Label	Element	Value
Risk Return [Abstract]	rr_RiskReturnAbstract
ProspectusDate	rr_ProspectusDate	Mar. 01, 2012
Alger Growth & Income Fund (First Prospectus Summary) | Alger Growth & Income Fund
Risk Return [Abstract]	rr_RiskReturnAbstract
Risk/Return, Heading	rr_RiskReturnHeading	Alger Growth & Income Fund
Investment Objective, Heading	rr_ObjectiveHeading	INVESTMENT OBJECTIVE
investment Objective, Primary	rr_ObjectivePrimaryTextBlock	Alger Growth & Income Fund seeks to provide capital appreciation and current income.
Expense, Heading	rr_ExpenseHeading	FUND FEES AND EXPENSES
Expense, Narrative	rr_ExpenseNarrativeTextBlock	This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. The numbers below are based on the Fund's expenses for the year ended October 31, 2011, adjusted for expenses currently in effect. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in Class A Shares of the Alger Family of Funds, including the Fund. More information about these and other discounts is available from your financial professional and in "Purchasing and Redeeming Fund Shares" beginning on page A-2 of the Fund's Prospectus and the sections "Right of Accumulation (Class A Shares)" and "Letter of Intent (Class A Shares)" on page 20 of the Fund's Statement of Additional Information.
Shareholder Fees, Caption	rr_ShareholderFeesCaption	Shareholder Fees (fees paid directly from your investment)
Operating Expenses, Caption	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	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 rate 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 examples, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 119.61% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	119.61%
Expense Breakpoint, Discounts	rr_ExpenseBreakpointDiscounts	You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $25,000 in Class A Shares of the Alger Family of Funds, including the Fund.
Expense Breakpoint, Minimum Investment Required Amount	rr_ExpenseBreakpointMinimumInvestmentRequiredAmount	25,000
Expense Example, Heading	rr_ExpenseExampleHeading	EXAMPLE
Expense Example, Narrative	rr_ExpenseExampleNarrativeTextBlock	The following 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 $10,000.00 in the Fund for the time periods indicated, that your investment has a 5% return each year and that the Fund's operating expenses remain the same.
Expense Example, By Year, Caption	rr_ExpenseExampleByYearCaption	Although your actual costs may be higher or lower, based on these assumptions you would pay the following expenses if you redeemed your shares at the end of each period:
Expense Example, No Redemption, By Year, Caption	rr_ExpenseExampleNoRedemptionByYearCaption	You would pay the following expenses if you did not redeem your shares:
Investment Strategy, Heading	rr_StrategyHeading	PRINCIPAL INVESTMENT STRATEGY
Investment Strategy, Narrative	rr_StrategyNarrativeTextBlock	Fred Alger Management, Inc. believes companies undergoing Positive Dynamic Change offer the best investment opportunities. Positive Dynamic Change refers to companies realizing High Unit Volume Growth or companies undergoing Positive Lifecycle Change. High Unit Volume Growth companies are traditional growth companies experiencing, for example, significantly growing demand or market dominance. Positive Lifecycle Change companies are, for example, companies benefitting from regulatory change, a new product introduction or management change. The Fund invests primarily in equity securities such as common or preferred stocks which Fred Alger Management, Inc. believes offer opportunities for capital appreciation and which also pay dividends. In considering such companies, Fred Alger Management, Inc, classifies them into three categories: Dividend Leaders - companies that generate high dividend payouts; Dividend Growers - companies that have a history of consistent dividend growth; and Kings of Cash Flow - companies that have strong potential for generating capital appreciation and the ability to return significant amounts of cash to investors as a result of their free cash flow. The Fund intends to invest at least 65% of its total assets in dividend paying equity securities. The Fund may invest up to 35% of its total assets in equity securities that do not pay dividends or in money market instruments and repurchase agreements. The Fund focuses on growing companies that, at the time of purchase of the securities, have a market capitalization equal to or greater than the market capitalization of companies included in the S&P 500 Index, as reported by the index as of the most recent quarter-end. This index is designed to track the performance of large-capitalization growth stocks. At December 31, 2011, the market capitalization of the companies in this index ranged from $1.2 billion to $417.5 billion. The Fund can also invest in derivative instruments. The Fund currently expects that its primary uses of derivatives will involve: (1) purchasing put and call options and selling (writing) covered put and call options, on securities and securities indexes, to increase gain, to hedge against the risk of unfavorable price movements in the underlying securities, or to provide diversification of risk, and (2) entering into forward currency contracts to hedge the Fund's foreign currency exposure when it holds, or proposes to hold, non-U.S. dollar denominated securities.
Risk, Heading	rr_RiskHeading	PRINCIPAL RISKS
Risk, Narrative	rr_RiskNarrativeTextBlock	As with any portfolio that invests in stocks, your investment will fluctuate in value, and the loss of your investment is a risk of investing. The Fund's price per share will fluctuate due to changes in the market prices of its investments. Also, the Fund's investments may not grow as fast as the rate of inflation and stocks tend to be more volatile than some other investments you could make, such as bonds. In addition, there are special risks associated with investing in preferred securities, including deferral and omission of distributions, subordination to bonds and other debt securities in a company's capital structure, limited liquidity, limited voting rights and special redemption rights. The market value of preferred stocks is generally more sensitive to changes in interest rates than the market value of common stocks. Prices of growth stocks tend to be higher in relation to their companies' earnings and may be more sensitive to market, political and economic developments than other stocks, making their prices more volatile. An investment in the Fund may be better suited to investors who seek long-term capital growth and can tolerate fluctuations in their investment's value. A small investment in derivatives could have a potentially large impact on the Fund's performance. When purchasing options, the Fund bears the risk that if the market value of the underlying security does not move to a level that would make exercise of the option profitable, the option will expire unexercised. When a call option written by the Fund is exercised, the Fund will not participate in any increase in the underlying security's value above the exercise price. When a put option written by the Fund is exercised, the Fund will be required to purchase the underlying security at a price in excess of its market value. Use of options on securities indexes is subject to the risk that trading in the options may be interrupted if trading in certain securities included in the index is interrupted, the risk that price movements in the Fund's portfolio securities may not correlate precisely with movements in the level of an index, and the risk that Fred Alger Management, Inc. may not predict correctly movements in the direction of a particular market or of the stock market generally. Because certain options may require settlement in cash, the Fund may be forced to liquidate portfolio securities to meet settlement obligations. Forward currency contracts are subject to currency exchange rate risks, the risk of non-performance by the contract counterparty, and the risk that Fred Alger Management, Inc. may not predict accurately future foreign exchange rates.    The following risk may also apply: • the possibility that companies may cut or fail to declare dividends due to market downturns or other reasons. • the possibility of greater risk by investing in smaller, less seasoned companies rather than larger, more established companies due to such factors as inexperienced management and limited product lines or financial resources.
Risk, Lose Money	rr_RiskLoseMoney	As with any portfolio that invests in stocks, your investment will fluctuate in value, and the loss of your investment is a risk of investing.
Bar Chart and Performance Table, Heading	rr_BarChartAndPerformanceTableHeading	PERFORMANCE
Performance, Narrative	rr_PerformanceNarrativeTextBlock	The following bar chart and the table beneath it provide some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year and by showing how the Fund's average annual returns for the indicated periods compare with those of an appropriate benchmark of market performance. Performance in the bar chart does not reflect the effect of the sales charge imposed on purchases of Class A Shares of the Fund. If the bar chart reflected the applicable sales charges, returns would be less than those shown. Prior to April 1, 2011, the Fund followed a different investment objective and different strategies under the name "Alger Balanced Fund." Remember that a Fund's past performance (before and after taxes) is not necessarily an indication of how it will perform in the future. Updated performance information is available on the Fund's website www.alger.com.
Performance, Information Illustrates Variability of Returns	rr_PerformanceInformationIllustratesVariabilityOfReturns	The following bar chart and the table beneath it provide some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year and by showing how the Fund's average annual returns for the indicated periods compare with those of an appropriate benchmark of market performance.
Performance, Availability Website Address	rr_PerformanceAvailabilityWebSiteAddress	www.alger.com
Performance, Past Does Not Indicate Future	rr_PerformancePastDoesNotIndicateFuture	Remember that a Fund's past performance (before and after taxes) is not necessarily an indication of how it will perform in the future.
Bar Chart, Heading	rr_BarChartHeading	ANNUAL TOTAL RETURN FOR CLASS A SHARES as of December 31 (%)
Bar Chart, Does Not Reflect Sales Loads	rr_BarChartDoesNotReflectSalesLoads	Performance in the bar chart does not reflect the effect of the sales charge imposed on purchases of Class A Shares of the Fund. If the bar chart reflected the applicable sales charges, returns would be less than those shown.
Bar Chart, Closing	rr_BarChartClosingTextBlock	Best Quarter: Q4 2011  12.46% Worst Quarter: Q4 2008  -17.68%
Index No Deduction for Fees, Expenses, Taxes	rr_IndexNoDeductionForFeesExpensesTaxes	reflects no deduction for fees, expenses or taxes
Performance Table, Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	In the foregoing table, after-tax returns are calculated using the historical highest individual federal marginal income 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 an investor's tax situation and may differ from those shown. The after-tax returns shown may not be relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.
Performance Table, One Class of after Tax Shown	rr_PerformanceTableOneClassOfAfterTaxShown	After-tax returns for Class B and C Shares, which are not shown, will vary from those shown for Class A Shares.
Performance Table, Explanation after Tax Higher	rr_PerformanceTableExplanationAfterTaxHigher	A "return after taxes on distributions and sale of fund shares" may sometimes be higher than the other two return figures; this happens where there is a capital loss on redemptions, giving rise to a tax benefit to the shareholder.
Performance Table, Closing	rr_PerformanceTableClosingTextBlock	In the foregoing table, after-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor's tax situation and may differ from those shown. The after-tax returns shown may not be relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for Class B and C Shares, which are not shown, will vary from those shown for Class A Shares. A "return after taxes on distributions and sale of fund shares" may sometimes be higher than the other two return figures; this happens where there is a capital loss on redemptions, giving rise to a tax benefit to the shareholder.
Average Annual Returns, Caption	rr_AverageAnnualReturnCaption	AVERAGE ANNUAL TOTAL RETURN AS OF DECEMBER 31, 2011
Alger Growth & Income Fund (First Prospectus Summary) | Alger Growth & Income Fund | S&P 500 Index
Risk Return [Abstract]	rr_RiskReturnAbstract
Average Annual Returns, Label	rr_AverageAnnualReturnLabel	S&P 500 Index (reflects no deduction for fees, expenses or taxes)
Average Annual Returns, 1 Year	rr_AverageAnnualReturnYear01	2.11%
Average Annual Returns, 5 Years	rr_AverageAnnualReturnYear05	(0.25%)
Average Annual Returns, 10 Years	rr_AverageAnnualReturnYear10	2.92%
Average Annual Returns, Since Inception	rr_AverageAnnualReturnSinceInception	5.45%
Average Annual Returns, Inception Date	rr_AverageAnnualReturnInceptionDate	Dec. 31, 1996	[1]
Alger Growth & Income Fund (First Prospectus Summary) | Alger Growth & Income Fund | Class A
Risk Return [Abstract]	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases as a % of offering price	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	5.25%
Maximum deferred sales charge (load) as a % of purchase price or redemption proceeds, whichever is lower	rr_MaximumDeferredSalesChargeOverOfferingPrice	none
Redemption Fee (as a % of amount redeemed or exchanged within 30 days)	rr_RedemptionFeeOverRedemption	(2.00%)
Management Fees	rr_ManagementFeesOverAssets	0.585%
Distribution and/or Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other Expenses	rr_OtherExpensesOverAssets	0.55%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	1.385%
Expense Example, With Redemption, 1 Year	rr_ExpenseExampleYear01	659
Expense Example, With Redemption, 3 Years	rr_ExpenseExampleYear03	940
Expense Example, With Redemption, 5 Years	rr_ExpenseExampleYear05	1,243
Expense Example, With Redemption, 10 Years	rr_ExpenseExampleYear10	2,101
Expense Example, No Redemption, 1 Year	rr_ExpenseExampleNoRedemptionYear01	659
Expense Example, No Redemption, 3 Years	rr_ExpenseExampleNoRedemptionYear03	940
Expense Example, No Redemption, 5 Years	rr_ExpenseExampleNoRedemptionYear05	1,243
Expense Example, No Redemption, 10 Years	rr_ExpenseExampleNoRedemptionYear10	2,101
Annual Return 2002	rr_AnnualReturn2002	(16.96%)
Annual Return 2003	rr_AnnualReturn2003	22.36%
Annual Return 2004	rr_AnnualReturn2004	4.60%
Annual Return 2005	rr_AnnualReturn2005	8.03%
Annual Return 2006	rr_AnnualReturn2006	4.37%
Annual Return 2007	rr_AnnualReturn2007	12.34%
Annual Return 2008	rr_AnnualReturn2008	(31.44%)
Annual Return 2009	rr_AnnualReturn2009	28.45%
Annual Return 2010	rr_AnnualReturn2010	9.57%
Annual Return 2011	rr_AnnualReturn2011	4.83%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Best Quarter:
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Dec. 31, 2011
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	12.46%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Worst Quarter:
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2008
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(17.68%)
Average Annual Returns, Label	rr_AverageAnnualReturnLabel	Class A Return Before Taxes
Average Annual Returns, 1 Year	rr_AverageAnnualReturnYear01	(0.69%)
Average Annual Returns, 5 Years	rr_AverageAnnualReturnYear05	1.48%
Average Annual Returns, 10 Years	rr_AverageAnnualReturnYear10	2.58%
Average Annual Returns, Since Inception	rr_AverageAnnualReturnSinceInception	6.10%
Average Annual Returns, Inception Date	rr_AverageAnnualReturnInceptionDate	Dec. 31, 1996	[1]
Alger Growth & Income Fund (First Prospectus Summary) | Alger Growth & Income Fund | Class A | After Taxes on Distributions
Risk Return [Abstract]	rr_RiskReturnAbstract
Average Annual Returns, Label	rr_AverageAnnualReturnLabel	Class A Return After Taxes on Distributions
Average Annual Returns, 1 Year	rr_AverageAnnualReturnYear01	(1.05%)
Average Annual Returns, 5 Years	rr_AverageAnnualReturnYear05	0.83%
Average Annual Returns, 10 Years	rr_AverageAnnualReturnYear10	2.03%
Average Annual Returns, Since Inception	rr_AverageAnnualReturnSinceInception	5.05%
Average Annual Returns, Inception Date	rr_AverageAnnualReturnInceptionDate	Dec. 31, 1996	[1]
Alger Growth & Income Fund (First Prospectus Summary) | Alger Growth & Income Fund | Class A | After Taxes on Distributions and Sales
Risk Return [Abstract]	rr_RiskReturnAbstract
Average Annual Returns, Label	rr_AverageAnnualReturnLabel	Class A Return After Taxes on Distributions and Sale of Fund Shares
Average Annual Returns, 1 Year	rr_AverageAnnualReturnYear01	(0.46%)
Average Annual Returns, 5 Years	rr_AverageAnnualReturnYear05	0.87%
Average Annual Returns, 10 Years	rr_AverageAnnualReturnYear10	1.87%
Average Annual Returns, Since Inception	rr_AverageAnnualReturnSinceInception	4.73%
Average Annual Returns, Inception Date	rr_AverageAnnualReturnInceptionDate	Dec. 31, 1996	[1]
Alger Growth & Income Fund (First Prospectus Summary) | Alger Growth & Income Fund | Class B
Risk Return [Abstract]	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases as a % of offering price	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum deferred sales charge (load) as a % of purchase price or redemption proceeds, whichever is lower	rr_MaximumDeferredSalesChargeOverOfferingPrice	5.00%
Redemption Fee (as a % of amount redeemed or exchanged within 30 days)	rr_RedemptionFeeOverRedemption	(2.00%)
Management Fees	rr_ManagementFeesOverAssets	0.585%
Distribution and/or Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	1.00%
Other Expenses	rr_OtherExpensesOverAssets	0.63%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	2.215%
Expense Example, With Redemption, 1 Year	rr_ExpenseExampleYear01	725
Expense Example, With Redemption, 3 Years	rr_ExpenseExampleYear03	993
Expense Example, With Redemption, 5 Years	rr_ExpenseExampleYear05	1,387
Expense Example, With Redemption, 10 Years	rr_ExpenseExampleYear10	2,340
Expense Example, No Redemption, 1 Year	rr_ExpenseExampleNoRedemptionYear01	225
Expense Example, No Redemption, 3 Years	rr_ExpenseExampleNoRedemptionYear03	693
Expense Example, No Redemption, 5 Years	rr_ExpenseExampleNoRedemptionYear05	1,187
Expense Example, No Redemption, 10 Years	rr_ExpenseExampleNoRedemptionYear10	2,340
Average Annual Returns, Label	rr_AverageAnnualReturnLabel	Class B Return Before Taxes
Average Annual Returns, 1 Year	rr_AverageAnnualReturnYear01	(1.05%)
Average Annual Returns, 5 Years	rr_AverageAnnualReturnYear05	1.37%
Average Annual Returns, 10 Years	rr_AverageAnnualReturnYear10	2.47%
Average Annual Returns, Since Inception	rr_AverageAnnualReturnSinceInception	6.04%
Average Annual Returns, Inception Date	rr_AverageAnnualReturnInceptionDate	Jun. 01, 1992	[1]
Alger Growth & Income Fund (First Prospectus Summary) | Alger Growth & Income Fund | Class C
Risk Return [Abstract]	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases as a % of offering price	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum deferred sales charge (load) as a % of purchase price or redemption proceeds, whichever is lower	rr_MaximumDeferredSalesChargeOverOfferingPrice	1.00%
Redemption Fee (as a % of amount redeemed or exchanged within 30 days)	rr_RedemptionFeeOverRedemption	(2.00%)
Management Fees	rr_ManagementFeesOverAssets	0.585%
Distribution and/or Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	1.00%
Other Expenses	rr_OtherExpensesOverAssets	0.54%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	2.125%
Expense Example, With Redemption, 1 Year	rr_ExpenseExampleYear01	316
Expense Example, With Redemption, 3 Years	rr_ExpenseExampleYear03	665
Expense Example, With Redemption, 5 Years	rr_ExpenseExampleYear05	1,142
Expense Example, With Redemption, 10 Years	rr_ExpenseExampleYear10	2,457
Expense Example, No Redemption, 1 Year	rr_ExpenseExampleNoRedemptionYear01	216
Expense Example, No Redemption, 3 Years	rr_ExpenseExampleNoRedemptionYear03	665
Expense Example, No Redemption, 5 Years	rr_ExpenseExampleNoRedemptionYear05	1,142
Expense Example, No Redemption, 10 Years	rr_ExpenseExampleNoRedemptionYear10	2,457
Average Annual Returns, Label	rr_AverageAnnualReturnLabel	Class C Return Before Taxes
Average Annual Returns, 1 Year	rr_AverageAnnualReturnYear01	3.06%
Average Annual Returns, 5 Years	rr_AverageAnnualReturnYear05	1.82%
Average Annual Returns, 10 Years	rr_AverageAnnualReturnYear10	2.36%
Average Annual Returns, Since Inception	rr_AverageAnnualReturnSinceInception	5.82%
Average Annual Returns, Inception Date	rr_AverageAnnualReturnInceptionDate	Jul. 31, 1997	[1]

[1] Performance of the Fund's Class C Shares prior to July 31, 1997 reflects the performance of the Fund's Class A Shares, as adjusted with currently applicable sales charges and operating expenses, which differ from historical charges and expenses. Since inception performance of the Fund's Class B Shares is available upon request.