Securities0.3%
Exchange-Traded Funds0.1%
Preferred Securities0.0%
Rights0.0%
Short-Term Investments6.6%
Other Assets and Liabilities(2.1)%
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 semi-annual shareholder report contains important information about Strategic Allocation: Moderate Fund for the period of August 1, 2025 to January 31, 2026.
Shareholder Report Annual or Semi-Annual semi-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 six months? (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$611.17%
Expenses Paid, Amount $ 61
Expense Ratio, Percent 1.17%
Net Assets $ 777,601,702
Holdings Count | holding 997
Advisory Fees Paid, Amount $ 2,217,191
Investment Company, Portfolio Turnover 36.00%
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds50.1%
Common Stocks24.5%
U.S. Treasury Securities8.0%
U.S. Government Agency Mortgage-Backed Securities3.3%
Sovereign Governments and Agencies3.2%
Corporate Bonds3.2%
Collateralized Mortgage Obligations1.7%
Asset-Backed Securities0.7%
Commercial Mortgage-Backed Securities0.4%
Municipal Securities0.3%
Exchange-Traded Funds0.1%
Preferred Securities0.0%
Rights0.0%
Short-Term Investments6.6%
Other Assets and Liabilities(2.1)%
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 semi-annual shareholder report contains important information about Strategic Allocation: Moderate Fund for the period of August 1, 2025 to January 31, 2026.
Shareholder Report Annual or Semi-Annual semi-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 six months? (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$250.47%
Expenses Paid, Amount $ 25
Expense Ratio, Percent 0.47%
Net Assets $ 777,601,702
Holdings Count | holding 997
Advisory Fees Paid, Amount $ 2,217,191
Investment Company, Portfolio Turnover 36.00%
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds50.1%
Common Stocks24.5%
U.S. Treasury Securities8.0%
U.S. Government Agency Mortgage-Backed Securities3.3%
Sovereign Governments and Agencies3.2%
Corporate Bonds3.2%
Collateralized Mortgage Obligations1.7%
Asset-Backed Securities0.7%
Commercial Mortgage-Backed Securities0.4%
Municipal Securities0.3%
Exchange-Traded Funds0.1%
Preferred Securities0.0%
Rights0.0%
Short-Term Investments6.6%
Other Assets and Liabilities(2.1)%
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 semi-annual shareholder report contains important information about Strategic Allocation: Moderate Fund for the period of August 1, 2025 to January 31, 2026.
Shareholder Report Annual or Semi-Annual semi-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 six months? (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$170.32%
Expenses Paid, Amount $ 17
Expense Ratio, Percent 0.32%
Net Assets $ 777,601,702
Holdings Count | holding 997
Advisory Fees Paid, Amount $ 2,217,191
Investment Company, Portfolio Turnover 36.00%
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds50.1%
Common Stocks24.5%
U.S. Treasury Securities8.0%
U.S. Government Agency Mortgage-Backed Securities3.3%
Sovereign Governments and Agencies3.2%
Corporate Bonds3.2%
Collateralized Mortgage Obligations1.7%
Asset-Backed Securities0.7%
Commercial Mortgage-Backed Securities0.4%
Municipal Securities0.3%
Exchange-Traded Funds0.1%
Preferred Securities0.0%
Rights0.0%
Short-Term Investments6.6%
Other Assets and Liabilities(2.1)%
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 semi-annual shareholder report contains important information about Strategic Allocation: Aggressive Fund for the period of August 1, 2025 to January 31, 2026.
Shareholder Report Annual or Semi-Annual semi-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 six months? (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$320.61%
Expenses Paid, Amount $ 32
Expense Ratio, Percent 0.61%
Net Assets $ 732,191,215
Holdings Count | holding 902
Advisory Fees Paid, Amount $ 1,719,739
Investment Company, Portfolio Turnover 32.00%
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds58.2%
Common Stocks30.2%
Corporate Bonds2.4%
U.S. Government Agency Mortgage-Backed Securities2.0%
U.S. Treasury Securities2.0%
Sovereign Governments and Agencies1.3%
Collateralized Mortgage Obligations1.0%
Convertible Preferred Securities0.6%
Asset-Backed Securities0.4%
Commercial Mortgage-Backed Securities0.3%
Exchange-Traded Funds0.2%
Preferred Securities0.0%
Municipal Securities0.0%
Rights0.0%
Short-Term Investments7.7%
Other Assets and Liabilities(6.3)%
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 semi-annual shareholder report contains important information about Strategic Allocation: Aggressive Fund for the period of August 1, 2025 to January 31, 2026.
Shareholder Report Annual or Semi-Annual semi-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 six months? (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$220.41%
Expenses Paid, Amount $ 22
Expense Ratio, Percent 0.41%
Net Assets $ 732,191,215
Holdings Count | holding 902
Advisory Fees Paid, Amount $ 1,719,739
Investment Company, Portfolio Turnover 32.00%
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds58.2%
Common Stocks30.2%
Corporate Bonds2.4%
U.S. Government Agency Mortgage-Backed Securities2.0%
U.S. Treasury Securities2.0%
Sovereign Governments and Agencies1.3%
Collateralized Mortgage Obligations1.0%
Convertible Preferred Securities0.6%
Asset-Backed Securities0.4%
Commercial Mortgage-Backed Securities0.3%
Exchange-Traded Funds0.2%
Preferred Securities0.0%
Municipal Securities0.0%
Rights0.0%
Short-Term Investments7.7%
Other Assets and Liabilities(6.3)%
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 semi-annual shareholder report contains important information about Strategic Allocation: Aggressive Fund for the period of August 1, 2025 to January 31, 2026.
Shareholder Report Annual or Semi-Annual semi-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 six months? (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$450.86%
Expenses Paid, Amount $ 45
Expense Ratio, Percent 0.86%
Net Assets $ 732,191,215
Holdings Count | holding 902
Advisory Fees Paid, Amount $ 1,719,739
Investment Company, Portfolio Turnover 32.00%
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds58.2%
Common Stocks30.2%
Corporate Bonds2.4%
U.S. Government Agency Mortgage-Backed Securities2.0%
U.S. Treasury Securities2.0%
Sovereign Governments and Agencies1.3%
Collateralized Mortgage Obligations1.0%
Convertible Preferred Securities0.6%
Asset-Backed Securities0.4%
Commercial Mortgage-Backed Securities0.3%
Exchange-Traded Funds0.2%
Preferred Securities0.0%
Municipal Securities0.0%
Rights0.0%
Short-Term Investments7.7%
Other Assets and Liabilities(6.3)%
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 semi-annual shareholder report contains important information about Strategic Allocation: Aggressive Fund for the period of August 1, 2025 to January 31, 2026.
Shareholder Report Annual or Semi-Annual semi-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 six months? (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$851.61%
Expenses Paid, Amount $ 85
Expense Ratio, Percent 1.61%
Net Assets $ 732,191,215
Holdings Count | holding 902
Advisory Fees Paid, Amount $ 1,719,739
Investment Company, Portfolio Turnover 32.00%
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds58.2%
Common Stocks30.2%
Corporate Bonds2.4%
U.S. Government Agency Mortgage-Backed Securities2.0%
U.S. Treasury Securities2.0%
Sovereign Governments and Agencies1.3%
Collateralized Mortgage Obligations1.0%
Convertible Preferred Securities0.6%
Asset-Backed Securities0.4%
Commercial Mortgage-Backed Securities0.3%
Exchange-Traded Funds0.2%
Preferred Securities0.0%
Municipal Securities0.0%
Rights0.0%
Short-Term Investments7.7%
Other Assets and Liabilities(6.3)%
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 semi-annual shareholder report contains important information about Strategic Allocation: Aggressive Fund for the period of August 1, 2025 to January 31, 2026.
Shareholder Report Annual or Semi-Annual semi-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 six months? (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$591.11%
Expenses Paid, Amount $ 59
Expense Ratio, Percent 1.11%
Net Assets $ 732,191,215
Holdings Count | holding 902
Advisory Fees Paid, Amount $ 1,719,739
Investment Company, Portfolio Turnover 32.00%
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds58.2%
Common Stocks30.2%
Corporate Bonds2.4%
U.S. Government Agency Mortgage-Backed Securities2.0%
U.S. Treasury Securities2.0%
Sovereign Governments and Agencies1.3%
Collateralized Mortgage Obligations1.0%
Convertible Preferred Securities0.6%
Asset-Backed Securities0.4%
Commercial Mortgage-Backed Securities0.3%
Exchange-Traded Funds0.2%
Preferred Securities0.0%
Municipal Securities0.0%
Rights0.0%
Short-Term Investments7.7%
Other Assets and Liabilities(6.3)%
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 semi-annual shareholder report contains important information about Strategic Allocation: Aggressive Fund for the period of August 1, 2025 to January 31, 2026.
Shareholder Report Annual or Semi-Annual semi-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 six months? (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$220.41%
Expenses Paid, Amount $ 22
Expense Ratio, Percent 0.41%
Net Assets $ 732,191,215
Holdings Count | holding 902
Advisory Fees Paid, Amount $ 1,719,739
Investment Company, Portfolio Turnover 32.00%
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds58.2%
Common Stocks30.2%
Corporate Bonds2.4%
U.S. Government Agency Mortgage-Backed Securities2.0%
U.S. Treasury Securities2.0%
Sovereign Governments and Agencies1.3%
Collateralized Mortgage Obligations1.0%
Convertible Preferred Securities0.6%
Asset-Backed Securities0.4%
Commercial Mortgage-Backed Securities0.3%
Exchange-Traded Funds0.2%
Preferred Securities0.0%
Municipal Securities0.0%
Rights0.0%
Short-Term Investments7.7%
Other Assets and Liabilities(6.3)%
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 semi-annual shareholder report contains important information about Strategic Allocation: Aggressive Fund for the period of August 1, 2025 to January 31, 2026.
Shareholder Report Annual or Semi-Annual semi-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 six months? (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$140.26%
Expenses Paid, Amount $ 14
Expense Ratio, Percent 0.26%
Net Assets $ 732,191,215
Holdings Count | holding 902
Advisory Fees Paid, Amount $ 1,719,739
Investment Company, Portfolio Turnover 32.00%
Holdings [Text Block]
Fund Holdings
Types of Investments in Portfolio (as a % of net assets)
Affiliated Funds58.2%
Common Stocks30.2%
Corporate Bonds2.4%
U.S. Government Agency Mortgage-Backed Securities2.0%
U.S. Treasury Securities2.0%
Sovereign Governments and Agencies1.3%
Collateralized Mortgage Obligations1.0%
Convertible Preferred Securities0.6%
Asset-Backed Securities0.4%
Commercial Mortgage-Backed Securities0.3%
Exchange-Traded Funds0.2%
Preferred Securities0.0%
Municipal Securities0.0%
Rights0.0%
Short-Term Investments7.7%
Other Assets and Liabilities(6.3)%