Label	Element	Value
Risk Return [Abstract]	rr_RiskReturnAbstract
ProspectusDate	rr_ProspectusDate	Oct. 01, 2012
Dreyfus Select Managers Small Cap Growth Fund (Prospectus Summary) | Dreyfus Select Managers Small Cap Growth Fund
Risk Return [Abstract]	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	Fund Summary
Objective [Heading]	rr_ObjectiveHeading	Investment Objective
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The fund seeks capital appreciation.
Expense [Heading]	rr_ExpenseHeading	Fees and Expenses
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 discounts if you and your family invest, or agree to invest in the future, at least $50,000 in certain funds in the Dreyfus Family of Funds. More information about these and other discounts is available from your financial professional and in the Shareholder Guide section on page 11 of the Prospectus and in the How to Buy Shares section and the Additional Information About How to Buy Shares section on page II-1 and page III-1, respectively, of the fund's Statement of Additional Information. Class A shares bought without an initial sales charge as part of an investment of $1 million or more may be charged a deferred sales charge of 1% if redeemed within one year.
Shareholder Fees Caption [Text]	rr_ShareholderFeesCaption	Shareholder Fees (fees paid directly from your investment)
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	Portfolio Turnover
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 107.62% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	107.62%
Expense Breakpoint Discounts [Text]	rr_ExpenseBreakpointDiscounts	You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in certain funds in the Dreyfus Family of Funds.
Expense Breakpoint, Minimum Investment Required [Amount]	rr_ExpenseBreakpointMinimumInvestmentRequiredAmount	50,000
Expense Example [Heading]	rr_ExpenseExampleHeading	Example
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	The Example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the fund's operating expenses remain the same. The one-year example and the first year of the three-, five- and ten-years examples are based on net operating expenses, which reflect the expense waiver/reimbursement by The Dreyfus Corporation. 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	You would pay the following expenses if you did not redeem your shares:
Strategy [Heading]	rr_StrategyHeading	Principal Investment Strategy
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	To pursue its goal, the fund normally invests at least 80% of its net assets, plus any borrowings for investment purposes, in the stocks of small cap companies. The fund currently considers small cap companies to be those companies with market capitalizations that fall within the range of companies in the Russell 2000® Growth Index at the time of purchase. Because the fund may continue to hold a security whose market capitalization increases or decreases, a substantial portion of the fund's holdings can have market capitalizations outside the range of the Russell 2000 Growth Index at any given time. The fund's portfolio is constructed so as to have a growth tilt. The fund may invest up to 15% of its net assets in foreign securities. The fund uses a "multi-manager" approach by selecting one or more subadvisers to manage the fund's assets. The fund may hire, terminate or replace subadvisers and modify material terms and conditions of subadvisory arrangements without shareholder approval. The fund's assets are currently allocated among five subadvisers, each of which acts independently of the others and uses its own methodology to select portfolio investments. The fund is non-diversified, which means that a relatively high percentage of the fund's assets may be invested in a limited number of issuers.
Risk [Heading]	rr_RiskHeading	Principal Risks
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	An investment in the fund is not a bank deposit. It is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency. It is not a complete investment program. The fund's share price fluctuates, sometimes dramatically, which means you could lose money. o Risks of stock investing. Stocks generally fluctuate more in value than bonds and may decline significantly over short time periods. There is the chance that stock prices overall will decline because stock markets tend to move in cycles, with periods of rising prices and falling prices. The market value of a stock may decline due to general weakness in the stock market or because of factors that affect the company or its particular industry. o Small and midsize company risk. Small and midsize companies carry additional risks because the operating histories of these companies tend to be more limited, their earnings and revenues less predictable (and some companies may be experiencing significant losses), and their share prices more volatile than those of larger, more established companies. The shares of smaller companies tend to trade less frequently than those of larger, more established companies, which can adversely affect the pricing of these securities and the fund's ability to sell these securities. o Growth stock risk. Investors often expect growth companies to increase their earnings at a certain rate. If these expectations are not met, investors can punish the stocks inordinately, even if earnings do increase. In addition, growth stocks may lack the dividend yield that may cushion stock prices in market downturns. o Market sector risk. The fund may significantly overweight or underweight certain companies, industries or market sectors, which may cause the fund's performance to be more or less sensitive to developments affecting those companies, industries or sectors. o Liquidity risk. When there is little or no active trading market for specific types of securities, it can become more difficult to sell the securities at or near their perceived value. In such a market, the value of such securities and the fund's share price may fall dramatically. Investments in foreign securities tend to have greater exposure to liquidity risk than domestic securities. o Foreign investment risk. Special risks associated with investments in foreign issuers include exposure to currency fluctuations, less liquidity, less developed or less efficient trading markets, lack of comprehensive company information, political and economic instability and differing auditing and legal standards. Investments denominated in foreign currencies are subject to the risk that such currencies will decline in value relative to the U.S. dollar and affect the value of these investments held by the fund. o Multi-manager risk. Each subadviser makes investment decisions independently, and it is possible that the investment styles of the subadvisers may not complement one another. As a result, the fund's exposure to a given stock, industry or investment style could unintentionally be greater or smaller than it would have been if the fund had a single adviser. In addition, if one subadviser buys a security during a time frame when another subadviser sells it, the fund will incur transaction costs and the fund's net position in the security may be approximately the same as it would have been with a single adviser and no such sale and purchase. o Allocation risk. There can be no assurance that the allocation of the fund's assets among the subadvisers will be effective in achieving the fund's investment goal. o Non-diversification risk. The fund is non-diversified, which means that the fund may invest a relatively high percentage of its assets in a limited number of issuers. Therefore, the fund's performance may be more vulnerable to changes in the market value of a single issuer or group of issuers and more susceptible to risks associated with a single economic, political or regulatory occurrence than a diversified fund.
Risk Lose Money [Text]	rr_RiskLoseMoney	The fund's share price fluctuates, sometimes dramatically, which means you could lose money.
Risk Nondiversified Status [Text]	rr_RiskNondiversifiedStatus	The fund is non-diversified, which means that the fund may invest a relatively high percentage of its assets in a limited number of issuers. Therefore, the fund's performance may be more vulnerable to changes in the market value of a single issuer or group of issuers and more susceptible to risks associated with a single economic, political or regulatory occurrence than a diversified fund.
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	An investment in the fund is not a bank deposit. It is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Performance
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The following bar chart and table provide some indication of the risks of investing in the fund. The table compares the average annual total returns of the fund's shares to those of a broad measure of market performance. The fund's past performance (before and after taxes) is no guarantee of future results. More recent performance information may be available at www.dreyfus.com.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The following bar chart and table provide some indication of the risks of investing in the fund.
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.dreyfus.com
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	The fund's past performance (before and after taxes) is no guarantee of future results.
Bar Chart [Heading]	rr_BarChartHeading	Year-by-Year Total Returns as of 12/31 each year (%) -- Class A
Bar Chart Narrative [Text Block]	rr_BarChartNarrativeTextBlock	The bar chart shows the performance of the fund's Class A shares for its first full calendar year of operations. Sales charges, if any, are not reflected in the bar chart, and if those charges were included, returns would have been less than those shown.
Bar Chart Does Not Reflect Sales Loads [Text]	rr_BarChartDoesNotReflectSalesLoads	Sales charges, if any, are not reflected in the bar chart, and if those charges were included, returns would have been less than those shown.
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Best Quarter     Q1, 2011: 11.18% Worst Quarter    Q3, 2011: -18.11%          The year-to-date total return of the fund's Class A shares as of                  6/30/12 was 9.01%.
Index No Deduction for Fees, Expenses, Taxes [Text]	rr_IndexNoDeductionForFeesExpensesTaxes	reflects no deduction for fees, expenses or taxes
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	After-tax returns are calculated using the historical highest individual federal marginal tax rates, and do not reflect the impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred	rr_PerformanceTableNotRelevantToTaxDeferred	Actual after-tax returns depend on the investor's tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
Performance Table One Class of after Tax Shown [Text]	rr_PerformanceTableOneClassOfAfterTaxShown	After-tax performance is shown only for Class A shares. After-tax performance of the fund's other share classes will vary.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	After-tax performance is shown only for Class A shares. After-tax performance of the fund's other share classes will vary. After-tax returns are calculated using the historical highest individual federal marginal tax rates, and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor's tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts.
Caption	rr_AverageAnnualReturnCaption	Average Annual Total Returns (as of 12/31/11)
Dreyfus Select Managers Small Cap Growth Fund (Prospectus Summary) | Dreyfus Select Managers Small Cap Growth Fund | Russell 2000 Growth Index
Risk Return [Abstract]	rr_RiskReturnAbstract
Label	rr_AverageAnnualReturnLabel	Russell 2000 Growth Index reflects no deduction for fees, expenses or taxes
1 Year	rr_AverageAnnualReturnYear01	(2.91%)
Since Inception	rr_AverageAnnualReturnSinceInception	18.07%
Dreyfus Select Managers Small Cap Growth Fund (Prospectus Summary) | Dreyfus Select Managers Small Cap Growth Fund | Class A
Risk Return [Abstract]	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	5.75%
Maximum deferred sales charge (load) (as a percentage of lower of purchase or sale price)	rr_MaximumDeferredSalesChargeOverOfferingPrice	none
Management fees	rr_ManagementFeesOverAssets	0.90%
Distribution and Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other expenses (including shareholder services fees)	rr_OtherExpensesOverAssets	0.53%
Total annual fund operating expenses	rr_ExpensesOverAssets	1.43%
Fee waiver and/or expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.03%)	[1]
Total annual fund operating expenses (after fee waiver and/or expense reimbursement)	rr_NetExpensesOverAssets	1.40%
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	2013-10-01
Expense Example, with Redemption, 1 Year	rr_ExpenseExampleYear01	709
Expense Example, with Redemption, 3 Years	rr_ExpenseExampleYear03	999
Expense Example, with Redemption, 5 Years	rr_ExpenseExampleYear05	1,309
Expense Example, with Redemption, 10 Years	rr_ExpenseExampleYear10	2,187
Expense Example, No Redemption, 1 Year	rr_ExpenseExampleNoRedemptionYear01	709
Expense Example, No Redemption, 3 Years	rr_ExpenseExampleNoRedemptionYear03	999
Expense Example, No Redemption, 5 Years	rr_ExpenseExampleNoRedemptionYear05	1,309
Expense Example, No Redemption, 10 Years	rr_ExpenseExampleNoRedemptionYear10	2,187
Annual Return 2011	rr_AnnualReturn2011	1.04%
Year to Date Return, Label	rr_YearToDateReturnLabel	year-to-date total return
Bar Chart, Year to Date Return, Date	rr_BarChartYearToDateReturnDate	Jun. 30, 2012
Bar Chart, Year to Date Return	rr_BarChartYearToDateReturn	9.01%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Best Quarter
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Mar. 31, 2011
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	11.18%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Worst Quarter
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Sep. 30, 2011
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(18.11%)
Label	rr_AverageAnnualReturnLabel	Class A returns before taxes
1 Year	rr_AverageAnnualReturnYear01	(4.78%)
Since Inception	rr_AverageAnnualReturnSinceInception	16.10%
Inception Date	rr_AverageAnnualReturnInceptionDate	Jul. 01, 2010
Dreyfus Select Managers Small Cap Growth Fund (Prospectus Summary) | Dreyfus Select Managers Small Cap Growth Fund | Class A | After Taxes on Distributions
Risk Return [Abstract]	rr_RiskReturnAbstract
Label	rr_AverageAnnualReturnLabel	Class A returns after taxes on distributions
1 Year	rr_AverageAnnualReturnYear01	(4.78%)
Since Inception	rr_AverageAnnualReturnSinceInception	16.05%
Inception Date	rr_AverageAnnualReturnInceptionDate	Jul. 01, 2010
Dreyfus Select Managers Small Cap Growth Fund (Prospectus Summary) | Dreyfus Select Managers Small Cap Growth Fund | Class A | After Taxes on Distributions and Sales
Risk Return [Abstract]	rr_RiskReturnAbstract
Label	rr_AverageAnnualReturnLabel	Class A returns after taxes on distributions and sale of fund shares
1 Year	rr_AverageAnnualReturnYear01	(3.11%)
Since Inception	rr_AverageAnnualReturnSinceInception	13.74%
Inception Date	rr_AverageAnnualReturnInceptionDate	Jul. 01, 2010
Dreyfus Select Managers Small Cap Growth Fund (Prospectus Summary) | Dreyfus Select Managers Small Cap Growth Fund | Class C
Risk Return [Abstract]	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 lower of purchase or sale price)	rr_MaximumDeferredSalesChargeOverOfferingPrice	1.00%
Management fees	rr_ManagementFeesOverAssets	0.90%
Distribution and Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	0.75%
Other expenses (including shareholder services fees)	rr_OtherExpensesOverAssets	0.51%
Total annual fund operating expenses	rr_ExpensesOverAssets	2.16%
Fee waiver and/or expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets	(0.01%)	[1]
Total annual fund operating expenses (after fee waiver and/or expense reimbursement)	rr_NetExpensesOverAssets	2.15%
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	2013-10-01
Expense Example, with Redemption, 1 Year	rr_ExpenseExampleYear01	318
Expense Example, with Redemption, 3 Years	rr_ExpenseExampleYear03	675
Expense Example, with Redemption, 5 Years	rr_ExpenseExampleYear05	1,158
Expense Example, with Redemption, 10 Years	rr_ExpenseExampleYear10	2,492
Expense Example, No Redemption, 1 Year	rr_ExpenseExampleNoRedemptionYear01	218
Expense Example, No Redemption, 3 Years	rr_ExpenseExampleNoRedemptionYear03	675
Expense Example, No Redemption, 5 Years	rr_ExpenseExampleNoRedemptionYear05	1,158
Expense Example, No Redemption, 10 Years	rr_ExpenseExampleNoRedemptionYear10	2,492
Label	rr_AverageAnnualReturnLabel	Class C returns before taxes
1 Year	rr_AverageAnnualReturnYear01	(0.69%)
Since Inception	rr_AverageAnnualReturnSinceInception	19.89%
Inception Date	rr_AverageAnnualReturnInceptionDate	Jul. 01, 2010
Dreyfus Select Managers Small Cap Growth Fund (Prospectus Summary) | Dreyfus Select Managers Small Cap Growth Fund | Class I
Risk Return [Abstract]	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 lower of purchase or sale price)	rr_MaximumDeferredSalesChargeOverOfferingPrice	none
Management fees	rr_ManagementFeesOverAssets	0.90%
Distribution and Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other expenses (including shareholder services fees)	rr_OtherExpensesOverAssets	0.13%
Total annual fund operating expenses	rr_ExpensesOverAssets	1.03%
Fee waiver and/or expense reimbursement	rr_FeeWaiverOrReimbursementOverAssets		[1]
Total annual fund operating expenses (after fee waiver and/or expense reimbursement)	rr_NetExpensesOverAssets	1.03%
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	2013-10-01
Expense Example, with Redemption, 1 Year	rr_ExpenseExampleYear01	105
Expense Example, with Redemption, 3 Years	rr_ExpenseExampleYear03	328
Expense Example, with Redemption, 5 Years	rr_ExpenseExampleYear05	569
Expense Example, with Redemption, 10 Years	rr_ExpenseExampleYear10	1,259
Expense Example, No Redemption, 1 Year	rr_ExpenseExampleNoRedemptionYear01	105
Expense Example, No Redemption, 3 Years	rr_ExpenseExampleNoRedemptionYear03	328
Expense Example, No Redemption, 5 Years	rr_ExpenseExampleNoRedemptionYear05	569
Expense Example, No Redemption, 10 Years	rr_ExpenseExampleNoRedemptionYear10	1,259
Label	rr_AverageAnnualReturnLabel	Class I returns before taxes
1 Year	rr_AverageAnnualReturnYear01	1.28%
Since Inception	rr_AverageAnnualReturnSinceInception	21.10%
Inception Date	rr_AverageAnnualReturnInceptionDate	Jul. 01, 2010

[1] The Dreyfus Corporation has contractually agreed, until at least October 1, 2013, to waive receipt of its fees and/or assume the expenses of the fund so that the expenses of none of the classes (excluding Rule 12b-1 fees, shareholder services fees, taxes, interest, brokerage commissions, commitment fees and extraordinary expenses) exceed 1.15%. On or after October 1, 2013, The Dreyfus Corporation may terminate the expense limitation at any time.