Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	AB CAP FUND, INC.
Prospectus Date	rr_ProspectusDate	Nov. 12, 2014
AB Global Core Equity Portfolio
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	AB GLOBAL CORE EQUITY PORTFOLIO
Objective [Heading]	rr_ObjectiveHeading	INVESTMENT OBJECTIVE
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Fund's investment objective is to seek long-term growth of capital.
Expense [Heading]	rr_ExpenseHeading	FEES AND EXPENSES OF THE FUND
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for sales charge reductions if you and members of your family invest, or agree to invest in the future, at least $100,000 in AB Mutual Funds. More information about these and other discounts is available from your financial intermediary and in Investing in the Fund--Sales Charge Reduction Programs for Class A Shares on page 16 of this Prospectus and in Purchase of Shares--Sales Charge Reduction Programs on page 66 of the Fund's Statement of Additional Information ("SAI").
Shareholder Fees Caption [Text]	rr_ShareholderFeesCaption	SHAREHOLDER FEES (fees paid directly from your investment)
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	November 12, 2015
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	PORTFOLIO TURNOVER
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The Fund pays transaction costs, such as commissions, when it buys or sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These transaction costs, which are not reflected in the Annual Fund Operating Expenses or in the Examples, affect the Fund's performance.
Expenses Deferred Charges [Text Block]	rr_ExpensesDeferredChargesTextBlock	Purchases of Class A shares in amounts of $1,000,000 or more, or by certain group retirement plans, may be subject to a 1%, 1-year contingent deferred sales charge ("CDSC"), which may be subject to waiver in certain circumstances. For Class C shares, the CDSC is 0% after the first year.
Expense Breakpoint Discounts [Text]	rr_ExpenseBreakpointDiscounts	You may qualify for sales charge reductions if you and members of your family invest, or agree to invest in the future, at least $100,000 in AB Mutual Funds.
Expense Breakpoint, Minimum Investment Required [Amount]	rr_ExpenseBreakpointMinimumInvestmentRequiredAmount	100,000
Other Expenses, New Fund, Based on Estimates [Text]	rr_OtherExpensesNewFundBasedOnEstimates	Total other expenses are based on estimated amounts for the current fiscal year.
Expense Example [Heading]	rr_ExpenseExampleHeading	EXAMPLES
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	The Examples are intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Examples assume that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Examples also assume that your investment has a 5% return each year, that the Fund's operating expenses stay the same and that the fee waiver and/or expense limitation is in effect for only the first year. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Expense Example, No Redemption, By Year, Caption [Text]	rr_ExpenseExampleNoRedemptionByYearCaption	For the share class listed below, you would pay the following expenses if you did not redeem your shares at the end of the period:
Strategy [Heading]	rr_StrategyHeading	PRINCIPAL STRATEGIES
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The Fund invests primarily in a portfolio of equity securities of issuers from markets around the world. Under normal circumstances, the Fund invests at least 80% of its net assets in equity securities, at least 40% of its net assets in securities of non-U.S. companies, and invests in companies in at least three countries (including the United States). The Fund is principally comprised of companies considered by the Adviser to offer good prospects for attractive returns relative to the general stock market. The Adviser will seek companies that are attractively valued and have the ability to generate high and sustainable returns on invested capital. In addition to returns on invested capital, other criteria that the Adviser will consider include strong business fundamentals, capable management, prudent corporate governance, strong balance sheet, strong earnings power, high earnings quality, low downside risk, and substantial upside potential. In managing the Fund, the Adviser will not seek to have a bias towards any investment style, economic sector, country or company size. The Fund's holdings of non-U.S. companies will frequently include companies located in emerging markets, and at times emerging market companies will make up a significant portion of the Fund. Fluctuations in currency exchange rates can have a dramatic impact of the returns of equity securities. While the Adviser may hedge the foreign currency exposure resulting from the Fund's security positions through the use of currency-related derivatives, it is not required to do so.
Risk [Heading]	rr_RiskHeading	PRINCIPAL RISKS
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	MARKET RISK: The value of the Fund's assets will fluctuate as the stock or bond market fluctuates. The value of its investments may decline, sometimes rapidly and unpredictably, simply because of economic changes or other events that affect large portions of the market. FOREIGN (NON-U.S.) RISK: Investments in securities of non-U.S. issuers may involve more risk than those of U.S. issuers. These securities may fluctuate more widely in price and may be less liquid due to adverse market, economic, political, regulatory or other factors. These risks may be heightened with respect to investments in emerging-market countries, where there may be an increased amount of economic, political and social instability. EMERGING MARKET RISK: Investments in emerging market countries may have more risk because the markets are less developed and less liquid as well as being subject to increased economic, political, regulatory or other uncertainties. CURRENCY RISK: Fluctuations in currency exchange rates may negatively affect the value of the Fund's investments or reduce its returns. DIVERSIFICATION RISK: The Fund may have more risk because it is "non-diversified", meaning that it can invest more of its assets in a smaller number of issuers. Accordingly, changes in the value of a single security may have a more significant effect, either negative or positive, on the Fund's net asset value, or NAV. MANAGEMENT RISK: The Fund is subject to management risk because it is an actively-managed investment fund. The Adviser will apply its investment techniques and risk analyses in making investment decisions for the Fund, but there is no guarantee that its techniques will produce the intended results. As with all investments, you may lose money by investing in the Fund.
Risk Lose Money [Text]	rr_RiskLoseMoney	As with all investments, you may lose money by investing in the Fund.
Risk Nondiversified Status [Text]	rr_RiskNondiversifiedStatus	DIVERSIFICATION RISK: The Fund may have more risk because it is "non-diversified", meaning that it can invest more of its assets in a smaller number of issuers. Accordingly, changes in the value of a single security may have a more significant effect, either negative or positive, on the Fund's net asset value, or NAV.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	BAR CHART AND PERFORMANCE INFORMATION
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	No performance information is available for the Fund because it has not yet been in operation for a full calendar year.
Performance One Year or Less [Text]	rr_PerformanceOneYearOrLess	No performance information is available for the Fund because it has not yet been in operation for a full calendar year.
AB Global Core Equity Portfolio | CLASS A
Risk/Return:	rr_RiskReturnAbstract
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	4.25%
Maximum Deferred Sales Charge (Load) (as a percentage of offering price or redemption proceeds, whichever is lower)	rr_MaximumDeferredSalesChargeOverOther	none	[1]
Exchange Fee	rr_ExchangeFeeOverRedemption	none
Management Fees	rr_ManagementFeesOverAssets	0.75%
Distribution and/or Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other Expenses: Transfer Agent	rr_Component1OtherExpensesOverAssets	0.08%
Other Expenses	rr_Component2OtherExpensesOverAssets	0.31%
Total Other Expenses	rr_OtherExpensesOverAssets	0.39%	[2]
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	1.39%
Fee Waiver and/or Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.24%)	[3]
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement	rr_NetExpensesOverAssets	1.15%
After 1 Year	rr_ExpenseExampleYear01	537
After 3 Years	rr_ExpenseExampleYear03	824
AB Global Core Equity Portfolio | CLASS C
Risk/Return:	rr_RiskReturnAbstract
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum Deferred Sales Charge (Load) (as a percentage of offering price or redemption proceeds, whichever is lower)	rr_MaximumDeferredSalesChargeOverOther	1.00%	[4]
Exchange Fee	rr_ExchangeFeeOverRedemption	none
Management Fees	rr_ManagementFeesOverAssets	0.75%
Distribution and/or Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	1.00%
Other Expenses: Transfer Agent	rr_Component1OtherExpensesOverAssets	0.10%
Other Expenses	rr_Component2OtherExpensesOverAssets	0.31%
Total Other Expenses	rr_OtherExpensesOverAssets	0.41%	[2]
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	2.16%
Fee Waiver and/or Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.26%)	[3]
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement	rr_NetExpensesOverAssets	1.90%
After 1 Year	rr_ExpenseExampleYear01	293
After 3 Years	rr_ExpenseExampleYear03	651
After 1 Year	rr_ExpenseExampleNoRedemptionYear01	193
After 3 Years	rr_ExpenseExampleNoRedemptionYear03	651
AB Global Core Equity Portfolio | ADVISOR CLASS
Risk/Return:	rr_RiskReturnAbstract
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum Deferred Sales Charge (Load) (as a percentage of offering price or redemption proceeds, whichever is lower)	rr_MaximumDeferredSalesChargeOverOther	none
Exchange Fee	rr_ExchangeFeeOverRedemption	none
Management Fees	rr_ManagementFeesOverAssets	0.75%
Distribution and/or Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses: Transfer Agent	rr_Component1OtherExpensesOverAssets	0.08%
Other Expenses	rr_Component2OtherExpensesOverAssets	0.31%
Total Other Expenses	rr_OtherExpensesOverAssets	0.39%	[2]
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	1.14%
Fee Waiver and/or Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.24%)	[3]
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement	rr_NetExpensesOverAssets	0.90%
After 1 Year	rr_ExpenseExampleYear01	92
After 3 Years	rr_ExpenseExampleYear03	338

[1] Purchases of Class A shares in amounts of $1,000,000 or more, or by certain group retirement plans, may be subject to a 1%, 1-year contingent deferred sales charge ("CDSC"), which may be subject to waiver in certain circumstances.

[2] Total other expenses are based on estimated amounts for the current fiscal year.

[3] The Adviser has contractually agreed to waive its management fees and/or to bear expenses of the Fund through November 12, 2015 to the extent necessary to prevent total Fund operating expenses (excluding acquired fund fees and expenses other than the advisory fees of any AB Mutual Funds in which the Fund may invest, interest expense, taxes, extraordinary expenses, and brokerage commissions and other transaction costs), on an annualized basis, from exceeding 1.15%, 1.90% and .90% of average daily net assets, respectively, for Class A, Class C and Advisor Class shares ("expense limitations"). Any fees waived and expenses borne by the Adviser may be reimbursed by the Fund until the end of the third fiscal year after the fiscal period in which the fee was waived or the expense was borne, provided that no reimbursement payment will be made that would cause the Fund's Total Annual Fund Operating Expenses to exceed the expense limitations.

[4] For Class C shares, the CDSC is 0% after the first year.