485BPOS

As filed with the Securities and Exchange Commission on June 10, 2013

Securities Act File No. 33-4959

Investment Company Act File No. 811-1355

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM N-1A

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933	x
Pre-Effective Amendment No.	o

     Post-Effective Amendment No. 77 x

and/or
REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY ACT OF 1940	x

     Amendment No. 79 x

(Check appropriate box or boxes)

THE ALGER FUNDS

(a Massachusetts business trust)

(Exact Name of Registrant as Specified in Charter)

360 Park Avenue South, New York, New York	10010
(Address of Principal Executive Offices)	(Zip Code)

Registrant’s Telephone Number, including Area Code: 212-806-8800

Hal Liebes

Fred Alger Management, Inc.

360 Park Avenue South,

New York, NY 10010

(Name and Address of Agent for Service)

copy to:

Gary L. Granik, Esq.

Stroock & Stroock & Lavan LLP

180 Maiden Lane

New York, New York 10038-4982

It is proposed that this filing will become effective (check appropriate box):

x       immediately upon filing pursuant to paragraph (b)

o        on [date] pursuant to paragraph (b)

o        60 days after filing pursuant to paragraph (a)(1)

o        on [date] pursuant to paragraph (a)(1)

o        75 days after filing pursuant to paragraph (a)(2)

o        on (date) pursuant to paragraph (a)(2) of Rule 485

If appropriate, check the following box:

o        This post-effective amendment designates a new effective date for a previously filed post-effective amendment.  

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933 and the Investment Company Act of 1940, as amended, the Registrant certifies that it meets all the requirements for effectiveness of this registration statement under Rule 485(b) under the Securities Act of 1933 and has duly caused this Post-Effective Amendment to the registration statement to be signed on its behalf by the undersigned, duly authorized, in the City of  New York and State of New York on the 10th day of June, 2013.

		THE ALGER FUNDS
		By: /s/ Hal Liebes
		Hal Liebes
		President
ATTEST: /s/	Lisa A. Moss
	Lisa A. Moss, Assistant Secretary

Pursuant to the requirements of the Securities Act of 1933, this Amendment has been signed below by the following persons in the capacities and on the dates indicated.

SIGNATURE	TITLE	DATE
/s/ Hal Liebes	President	June 10, 2013
Hal Liebes	(Principal Executive Officer)
/s/ Michael D. Martins	Treasurer	June 10, 2013
Michael D. Martins	(Chief Financial Officer)
*	Trustee	June 10, 2013
Charles F. Baird, Jr.
*	Trustee	June 10, 2013
Roger P. Cheever
*	Trustee	June 10, 2013
Lester L. Colbert, Jr.
*	Trustee	June 10, 2013
Hilary M. Alger
*	Trustee	June 10, 2013
Nathan E. Saint-Amand
*	Trustee	June 10, 2013
Stephen E. O’Neil
*	Trustee	June 10, 2013
David Rosenberg

*By: /s/ Hal Liebes

 Hal Liebes

 Attorney-In-Fact

EXHIBIT INDEX

Index No.	Description of Exhibit
EX-101.INS	XBRL Instance Document
EX-101.SCH	XBRL Taxonomy Extension Schema Document
EX-101.CAL	XBRL Taxonomy Extension Calculation Linkbase
EX-101.DEF	XBRL Taxonomy Extension Definition Linkbase
EX-101.LAB	XBRL Taxonomy Extension Labels Linkbase
EX-101.PRE	XBRL Taxonomy Extension Presentation Linkbase

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Alger Health Sciences Fund

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

Alger Health Sciences Fund seeks long-term capital appreciation.

Expense [Heading]

rr_ExpenseHeading

FUND 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 $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 26 of the Fund's Statement of Additional Information.

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 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 110.37% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

110.37%

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

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 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 [Text]

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 [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

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.

Under normal circumstances, the Fund invests at least 80% of its net assets, plus any borrowings for investment purposes, in equity securities of companies of any market capitalization that are engaged in the health sciences sector. A company will be considered to be engaged in the health sciences sector if it derives at least 50% of its earnings or revenues from, or devotes at least 50% of its assets to, activities in any area of the health sciences sector, including health care services, pharmaceuticals, medical equipment and supplies and applied research and development. Such companies include, but are not limited to:

•  hospitals, clinical test laboratories, convalescent and mental health care facilities, home care providers, and companies that supply services to any of the foregoing;

•  companies involved in pharmaceuticals, biotechnology, biochemistry and diagnostics; and

•  producers and manufacturers of medical, dental and optical supplies and equipment.

The Fund can leverage, that is, borrow money to buy additional securities. By borrowing money, the Fund has the potential to increase its returns if the increase in the value of the securities purchased exceeds the cost of borrowing, including interest paid on the money borrowed.

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 [Text Block]

rr_RiskNarrativeTextBlock

As with any fund 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.

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 and the risk of non-performance by the contract counterparty.

The following risks also apply:

•  investing in companies of all capitalizations involves the risk that smaller issuers in which the Fund invests may have limited product lines or financial resources, or lack management depth.

•  it may be difficult or impossible to liquidate a security position at a time and price acceptable to the Fund because of the potentially less frequent trading of stocks of smaller market capitalization.

•  the cost of borrowing money to leverage may exceed the returns for the securities purchased or the securities purchased may actually go down in value; thus, the Fund's net asset value could decrease more quickly than if it had not borrowed.

•  since the Fund concentrates its investments in the health sciences sector, the value of the Fund's shares may be more volatile than mutual funds that do not similarly concentrate their investments. Furthermore, because many of the industries in the health sciences sector are subject to substantial government regulation, changes in applicable regulations could adversely affect companies in those industries. In addition, the comparative rapidity of product development and technological advancement in many areas of the sector may be reflected in greater volatility of the stocks of companies operating in those areas.

An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Risk Lose Money [Text]

rr_RiskLoseMoney

As with any fund that invests in stocks, your investment will fluctuate in value, and the loss of your investment is a risk of investing.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation 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 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. Remember that the 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 [Text]

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 [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.alger.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Remember that the 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 [Text]

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 [Text Block]

rr_BarChartClosingTextBlock

Best Quarter:

Q2 2003 16.75%

Worst Quarter:

Q4 2008 -16.20%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best Quarter:

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2003

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

16.75%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst Quarter:

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(16.20%)

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

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

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 [Text]

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 [Text Block]

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.

Caption

rr_AverageAnnualReturnCaption

AVERAGE ANNUAL TOTAL RETURN AS OF DECEMBER 31, 2012

S&P 500 Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

Average Annual Returns, 1 Year

rr_AverageAnnualReturnYear01

16.00%

Average Annual Returns, 5 Years

rr_AverageAnnualReturnYear05

1.66%

Average Annual Returns, 10 Years

rr_AverageAnnualReturnYear10

7.10%

Average Annual Returns, Since Inception

rr_AverageAnnualReturnSinceInception

4.67%

Average Annual Returns, Inception Date

rr_AverageAnnualReturnInceptionDate

May 01, 2002

Alger Health Sciences Fund Class A

Risk/Return:

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_MaximumDeferredSalesChargeOverOther

1.00%

^[1]

Redemption Fee (as a percentage of Amount Redeemed)

rr_RedemptionFeeOverRedemption

(2.00%)

Management Fees

rr_ManagementFeesOverAssets

0.81%

Distribution and/or Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other Expenses

rr_OtherExpensesOverAssets

0.31%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.37%

Expenses Deferred Charges [Text Block]

rr_ExpensesDeferredChargesTextBlock

Purchases of $1 million of Class A Shares at net asset value may be subject to a contingent deferred sales charge of 1.00% on redemptions made within 12 months of purchase.

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 $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, with Redemption, 1 Year

rr_ExpenseExampleYear01

657

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

936

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

1,236

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

2,085

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

657

Expense Example, No Redemption, 3 Years

rr_ExpenseExampleNoRedemptionYear03

936

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

1,236

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

2,085

Annual Return 2003

rr_AnnualReturn2003

41.34%

Annual Return 2004

rr_AnnualReturn2004

18.10%

Annual Return 2005

rr_AnnualReturn2005

18.24%

Annual Return 2006

rr_AnnualReturn2006

9.26%

Annual Return 2007

rr_AnnualReturn2007

16.09%

Annual Return 2008

rr_AnnualReturn2008

(26.16%)

Annual Return 2009

rr_AnnualReturn2009

27.38%

Annual Return 2010

rr_AnnualReturn2010

2.99%

Annual Return 2011

rr_AnnualReturn2011

10.60%

Annual Return 2012

rr_AnnualReturn2012

11.38%

Average Annual Returns, 1 Year

rr_AverageAnnualReturnYear01

5.52%

Average Annual Returns, 5 Years

rr_AverageAnnualReturnYear05

2.48%

Average Annual Returns, 10 Years

rr_AverageAnnualReturnYear10

10.96%

Average Annual Returns, Since Inception

rr_AverageAnnualReturnSinceInception

9.36%

Average Annual Returns, Inception Date

rr_AverageAnnualReturnInceptionDate

May 01, 2002

Alger Health Sciences Fund Class A | After Taxes on Distributions

Risk/Return:

rr_RiskReturnAbstract

Average Annual Returns, 1 Year

rr_AverageAnnualReturnYear01

3.62%

Average Annual Returns, 5 Years

rr_AverageAnnualReturnYear05

2.11%

Average Annual Returns, 10 Years

rr_AverageAnnualReturnYear10

10.12%

Average Annual Returns, Since Inception

rr_AverageAnnualReturnSinceInception

8.57%

Alger Health Sciences Fund Class A | After Taxes on Distributions and Sale of Fund Shares

Risk/Return:

rr_RiskReturnAbstract

Average Annual Returns, 1 Year

rr_AverageAnnualReturnYear01

5.78%

Average Annual Returns, 5 Years

rr_AverageAnnualReturnYear05

2.09%

Average Annual Returns, 10 Years

rr_AverageAnnualReturnYear10

9.41%

Average Annual Returns, Since Inception

rr_AverageAnnualReturnSinceInception

7.98%

Alger Health Sciences Fund Class B

Risk/Return:

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_MaximumDeferredSalesChargeOverOther

5.00%

Redemption Fee (as a percentage of Amount Redeemed)

rr_RedemptionFeeOverRedemption

(2.00%)

Management Fees

rr_ManagementFeesOverAssets

0.81%

Distribution and/or Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other Expenses

rr_OtherExpensesOverAssets

0.35%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

2.16%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

719

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

976

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

1,359

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

2,292

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

219

Expense Example, No Redemption, 3 Years

rr_ExpenseExampleNoRedemptionYear03

676

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

1,159

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

2,292

Average Annual Returns, 1 Year

rr_AverageAnnualReturnYear01

5.61%

Average Annual Returns, 5 Years

rr_AverageAnnualReturnYear05

2.38%

Average Annual Returns, 10 Years

rr_AverageAnnualReturnYear10

10.88%

Average Annual Returns, Since Inception

rr_AverageAnnualReturnSinceInception

9.27%

Average Annual Returns, Inception Date

rr_AverageAnnualReturnInceptionDate

May 01, 2002

Alger Health Sciences Fund Class C

Risk/Return:

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_MaximumDeferredSalesChargeOverOther

1.00%

Redemption Fee (as a percentage of Amount Redeemed)

rr_RedemptionFeeOverRedemption

(2.00%)

Management Fees

rr_ManagementFeesOverAssets

0.81%

Distribution and/or Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other Expenses

rr_OtherExpensesOverAssets

0.33%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

2.14%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

317

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

670

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

1,149

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

2,472

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

217

Expense Example, No Redemption, 3 Years

rr_ExpenseExampleNoRedemptionYear03

670

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

1,149

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

2,472

Average Annual Returns, 1 Year

rr_AverageAnnualReturnYear01

9.55%

Average Annual Returns, 5 Years

rr_AverageAnnualReturnYear05

2.79%

Average Annual Returns, 10 Years

rr_AverageAnnualReturnYear10

10.72%

Average Annual Returns, Since Inception

rr_AverageAnnualReturnSinceInception

9.08%

Average Annual Returns, Inception Date

rr_AverageAnnualReturnInceptionDate

May 01, 2002

[1] Purchases of $1 million of Class A Shares at net asset value may be subject to a contingent deferred sales charge of 1.00% on redemptions made within 12 months of purchase.

XML

Alger Health Sciences Fund

Alger Health Sciences Fund

INVESTMENT OBJECTIVE

Alger Health Sciences Fund seeks long-term capital appreciation.

FUND FEES AND EXPENSES

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 $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 26 of the Fund's Statement of Additional Information.

Shareholder Fees (fees paid directly from your investment)

Shareholder Fees Alger Health Sciences Fund	Alger Health Sciences Fund Class A		Alger Health Sciences Fund Class B	Alger Health Sciences Fund Class C
Maximum sales charge (load) imposed on purchases as a % of offering price	5.25%		none	none
Maximum deferred sales charge (load) as a % of purchase price or redemption proceeds, whichever is lower	1.00%	[1]	5.00%	1.00%
Redemption Fee (as a % of amount redeemed or exchanged within 30 days)	2.00%		2.00%	2.00%

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses Alger Health Sciences Fund	Alger Health Sciences Fund Class A	Alger Health Sciences Fund Class B	Alger Health Sciences Fund Class C
Management Fees	0.81%	0.81%	0.81%
Distribution and/or Service (12b-1) Fees	0.25%	1.00%	1.00%
Other Expenses	0.31%	0.35%	0.33%
Total Annual Fund Operating Expenses	1.37%	2.16%	2.14%

EXAMPLE

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 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.

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 Alger Health Sciences Fund (USD $)	1 YEAR	3 YEARS	5 YEARS	10 YEARS
Alger Health Sciences Fund Class A	657	936	1,236	2,085
Alger Health Sciences Fund Class B	719	976	1,359	2,292
Alger Health Sciences Fund Class C	317	670	1,149	2,472

You would pay the following expenses if you did not redeem your shares:

Expense Example No Redemption Alger Health Sciences Fund (USD $)	1 YEAR	3 YEARS	5 YEARS	10 YEARS
Alger Health Sciences Fund Class A	657	936	1,236	2,085
Alger Health Sciences Fund Class B	219	676	1,159	2,292
Alger Health Sciences Fund Class C	217	670	1,149	2,472

PORTFOLIO TURNOVER

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 110.37% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGY

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.

Under normal circumstances, the Fund invests at least 80% of its net assets, plus any borrowings for investment purposes, in equity securities of companies of any market capitalization that are engaged in the health sciences sector. A company will be considered to be engaged in the health sciences sector if it derives at least 50% of its earnings or revenues from, or devotes at least 50% of its assets to, activities in any area of the health sciences sector, including health care services, pharmaceuticals, medical equipment and supplies and applied research and development. Such companies include, but are not limited to:

•  hospitals, clinical test laboratories, convalescent and mental health care facilities, home care providers, and companies that supply services to any of the foregoing;

•  companies involved in pharmaceuticals, biotechnology, biochemistry and diagnostics; and

•  producers and manufacturers of medical, dental and optical supplies and equipment.

The Fund can leverage, that is, borrow money to buy additional securities. By borrowing money, the Fund has the potential to increase its returns if the increase in the value of the securities purchased exceeds the cost of borrowing, including interest paid on the money borrowed.

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.

PRINCIPAL RISKS

As with any fund 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.

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 and the risk of non-performance by the contract counterparty.

The following risks also apply:

•  investing in companies of all capitalizations involves the risk that smaller issuers in which the Fund invests may have limited product lines or financial resources, or lack management depth.

•  it may be difficult or impossible to liquidate a security position at a time and price acceptable to the Fund because of the potentially less frequent trading of stocks of smaller market capitalization.

•  the cost of borrowing money to leverage may exceed the returns for the securities purchased or the securities purchased may actually go down in value; thus, the Fund's net asset value could decrease more quickly than if it had not borrowed.

•  since the Fund concentrates its investments in the health sciences sector, the value of the Fund's shares may be more volatile than mutual funds that do not similarly concentrate their investments. Furthermore, because many of the industries in the health sciences sector are subject to substantial government regulation, changes in applicable regulations could adversely affect companies in those industries. In addition, the comparative rapidity of product development and technological advancement in many areas of the sector may be reflected in greater volatility of the stocks of companies operating in those areas.

An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

PERFORMANCE

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. Remember that the 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.

ANNUAL TOTAL RETURN FOR CLASS A SHARES as of December 31 (%)

Best Quarter:

Q2 2003 16.75%

Worst Quarter:

Q4 2008 -16.20%

AVERAGE ANNUAL TOTAL RETURN AS OF DECEMBER 31, 2012

Average Annual Returns Alger Health Sciences Fund	Average Annual Returns, 1 Year	Average Annual Returns, 5 Years	Average Annual Returns, 10 Years	Average Annual Returns, Since Inception	Average Annual Returns, Inception Date
Alger Health Sciences Fund Class A	5.52%	2.48%	10.96%	9.36%	May 01, 2002
Alger Health Sciences Fund Class B	5.61%	2.38%	10.88%	9.27%	May 01, 2002
Alger Health Sciences Fund Class C	9.55%	2.79%	10.72%	9.08%	May 01, 2002
After Taxes on Distributions Alger Health Sciences Fund Class A	3.62%	2.11%	10.12%	8.57%
After Taxes on Distributions and Sale of Fund Shares Alger Health Sciences Fund Class A	5.78%	2.09%	9.41%	7.98%
S&P 500 Index (reflects no deduction for fees, expenses or taxes)	16.00%	1.66%	7.10%	4.67%	May 01, 2002

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.

[1] Purchases of $1 million of Class A Shares at net asset value may be subject to a contingent deferred sales charge of 1.00% on redemptions made within 12 months of purchase.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Alger International Growth Fund

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

Alger International Growth Fund seeks long-term capital appreciation.

Expense [Heading]

rr_ExpenseHeading

FUND 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. There are no sales charges on purchases or redemptions. "Other Expenses" below are estimated assuming $20 million in net assets. If actual net assets are less, the actual expense ratio will be higher.

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

2014-05-30

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 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 148.66% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

148.66%

Other Expenses, New Fund, Based on Estimates [Text]

rr_OtherExpensesNewFundBasedOnEstimates

"Other Expenses" below are estimated assuming $20 million in net assets.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following 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, that your investment has a 5% return each year and that the Fund's operating expenses remain the same.

Expense Example by, Year, Caption [Text]

rr_ExpenseExampleByYearCaption

Although your actual costs may be higher or lower, based on these assumptions you would pay the following expenses whether or not you redeemed your shares at the end of each period:

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGY

Strategy Narrative [Text Block]

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.

Under normal circumstances, the Fund invests at least 80% of its net assets in equity securities, including common stocks, American Depositary Receipts and Global Depositary Receipts, of foreign companies. Foreign companies are companies (i) that are organized under the laws of a foreign country; (ii) whose principal trading market is in a foreign country; or (iii) that have a majority of their assets, or that derive more than 50% of their revenue or profits from businesses, investments, or sales, outside the U.S. The Fund normally focuses its foreign investments in developed countries, but may also invest in emerging market securities. The Fund may invest in companies of any market capitalization, from large, well-established companies to small, emerging growth companies.

The Fund generally invests in at least three foreign countries, and, at times, may invest a substantial portion of its assets in a single foreign country. The Fund's benchmark is the Morgan Stanley Capital International (MSCI) All Country World Index (ACWI) ex USA, which is a market capitalization weighted index designed to provide a broad measure of equity market performance throughout the world, including both developed and emerging markets, but excluding the United States. The Fund may also compare its performance to the MSCI Europe, Australasia, and Far East (EAFE) Index, which is an unmanaged, market capitalization-weighted index that is designed to measure the performance of publicly traded stocks issued by companies in developed markets, excluding the United States and Canada. While the MSCI EAFE Index excludes stocks of Canadian companies, the Fund may invest in such stocks.

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 [Text Block]

rr_RiskNarrativeTextBlock

As with any fund 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.

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.

The Fund's performance will be influenced by political, social and economic factors affecting investments in foreign issuers, particularly emerging country issuers. Special risks associated with investments in emerging country issuers include exposure to currency fluctuations, less liquidity, less developed or less efficient trading markets, lack of comprehensive company information, political instability and differing auditing and legal standards. The securities of issuers located in emerging markets can be more volatile, and less liquid, than those of issuers in more mature economies.

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 correspond 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 and the risk of non-performance by the contract counterparty.

The following risks also apply:

•  investing in companies of all capitalizations involves the risk that smaller issuers in which the Fund invests may have limited product lines or financial resources, or lack management depth.

•  it may be difficult or impossible to liquidate a security position at a time and price acceptable to the Fund owing to the potentially less frequent trading of stocks of smaller market capitalization.

An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Risk Lose Money [Text]

rr_RiskLoseMoney

As with any fund that invests in stocks, your investment will fluctuate in value, and the loss of your investment is a risk of investing.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation 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 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. Class I Shares were not offered prior to May 31, 2013. Historical performance prior to May 31, 2013 is that of the Fund's Class A Shares. Performance in the bar chart does not reflect the effect of the sales charges imposed on Class A Shares of the Fund. If the bar chart reflected the applicable sales charges, returns would be less than those shown. Previously, the Fund followed different investment strategies under the name "Alger Large Cap Growth Fund" and was managed by a different portfolio manager. Performance prior to May 31, 2013 reflects that management style and does not reflect the Fund's current investment strategies and investment personnel. Prior to May 31, 2013, the Fund compared its performance to the Russell 1000 Growth Index. The Fund will compare its performance to the MSCI ACWI ex USA Index to better reflect its investment strategies. Remember that the 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 [Text]

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 [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.alger.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Remember that the 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 [Text]

rr_BarChartDoesNotReflectSalesLoads

Performance in the bar chart does not reflect the effect of the sales charges imposed on 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 [Text Block]

rr_BarChartClosingTextBlock

Best Quarter:

Q2 2003 17.39%

Worst Quarter:

Q4 2008 -26.33%

The total return for Class A Shares for the three months ended March 31, 2013 was 8.39%.

Year to Date Return, Label

rr_YearToDateReturnLabel

total return for Class A shares

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2013

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

8.39%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best Quarter:

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2003

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

17.39%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst Quarter:

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(26.33%)

Performance Table Market Index Changed

rr_PerformanceTableMarketIndexChanged

Prior to May 31, 2013, the Fund compared its performance to the Russell 1000 Growth Index. The Fund will compare its performance to the MSCI ACWI ex USA Index to better reflect its investment strategies.

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

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

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 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 [Text Block]

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. 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.

Caption

rr_AverageAnnualReturnCaption

AVERAGE ANNUAL TOTAL RETURN AS OF DECEMBER 31, 2012

MSCI ACWI ex USA (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

Average Annual Returns, 1 Year

rr_AverageAnnualReturnYear01

17.39%

Average Annual Returns, 5 Years

rr_AverageAnnualReturnYear05

(2.44%)

Average Annual Returns, 10 Years

rr_AverageAnnualReturnYear10

10.22%

Average Annual Returns, Since Inception

rr_AverageAnnualReturnSinceInception

5.51%

Average Annual Returns, Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 31, 1996

MSCI EAFE Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

Average Annual Returns, 1 Year

rr_AverageAnnualReturnYear01

17.90%

Average Annual Returns, 5 Years

rr_AverageAnnualReturnYear05

(3.21%)

Average Annual Returns, 10 Years

rr_AverageAnnualReturnYear10

8.70%

Average Annual Returns, Since Inception

rr_AverageAnnualReturnSinceInception

4.62%

Average Annual Returns, Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 31, 1996

Russell 1000 Growth Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

Average Annual Returns, 1 Year

rr_AverageAnnualReturnYear01

15.26%

Average Annual Returns, 5 Years

rr_AverageAnnualReturnYear05

3.12%

Average Annual Returns, 10 Years

rr_AverageAnnualReturnYear10

7.52%

Average Annual Returns, Since Inception

rr_AverageAnnualReturnSinceInception

5.10%

Average Annual Returns, Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 31, 1996

Alger LargeCap Growth Fund Class A

Risk/Return:

rr_RiskReturnAbstract

Annual Return 2003

rr_AnnualReturn2003

34.58%

Annual Return 2004

rr_AnnualReturn2004

5.67%

Annual Return 2005

rr_AnnualReturn2005

11.45%

Annual Return 2006

rr_AnnualReturn2006

4.91%

Annual Return 2007

rr_AnnualReturn2007

19.50%

Annual Return 2008

rr_AnnualReturn2008

(45.83%)

Annual Return 2009

rr_AnnualReturn2009

40.97%

Annual Return 2010

rr_AnnualReturn2010

12.67%

Annual Return 2011

rr_AnnualReturn2011

(0.51%)

Annual Return 2012

rr_AnnualReturn2012

9.31%

Average Annual Returns, 1 Year

rr_AverageAnnualReturnYear01

3.58%

Average Annual Returns, 5 Years

rr_AverageAnnualReturnYear05

(2.37%)

Average Annual Returns, 10 Years

rr_AverageAnnualReturnYear10

5.83%

Average Annual Returns, Since Inception

rr_AverageAnnualReturnSinceInception

4.82%

Average Annual Returns, Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 31, 1996

Alger LargeCap Growth Fund Class A | After Taxes on Distributions

Risk/Return:

rr_RiskReturnAbstract

Average Annual Returns, 1 Year

rr_AverageAnnualReturnYear01

3.31%

Average Annual Returns, 5 Years

rr_AverageAnnualReturnYear05

(2.46%)

Average Annual Returns, 10 Years

rr_AverageAnnualReturnYear10

5.79%

Average Annual Returns, Since Inception

rr_AverageAnnualReturnSinceInception

3.99%

Alger LargeCap Growth Fund Class A | After Taxes on Distributions and Sale of Fund Shares

Risk/Return:

rr_RiskReturnAbstract

Average Annual Returns, 1 Year

rr_AverageAnnualReturnYear01

2.33%

Average Annual Returns, 5 Years

rr_AverageAnnualReturnYear05

(2.05%)

Average Annual Returns, 10 Years

rr_AverageAnnualReturnYear10

5.10%

Average Annual Returns, Since Inception

rr_AverageAnnualReturnSinceInception

3.82%

Class I

Risk/Return:

rr_RiskReturnAbstract

Shareholder Fees (fees paid directly from your investment)

rr_ShareholderFeeOther

none

Management Fees

rr_ManagementFeesOverAssets

0.71%

Distribution and/or Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other Expenses

rr_OtherExpensesOverAssets

0.33%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.29%

Fee Waiver or Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.14%)

^[1]

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

1.15%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

117

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

395

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

694

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

1,544

Performance One Year or Less [Text]

rr_PerformanceOneYearOrLess

Class I Shares were not offered prior to May 31, 2013.

Average Annual Returns, Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 31, 1996

[1] Fred Alger Management, Inc. has contractually agreed to reimburse Fund expenses (excluding interest, taxes, brokerage, and extraordinary expenses) through May 30, 2014 to the extent necessary to limit the total annual fund operating expenses of the Class I Shares of the Fund to 1.15% of the class's average daily net assets. This expense reimbursement cannot be terminated.

XML

Class I Prospectus | Alger International Growth Fund

Alger International Growth Fund

INVESTMENT OBJECTIVE

Alger International Growth Fund seeks long-term capital appreciation.

FUND FEES AND EXPENSES

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. There are no sales charges on purchases or redemptions. "Other Expenses" below are estimated assuming $20 million in net assets. If actual net assets are less, the actual expense ratio will be higher.

Shareholder Fees (fees paid directly from your investment)

Shareholder Fees (USD $)	Class I Prospectus Alger International Growth Fund Class I
Shareholder Fees (fees paid directly from your investment)	none

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Class I Prospectus Alger International Growth Fund Class I
Management Fees		0.71%
Distribution and/or Shareholder Servicing (12b-1) Fees		0.25%
Other Expenses		0.33%
Total Annual Fund Operating Expenses		1.29%
Expense Reimbursement	[1]	0.14%
Total Annual Fund Operating Expenses After Expense Reimbursement		1.15%

EXAMPLE

The following 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, that your investment has a 5% return each year and that the Fund's operating expenses remain the same.

Although your actual costs may be higher or lower, based on these assumptions you would pay the following expenses whether or not you redeemed your shares at the end of each period:

Expense Example (USD $)	1 YEAR	3 YEARS	5 YEARS	10 YEARS
Class I Prospectus Alger International Growth Fund Class I	117	395	694	1,544

PORTFOLIO TURNOVER

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 148.66% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGY

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.

Under normal circumstances, the Fund invests at least 80% of its net assets in equity securities, including common stocks, American Depositary Receipts and Global Depositary Receipts, of foreign companies. Foreign companies are companies (i) that are organized under the laws of a foreign country; (ii) whose principal trading market is in a foreign country; or (iii) that have a majority of their assets, or that derive more than 50% of their revenue or profits from businesses, investments, or sales, outside the U.S. The Fund normally focuses its foreign investments in developed countries, but may also invest in emerging market securities. The Fund may invest in companies of any market capitalization, from large, well-established companies to small, emerging growth companies.

The Fund generally invests in at least three foreign countries, and, at times, may invest a substantial portion of its assets in a single foreign country. The Fund's benchmark is the Morgan Stanley Capital International (MSCI) All Country World Index (ACWI) ex USA, which is a market capitalization weighted index designed to provide a broad measure of equity market performance throughout the world, including both developed and emerging markets, but excluding the United States. The Fund may also compare its performance to the MSCI Europe, Australasia, and Far East (EAFE) Index, which is an unmanaged, market capitalization-weighted index that is designed to measure the performance of publicly traded stocks issued by companies in developed markets, excluding the United States and Canada. While the MSCI EAFE Index excludes stocks of Canadian companies, the Fund may invest in such stocks.

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.

PRINCIPAL RISKS

As with any fund 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.

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.

The Fund's performance will be influenced by political, social and economic factors affecting investments in foreign issuers, particularly emerging country issuers. Special risks associated with investments in emerging country issuers include exposure to currency fluctuations, less liquidity, less developed or less efficient trading markets, lack of comprehensive company information, political instability and differing auditing and legal standards. The securities of issuers located in emerging markets can be more volatile, and less liquid, than those of issuers in more mature economies.

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 correspond 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 and the risk of non-performance by the contract counterparty.

The following risks also apply:

•  investing in companies of all capitalizations involves the risk that smaller issuers in which the Fund invests may have limited product lines or financial resources, or lack management depth.

•  it may be difficult or impossible to liquidate a security position at a time and price acceptable to the Fund owing to the potentially less frequent trading of stocks of smaller market capitalization.

An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

PERFORMANCE

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. Class I Shares were not offered prior to May 31, 2013. Historical performance prior to May 31, 2013 is that of the Fund's Class A Shares. Performance in the bar chart does not reflect the effect of the sales charges imposed on Class A Shares of the Fund. If the bar chart reflected the applicable sales charges, returns would be less than those shown. Previously, the Fund followed different investment strategies under the name "Alger Large Cap Growth Fund" and was managed by a different portfolio manager. Performance prior to May 31, 2013 reflects that management style and does not reflect the Fund's current investment strategies and investment personnel. Prior to May 31, 2013, the Fund compared its performance to the Russell 1000 Growth Index. The Fund will compare its performance to the MSCI ACWI ex USA Index to better reflect its investment strategies. Remember that the 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.

ANNUAL TOTAL RETURN FOR CLASS A SHARES as of December 31 (%)

Best Quarter:

Q2 2003 17.39%

Worst Quarter:

Q4 2008 -26.33%

The total return for Class A Shares for the three months ended March 31, 2013 was 8.39%.

AVERAGE ANNUAL TOTAL RETURN AS OF DECEMBER 31, 2012

Average Annual Returns Class I Prospectus Alger International Growth Fund	Average Annual Returns, 1 Year	Average Annual Returns, 5 Years	Average Annual Returns, 10 Years	Average Annual Returns, Since Inception	Average Annual Returns, Inception Date
Alger LargeCap Growth Fund Class A	3.58%	(2.37%)	5.83%	4.82%	Dec. 31, 1996
After Taxes on Distributions Alger LargeCap Growth Fund Class A	3.31%	(2.46%)	5.79%	3.99%
After Taxes on Distributions and Sale of Fund Shares Alger LargeCap Growth Fund Class A	2.33%	(2.05%)	5.10%	3.82%
MSCI ACWI ex USA (reflects no deduction for fees, expenses or taxes)	17.39%	(2.44%)	10.22%	5.51%	Dec. 31, 1996
MSCI EAFE Index (reflects no deduction for fees, expenses or taxes)	17.90%	(3.21%)	8.70%	4.62%	Dec. 31, 1996
Russell 1000 Growth Index (reflects no deduction for fees, expenses or taxes)	15.26%	3.12%	7.52%	5.10%	Dec. 31, 1996

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. 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.

[1] Fred Alger Management, Inc. has contractually agreed to reimburse Fund expenses (excluding interest, taxes, brokerage, and extraordinary expenses) through May 30, 2014 to the extent necessary to limit the total annual fund operating expenses of the Class I Shares of the Fund to 1.15% of the class's average daily net assets. This expense reimbursement cannot be terminated.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Alger International Growth Fund

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

Alger International Growth Fund seeks long-term capital appreciation.

Expense [Heading]

rr_ExpenseHeading

FUND 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. There are no sales charges on purchases or redemptions. Total Annual Fund Operating Expenses are as of October 31, 2013, revised to reflect current fees.

Shareholder Fees Caption [Text]

rr_ShareholderFeesCaption

Shareholder Fees (fees paid directly from your investment)

Shareholder Fees (fees paid directly from your investment)

rr_ShareholderFeeOther

none

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)

Management Fees

rr_ManagementFeesOverAssets

0.71%

Distribution and/or Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

Other Expenses

rr_OtherExpensesOverAssets

0.37%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.08%

Fee Waiver or Reimbursement

rr_FeeWaiverOrReimbursementOverAssets

(0.19%)

^[1]

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

0.89%

Fee Waiver or Reimbursement over Assets, Date of Termination

rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination

2014-05-30

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 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 148.66% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

148.66%

Expenses Restated to Reflect Current [Text]

rr_ExpensesRestatedToReflectCurrent

Total Annual Fund Operating Expenses are as of October 31, 2013, revised to reflect current fees.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

rr_ExpenseExampleNarrativeTextBlock

The following 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, that your investment has a 5% return each year and that the Fund's operating expenses remain the same.

Expense Example by, Year, Caption [Text]

rr_ExpenseExampleByYearCaption

Although your actual costs may be higher or lower, based on these assumptions you would pay the following expenses regardless of whether you redeemed your shares at the end of each period:

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

91

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

325

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

577

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

$ 1,300

Strategy [Heading]

rr_StrategyHeading

PRINCIPAL INVESTMENT STRATEGY

Strategy Narrative [Text Block]

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.

Under normal circumstances, the Fund invests at least 80% of its net assets in equity securities, including common stocks, American Depositary Receipts and Global Depositary Receipts, of foreign companies. Foreign companies are companies (i) that are organized under the laws of a foreign country; (ii) whose principal trading market is in a foreign country; or (iii) that have a majority of their assets, or that derive more than 50% of their revenue or profits from businesses, investments, or sales, outside the U.S. The Fund normally focuses its foreign investments in developed countries, but may also invest in emerging market securities. The Fund may invest in companies of any market capitalization, from large, well-established companies to small, emerging growth companies.

The Fund generally invests in at least three foreign countries, and, at times, may invest a substantial portion of its assets in a single foreign country. The Fund's benchmark is the Morgan Stanley Capital International (MSCI) All Country World Index (ACWI) ex USA, which is a market capitalization weighted index designed to provide a broad measure of equity market performance throughout the world, including both developed and emerging markets, but excluding the United States. The Fund may also compare its performance to the MSCI Europe, Australasia, and Far East (EAFE) Index, which is an unmanaged, market capitalization-weighted index that is designed to measure the performance of publicly traded stocks issued by companies in developed markets, excluding the United States and Canada. While the MSCI EAFE Index excludes stocks of Canadian companies, the Fund may invest in such stocks.

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 [Text Block]

rr_RiskNarrativeTextBlock

As with any fund 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.

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.

The Fund's performance will be influenced by political, social and economic factors affecting investments in foreign issuers, particularly emerging country issuers. Special risks associated with investments in emerging country issuers include exposure to currency fluctuations, less liquidity, less developed or less efficient trading markets, lack of comprehensive company information, political instability and differing auditing and legal standards. The securities of issuers located in emerging markets can be more volatile, and less liquid, than those of issuers in more mature economies.

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 and the risk of non-performance by the contract counterparty.

The following risks also apply:

•  investing in companies of all capitalizations involves the risk that smaller issuers in which the Fund invests may have limited product lines or financial resources, or lack management depth.

•  it may be difficult or impossible to liquidate a security position at a time and price acceptable to the Fund owing to the potentially less frequent trading of stocks of smaller market capitalization.

An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Risk Lose Money [Text]

rr_RiskLoseMoney

As with any fund that invests in stocks, your investment will fluctuate in value, and the loss of your investment is a risk of investing.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation 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 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. Previously, the Fund followed different investment strategies under the name "Alger Large Cap Growth Fund" and was managed by a different portfolio manager. Performance prior to May 31, 2013 reflects that management style and does not reflect the Fund's current investment strategies and investment personnel. Prior to May 31, 2013, the Fund compared its performance to the Russell 1000 Growth Index. The Fund will compare its performance to the MSCI ACWI ex USA Index to better reflect its investment strategies. Remember that the 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 [Text]

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 [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.alger.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Remember that the 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 Z SHARES as of December 31 (%)

Annual Return 2011

rr_AnnualReturn2011

(0.34%)

Annual Return 2012

rr_AnnualReturn2012

9.77%

Bar Chart Closing [Text Block]

rr_BarChartClosingTextBlock

Best Quarter:

Q3 2012 14.29%

Worst Quarter:

Q3 2011 -14.31

The total return for the Class Z Shares for the three months ended March 31, 2013 was 8.54%.

Year to Date Return, Label

rr_YearToDateReturnLabel

total return for the Class Z Shares

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2013

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

8.54%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best Quarter:

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Sep. 30, 2012

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

14.29%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst Quarter:

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Sep. 30, 2011

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(14.31%)

Performance Table Market Index Changed

rr_PerformanceTableMarketIndexChanged

Prior to May 31, 2013, the Fund compared its performance to the Russell 1000 Growth Index. The Fund will compare its performance to the MSCI ACWI ex USA Index to better reflect its investment strategies.

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

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

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 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 [Text Block]

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. 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.

Caption

rr_AverageAnnualReturnCaption

Average Annual Total Return as of December 31, 2012

Average Annual Returns, 1 Year

rr_AverageAnnualReturnYear01

9.77%

Average Annual Returns, Since Inception

rr_AverageAnnualReturnSinceInception

4.45%

Average Annual Returns, Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 29, 2010

After Taxes on Distributions

Risk/Return:

rr_RiskReturnAbstract

Average Annual Returns, 1 Year

rr_AverageAnnualReturnYear01

9.35%

Average Annual Returns, Since Inception

rr_AverageAnnualReturnSinceInception

4.25%

After Taxes on Distributions and Sale of Fund Shares

Risk/Return:

rr_RiskReturnAbstract

Average Annual Returns, 1 Year

rr_AverageAnnualReturnYear01

6.35%

Average Annual Returns, Since Inception

rr_AverageAnnualReturnSinceInception

3.68%

MSCI ACWI ex USA (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

Average Annual Returns, 1 Year

rr_AverageAnnualReturnYear01

17.39%

Average Annual Returns, Since Inception

rr_AverageAnnualReturnSinceInception

1.14%

Average Annual Returns, Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 29, 2010

MSCI EAFE Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

Average Annual Returns, 1 Year

rr_AverageAnnualReturnYear01

17.90%

Average Annual Returns, Since Inception

rr_AverageAnnualReturnSinceInception

2.14%

Average Annual Returns, Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 29, 2010

Russell 1000 Growth Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

Average Annual Returns, 1 Year

rr_AverageAnnualReturnYear01

15.26%

Average Annual Returns, Since Inception

rr_AverageAnnualReturnSinceInception

8.59%

Average Annual Returns, Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 29, 2010

[1] Fred Alger Management, Inc. has contractually agreed to reimburse Fund expenses (including interest, taxes, brokerage, and extraordinary expenses) through May 30, 2014 to the extent necessary to limit the total annual fund operating expenses of the Class Z Shares of the Fund to .89% of the class's average daily net assets. This expense reimbursement cannot be terminated.

XML

Class Z Prospectus | Alger International Growth Fund | Alger LargeCap Growth Fund Class Z

Alger International Growth Fund

INVESTMENT OBJECTIVE

Alger International Growth Fund seeks long-term capital appreciation.

FUND FEES AND EXPENSES

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. There are no sales charges on purchases or redemptions. Total Annual Fund Operating Expenses are as of October 31, 2013, revised to reflect current fees.

Shareholder Fees (fees paid directly from your investment)

Shareholder Fees (USD $)	Class Z Prospectus Alger International Growth Fund Alger LargeCap Growth Fund Class Z
Shareholder Fees (fees paid directly from your investment)	none

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses		Class Z Prospectus Alger International Growth Fund Alger LargeCap Growth Fund Class Z
Management Fees		0.71%
Distribution and/or Service (12b-1) Fees		none
Other Expenses		0.37%
Total Annual Fund Operating Expenses		1.08%
Expense Reimbursement	[1]	0.19%
Total Annual Fund Operating Expenses After Expense Reimbursement		0.89%

EXAMPLE

The following 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, that your investment has a 5% return each year and that the Fund's operating expenses remain the same.

Although your actual costs may be higher or lower, based on these assumptions you would pay the following expenses regardless of whether you redeemed your shares at the end of each period:

Expense Example (USD $)	1 YEAR	3 YEARS	5 YEARS	10 YEARS
Class Z Prospectus Alger International Growth Fund Alger LargeCap Growth Fund Class Z	91	325	577	1,300

PORTFOLIO TURNOVER

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 148.66% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGY

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.

Under normal circumstances, the Fund invests at least 80% of its net assets in equity securities, including common stocks, American Depositary Receipts and Global Depositary Receipts, of foreign companies. Foreign companies are companies (i) that are organized under the laws of a foreign country; (ii) whose principal trading market is in a foreign country; or (iii) that have a majority of their assets, or that derive more than 50% of their revenue or profits from businesses, investments, or sales, outside the U.S. The Fund normally focuses its foreign investments in developed countries, but may also invest in emerging market securities. The Fund may invest in companies of any market capitalization, from large, well-established companies to small, emerging growth companies.

The Fund generally invests in at least three foreign countries, and, at times, may invest a substantial portion of its assets in a single foreign country. The Fund's benchmark is the Morgan Stanley Capital International (MSCI) All Country World Index (ACWI) ex USA, which is a market capitalization weighted index designed to provide a broad measure of equity market performance throughout the world, including both developed and emerging markets, but excluding the United States. The Fund may also compare its performance to the MSCI Europe, Australasia, and Far East (EAFE) Index, which is an unmanaged, market capitalization-weighted index that is designed to measure the performance of publicly traded stocks issued by companies in developed markets, excluding the United States and Canada. While the MSCI EAFE Index excludes stocks of Canadian companies, the Fund may invest in such stocks.

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.

PRINCIPAL RISKS

As with any fund 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.

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.

The Fund's performance will be influenced by political, social and economic factors affecting investments in foreign issuers, particularly emerging country issuers. Special risks associated with investments in emerging country issuers include exposure to currency fluctuations, less liquidity, less developed or less efficient trading markets, lack of comprehensive company information, political instability and differing auditing and legal standards. The securities of issuers located in emerging markets can be more volatile, and less liquid, than those of issuers in more mature economies.

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 and the risk of non-performance by the contract counterparty.

The following risks also apply:

•  investing in companies of all capitalizations involves the risk that smaller issuers in which the Fund invests may have limited product lines or financial resources, or lack management depth.

•  it may be difficult or impossible to liquidate a security position at a time and price acceptable to the Fund owing to the potentially less frequent trading of stocks of smaller market capitalization.

An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

PERFORMANCE

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. Previously, the Fund followed different investment strategies under the name "Alger Large Cap Growth Fund" and was managed by a different portfolio manager. Performance prior to May 31, 2013 reflects that management style and does not reflect the Fund's current investment strategies and investment personnel. Prior to May 31, 2013, the Fund compared its performance to the Russell 1000 Growth Index. The Fund will compare its performance to the MSCI ACWI ex USA Index to better reflect its investment strategies. Remember that the 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.

ANNUAL TOTAL RETURN FOR CLASS Z SHARES as of December 31 (%)

Best Quarter:

Q3 2012 14.29%

Worst Quarter:

Q3 2011 -14.31

The total return for the Class Z Shares for the three months ended March 31, 2013 was 8.54%.

Average Annual Total Return as of December 31, 2012

Average Annual Returns Class Z Prospectus Alger International Growth Fund	Average Annual Returns, 1 Year	Average Annual Returns, Since Inception	Average Annual Returns, Inception Date
Alger LargeCap Growth Fund Class Z	9.77%	4.45%	Dec. 29, 2010
Alger LargeCap Growth Fund Class Z After Taxes on Distributions	9.35%	4.25%
Alger LargeCap Growth Fund Class Z After Taxes on Distributions and Sale of Fund Shares	6.35%	3.68%
Alger LargeCap Growth Fund Class Z MSCI ACWI ex USA (reflects no deduction for fees, expenses or taxes)	17.39%	1.14%	Dec. 29, 2010
Alger LargeCap Growth Fund Class Z MSCI EAFE Index (reflects no deduction for fees, expenses or taxes)	17.90%	2.14%	Dec. 29, 2010
Alger LargeCap Growth Fund Class Z Russell 1000 Growth Index (reflects no deduction for fees, expenses or taxes)	15.26%	8.59%	Dec. 29, 2010

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. 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.

[1] Fred Alger Management, Inc. has contractually agreed to reimburse Fund expenses (including interest, taxes, brokerage, and extraordinary expenses) through May 30, 2014 to the extent necessary to limit the total annual fund operating expenses of the Class Z Shares of the Fund to .89% of the class's average daily net assets. This expense reimbursement cannot be terminated.

XML

Label

Element

Value

Risk/Return:

rr_RiskReturnAbstract

Risk/Return [Heading]

rr_RiskReturnHeading

Alger International Growth Fund

Objective [Heading]

rr_ObjectiveHeading

INVESTMENT OBJECTIVE

Objective, Primary [Text Block]

rr_ObjectivePrimaryTextBlock

Alger International Growth Fund seeks long-term capital appreciation.

Expense [Heading]

rr_ExpenseHeading

FUND 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 $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 26 of the Fund's Statement of Additional Information. Total Annual Fund Operating Expenses are as of October 31, 2012, revised to reflect current fees.

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 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 148.66% of the average value of its portfolio.

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

148.66%

Expenses Restated to Reflect Current [Text]

rr_ExpensesRestatedToReflectCurrent

Total Annual Fund Operating Expenses are as of October 31, 2012, revised to reflect current fees.

Expense Example [Heading]

rr_ExpenseExampleHeading

EXAMPLE

Expense Example Narrative [Text Block]

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 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 [Text]

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 [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

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.

Under normal circumstances, the Fund invests at least 80% of its net assets in equity securities, including common stocks, American Depositary Receipts and Global Depositary Receipts, of foreign companies. Foreign companies are companies (i) that are organized under the laws of a foreign country; (ii) whose principal trading market is in a foreign country; or (iii) that have a majority of their assets, or that derive more than 50% of their revenue or profits from businesses, investments, or sales, outside the U.S. The Fund normally focuses its foreign investments in developed countries, but may also invest in emerging market securities. The Fund may invest in companies of any market capitalization, from large, well-established companies to small, emerging growth companies.

The Fund generally invests in at least three foreign countries, and, at times, may invest a substantial portion of its assets in a single foreign country. The Fund's benchmark is the Morgan Stanley Capital International (MSCI) All Country World Index (ACWI) ex USA, which is a market capitalization weighted index designed to provide a broad measure of equity market performance throughout the world, including both developed and emerging markets, but excluding the United States. The Fund may also compare its performance to the MSCI Europe, Australasia, and Far East (EAFE) Index, which is an unmanaged, market capitalization-weighted index that is designed to measure the performance of publicly traded stocks issued by companies in developed markets, excluding the United States and Canada. While the MSCI EAFE Index excludes stocks of Canadian companies, the Fund may invest in such stocks.

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 [Text Block]

rr_RiskNarrativeTextBlock

As with any fund 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.

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.

The Fund's performance will be influenced by political, social and economic factors affecting investments in foreign issuers, particularly emerging country issuers. Special risks associated with investments in emerging country issuers include exposure to currency fluctuations, less liquidity, less developed or less efficient trading markets, lack of comprehensive company information, political instability and differing auditing and legal standards. The securities of issuers located in emerging markets can be more volatile, and less liquid, than those of issuers in more mature economies.

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 and the risk of non-performance by the contract counterparty.

The following risks also apply:

•  investing in companies of all capitalizations involves the risk that smaller issuers in which the Fund invests may have limited product lines or financial resources, or lack management depth.

•  it may be difficult or impossible to liquidate a security position at a time and price acceptable to the Fund owing to the potentially less frequent trading of stocks of smaller market capitalization.

An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Risk Lose Money [Text]

rr_RiskLoseMoney

As with any fund that invests in stocks, your investment will fluctuate in value, and the loss of your investment is a risk of investing.

Risk Not Insured Depository Institution [Text]

rr_RiskNotInsuredDepositoryInstitution

An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation 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 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. Previously, the Fund followed different investment strategies under the name "Alger Large Cap Growth Fund" and was managed by a different portfolio manager. Performance prior to May 31, 2013 reflects that management style and does not reflect the Fund's current investment strategies and investment personnel. Prior to May 31, 2013, the Fund compared its performance to the Russell 1000 Growth Index. The Fund will compare its performance to the MSCI ACWI ex USA Index to better reflect its investment strategies. Remember that the 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 [Text]

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 [Text]

rr_PerformanceAvailabilityWebSiteAddress

www.alger.com

Performance Past Does Not Indicate Future [Text]

rr_PerformancePastDoesNotIndicateFuture

Remember that the 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 [Text]

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 [Text Block]

rr_BarChartClosingTextBlock

Best Quarter:

Q2 2003 17.39%

Worst Quarter:

Q4 2008 -26.33%

The total return for Class A Shares for the three months ended March 31, 2013 was 8.39%.

Year to Date Return, Label

rr_YearToDateReturnLabel

total return for Class A Shares

Bar Chart, Year to Date Return, Date

rr_BarChartYearToDateReturnDate

Mar. 31, 2013

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

8.39%

Highest Quarterly Return, Label

rr_HighestQuarterlyReturnLabel

Best Quarter:

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Jun. 30, 2003

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

17.39%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst Quarter:

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Dec. 31, 2008

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(26.33%)

Performance Table Market Index Changed

rr_PerformanceTableMarketIndexChanged

Prior to May 31, 2013, the Fund compared its performance to the Russell 1000 Growth Index. The Fund will compare its performance to the MSCI ACWI ex USA Index to better reflect its investment strategies.

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

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

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 [Text]

rr_PerformanceTableOneClassOfAfterTaxShown

After-tax returns for Class B and Class 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 [Text Block]

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 Class 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.

Caption

rr_AverageAnnualReturnCaption

AVERAGE ANNUAL TOTAL RETURN AS OF DECEMBER 31, 2012

MSCI ACWI ex USA (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

Average Annual Returns, 1 Year

rr_AverageAnnualReturnYear01

17.39%

Average Annual Returns, 5 Years

rr_AverageAnnualReturnYear05

(2.44%)

Average Annual Returns, 10 Years

rr_AverageAnnualReturnYear10

10.22%

Average Annual Returns, Since Inception

rr_AverageAnnualReturnSinceInception

5.51%

^[1]

Average Annual Returns, Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 31, 1996

MSCI EAFE Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

Average Annual Returns, 1 Year

rr_AverageAnnualReturnYear01

17.90%

Average Annual Returns, 5 Years

rr_AverageAnnualReturnYear05

(3.21%)

Average Annual Returns, 10 Years

rr_AverageAnnualReturnYear10

8.70%

Average Annual Returns, Since Inception

rr_AverageAnnualReturnSinceInception

4.62%

^[1]

Average Annual Returns, Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 31, 1996

Russell 1000 Growth Index (reflects no deduction for fees, expenses or taxes)

Risk/Return:

rr_RiskReturnAbstract

Average Annual Returns, 1 Year

rr_AverageAnnualReturnYear01

15.26%

Average Annual Returns, 5 Years

rr_AverageAnnualReturnYear05

3.12%

Average Annual Returns, 10 Years

rr_AverageAnnualReturnYear10

7.52%

Average Annual Returns, Since Inception

rr_AverageAnnualReturnSinceInception

5.10%

^[1]

Average Annual Returns, Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 31, 1996

Alger LargeCap Growth Fund Class A

Risk/Return:

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_MaximumDeferredSalesChargeOverOther

1.00%

^[2]

Redemption Fee (as a percentage of Amount Redeemed)

rr_RedemptionFeeOverRedemption

(2.00%)

Management Fees

rr_ManagementFeesOverAssets

0.71%

Distribution and/or Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Other Expenses

rr_OtherExpensesOverAssets

0.49%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.45%

Expenses Deferred Charges [Text Block]

rr_ExpensesDeferredChargesTextBlock

Purchases of $1 million of Class A Shares at net asset value may be subject to a contingent deferred sales charge of 1.00% on redemptions made within 12 months of purchase.

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 $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, with Redemption, 1 Year

rr_ExpenseExampleYear01

665

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

960

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

1,276

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

2,169

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

665

Expense Example, No Redemption, 3 Years

rr_ExpenseExampleNoRedemptionYear03

960

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

1,276

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

2,169

Annual Return 2003

rr_AnnualReturn2003

34.58%

Annual Return 2004

rr_AnnualReturn2004

5.67%

Annual Return 2005

rr_AnnualReturn2005

11.45%

Annual Return 2006

rr_AnnualReturn2006

4.91%

Annual Return 2007

rr_AnnualReturn2007

19.50%

Annual Return 2008

rr_AnnualReturn2008

(45.83%)

Annual Return 2009

rr_AnnualReturn2009

40.97%

Annual Return 2010

rr_AnnualReturn2010

12.67%

Annual Return 2011

rr_AnnualReturn2011

(0.51%)

Annual Return 2012

rr_AnnualReturn2012

9.31%

Average Annual Returns, 1 Year

rr_AverageAnnualReturnYear01

3.58%

Average Annual Returns, 5 Years

rr_AverageAnnualReturnYear05

(2.37%)

Average Annual Returns, 10 Years

rr_AverageAnnualReturnYear10

5.83%

Average Annual Returns, Since Inception

rr_AverageAnnualReturnSinceInception

4.82%

^[1]

Average Annual Returns, Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 31, 1996

Alger LargeCap Growth Fund Class A | After Taxes on Distributions

Risk/Return:

rr_RiskReturnAbstract

Average Annual Returns, 1 Year

rr_AverageAnnualReturnYear01

3.31%

Average Annual Returns, 5 Years

rr_AverageAnnualReturnYear05

(2.46%)

Average Annual Returns, 10 Years

rr_AverageAnnualReturnYear10

5.79%

Average Annual Returns, Since Inception

rr_AverageAnnualReturnSinceInception

3.99%

^[1]

Alger LargeCap Growth Fund Class A | After Taxes on Distributions and Sale of Fund Shares

Risk/Return:

rr_RiskReturnAbstract

Average Annual Returns, 1 Year

rr_AverageAnnualReturnYear01

2.33%

Average Annual Returns, 5 Years

rr_AverageAnnualReturnYear05

(2.05%)

Average Annual Returns, 10 Years

rr_AverageAnnualReturnYear10

5.10%

Average Annual Returns, Since Inception

rr_AverageAnnualReturnSinceInception

3.82%

^[1]

Alger LargeCap Growth Fund Class B

Risk/Return:

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_MaximumDeferredSalesChargeOverOther

5.00%

Redemption Fee (as a percentage of Amount Redeemed)

rr_RedemptionFeeOverRedemption

(2.00%)

Management Fees

rr_ManagementFeesOverAssets

0.71%

Distribution and/or Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other Expenses

rr_OtherExpensesOverAssets

0.38%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

2.09%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

712

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

955

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

1,324

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

2,257

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

212

Expense Example, No Redemption, 3 Years

rr_ExpenseExampleNoRedemptionYear03

655

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

1,124

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

2,257

Average Annual Returns, 1 Year

rr_AverageAnnualReturnYear01

3.61%

Average Annual Returns, 5 Years

rr_AverageAnnualReturnYear05

(2.38%)

Average Annual Returns, 10 Years

rr_AverageAnnualReturnYear10

5.82%

Average Annual Returns, Since Inception

rr_AverageAnnualReturnSinceInception

4.78%

^[1]

Average Annual Returns, Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 31, 1996

Alger LargeCap Growth Fund Class C

Risk/Return:

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_MaximumDeferredSalesChargeOverOther

1.00%

Redemption Fee (as a percentage of Amount Redeemed)

rr_RedemptionFeeOverRedemption

(2.00%)

Management Fees

rr_ManagementFeesOverAssets

0.71%

Distribution and/or Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Other Expenses

rr_OtherExpensesOverAssets

0.49%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

2.20%

Expense Example, with Redemption, 1 Year

rr_ExpenseExampleYear01

323

Expense Example, with Redemption, 3 Years

rr_ExpenseExampleYear03

688

Expense Example, with Redemption, 5 Years

rr_ExpenseExampleYear05

1,180

Expense Example, with Redemption, 10 Years

rr_ExpenseExampleYear10

2,534

Expense Example, No Redemption, 1 Year

rr_ExpenseExampleNoRedemptionYear01

223

Expense Example, No Redemption, 3 Years

rr_ExpenseExampleNoRedemptionYear03

688

Expense Example, No Redemption, 5 Years

rr_ExpenseExampleNoRedemptionYear05

1,180

Expense Example, No Redemption, 10 Years

rr_ExpenseExampleNoRedemptionYear10

2,534

Average Annual Returns, 1 Year

rr_AverageAnnualReturnYear01

7.52%

Average Annual Returns, 5 Years

rr_AverageAnnualReturnYear05

(2.08%)

Average Annual Returns, 10 Years

rr_AverageAnnualReturnYear10

5.61%

Average Annual Returns, Since Inception

rr_AverageAnnualReturnSinceInception

4.56%

^[1]

Average Annual Returns, Inception Date

rr_AverageAnnualReturnInceptionDate

Dec. 31, 1996

[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.

[2] Purchases of $1 million of Class A Shares at net asset value may be subject to a contingent deferred sales charge of 1.00% on redemptions made within 12 months of purchase.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Prospectus Date	rr_ProspectusDate	Mar. 01, 2013

XML

Class A,B,C Prospectus | Alger International Growth Fund

Alger International Growth Fund

INVESTMENT OBJECTIVE

Alger International Growth Fund seeks long-term capital appreciation.

FUND FEES AND EXPENSES

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 $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 26 of the Fund's Statement of Additional Information. Total Annual Fund Operating Expenses are as of October 31, 2012, revised to reflect current fees.

Shareholder Fees (fees paid directly from your investment)

Shareholder Fees Class A,B,C Prospectus Alger International Growth Fund	Alger LargeCap Growth Fund Class A		Alger LargeCap Growth Fund Class B	Alger LargeCap Growth Fund Class C
Maximum sales charge (load) imposed on purchases as a % of offering price	5.25%		none	none
Maximum deferred sales charge (load) as a % of purchase price or redemption proceeds, whichever is lower	1.00%	[1]	5.00%	1.00%
Redemption Fee (as a % of amount redeemed or exchanged within 30 days)	2.00%		2.00%	2.00%

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses Class A,B,C Prospectus Alger International Growth Fund	Alger LargeCap Growth Fund Class A	Alger LargeCap Growth Fund Class B	Alger LargeCap Growth Fund Class C
Management Fees	0.71%	0.71%	0.71%
Distribution and/or Service (12b-1) Fees	0.25%	1.00%	1.00%
Other Expenses	0.49%	0.38%	0.49%
Total Annual Fund Operating Expenses	1.45%	2.09%	2.20%

EXAMPLE

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 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.

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 Class A,B,C Prospectus Alger International Growth Fund (USD $)	1 YEAR	3 YEARS	5 YEARS	10 YEARS
Alger LargeCap Growth Fund Class A	665	960	1,276	2,169
Alger LargeCap Growth Fund Class B	712	955	1,324	2,257
Alger LargeCap Growth Fund Class C	323	688	1,180	2,534

You would pay the following expenses if you did not redeem your shares:

Expense Example No Redemption Class A,B,C Prospectus Alger International Growth Fund (USD $)	1 YEAR	3 YEARS	5 YEARS	10 YEARS
Alger LargeCap Growth Fund Class A	665	960	1,276	2,169
Alger LargeCap Growth Fund Class B	212	655	1,124	2,257
Alger LargeCap Growth Fund Class C	223	688	1,180	2,534

PORTFOLIO TURNOVER

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 148.66% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGY

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.

Under normal circumstances, the Fund invests at least 80% of its net assets in equity securities, including common stocks, American Depositary Receipts and Global Depositary Receipts, of foreign companies. Foreign companies are companies (i) that are organized under the laws of a foreign country; (ii) whose principal trading market is in a foreign country; or (iii) that have a majority of their assets, or that derive more than 50% of their revenue or profits from businesses, investments, or sales, outside the U.S. The Fund normally focuses its foreign investments in developed countries, but may also invest in emerging market securities. The Fund may invest in companies of any market capitalization, from large, well-established companies to small, emerging growth companies.

The Fund generally invests in at least three foreign countries, and, at times, may invest a substantial portion of its assets in a single foreign country. The Fund's benchmark is the Morgan Stanley Capital International (MSCI) All Country World Index (ACWI) ex USA, which is a market capitalization weighted index designed to provide a broad measure of equity market performance throughout the world, including both developed and emerging markets, but excluding the United States. The Fund may also compare its performance to the MSCI Europe, Australasia, and Far East (EAFE) Index, which is an unmanaged, market capitalization-weighted index that is designed to measure the performance of publicly traded stocks issued by companies in developed markets, excluding the United States and Canada. While the MSCI EAFE Index excludes stocks of Canadian companies, the Fund may invest in such stocks.

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.

PRINCIPAL RISKS

As with any fund 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.

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.

The Fund's performance will be influenced by political, social and economic factors affecting investments in foreign issuers, particularly emerging country issuers. Special risks associated with investments in emerging country issuers include exposure to currency fluctuations, less liquidity, less developed or less efficient trading markets, lack of comprehensive company information, political instability and differing auditing and legal standards. The securities of issuers located in emerging markets can be more volatile, and less liquid, than those of issuers in more mature economies.

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 and the risk of non-performance by the contract counterparty.

The following risks also apply:

•  investing in companies of all capitalizations involves the risk that smaller issuers in which the Fund invests may have limited product lines or financial resources, or lack management depth.

•  it may be difficult or impossible to liquidate a security position at a time and price acceptable to the Fund owing to the potentially less frequent trading of stocks of smaller market capitalization.

An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

PERFORMANCE

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. Previously, the Fund followed different investment strategies under the name "Alger Large Cap Growth Fund" and was managed by a different portfolio manager. Performance prior to May 31, 2013 reflects that management style and does not reflect the Fund's current investment strategies and investment personnel. Prior to May 31, 2013, the Fund compared its performance to the Russell 1000 Growth Index. The Fund will compare its performance to the MSCI ACWI ex USA Index to better reflect its investment strategies. Remember that the 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.

ANNUAL TOTAL RETURN FOR CLASS A SHARES as of December 31 (%)

Best Quarter:

Q2 2003 17.39%

Worst Quarter:

Q4 2008 -26.33%

The total return for Class A Shares for the three months ended March 31, 2013 was 8.39%.

AVERAGE ANNUAL TOTAL RETURN AS OF DECEMBER 31, 2012

Average Annual Returns Class A,B,C Prospectus Alger International Growth Fund	Average Annual Returns, 1 Year	Average Annual Returns, 5 Years	Average Annual Returns, 10 Years	Average Annual Returns, Since Inception		Average Annual Returns, Inception Date
Alger LargeCap Growth Fund Class A	3.58%	(2.37%)	5.83%	4.82%	[1]	Dec. 31, 1996
Alger LargeCap Growth Fund Class B	3.61%	(2.38%)	5.82%	4.78%	[1]	Dec. 31, 1996
Alger LargeCap Growth Fund Class C	7.52%	(2.08%)	5.61%	4.56%	[1]	Dec. 31, 1996
After Taxes on Distributions Alger LargeCap Growth Fund Class A	3.31%	(2.46%)	5.79%	3.99%	[1]
After Taxes on Distributions and Sale of Fund Shares Alger LargeCap Growth Fund Class A	2.33%	(2.05%)	5.10%	3.82%	[1]
MSCI ACWI ex USA (reflects no deduction for fees, expenses or taxes)	17.39%	(2.44%)	10.22%	5.51%	[1]	Dec. 31, 1996
MSCI EAFE Index (reflects no deduction for fees, expenses or taxes)	17.90%	(3.21%)	8.70%	4.62%	[1]	Dec. 31, 1996
Russell 1000 Growth Index (reflects no deduction for fees, expenses or taxes)	15.26%	3.12%	7.52%	5.10%	[1]	Dec. 31, 1996

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 Class 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.

[1] Purchases of $1 million of Class A Shares at net asset value may be subject to a contingent deferred sales charge of 1.00% on redemptions made within 12 months of purchase.

[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.

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Document and Entity Information	0 Months Ended
	Oct. 31, 2012
Risk/Return:
Document Type	485BPOS
Document Period End Date	Oct. 31, 2012
Registrant Name	ALGER FUNDS
Central Index Key	0000003521
Amendment Flag	false
Document Creation Date	May 28, 2013
Document Effective Date	May 31, 2013
Prospectus Date	Mar. 01, 2013
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