v3.25.2
Shareholder Report
 6 Months Ended
Jun. 30, 2025
USD ($)
Holding
Shareholder Report [Line Items]  
Document Type N-CSRS
Amendment Flag false
Registrant Name Gabelli Investor Funds, Inc.
Entity Central Index Key 0000893783
Entity Investment Company Type N-1A
Document Period End Date Jun. 30, 2025
C000002886  
Shareholder Report [Line Items]  
Fund Name The Gabelli ABC Fund
Class Name Class AAA
Trading Symbol GABCX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about The Gabelli ABC Fund (the Fund) for the period of January 1, 2025 to June 30, 2025.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You may find additional information about the Fund at www.gabelli.com/funds/open_ends. You may also request  information by contacting us at 800-GABELLI (800-422-3554).
Additional Information Phone Number 800-GABELLI (800-422-3554)
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 12px; font-weight: 400; grid-area: auto; line-height: 18px; margin: 0px; overflow: visible; text-align: justify; text-align-last: left; white-space-collapse: preserve-breaks;">www.gabelli.com/funds/open_ends</span>
Expenses [Text Block]

What were the Fund costs for the last six months? 

(based on a hypothetical $10,000 investment)

Class Name
Costs of a $10k Investment
Costs Paid as a % of a $10k Investment
The Gabelli ABC Fund - Class AAA
$48
0.96%
Expenses Paid, Amount $ 48
Expense Ratio, Percent 0.96%
Factors Affecting Performance [Text Block]

How did the Fund perform?

For the six months ended June 30, 2025, Gabelli ABC Fund underperformed its broad-based benchmark, the S&P 500 Index, while outperforming its comparatives, the ICE BofA 3 Month US Treasury Bill Index and the Lipper US Treasury Money Market Fund Average. Global merger and acquisition activity was strong in the first half of the year despite the uncertainty of tariffs and the current geopolitical environment. Changes at the FTC may mark a turning point, allowing more transactions to proceed and restoring corporate confidence in the regulatory process.
Performance Past Does Not Indicate Future [Text] Past performance does not guarantee future results.
Line Graph [Table Text Block]
Growth of 10K Chart
The Gabelli ABC Fund - Class AAA
S&P 500 Index
ICE BofA 3 Month U.S. Treasury Bill Index
Lipper U.S. Treasury Money-Market Fund Average
6/15
10,000
10,000
10,000
10,000
6/16
10,183
10,399
10,019
10,002
6/17
10,517
12,260
10,068
10,018
6/18
10,664
14,022
10,205
10,107
6/19
10,910
15,483
10,441
10,303
6/20
10,927
16,646
10,612
10,421
6/21
11,862
23,436
10,622
10,423
6/22
11,568
20,947
10,640
10,433
6/23
12,158
25,051
11,022
10,793
6/24
12,877
31,203
11,617
11,348
6/25
13,857
35,934
12,160
11,853
Average Annual Return [Table Text Block]
6 months
1 Year
5 Year
10 Year
The Gabelli ABC Fund - Class AAA
2.51%
7.61%
4.87%
3.32%
S&P 500 Index
6.20%
15.16%
16.64%
13.65%
ICE BofA 3 Month U.S. Treasury Bill Index
2.07%
4.68%
2.76%
1.98%
Lipper U.S. Treasury Money-Market Fund Average
2.01%
4.45%
2.61%
1.71%
No Deduction of Taxes [Text Block] The table and graph presented above do not reflect the deduction of taxes a shareholder would pay on fund distributions or the redemption of fund shares.
AssetsNet $ 430,427,592
Holdings Count | Holding 247
Advisory Fees Paid, Amount $ 1,073,658
InvestmentCompanyPortfolioTurnover 48.00%
Additional Fund Statistics [Text Block]

Fund Statistics

  • Total Net Assets$430,427,592
  • Number of Portfolio Holdings247
  • Portfolio Turnover Rate48%
  • Management Fees$1,073,658
Holdings [Text Block]

Portfolio Weighting (% of net assets)

Common Stocks
62.1%
Common Stocks – Securities Sold Short
(18.6)%
U.S. Government Obligations
40.4%
Rights
0.3%
Closed-End Funds
0.1%
Other Assets and Liabilities (Net)
15.7%

Industry Allocation (% of net assets)

Bar Graph showing Allocation by Industry
Value
Value
U.S. Government Obligations
40.4%
Building and Construction - Long
19.8%
Building and Construction - Short
(16.3)%
Health Care
7.6%
Energy and Utilities
6.3%
Financial Services
3.3%
Telecommunications
3.2%
Entertainment
3.0%
Real Estate - Long
2.9%
Real Estate - Short
(2.2)%
Other Industry sectors
16.3%
Other Assets and Liabilities (Net)
15.7%
Largest Holdings [Text Block]

Top 10 Holdings (% of net assets)

Lennar Corp. Cl B
19.7%
Lennar Corp. Cl A
(16.3)%
Millrose Properties Inc.
0.5%
SpringWorks Therapeutics Inc.
3.6%
FARO Technologies Inc.
1.5%
Fox Corp. Cl B
1.5%
TXNM Energy Inc.
1.4%
KKR & Co. Inc.
1.3%
Juniper Networks Inc.
1.1%
Dun & Bradstreet Holdings Inc.
1.1%
National Fuel Gas Co.
0.9%
Material Fund Change [Text Block]
Updated Prospectus Phone Number 800-GABELLI (800-422-3554)
Updated Prospectus Email Address <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 12px; font-weight: 400; grid-area: auto; line-height: 18px; margin: 0px; overflow: visible; text-align: justify; text-align-last: left; white-space-collapse: preserve-breaks;">info@gabelli.com</span>
Updated Prospectus Web Address <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 12px; font-weight: 400; grid-area: auto; line-height: 18px; margin: 0px; overflow: visible; text-align: justify; text-align-last: left; white-space-collapse: preserve-breaks;">www.gabelli.com/funds/open_ends</span>
C000050409  
Shareholder Report [Line Items]  
Fund Name The Gabelli ABC Fund
Class Name Advisor Class
Trading Symbol GADVX
Annual or Semi-Annual Statement [Text Block] This semi-annual shareholder report contains important information about The Gabelli ABC Fund (the Fund) for the period of January 1, 2025 to June 30, 2025.
Shareholder Report Annual or Semi-Annual semi-annual shareholder report
Additional Information [Text Block] You may find additional information about the Fund at www.gabelli.com/funds/open_ends. You may also request  information by contacting us at 800-GABELLI (800-422-3554).
Additional Information Phone Number 800-GABELLI (800-422-3554)
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 12px; font-weight: 400; grid-area: auto; line-height: 18px; margin: 0px; overflow: visible; text-align: justify; text-align-last: left; white-space-collapse: preserve-breaks;">www.gabelli.com/funds/open_ends</span>
Expenses [Text Block]

What were the Fund costs for the last six months? 

(based on a hypothetical $10,000 investment)

Class Name
Costs of a $10k Investment
Costs Paid as a % of a $10k Investment
The Gabelli ABC Fund - Advisor Class
$61
1.21%
Expenses Paid, Amount $ 61
Expense Ratio, Percent 1.21%
Factors Affecting Performance [Text Block]

How did the Fund perform?

For the six months ended June 30, 2025, Gabelli ABC Fund underperformed its broad-based benchmark, the S&P 500 Index, while outperforming its comparatives, the ICE BofA 3 Month US Treasury Bill Index and the Lipper US Treasury Money Market Fund Average. Global merger and acquisition activity was strong in the first half of the year despite the uncertainty of tariffs and the current geopolitical environment. Changes at the FTC may mark a turning point, allowing more transactions to proceed and restoring corporate confidence in the regulatory process.
Performance Past Does Not Indicate Future [Text] Past performance does not guarantee future results.
Line Graph [Table Text Block]
Growth of 10K Chart
The Gabelli ABC Fund - Advisor Class
S&P 500 Index
ICE BofA 3 Month U.S. Treasury Bill Index
Lipper U.S. Treasury Money-Market Fund Average
6/15
10,000
10,000
10,000
10,000
6/16
10,161
10,399
10,019
10,002
6/17
10,461
12,260
10,068
10,018
6/18
10,588
14,022
10,205
10,107
6/19
10,806
15,483
10,441
10,303
6/20
10,791
16,646
10,612
10,421
6/21
11,688
23,436
10,622
10,423
6/22
11,377
20,947
10,640
10,433
6/23
11,924
25,051
11,022
10,793
6/24
12,597
31,203
11,617
11,348
6/25
13,516
35,934
12,160
11,853
Average Annual Return [Table Text Block]
6 months
1 Year
5 Year
10 Year
The Gabelli ABC Fund - Advisor Class
2.35%
7.29%
4.61%
3.06%
S&P 500 Index
6.20%
15.16%
16.64%
13.65%
ICE BofA 3 Month U.S. Treasury Bill Index
2.07%
4.68%
2.76%
1.98%
Lipper U.S. Treasury Money-Market Fund Average
2.01%
4.45%
2.61%
1.71%
No Deduction of Taxes [Text Block] The table and graph presented above do not reflect the deduction of taxes a shareholder would pay on fund distributions or the redemption of fund shares.
AssetsNet $ 430,427,592
Holdings Count | Holding 247
Advisory Fees Paid, Amount $ 1,073,658
InvestmentCompanyPortfolioTurnover 48.00%
Additional Fund Statistics [Text Block]

Fund Statistics

  • Total Net Assets$430,427,592
  • Number of Portfolio Holdings247
  • Portfolio Turnover Rate48%
  • Management Fees$1,073,658
Holdings [Text Block]

Portfolio Weighting (% of net assets)

Common Stocks
62.1%
Common Stocks – Securities Sold Short
(18.6)%
U.S. Government Obligations
40.4%
Rights
0.3%
Closed-End Funds
0.1%
Other Assets and Liabilities (Net)
15.7%

Industry Allocation (% of net assets)

Bar Graph showing Allocation by Industry
Value
Value
U.S. Government Obligations
40.4%
Building and Construction - Long
19.8%
Building and Construction - Short
(16.3)%
Health Care
7.6%
Energy and Utilities
6.3%
Financial Services
3.3%
Telecommunications
3.2%
Entertainment
3.0%
Real Estate - Long
2.9%
Real Estate - Short
(2.2)%
Other Industry sectors
16.3%
Other Assets and Liabilities (Net)
15.7%
Largest Holdings [Text Block]

Top 10 Holdings (% of net assets)

Lennar Corp. Cl B
19.7%
Lennar Corp. Cl A
(16.3)%
Millrose Properties Inc.
0.5%
SpringWorks Therapeutics Inc.
3.6%
FARO Technologies Inc.
1.5%
Fox Corp. Cl B
1.5%
TXNM Energy Inc.
1.4%
KKR & Co. Inc.
1.3%
Juniper Networks Inc.
1.1%
Dun & Bradstreet Holdings Inc.
1.1%
National Fuel Gas Co.
0.9%
Material Fund Change [Text Block]
Updated Prospectus Phone Number 800-GABELLI (800-422-3554)
Updated Prospectus Email Address <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 12px; font-weight: 400; grid-area: auto; line-height: 18px; margin: 0px; overflow: visible; text-align: justify; text-align-last: left; white-space-collapse: preserve-breaks;">info@gabelli.com</span>
Updated Prospectus Web Address <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 12px; font-weight: 400; grid-area: auto; line-height: 18px; margin: 0px; overflow: visible; text-align: justify; text-align-last: left; white-space-collapse: preserve-breaks;">www.gabelli.com/funds/open_ends</span>