Label	Element	Value
Prospectus:	rr_ProspectusTable
Document Type	dei_DocumentType	497
Document Period End Date	dei_DocumentPeriodEndDate	Jul. 31, 2018
Entity Registrant Name	dei_EntityRegistrantName	AMERICAN CENTURY GROWTH FUNDS, INC.
Central Index Key	dei_EntityCentralIndexKey	0001353176
Amendment Flag	dei_AmendmentFlag	false
Document Creation Date	dei_DocumentCreationDate	Jul. 31, 2018
Document Effective Date	dei_DocumentEffectiveDate	Dec. 01, 2017
Prospectus Date	rr_ProspectusDate	Dec. 01, 2017
American Century Growth Funds | LEGACY FOCUSED LARGE CAP FUND
Prospectus:	rr_ProspectusTable
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
American Century Growth Funds | LEGACY FOCUSED LARGE CAP FUND | INVESTOR CLASS
Prospectus:	rr_ProspectusTable
Management Fees (as a percentage of Assets)	rr_ManagementFeesOverAssets	1.02%	[1]
Distribution and Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses (as a percentage of Assets):	rr_OtherExpensesOverAssets	none
Expenses (as a percentage of Assets)	rr_ExpensesOverAssets	1.02%
Expense Example, with Redemption, 1 Year	rr_ExpenseExampleYear01	$ 104
Expense Example, with Redemption, 3 Years	rr_ExpenseExampleYear03	325
Expense Example, with Redemption, 5 Years	rr_ExpenseExampleYear05	564
Expense Example, with Redemption, 10 Years	rr_ExpenseExampleYear10	$ 1,248
American Century Growth Funds | LEGACY FOCUSED LARGE CAP FUND | I CLASS
Prospectus:	rr_ProspectusTable
Management Fees (as a percentage of Assets)	rr_ManagementFeesOverAssets	0.82%	[1]
Distribution and Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses (as a percentage of Assets):	rr_OtherExpensesOverAssets	none
Expenses (as a percentage of Assets)	rr_ExpensesOverAssets	0.82%
Expense Example, with Redemption, 1 Year	rr_ExpenseExampleYear01	$ 84
Expense Example, with Redemption, 3 Years	rr_ExpenseExampleYear03	262
Expense Example, with Redemption, 5 Years	rr_ExpenseExampleYear05	456
Expense Example, with Redemption, 10 Years	rr_ExpenseExampleYear10	$ 1,014
American Century Growth Funds | LEGACY FOCUSED LARGE CAP FUND | ADVISOR CLASS
Prospectus:	rr_ProspectusTable
Management Fees (as a percentage of Assets)	rr_ManagementFeesOverAssets	1.02%	[1]
Distribution and Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other Expenses (as a percentage of Assets):	rr_OtherExpensesOverAssets	none
Expenses (as a percentage of Assets)	rr_ExpensesOverAssets	1.27%
Expense Example, with Redemption, 1 Year	rr_ExpenseExampleYear01	$ 130
Expense Example, with Redemption, 3 Years	rr_ExpenseExampleYear03	403
Expense Example, with Redemption, 5 Years	rr_ExpenseExampleYear05	698
Expense Example, with Redemption, 10 Years	rr_ExpenseExampleYear10	$ 1,533
American Century Growth Funds | LEGACY FOCUSED LARGE CAP FUND | R CLASS
Prospectus:	rr_ProspectusTable
Management Fees (as a percentage of Assets)	rr_ManagementFeesOverAssets	1.02%	[1]
Distribution and Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	0.50%
Other Expenses (as a percentage of Assets):	rr_OtherExpensesOverAssets	none
Expenses (as a percentage of Assets)	rr_ExpensesOverAssets	1.52%
Expense Example, with Redemption, 1 Year	rr_ExpenseExampleYear01	$ 155
Expense Example, with Redemption, 3 Years	rr_ExpenseExampleYear03	481
Expense Example, with Redemption, 5 Years	rr_ExpenseExampleYear05	830
Expense Example, with Redemption, 10 Years	rr_ExpenseExampleYear10	$ 1,811
American Century Growth Funds | LEGACY FOCUSED LARGE CAP FUND | R6 Class
Prospectus:	rr_ProspectusTable
Management Fees (as a percentage of Assets)	rr_ManagementFeesOverAssets	0.67%	[1]
Distribution and Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses (as a percentage of Assets):	rr_OtherExpensesOverAssets	none
Expenses (as a percentage of Assets)	rr_ExpensesOverAssets	0.67%
Expense Example, with Redemption, 1 Year	rr_ExpenseExampleYear01	$ 69
Expense Example, with Redemption, 3 Years	rr_ExpenseExampleYear03	215
Expense Example, with Redemption, 5 Years	rr_ExpenseExampleYear05	374
Expense Example, with Redemption, 10 Years	rr_ExpenseExampleYear10	$ 835

[1] The management fee has been restated to reflect the decrease in the management fee schedule effective August 1, 2018.