Shareholder Report
|
6 Months Ended |
|
Apr. 30, 2026
USD ($)
Holding
|
|---|
| Shareholder Report [Line Items] |
|
|
| Document Type |
N-CSRS
|
|
| Amendment Flag |
false
|
|
| Registrant Name |
ALGER FUNDS
|
|
| Entity Central Index Key |
0000003521
|
|
| Entity Investment Company Type |
N-1A
|
|
| Document Period End Date |
Apr. 30, 2026
|
|
| C000059337 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Small Cap Focus Fund
|
|
| Class Name |
Class A
|
|
| Trading Symbol |
AOFAX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Small Cap Focus Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Small Cap Focus Fund
(Class A / AOFAX) |
$64 |
1.31%(a) |
|
|
| Expenses Paid, Amount |
$ 64
|
|
| Expense Ratio, Percent |
1.31%
|
[1] |
| Net Assets |
$ 789,401,281
|
|
| Holdings Count | Holding |
51
|
[2] |
| Investment Company Portfolio Turnover |
44.31%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$789,401,281 |
| Total number of portfolio holdings1 |
51 |
| Portfolio turnover rate |
44.31% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Consumer Discretionary |
0.9% |
| Health Care |
43.1% |
| Industrials |
40.6% |
| Information Technology |
15.4% |
| Short-Term Investments and Other Net Assets |
0.0% |
|
100.0% |
|
|
| C000059339 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Small Cap Focus Fund
|
|
| Class Name |
Class C
|
|
| Trading Symbol |
AOFCX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Small Cap Focus Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Small Cap Focus Fund
(Class C / AOFCX) |
$99 |
2.03%(a) |
|
|
| Expenses Paid, Amount |
$ 99
|
|
| Expense Ratio, Percent |
2.03%
|
[3] |
| Net Assets |
$ 789,401,281
|
|
| Holdings Count | Holding |
51
|
[4] |
| Investment Company Portfolio Turnover |
44.31%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$789,401,281 |
| Total number of portfolio holdings1 |
51 |
| Portfolio turnover rate |
44.31% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Consumer Discretionary |
0.9% |
| Health Care |
43.1% |
| Industrials |
40.6% |
| Information Technology |
15.4% |
| Short-Term Investments and Other Net Assets |
0.0% |
|
100.0% |
|
|
| C000059340 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Small Cap Focus Fund
|
|
| Class Name |
Class I
|
|
| Trading Symbol |
AOFIX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Small Cap Focus Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Small Cap Focus Fund
(Class I / AOFIX) |
$62 |
1.26%(a) |
|
|
| Expenses Paid, Amount |
$ 62
|
|
| Expense Ratio, Percent |
1.26%
|
[5] |
| Net Assets |
$ 789,401,281
|
|
| Holdings Count | Holding |
51
|
[6] |
| Investment Company Portfolio Turnover |
44.31%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$789,401,281 |
| Total number of portfolio holdings1 |
51 |
| Portfolio turnover rate |
44.31% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Consumer Discretionary |
0.9% |
| Health Care |
43.1% |
| Industrials |
40.6% |
| Information Technology |
15.4% |
| Short-Term Investments and Other Net Assets |
0.0% |
|
100.0% |
|
|
| C000095961 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Small Cap Focus Fund
|
|
| Class Name |
Class Y
|
|
| Trading Symbol |
AOFYX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Small Cap Focus Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Small Cap Focus Fund
(Class Y / AOFYX) |
$42 |
0.86%(a) |
|
|
| Expenses Paid, Amount |
$ 42
|
|
| Expense Ratio, Percent |
0.86%
|
[7] |
| Net Assets |
$ 789,401,281
|
|
| Holdings Count | Holding |
51
|
[8] |
| Investment Company Portfolio Turnover |
44.31%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$789,401,281 |
| Total number of portfolio holdings1 |
51 |
| Portfolio turnover rate |
44.31% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Consumer Discretionary |
0.9% |
| Health Care |
43.1% |
| Industrials |
40.6% |
| Information Technology |
15.4% |
| Short-Term Investments and Other Net Assets |
0.0% |
|
100.0% |
|
|
| C000179520 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Small Cap Focus Fund
|
|
| Class Name |
Class Z
|
|
| Trading Symbol |
AGOZX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Small Cap Focus Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Small Cap Focus Fund
(Class Z / AGOZX) |
$44 |
0.90%(a) |
|
|
| Expenses Paid, Amount |
$ 44
|
|
| Expense Ratio, Percent |
0.90%
|
[9] |
| Net Assets |
$ 789,401,281
|
|
| Holdings Count | Holding |
51
|
[10] |
| Investment Company Portfolio Turnover |
44.31%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$789,401,281 |
| Total number of portfolio holdings1 |
51 |
| Portfolio turnover rate |
44.31% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Consumer Discretionary |
0.9% |
| Health Care |
43.1% |
| Industrials |
40.6% |
| Information Technology |
15.4% |
| Short-Term Investments and Other Net Assets |
0.0% |
|
100.0% |
|
|
| C000199574 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger 35 Fund
|
|
| Class Name |
Class Z
|
|
| Trading Symbol |
ATVPX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger 35 Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger 35 Fund
(Class Z / ATVPX) |
$30 |
0.60%(a) |
|
|
| Expenses Paid, Amount |
$ 30
|
|
| Expense Ratio, Percent |
0.60%
|
[11] |
| Net Assets |
$ 43,383,580
|
|
| Holdings Count | Holding |
35
|
[12] |
| Investment Company Portfolio Turnover |
99.45%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$43,383,580 |
| Total number of portfolio holdings1 |
35 |
| Portfolio turnover rate |
99.45% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Communication Services |
15.5% |
| Consumer Discretionary |
9.6% |
| Financials |
2.3% |
| Health Care |
9.2% |
| Industrials |
7.9% |
| Information Technology |
52.8% |
| Utilities |
2.4% |
| Short-Term Investments and Other Net Assets |
0.3% |
|
100.0% |
|
|
| C000193201 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Weatherbie Specialized Growth Fund
|
|
| Class Name |
Class Z
|
|
| Trading Symbol |
ASMZX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Weatherbie Specialized Growth Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Weatherbie Specialized Growth Fund
(Class Z / ASMZX) |
$50 |
0.99%(a) |
|
|
| Expenses Paid, Amount |
$ 50
|
|
| Expense Ratio, Percent |
0.99%
|
[13] |
| Net Assets |
$ 279,879,322
|
|
| Holdings Count | Holding |
50
|
[14] |
| Investment Company Portfolio Turnover |
37.29%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$279,879,322 |
| Total number of portfolio holdings1 |
50 |
| Portfolio turnover rate |
37.29% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Consumer Discretionary |
10.7% |
| Energy |
1.0% |
| Financials |
11.0% |
| Health Care |
18.9% |
| Industrials |
35.8% |
| Information Technology |
16.5% |
| Real Estate |
4.9% |
| Short-Term Investments and Other Net Assets |
1.2% |
|
100.0% |
|
|
| C000095960 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Weatherbie Specialized Growth Fund
|
|
| Class Name |
Class Y
|
|
| Trading Symbol |
ASYMX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Weatherbie Specialized Growth Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Weatherbie Specialized Growth Fund
(Class Y / ASYMX) |
$45 |
0.89%(a) |
|
|
| Expenses Paid, Amount |
$ 45
|
|
| Expense Ratio, Percent |
0.89%
|
[15] |
| Net Assets |
$ 279,879,322
|
|
| Holdings Count | Holding |
50
|
[16] |
| Investment Company Portfolio Turnover |
37.29%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$279,879,322 |
| Total number of portfolio holdings1 |
50 |
| Portfolio turnover rate |
37.29% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Consumer Discretionary |
10.7% |
| Energy |
1.0% |
| Financials |
11.0% |
| Health Care |
18.9% |
| Industrials |
35.8% |
| Information Technology |
16.5% |
| Real Estate |
4.9% |
| Short-Term Investments and Other Net Assets |
1.2% |
|
100.0% |
|
|
| C000156505 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Health Sciences Fund
|
|
| Class Name |
Class Z
|
|
| Trading Symbol |
AHSZX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Health Sciences Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Health Sciences Fund
(Class Z / AHSZX) |
$40 |
0.77%(a) |
|
|
| Expenses Paid, Amount |
$ 40
|
|
| Expense Ratio, Percent |
0.77%
|
[17] |
| Net Assets |
$ 60,835,522
|
|
| Holdings Count | Holding |
58
|
[18] |
| Investment Company Portfolio Turnover |
163.34%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$60,835,522 |
| Total number of portfolio holdings1 |
58 |
| Portfolio turnover rate |
163.34% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Financials |
0.6% |
| Health Care |
88.6% |
| Materials |
2.6% |
| Real Estate |
5.3% |
| Short-Term Investments and Other Net Assets |
2.9% |
|
100.0% |
|
|
| C000024915 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Health Sciences Fund
|
|
| Class Name |
Class A
|
|
| Trading Symbol |
AHSAX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Health Sciences Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Health Sciences Fund
(Class A / AHSAX) |
$62 |
1.20%(a) |
|
|
| Expenses Paid, Amount |
$ 62
|
|
| Expense Ratio, Percent |
1.20%
|
[19] |
| Net Assets |
$ 60,835,522
|
|
| Holdings Count | Holding |
58
|
[20] |
| Investment Company Portfolio Turnover |
163.34%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$60,835,522 |
| Total number of portfolio holdings1 |
58 |
| Portfolio turnover rate |
163.34% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Financials |
0.6% |
| Health Care |
88.6% |
| Materials |
2.6% |
| Real Estate |
5.3% |
| Short-Term Investments and Other Net Assets |
2.9% |
|
100.0% |
|
|
| C000024917 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Health Sciences Fund
|
|
| Class Name |
Class C
|
|
| Trading Symbol |
AHSCX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Health Sciences Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Health Sciences Fund
(Class C / AHSCX) |
$104 |
2.02%(a) |
|
|
| Expenses Paid, Amount |
$ 104
|
|
| Expense Ratio, Percent |
2.02%
|
[21] |
| Net Assets |
$ 60,835,522
|
|
| Holdings Count | Holding |
58
|
[22] |
| Investment Company Portfolio Turnover |
163.34%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$60,835,522 |
| Total number of portfolio holdings1 |
58 |
| Portfolio turnover rate |
163.34% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Financials |
0.6% |
| Health Care |
88.6% |
| Materials |
2.6% |
| Real Estate |
5.3% |
| Short-Term Investments and Other Net Assets |
2.9% |
|
100.0% |
|
|
| C000024918 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Weatherbie Specialized Growth Fund
|
|
| Class Name |
Class A
|
|
| Trading Symbol |
ALMAX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Weatherbie Specialized Growth Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Weatherbie Specialized Growth Fund
(Class A / ALMAX) |
$67 |
1.34%(a) |
|
|
| Expenses Paid, Amount |
$ 67
|
|
| Expense Ratio, Percent |
1.34%
|
[23] |
| Net Assets |
$ 279,879,322
|
|
| Holdings Count | Holding |
50
|
[24] |
| Investment Company Portfolio Turnover |
37.29%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$279,879,322 |
| Total number of portfolio holdings1 |
50 |
| Portfolio turnover rate |
37.29% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Consumer Discretionary |
10.7% |
| Energy |
1.0% |
| Financials |
11.0% |
| Health Care |
18.9% |
| Industrials |
35.8% |
| Information Technology |
16.5% |
| Real Estate |
4.9% |
| Short-Term Investments and Other Net Assets |
1.2% |
|
100.0% |
|
|
| C000024920 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Weatherbie Specialized Growth Fund
|
|
| Class Name |
Class C
|
|
| Trading Symbol |
ALMCX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Weatherbie Specialized Growth Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Weatherbie Specialized Growth Fund
(Class C / ALMCX) |
$107 |
2.14%(a) |
|
|
| Expenses Paid, Amount |
$ 107
|
|
| Expense Ratio, Percent |
2.14%
|
[25] |
| Net Assets |
$ 279,879,322
|
|
| Holdings Count | Holding |
50
|
[26] |
| Investment Company Portfolio Turnover |
37.29%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$279,879,322 |
| Total number of portfolio holdings1 |
50 |
| Portfolio turnover rate |
37.29% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Consumer Discretionary |
10.7% |
| Energy |
1.0% |
| Financials |
11.0% |
| Health Care |
18.9% |
| Industrials |
35.8% |
| Information Technology |
16.5% |
| Real Estate |
4.9% |
| Short-Term Investments and Other Net Assets |
1.2% |
|
100.0% |
|
|
| C000051550 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Weatherbie Specialized Growth Fund
|
|
| Class Name |
Class I
|
|
| Trading Symbol |
ASIMX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Weatherbie Specialized Growth Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Weatherbie Specialized Growth Fund
(Class I / ASIMX) |
$73 |
1.47%(a) |
|
|
| Expenses Paid, Amount |
$ 73
|
|
| Expense Ratio, Percent |
1.47%
|
[27] |
| Net Assets |
$ 279,879,322
|
|
| Holdings Count | Holding |
50
|
[28] |
| Investment Company Portfolio Turnover |
37.29%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$279,879,322 |
| Total number of portfolio holdings1 |
50 |
| Portfolio turnover rate |
37.29% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Consumer Discretionary |
10.7% |
| Energy |
1.0% |
| Financials |
11.0% |
| Health Care |
18.9% |
| Industrials |
35.8% |
| Information Technology |
16.5% |
| Real Estate |
4.9% |
| Short-Term Investments and Other Net Assets |
1.2% |
|
100.0% |
|
|
| C000024912 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Capital Appreciation Fund
|
|
| Class Name |
Class A
|
|
| Trading Symbol |
ACAAX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Capital Appreciation Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Capital Appreciation Fund
(Class A / ACAAX) |
$61 |
1.23%(a) |
|
|
| Expenses Paid, Amount |
$ 61
|
|
| Expense Ratio, Percent |
1.23%
|
[29] |
| Net Assets |
$ 2,673,454,626
|
|
| Holdings Count | Holding |
81
|
[30] |
| Investment Company Portfolio Turnover |
33.20%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$2,673,454,626 |
| Total number of portfolio holdings1 |
81 |
| Portfolio turnover rate |
33.20% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Communication Services |
12.3% |
| Consumer Discretionary |
12.1% |
| Consumer Staples |
0.2% |
| Energy |
0.7% |
| Financials |
1.9% |
| Health Care |
6.9% |
| Industrials |
5.7% |
| Information Technology |
56.6% |
| Materials |
0.2% |
| Real Estate |
0.7% |
| Utilities |
2.1% |
| Short-Term Investments and Other Net Assets |
0.6% |
|
100.0% |
|
|
| C000024914 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Capital Appreciation Fund
|
|
| Class Name |
Class C
|
|
| Trading Symbol |
ALCCX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Capital Appreciation Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Capital Appreciation Fund
(Class C / ALCCX) |
$98 |
1.99%(a) |
|
|
| Expenses Paid, Amount |
$ 98
|
|
| Expense Ratio, Percent |
1.99%
|
[31] |
| Net Assets |
$ 2,673,454,626
|
|
| Holdings Count | Holding |
81
|
[32] |
| Investment Company Portfolio Turnover |
33.20%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$2,673,454,626 |
| Total number of portfolio holdings1 |
81 |
| Portfolio turnover rate |
33.20% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Communication Services |
12.3% |
| Consumer Discretionary |
12.1% |
| Consumer Staples |
0.2% |
| Energy |
0.7% |
| Financials |
1.9% |
| Health Care |
6.9% |
| Industrials |
5.7% |
| Information Technology |
56.6% |
| Materials |
0.2% |
| Real Estate |
0.7% |
| Utilities |
2.1% |
| Short-Term Investments and Other Net Assets |
0.6% |
|
100.0% |
|
|
| C000095959 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Capital Appreciation Fund
|
|
| Class Name |
Class Z
|
|
| Trading Symbol |
ACAZX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Capital Appreciation Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Capital Appreciation Fund
(Class Z / ACAZX) |
$43 |
0.86%(a) |
|
|
| Expenses Paid, Amount |
$ 43
|
|
| Expense Ratio, Percent |
0.86%
|
[33] |
| Net Assets |
$ 2,673,454,626
|
|
| Holdings Count | Holding |
81
|
[34] |
| Investment Company Portfolio Turnover |
33.20%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$2,673,454,626 |
| Total number of portfolio holdings1 |
81 |
| Portfolio turnover rate |
33.20% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Communication Services |
12.3% |
| Consumer Discretionary |
12.1% |
| Consumer Staples |
0.2% |
| Energy |
0.7% |
| Financials |
1.9% |
| Health Care |
6.9% |
| Industrials |
5.7% |
| Information Technology |
56.6% |
| Materials |
0.2% |
| Real Estate |
0.7% |
| Utilities |
2.1% |
| Short-Term Investments and Other Net Assets |
0.6% |
|
100.0% |
|
|
| C000156504 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Mid Cap Growth Fund
|
|
| Class Name |
Class Z
|
|
| Trading Symbol |
AMCZX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Mid Cap Growth Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Mid Cap Growth Fund
(Class Z / AMCZX) |
$44 |
0.91%(a) |
|
|
| Expenses Paid, Amount |
$ 44
|
|
| Expense Ratio, Percent |
0.91%
|
[35] |
| Net Assets |
$ 278,855,342
|
|
| Holdings Count | Holding |
68
|
[36] |
| Investment Company Portfolio Turnover |
43.28%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$278,855,342 |
| Total number of portfolio holdings1 |
68 |
| Portfolio turnover rate |
43.28% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Communication Services |
3.9% |
| Consumer Discretionary |
12.4% |
| Consumer Staples |
2.6% |
| Energy |
0.9% |
| Financials |
7.0% |
| Health Care |
13.0% |
| Industrials |
29.1% |
| Information Technology |
22.1% |
| Materials |
1.8% |
| Real Estate |
2.6% |
| Utilities |
2.4% |
| Short-Term Investments and Other Net Assets |
2.2% |
|
100.0% |
|
|
| C000024909 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Mid Cap Growth Fund
|
|
| Class Name |
Class A
|
|
| Trading Symbol |
AMGAX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Mid Cap Growth Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Mid Cap Growth Fund
(Class A / AMGAX) |
$59 |
1.21%(a) |
|
|
| Expenses Paid, Amount |
$ 59
|
|
| Expense Ratio, Percent |
1.21%
|
[37] |
| Net Assets |
$ 278,855,342
|
|
| Holdings Count | Holding |
68
|
[38] |
| Investment Company Portfolio Turnover |
43.28%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$278,855,342 |
| Total number of portfolio holdings1 |
68 |
| Portfolio turnover rate |
43.28% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Communication Services |
3.9% |
| Consumer Discretionary |
12.4% |
| Consumer Staples |
2.6% |
| Energy |
0.9% |
| Financials |
7.0% |
| Health Care |
13.0% |
| Industrials |
29.1% |
| Information Technology |
22.1% |
| Materials |
1.8% |
| Real Estate |
2.6% |
| Utilities |
2.4% |
| Short-Term Investments and Other Net Assets |
2.2% |
|
100.0% |
|
|
| C000024911 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Mid Cap Growth Fund
|
|
| Class Name |
Class C
|
|
| Trading Symbol |
AMGCX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Mid Cap Growth Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Mid Cap Growth Fund
(Class C / AMGCX) |
$99 |
2.03%(a) |
|
|
| Expenses Paid, Amount |
$ 99
|
|
| Expense Ratio, Percent |
2.03%
|
[39] |
| Net Assets |
$ 278,855,342
|
|
| Holdings Count | Holding |
68
|
[40] |
| Investment Company Portfolio Turnover |
43.28%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$278,855,342 |
| Total number of portfolio holdings1 |
68 |
| Portfolio turnover rate |
43.28% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Communication Services |
3.9% |
| Consumer Discretionary |
12.4% |
| Consumer Staples |
2.6% |
| Energy |
0.9% |
| Financials |
7.0% |
| Health Care |
13.0% |
| Industrials |
29.1% |
| Information Technology |
22.1% |
| Materials |
1.8% |
| Real Estate |
2.6% |
| Utilities |
2.4% |
| Short-Term Investments and Other Net Assets |
2.2% |
|
100.0% |
|
|
| C000024910 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Mid Cap Growth Fund
|
|
| Class Name |
Class B
|
|
| Trading Symbol |
AMCGX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Mid Cap Growth Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Mid Cap Growth Fund
(Class B / AMCGX) |
$68 |
1.40%(a) |
|
|
| Expenses Paid, Amount |
$ 68
|
|
| Expense Ratio, Percent |
1.40%
|
[41] |
| Net Assets |
$ 278,855,342
|
|
| Holdings Count | Holding |
68
|
[42] |
| Investment Company Portfolio Turnover |
43.28%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$278,855,342 |
| Total number of portfolio holdings1 |
68 |
| Portfolio turnover rate |
43.28% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Communication Services |
3.9% |
| Consumer Discretionary |
12.4% |
| Consumer Staples |
2.6% |
| Energy |
0.9% |
| Financials |
7.0% |
| Health Care |
13.0% |
| Industrials |
29.1% |
| Information Technology |
22.1% |
| Materials |
1.8% |
| Real Estate |
2.6% |
| Utilities |
2.4% |
| Short-Term Investments and Other Net Assets |
2.2% |
|
100.0% |
|
|
| C000111113 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Growth & Income Fund
|
|
| Class Name |
Class Z
|
|
| Trading Symbol |
AGIZX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Growth & Income Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Growth & Income Fund
(Class Z / AGIZX) |
$32 |
0.61%(a) |
|
|
| Expenses Paid, Amount |
$ 32
|
|
| Expense Ratio, Percent |
0.61%
|
[43] |
| Net Assets |
$ 892,240,244
|
|
| Holdings Count | Holding |
78
|
[44] |
| Investment Company Portfolio Turnover |
1.80%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$892,240,244 |
| Total number of portfolio holdings1 |
78 |
| Portfolio turnover rate |
1.80% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Communication Services |
12.8% |
| Consumer Discretionary |
6.9% |
| Consumer Staples |
5.1% |
| Energy |
4.5% |
| Financials |
12.5% |
| Health Care |
8.5% |
| Industrials |
5.1% |
| Information Technology |
33.0% |
| Materials |
2.1% |
| Real Estate |
2.8% |
| Utilities |
1.4% |
| Short-Term Investments and Other Net Assets |
5.3% |
|
100.0% |
|
|
| C000024906 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Growth & Income Fund
|
|
| Class Name |
Class A
|
|
| Trading Symbol |
ALBAX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Growth & Income Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Growth & Income Fund
(Class A / ALBAX) |
$48 |
0.92%(a) |
|
|
| Expenses Paid, Amount |
$ 48
|
|
| Expense Ratio, Percent |
0.92%
|
[45] |
| Net Assets |
$ 892,240,244
|
|
| Holdings Count | Holding |
78
|
[46] |
| Investment Company Portfolio Turnover |
1.80%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$892,240,244 |
| Total number of portfolio holdings1 |
78 |
| Portfolio turnover rate |
1.80% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Communication Services |
12.8% |
| Consumer Discretionary |
6.9% |
| Consumer Staples |
5.1% |
| Energy |
4.5% |
| Financials |
12.5% |
| Health Care |
8.5% |
| Industrials |
5.1% |
| Information Technology |
33.0% |
| Materials |
2.1% |
| Real Estate |
2.8% |
| Utilities |
1.4% |
| Short-Term Investments and Other Net Assets |
5.3% |
|
100.0% |
|
|
| C000024908 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Growth & Income Fund
|
|
| Class Name |
Class C
|
|
| Trading Symbol |
ALBCX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Growth & Income Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Growth & Income Fund
(Class C / ALBCX) |
$87 |
1.67%(a) |
|
|
| Expenses Paid, Amount |
$ 87
|
|
| Expense Ratio, Percent |
1.67%
|
[47] |
| Net Assets |
$ 892,240,244
|
|
| Holdings Count | Holding |
78
|
[48] |
| Investment Company Portfolio Turnover |
1.80%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$892,240,244 |
| Total number of portfolio holdings1 |
78 |
| Portfolio turnover rate |
1.80% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Communication Services |
12.8% |
| Consumer Discretionary |
6.9% |
| Consumer Staples |
5.1% |
| Energy |
4.5% |
| Financials |
12.5% |
| Health Care |
8.5% |
| Industrials |
5.1% |
| Information Technology |
33.0% |
| Materials |
2.1% |
| Real Estate |
2.8% |
| Utilities |
1.4% |
| Short-Term Investments and Other Net Assets |
5.3% |
|
100.0% |
|
|
| C000232602 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Small Cap Growth Fund
|
|
| Class Name |
Class Z
|
|
| Trading Symbol |
ASCZX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Small Cap Growth Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Small Cap Growth Fund
(Class Z / ASCZX) |
$50 |
0.99%(a) |
|
|
| Expenses Paid, Amount |
$ 50
|
|
| Expense Ratio, Percent |
0.99%
|
[49] |
| Net Assets |
$ 190,673,610
|
|
| Holdings Count | Holding |
108
|
[50] |
| Investment Company Portfolio Turnover |
8.42%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$190,673,610 |
| Total number of portfolio holdings1 |
108 |
| Portfolio turnover rate |
8.42% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Communication Services |
0.8% |
| Consumer Discretionary |
7.5% |
| Consumer Staples |
0.9% |
| Energy |
0.5% |
| Financials |
2.7% |
| Health Care |
33.0% |
| Industrials |
28.6% |
| Information Technology |
24.1% |
| Materials |
0.1% |
| Utilities |
0.6% |
| Short-Term Investments and Other Net Assets |
1.2% |
|
100.0% |
|
|
| C000095958 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Small Cap Growth Fund
|
|
| Class Name |
Class Y
|
|
| Trading Symbol |
ASCYX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Small Cap Growth Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Small Cap Growth Fund
(Class Y / ASCYX) |
$42 |
0.84%(a) |
|
|
| Expenses Paid, Amount |
$ 42
|
|
| Expense Ratio, Percent |
0.84%
|
[51] |
| Net Assets |
$ 190,673,610
|
|
| Holdings Count | Holding |
108
|
[52] |
| Investment Company Portfolio Turnover |
8.42%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$190,673,610 |
| Total number of portfolio holdings1 |
108 |
| Portfolio turnover rate |
8.42% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Communication Services |
0.8% |
| Consumer Discretionary |
7.5% |
| Consumer Staples |
0.9% |
| Energy |
0.5% |
| Financials |
2.7% |
| Health Care |
33.0% |
| Industrials |
28.6% |
| Information Technology |
24.1% |
| Materials |
0.1% |
| Utilities |
0.6% |
| Short-Term Investments and Other Net Assets |
1.2% |
|
100.0% |
|
|
| C000024905 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Small Cap Growth Fund
|
|
| Class Name |
Class C
|
|
| Trading Symbol |
AGSCX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Small Cap Growth Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Small Cap Growth Fund
(Class C / AGSCX) |
$106 |
2.12%(a) |
|
|
| Expenses Paid, Amount |
$ 106
|
|
| Expense Ratio, Percent |
2.12%
|
[53] |
| Net Assets |
$ 190,673,610
|
|
| Holdings Count | Holding |
108
|
[54] |
| Investment Company Portfolio Turnover |
8.42%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$190,673,610 |
| Total number of portfolio holdings1 |
108 |
| Portfolio turnover rate |
8.42% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Communication Services |
0.8% |
| Consumer Discretionary |
7.5% |
| Consumer Staples |
0.9% |
| Energy |
0.5% |
| Financials |
2.7% |
| Health Care |
33.0% |
| Industrials |
28.6% |
| Information Technology |
24.1% |
| Materials |
0.1% |
| Utilities |
0.6% |
| Short-Term Investments and Other Net Assets |
1.2% |
|
100.0% |
|
|
| C000024903 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Small Cap Growth Fund
|
|
| Class Name |
Class A
|
|
| Trading Symbol |
ALSAX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Small Cap Growth Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Small Cap Growth Fund
(Class A / ALSAX) |
$66 |
1.32%(a) |
|
|
| Expenses Paid, Amount |
$ 66
|
|
| Expense Ratio, Percent |
1.32%
|
[55] |
| Net Assets |
$ 190,673,610
|
|
| Holdings Count | Holding |
108
|
[56] |
| Investment Company Portfolio Turnover |
8.42%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$190,673,610 |
| Total number of portfolio holdings1 |
108 |
| Portfolio turnover rate |
8.42% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Communication Services |
0.8% |
| Consumer Discretionary |
7.5% |
| Consumer Staples |
0.9% |
| Energy |
0.5% |
| Financials |
2.7% |
| Health Care |
33.0% |
| Industrials |
28.6% |
| Information Technology |
24.1% |
| Materials |
0.1% |
| Utilities |
0.6% |
| Short-Term Investments and Other Net Assets |
1.2% |
|
100.0% |
|
|
| C000024904 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Small Cap Growth Fund
|
|
| Class Name |
Class B
|
|
| Trading Symbol |
ALSCX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Small Cap Growth Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Small Cap Growth Fund
(Class B / ALSCX) |
$55 |
1.09%(a) |
|
|
| Expenses Paid, Amount |
$ 55
|
|
| Expense Ratio, Percent |
1.09%
|
[57] |
| Net Assets |
$ 190,673,610
|
|
| Holdings Count | Holding |
108
|
[58] |
| Investment Company Portfolio Turnover |
8.42%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$190,673,610 |
| Total number of portfolio holdings1 |
108 |
| Portfolio turnover rate |
8.42% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Communication Services |
0.8% |
| Consumer Discretionary |
7.5% |
| Consumer Staples |
0.9% |
| Energy |
0.5% |
| Financials |
2.7% |
| Health Care |
33.0% |
| Industrials |
28.6% |
| Information Technology |
24.1% |
| Materials |
0.1% |
| Utilities |
0.6% |
| Short-Term Investments and Other Net Assets |
1.2% |
|
100.0% |
|
|
| C000024900 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger International Opportunities Fund
|
|
| Class Name |
Class A
|
|
| Trading Symbol |
ALGAX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger International Opportunities Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger International Opportunities Fund
(Class A / ALGAX) |
$62 |
1.23%(a) |
|
|
| Expenses Paid, Amount |
$ 62
|
|
| Expense Ratio, Percent |
1.23%
|
[59] |
| Net Assets |
$ 172,192,294
|
|
| Holdings Count | Holding |
40
|
[60] |
| Investment Company Portfolio Turnover |
28.03%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$172,192,294 |
| Total number of portfolio holdings1 |
40 |
| Portfolio turnover rate |
28.03% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Geographical Allocation †
| Belgium |
1.8% |
| Brazil |
5.4% |
| Canada |
6.6% |
| China |
2.9% |
| Denmark |
3.4% |
| France |
1.6% |
| Germany |
4.5% |
| Greece |
2.7% |
| Hungary |
1.4% |
| Italy |
4.5% |
| Japan |
20.3% |
| Netherlands |
1.7% |
| Norway |
2.0% |
| Peru |
2.5% |
| South Korea |
8.4% |
| Spain |
4.6% |
| Sweden |
1.8% |
| Switzerland |
1.7% |
| Taiwan |
8.3% |
| United Kingdom |
7.1% |
| United States |
4.4% |
| Short-Term Investments and Net Other Assets |
2.4% |
|
100.0% |
|
|
| C000024901 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger International Opportunities Fund
|
|
| Class Name |
Class B
|
|
| Trading Symbol |
AFGPX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger International Opportunities Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months? (Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger International Opportunities Fund
(Class B / AFGPX) |
$64 |
1.28%(a) |
|
|
| Expenses Paid, Amount |
$ 64
|
|
| Expense Ratio, Percent |
1.28%
|
[61] |
| Net Assets |
$ 172,192,294
|
|
| Holdings Count | Holding |
40
|
[62] |
| Investment Company Portfolio Turnover |
28.03%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$172,192,294 |
| Total number of portfolio holdings1 |
40 |
| Portfolio turnover rate |
28.03% |
|
1 |
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds. |
|
|
| Holdings [Text Block] |
Geographical Allocation †
| Belgium |
1.8% |
| Brazil |
5.4% |
| Canada |
6.6% |
| China |
2.9% |
| Denmark |
3.4% |
| France |
1.6% |
| Germany |
4.5% |
| Greece |
2.7% |
| Hungary |
1.4% |
| Italy |
4.5% |
| Japan |
20.3% |
| Netherlands |
1.7% |
| Norway |
2.0% |
| Peru |
2.5% |
| South Korea |
8.4% |
| Spain |
4.6% |
| Sweden |
1.8% |
| Switzerland |
1.7% |
| Taiwan |
8.3% |
| United Kingdom |
7.1% |
| United States |
4.4% |
| Short-Term Investments and Net Other Assets |
2.4% |
|
100.0% |
|
|
| C000095957 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger International Opportunities Fund
|
|
| Class Name |
Class Z
|
|
| Trading Symbol |
ALCZX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger International Opportunities Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger International Opportunities Fund
(Class Z / ALCZX) |
$43 |
0.85%(a) |
|
|
| Expenses Paid, Amount |
$ 43
|
|
| Expense Ratio, Percent |
0.85%
|
[63] |
| Net Assets |
$ 172,192,294
|
|
| Holdings Count | Holding |
40
|
[64] |
| Investment Company Portfolio Turnover |
28.03%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$172,192,294 |
| Total number of portfolio holdings1 |
40 |
| Portfolio turnover rate |
28.03% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Geographical Allocation †
| Belgium |
1.8% |
| Brazil |
5.4% |
| Canada |
6.6% |
| China |
2.9% |
| Denmark |
3.4% |
| France |
1.6% |
| Germany |
4.5% |
| Greece |
2.7% |
| Hungary |
1.4% |
| Italy |
4.5% |
| Japan |
20.3% |
| Netherlands |
1.7% |
| Norway |
2.0% |
| Peru |
2.5% |
| South Korea |
8.4% |
| Spain |
4.6% |
| Sweden |
1.8% |
| Switzerland |
1.7% |
| Taiwan |
8.3% |
| United Kingdom |
7.1% |
| United States |
4.4% |
| Short-Term Investments and Net Other Assets |
2.4% |
|
100.0% |
|
|
| C000039971 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger International Opportunities Fund
|
|
| Class Name |
Class I
|
|
| Trading Symbol |
AIGIX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger International Opportunities Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months? (Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger International Opportunities Fund
(Class I / AIGIX) |
$62 |
1.24%(a) |
|
|
| Expenses Paid, Amount |
$ 62
|
|
| Expense Ratio, Percent |
1.24%
|
[65] |
| Net Assets |
$ 172,192,294
|
|
| Holdings Count | Holding |
40
|
[66] |
| Investment Company Portfolio Turnover |
28.03%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$172,192,294 |
| Total number of portfolio holdings1 |
40 |
| Portfolio turnover rate |
28.03% |
|
1 |
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds. |
|
|
| Holdings [Text Block] |
Geographical Allocation †
| Belgium |
1.8% |
| Brazil |
5.4% |
| Canada |
6.6% |
| China |
2.9% |
| Denmark |
3.4% |
| France |
1.6% |
| Germany |
4.5% |
| Greece |
2.7% |
| Hungary |
1.4% |
| Italy |
4.5% |
| Japan |
20.3% |
| Netherlands |
1.7% |
| Norway |
2.0% |
| Peru |
2.5% |
| South Korea |
8.4% |
| Spain |
4.6% |
| Sweden |
1.8% |
| Switzerland |
1.7% |
| Taiwan |
8.3% |
| United Kingdom |
7.1% |
| United States |
4.4% |
| Short-Term Investments and Net Other Assets |
2.4% |
|
100.0% |
|
|
| C000024902 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger International Opportunities Fund
|
|
| Class Name |
Class C
|
|
| Trading Symbol |
ALGCX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger International Opportunities Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months? (Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger International Opportunities Fund
(Class C / ALGCX) |
$102 |
2.04%(a) |
|
|
| Expenses Paid, Amount |
$ 102
|
|
| Expense Ratio, Percent |
2.04%
|
[67] |
| Net Assets |
$ 172,192,294
|
|
| Holdings Count | Holding |
40
|
[68] |
| Investment Company Portfolio Turnover |
28.03%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$172,192,294 |
| Total number of portfolio holdings1 |
40 |
| Portfolio turnover rate |
28.03% |
|
1 |
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds. |
|
|
| Holdings [Text Block] |
Geographical Allocation †
| Belgium |
1.8% |
| Brazil |
5.4% |
| Canada |
6.6% |
| China |
2.9% |
| Denmark |
3.4% |
| France |
1.6% |
| Germany |
4.5% |
| Greece |
2.7% |
| Hungary |
1.4% |
| Italy |
4.5% |
| Japan |
20.3% |
| Netherlands |
1.7% |
| Norway |
2.0% |
| Peru |
2.5% |
| South Korea |
8.4% |
| Spain |
4.6% |
| Sweden |
1.8% |
| Switzerland |
1.7% |
| Taiwan |
8.3% |
| United Kingdom |
7.1% |
| United States |
4.4% |
| Short-Term Investments and Net Other Assets |
2.4% |
|
100.0% |
|
|
| C000248570 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Concentrated Equity Fund
|
|
| Class Name |
Class Z
|
|
| Trading Symbol |
CNEZX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Concentrated Equity Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Concentrated Equity Fund
(Class Z / CNEZX) |
$28 |
0.56%(a) |
|
|
| Expenses Paid, Amount |
$ 28
|
|
| Expense Ratio, Percent |
0.56%
|
[69] |
| Net Assets |
$ 8,811,882
|
|
| Holdings Count | Holding |
29
|
[70] |
| Investment Company Portfolio Turnover |
29.34%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$8,811,882 |
| Total number of portfolio holdings1 |
29 |
| Portfolio turnover rate |
29.34% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Communication Services |
11.3% |
| Consumer Discretionary |
12.6% |
| Financials |
1.5% |
| Health Care |
4.3% |
| Industrials |
10.4% |
| Information Technology |
55.5% |
| Utilities |
2.7% |
| Short-Term Investments and Other Net Assets |
1.7% |
|
100.0% |
|
|
| C000248568 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Concentrated Equity Fund
|
|
| Class Name |
Class I
|
|
| Trading Symbol |
CNEIX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Concentrated Equity Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Concentrated Equity Fund
(Class I / CNEIX) |
$40 |
0.81%(a) |
|
|
| Expenses Paid, Amount |
$ 40
|
|
| Expense Ratio, Percent |
0.81%
|
[71] |
| Net Assets |
$ 8,811,882
|
|
| Holdings Count | Holding |
29
|
[72] |
| Investment Company Portfolio Turnover |
29.34%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$8,811,882 |
| Total number of portfolio holdings1 |
29 |
| Portfolio turnover rate |
29.34% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Communication Services |
11.3% |
| Consumer Discretionary |
12.6% |
| Financials |
1.5% |
| Health Care |
4.3% |
| Industrials |
10.4% |
| Information Technology |
55.5% |
| Utilities |
2.7% |
| Short-Term Investments and Other Net Assets |
1.7% |
|
100.0% |
|
|
| C000248569 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Concentrated Equity Fund
|
|
| Class Name |
Class Y
|
|
| Trading Symbol |
CNEYX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Concentrated Equity Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Concentrated Equity Fund
(Class Y / CNEYX) |
$28 |
0.56%(a) |
|
|
| Expenses Paid, Amount |
$ 28
|
|
| Expense Ratio, Percent |
0.56%
|
[73] |
| Net Assets |
$ 8,811,882
|
|
| Holdings Count | Holding |
29
|
[74] |
| Investment Company Portfolio Turnover |
29.34%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$8,811,882 |
| Total number of portfolio holdings1 |
29 |
| Portfolio turnover rate |
29.34% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Communication Services |
11.3% |
| Consumer Discretionary |
12.6% |
| Financials |
1.5% |
| Health Care |
4.3% |
| Industrials |
10.4% |
| Information Technology |
55.5% |
| Utilities |
2.7% |
| Short-Term Investments and Other Net Assets |
1.7% |
|
100.0% |
|
|
| C000248571 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Concentrated Equity Fund
|
|
| Class Name |
Class A
|
|
| Trading Symbol |
CNEAX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Concentrated Equity Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Concentrated Equity Fund
(Class A / CNEAX) |
$40 |
0.81%(a) |
|
|
| Expenses Paid, Amount |
$ 40
|
|
| Expense Ratio, Percent |
0.81%
|
[75] |
| Net Assets |
$ 8,811,882
|
|
| Holdings Count | Holding |
29
|
[76] |
| Investment Company Portfolio Turnover |
29.34%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$8,811,882 |
| Total number of portfolio holdings1 |
29 |
| Portfolio turnover rate |
29.34% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Communication Services |
11.3% |
| Consumer Discretionary |
12.6% |
| Financials |
1.5% |
| Health Care |
4.3% |
| Industrials |
10.4% |
| Information Technology |
55.5% |
| Utilities |
2.7% |
| Short-Term Investments and Other Net Assets |
1.7% |
|
100.0% |
|
|
| C000248567 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Concentrated Equity Fund
|
|
| Class Name |
Class C
|
|
| Trading Symbol |
CNECX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Concentrated Equity Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Concentrated Equity Fund
(Class C / CNECX) |
$78 |
1.56%(a) |
|
|
| Expenses Paid, Amount |
$ 78
|
|
| Expense Ratio, Percent |
1.56%
|
[77] |
| Net Assets |
$ 8,811,882
|
|
| Holdings Count | Holding |
29
|
[78] |
| Investment Company Portfolio Turnover |
29.34%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$8,811,882 |
| Total number of portfolio holdings1 |
29 |
| Portfolio turnover rate |
29.34% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Communication Services |
11.3% |
| Consumer Discretionary |
12.6% |
| Financials |
1.5% |
| Health Care |
4.3% |
| Industrials |
10.4% |
| Information Technology |
55.5% |
| Utilities |
2.7% |
| Short-Term Investments and Other Net Assets |
1.7% |
|
100.0% |
|
|
| C000206144 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Mid Cap Focus Fund
|
|
| Class Name |
Class I
|
|
| Trading Symbol |
AFOIX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Mid Cap Focus Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Mid Cap Focus Fund
(Class I / AFOIX) |
$55 |
1.14%(a) |
|
|
| Expenses Paid, Amount |
$ 55
|
|
| Expense Ratio, Percent |
1.14%
|
[79] |
| Net Assets |
$ 317,706,767
|
|
| Holdings Count | Holding |
50
|
[80] |
| Investment Company Portfolio Turnover |
96.30%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$317,706,767 |
| Total number of portfolio holdings1 |
50 |
| Portfolio turnover rate |
96.30% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Communication Services |
1.0% |
| Consumer Discretionary |
3.5% |
| Financials |
1.2% |
| Health Care |
24.6% |
| Industrials |
33.0% |
| Information Technology |
29.0% |
| Materials |
1.3% |
| Utilities |
1.9% |
| Short-Term Investments and Other Net Assets |
4.5% |
|
100.0% |
|
|
| C000225967 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Mid Cap Focus Fund
|
|
| Class Name |
Class Y
|
|
| Trading Symbol |
ALOYX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Mid Cap Focus Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Mid Cap Focus Fund
(Class Y / ALOYX) |
$35 |
0.72%(a) |
|
|
| Expenses Paid, Amount |
$ 35
|
|
| Expense Ratio, Percent |
0.72%
|
[81] |
| Net Assets |
$ 317,706,767
|
|
| Holdings Count | Holding |
50
|
[82] |
| Investment Company Portfolio Turnover |
96.30%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$317,706,767 |
| Total number of portfolio holdings1 |
50 |
| Portfolio turnover rate |
96.30% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Communication Services |
1.0% |
| Consumer Discretionary |
3.5% |
| Financials |
1.2% |
| Health Care |
24.6% |
| Industrials |
33.0% |
| Information Technology |
29.0% |
| Materials |
1.3% |
| Utilities |
1.9% |
| Short-Term Investments and Other Net Assets |
4.5% |
|
100.0% |
|
|
| C000206145 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Mid Cap Focus Fund
|
|
| Class Name |
Class Z
|
|
| Trading Symbol |
AFOZX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Mid Cap Focus Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Mid Cap Focus Fund
(Class Z / AFOZX) |
$39 |
0.80%(a) |
|
|
| Expenses Paid, Amount |
$ 39
|
|
| Expense Ratio, Percent |
0.80%
|
[83] |
| Net Assets |
$ 317,706,767
|
|
| Holdings Count | Holding |
50
|
[84] |
| Investment Company Portfolio Turnover |
96.30%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$317,706,767 |
| Total number of portfolio holdings1 |
50 |
| Portfolio turnover rate |
96.30% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Communication Services |
1.0% |
| Consumer Discretionary |
3.5% |
| Financials |
1.2% |
| Health Care |
24.6% |
| Industrials |
33.0% |
| Information Technology |
29.0% |
| Materials |
1.3% |
| Utilities |
1.9% |
| Short-Term Investments and Other Net Assets |
4.5% |
|
100.0% |
|
|
| C000228969 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Mid Cap Focus Fund
|
|
| Class Name |
Class A
|
|
| Trading Symbol |
ALOAX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Mid Cap Focus Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Mid Cap Focus Fund
(Class A / ALOAX) |
$54 |
1.11%(a) |
|
|
| Expenses Paid, Amount |
$ 54
|
|
| Expense Ratio, Percent |
1.11%
|
[85] |
| Net Assets |
$ 317,706,767
|
|
| Holdings Count | Holding |
50
|
[86] |
| Investment Company Portfolio Turnover |
96.30%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$317,706,767 |
| Total number of portfolio holdings1 |
50 |
| Portfolio turnover rate |
96.30% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Communication Services |
1.0% |
| Consumer Discretionary |
3.5% |
| Financials |
1.2% |
| Health Care |
24.6% |
| Industrials |
33.0% |
| Information Technology |
29.0% |
| Materials |
1.3% |
| Utilities |
1.9% |
| Short-Term Investments and Other Net Assets |
4.5% |
|
100.0% |
|
|
| C000228970 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger Mid Cap Focus Fund
|
|
| Class Name |
Class C
|
|
| Trading Symbol |
ALOCX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger Mid Cap Focus Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger Mid Cap Focus Fund
(Class C / ALOCX) |
$91 |
1.88%(a) |
|
|
| Expenses Paid, Amount |
$ 91
|
|
| Expense Ratio, Percent |
1.88%
|
[87] |
| Net Assets |
$ 317,706,767
|
|
| Holdings Count | Holding |
50
|
[88] |
| Investment Company Portfolio Turnover |
96.30%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$317,706,767 |
| Total number of portfolio holdings1 |
50 |
| Portfolio turnover rate |
96.30% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Communication Services |
1.0% |
| Consumer Discretionary |
3.5% |
| Financials |
1.2% |
| Health Care |
24.6% |
| Industrials |
33.0% |
| Information Technology |
29.0% |
| Materials |
1.3% |
| Utilities |
1.9% |
| Short-Term Investments and Other Net Assets |
4.5% |
|
100.0% |
|
|
| C000248576 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger AI Enablers & Adopters Fund
|
|
| Class Name |
Class A
|
|
| Trading Symbol |
AIFAX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger AI Enablers & Adopters Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger AI Enablers & Adopters Fund
(Class A / AIFAX) |
$42 |
0.83%(a) |
|
|
| Expenses Paid, Amount |
$ 42
|
|
| Expense Ratio, Percent |
0.83%
|
[89] |
| Net Assets |
$ 22,854,360
|
|
| Holdings Count | Holding |
60
|
[90] |
| Investment Company Portfolio Turnover |
89.63%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$22,854,360 |
| Total number of portfolio holdings1 |
60 |
| Portfolio turnover rate |
89.63% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Communication Services |
13.4% |
| Consumer Discretionary |
12.4% |
| Financials |
1.3% |
| Health Care |
2.6% |
| Industrials |
3.2% |
| Information Technology |
65.0% |
| Utilities |
1.7% |
| Short-Term Investments and Other Net Assets |
0.4% |
|
100.0% |
|
|
| C000248572 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger AI Enablers & Adopters Fund
|
|
| Class Name |
Class C
|
|
| Trading Symbol |
AAICX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger AI Enablers & Adopters Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger AI Enablers & Adopters Fund
(Class C / AAICX) |
$80 |
1.58%(a) |
|
|
| Expenses Paid, Amount |
$ 80
|
|
| Expense Ratio, Percent |
1.58%
|
[91] |
| Net Assets |
$ 22,854,360
|
|
| Holdings Count | Holding |
60
|
[92] |
| Investment Company Portfolio Turnover |
89.63%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$22,854,360 |
| Total number of portfolio holdings1 |
60 |
| Portfolio turnover rate |
89.63% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Communication Services |
13.4% |
| Consumer Discretionary |
12.4% |
| Financials |
1.3% |
| Health Care |
2.6% |
| Industrials |
3.2% |
| Information Technology |
65.0% |
| Utilities |
1.7% |
| Short-Term Investments and Other Net Assets |
0.4% |
|
100.0% |
|
|
| C000248573 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger AI Enablers & Adopters Fund
|
|
| Class Name |
Class I
|
|
| Trading Symbol |
AIFIX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger AI Enablers & Adopters Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger AI Enablers & Adopters Fund
(Class I / AIFIX) |
$42 |
0.83%(a) |
|
|
| Expenses Paid, Amount |
$ 42
|
|
| Expense Ratio, Percent |
0.83%
|
[93] |
| Net Assets |
$ 22,854,360
|
|
| Holdings Count | Holding |
60
|
[94] |
| Investment Company Portfolio Turnover |
89.63%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$22,854,360 |
| Total number of portfolio holdings1 |
60 |
| Portfolio turnover rate |
89.63% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Communication Services |
13.4% |
| Consumer Discretionary |
12.4% |
| Financials |
1.3% |
| Health Care |
2.6% |
| Industrials |
3.2% |
| Information Technology |
65.0% |
| Utilities |
1.7% |
| Short-Term Investments and Other Net Assets |
0.4% |
|
100.0% |
|
|
| C000248574 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger AI Enablers & Adopters Fund
|
|
| Class Name |
Class Y
|
|
| Trading Symbol |
AAIYX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger AI Enablers & Adopters Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger AI Enablers & Adopters Fund
(Class Y / AAIYX) |
$29 |
0.57%(a) |
|
|
| Expenses Paid, Amount |
$ 29
|
|
| Expense Ratio, Percent |
0.57%
|
[95] |
| Net Assets |
$ 22,854,360
|
|
| Holdings Count | Holding |
60
|
[96] |
| Investment Company Portfolio Turnover |
89.63%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$22,854,360 |
| Total number of portfolio holdings1 |
60 |
| Portfolio turnover rate |
89.63% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Communication Services |
13.4% |
| Consumer Discretionary |
12.4% |
| Financials |
1.3% |
| Health Care |
2.6% |
| Industrials |
3.2% |
| Information Technology |
65.0% |
| Utilities |
1.7% |
| Short-Term Investments and Other Net Assets |
0.4% |
|
100.0% |
|
|
| C000248575 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger AI Enablers & Adopters Fund
|
|
| Class Name |
Class Z
|
|
| Trading Symbol |
AAIZX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger AI Enablers & Adopters Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger AI Enablers & Adopters Fund
(Class Z / AAIZX) |
$29 |
0.58%(a) |
|
|
| Expenses Paid, Amount |
$ 29
|
|
| Expense Ratio, Percent |
0.58%
|
[97] |
| Net Assets |
$ 22,854,360
|
|
| Holdings Count | Holding |
60
|
[98] |
| Investment Company Portfolio Turnover |
89.63%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2026.
| Fund net assets |
$22,854,360 |
| Total number of portfolio holdings1 |
60 |
| Portfolio turnover rate |
89.63% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Sector Allocation †
| Communication Services |
13.4% |
| Consumer Discretionary |
12.4% |
| Financials |
1.3% |
| Health Care |
2.6% |
| Industrials |
3.2% |
| Information Technology |
65.0% |
| Utilities |
1.7% |
| Short-Term Investments and Other Net Assets |
0.4% |
|
100.0% |
|
|
| C000261739 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger International Small Cap Fund
|
|
| Class Name |
Class A
|
|
| Trading Symbol |
AFAIX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger International Small Cap Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
|
| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months?
(Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger International Small Cap Fund
(Class A / AFAIX) |
$62 |
1.20%(a) |
|
|
| Expenses Paid, Amount |
$ 62
|
|
| Expense Ratio, Percent |
1.20%
|
[99] |
| Net Assets |
$ 4,041,614
|
|
| Holdings Count | Holding |
47
|
[100] |
| Investment Company Portfolio Turnover |
21.97%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics
The following table outlines key fund statistics as of the fiscal six-month periodperiod ended April 30, 2026.
| Fund net assets |
$4,041,614 |
| Total number of portfolio holdings1 |
47 |
| Portfolio turnover rate |
21.97% |
|
1
|
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds.
|
|
|
| Holdings [Text Block] |
Geographical Allocation †
| Australia |
1.0% |
| Austria |
2.2% |
| Belgium |
2.5% |
| Brazil |
2.9% |
| Canada |
5.2% |
| Denmark |
3.0% |
| France |
4.2% |
| Germany |
6.6% |
| Hong Kong |
4.2% |
| Israel |
4.9% |
| Italy |
9.5% |
| Japan |
31.5% |
| Spain |
1.8% |
| Sweden |
3.7% |
| Switzerland |
2.1% |
| United Kingdom |
12.5% |
| Short-Term Investments and Net Other Assets |
2.2% |
|
100.0% |
|
|
| C000261740 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Alger International Small Cap Fund
|
|
| Class Name |
Class Z
|
|
| Trading Symbol |
AZISX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Alger International Small Cap Fund (“Fund”) for the period from November 1, 2025 to April 30, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information about the Fund at www.alger.com/fundliterature. You can also request a copy of the semi-annual report by contacting us at (800) 992-3863.
|
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| Additional Information Phone Number |
(800) 992-3863
|
|
| Additional Information Website |
www.alger.com/fundliterature
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|
| Expenses [Text Block] |
What were the Fund costs for the last six months? (Based on a hypothetical $10,000 investment)
| Fund (Class/Ticker) |
Costs of a $10,000 investment |
Costs paid as a percentage of a $10,000 investment |
Alger International Small Cap Fund
(Class Z / AZISX) |
$44 |
0.85%(a) |
|
|
| Expenses Paid, Amount |
$ 44
|
|
| Expense Ratio, Percent |
0.85%
|
[101] |
| Net Assets |
$ 4,041,614
|
|
| Holdings Count | Holding |
47
|
[102] |
| Investment Company Portfolio Turnover |
21.97%
|
|
| Additional Fund Statistics [Text Block] |
Key Fund Statistics The following table outlines key fund statistics as of the fiscal six-month periodperiod ended April 30, 2026.
| Fund net assets |
$4,041,614 |
| Total number of portfolio holdings1 |
47 |
| Portfolio turnover rate |
21.97% |
|
1 |
Number of portfolio holdings is calculated at the issuer level. Excludes Money Market Funds. |
|
|
| Holdings [Text Block] |
Geographical Allocation †
| Australia |
1.0% |
| Austria |
2.2% |
| Belgium |
2.5% |
| Brazil |
2.9% |
| Canada |
5.2% |
| Denmark |
3.0% |
| France |
4.2% |
| Germany |
6.6% |
| Hong Kong |
4.2% |
| Israel |
4.9% |
| Italy |
9.5% |
| Japan |
31.5% |
| Spain |
1.8% |
| Sweden |
3.7% |
| Switzerland |
2.1% |
| United Kingdom |
12.5% |
| Short-Term Investments and Net Other Assets |
2.2% |
|
100.0% |
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