Shareholder Report
|
6 Months Ended |
|
Feb. 28, 2026
USD ($)
Holding
|
|---|
| Shareholder Report [Line Items] |
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|
| Document Type |
N-CSRS/A
|
|
| Amendment Flag |
false
|
|
| Registrant Name |
NUVEEN INVESTMENT FUNDS INC
|
|
| Entity Central Index Key |
0000820892
|
|
| Entity Investment Company Type |
N-1A
|
|
| Document Period End Date |
Feb. 28, 2026
|
|
| C000015080 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Nuveen Credit Income Fund
|
|
| Class Name |
Class I Shares
|
|
| Trading Symbol |
FJSYX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Class I Shares of the Nuveen Credit Income Fund for the period of September 1, 2025 to February 28, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information at https://www.nuveen.com/en‑us/mutual‑funds/prospectuses. You can also request this information by contacting us at (800) 257‑8787.
|
|
| Additional Information Phone Number |
(800) 257‑8787
|
|
| Additional Information Website |
https://www.nuveen.com/en‑us/mutual‑funds/prospectuses
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months? (based on a hypothetical $10,000 investment)
|
|
|
|
|
|
|
|
| |
|
Cost of a $10,000 investment |
|
Costs paid as a percentage of $10,000 investment* |
| |
|
|
| Class I Shares |
|
$36 |
|
0.70% | * Annualized for period less than one year.
|
|
| Expenses Paid, Amount |
$ 36
|
|
| Expense Ratio, Percent |
0.70%
|
[1] |
| Net Assets |
$ 364,856,428
|
|
| Holdings Count | Holding |
571
|
|
| Investment Company Portfolio Turnover |
31.00%
|
|
| Additional Fund Statistics [Text Block] |
Fund Statistics (as of February 28, 2026)
|
|
|
|
|
|
|
| Fund net assets |
|
$ |
364,856,428 |
|
|
|
| Total number of portfolio holdings |
|
|
571 |
|
|
|
| Portfolio turnover (%) |
|
|
31% |
|
|
|
| Holdings [Text Block] |
(1) Includes 7.8% of $1,000 Par Preferred and/or Contingent Capital Securities. (2) The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
|
|
| Credit Ratings Selection [Text Block] |
The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
|
|
| C000015078 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Nuveen Credit Income Fund
|
|
| Class Name |
Class C Shares
|
|
| Trading Symbol |
FCSIX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Class C Shares of the Nuveen Credit Income Fund for the period of September 1, 2025 to February 28, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information athttps://www.nuveen.com/en-us/mutual-funds/prospectuses. You can also request this information by contacting us at (800) 257-8787.
|
|
| Additional Information Phone Number |
(800) 257-8787
|
|
| Additional Information Website |
https://www.nuveen.com/en-us/mutual-funds/prospectuses
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months? (based on a hypothetical $10,000 investment)
|
|
|
|
|
|
|
|
| |
|
Cost of a $10,000 investment |
|
Costs paid as a percentage of $10,000 investment* |
| |
|
|
| Class C Shares |
|
$87 |
|
1.71% | * Annualized for period less than one year.
|
|
| Expenses Paid, Amount |
$ 87
|
|
| Expense Ratio, Percent |
1.71%
|
[2] |
| Net Assets |
$ 364,856,428
|
|
| Holdings Count | Holding |
571
|
|
| Investment Company Portfolio Turnover |
31.00%
|
|
| Additional Fund Statistics [Text Block] |
Fund Statistics (as of February 28, 2026)
|
|
|
|
|
|
|
| Fund net assets |
|
$ |
364,856,428 |
|
|
|
| Total number of portfolio holdings |
|
|
571 |
|
|
|
| Portfolio turnover (%) |
|
|
31% |
|
|
|
| Holdings [Text Block] |
(1) Includes 7.8% of $1,000 Par Preferred and/or Contingent Capital Securities. (2) The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
|
|
| Credit Ratings Selection [Text Block] |
The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
|
|
| C000015076 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Nuveen Credit Income Fund
|
|
| Class Name |
Class A Shares
|
|
| Trading Symbol |
FJSIX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Class A Shares of the Nuveen Credit Income Fund for the period of September 1, 2025 to February 28, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information athttps://www.nuveen.com/en‑us/mutual‑funds/prospectuses. You can also request this information by contacting us at (800) 257‑8787.
|
|
| Additional Information Phone Number |
(800) 257‑8787
|
|
| Additional Information Website |
https://www.nuveen.com/en‑us/mutual‑funds/prospectuses
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months? (based on a hypothetical $10,000 investment)
|
|
|
|
|
|
|
|
| |
|
Cost of a $10,000 investment |
|
Costs paid as a percentage of $10,000 investment* |
| |
|
|
| Class A Shares |
|
$49 |
|
0.96% | * Annualized for period less than one year.
|
|
| Expenses Paid, Amount |
$ 49
|
|
| Expense Ratio, Percent |
0.96%
|
[3] |
| Net Assets |
$ 364,856,428
|
|
| Holdings Count | Holding |
571
|
|
| Investment Company Portfolio Turnover |
31.00%
|
|
| Additional Fund Statistics [Text Block] |
Fund Statistics (as of February 28, 2026)
|
|
|
|
|
|
|
| Fund net assets |
|
$ |
364,856,428 |
|
|
|
| Total number of portfolio holdings |
|
|
571 |
|
|
|
| Portfolio turnover (%) |
|
|
31% |
|
|
|
| Holdings [Text Block] |
(1) Includes 7.8% of $1,000 Par Preferred and/or Contingent Capital Securities. (2) The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
|
|
| Credit Ratings Selection [Text Block] |
The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
|
|
| C000015185 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Nuveen Strategic Income Fund
|
|
| Class Name |
Class A Shares
|
|
| Trading Symbol |
FCDDX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Class A Shares of the Nuveen Strategic Income Fund for the period of September 1, 2025 to February 28, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information athttps://www.nuveen.com/en-us/mutual-funds/prospectuses. You can also request this information by contacting us at (800) 257-8787.
|
|
| Additional Information Phone Number |
(800) 257-8787
|
|
| Additional Information Website |
https://www.nuveen.com/en-us/mutual-funds/prospectuses
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months? (based on a hypothetical $10,000 investment)
|
|
|
|
|
|
|
|
| |
|
Cost of a $10,000 investment |
|
Costs paid as a percentage of $10,000 investment* |
| |
|
|
| Class A Shares |
|
$41 |
|
0.80% | * Annualized for period less than one year.
|
|
| Expenses Paid, Amount |
$ 41
|
|
| Expense Ratio, Percent |
0.80%
|
[4] |
| Net Assets |
$ 1,359,904,229
|
|
| Holdings Count | Holding |
672
|
|
| Investment Company Portfolio Turnover |
54.00%
|
|
| Additional Fund Statistics [Text Block] |
Fund Statistics (as of February 28, 2026)
|
|
|
|
|
|
|
| Fund net assets |
|
$ |
1,359,904,229 |
|
|
|
| Total number of portfolio holdings |
|
|
672 |
|
|
|
| Portfolio turnover (%) |
|
|
54% |
|
|
|
| Holdings [Text Block] |
(1) Includes 12.0% of $1,000 Par Preferred and/or Contingent Capital Securities. (2) The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
|
|
| Credit Ratings Selection [Text Block] |
The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
|
|
| C000015187 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Nuveen Strategic Income Fund
|
|
| Class Name |
Class C Shares
|
|
| Trading Symbol |
FCBCX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Class C Shares of the Nuveen Strategic Income Fund for the period of September 1, 2025 to February 28, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information at https://www.nuveen.com/en‑us/mutual‑funds/prospectuses. You can also request this information by contacting us at (800) 257‑8787.
|
|
| Additional Information Phone Number |
(800) 257‑8787
|
|
| Additional Information Website |
https://www.nuveen.com/en‑us/mutual‑funds/prospectuses
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months? (based on a hypothetical $10,000 investment)
|
|
|
|
|
|
|
|
| |
|
Cost of a $10,000 investment |
|
Costs paid as a percentage of
$10,000 investment* |
| |
|
|
| Class C Shares |
|
$79 |
|
1.55% | * Annualized for period less than one year.
|
|
| Expenses Paid, Amount |
$ 79
|
|
| Expense Ratio, Percent |
1.55%
|
[5] |
| Net Assets |
$ 1,359,904,229
|
|
| Holdings Count | Holding |
672
|
|
| Investment Company Portfolio Turnover |
54.00%
|
|
| Additional Fund Statistics [Text Block] |
Fund Statistics (as of February 28, 2026)
|
|
|
|
|
|
|
| Fund net assets |
|
|
$1,359,904,229 |
|
|
|
| Total number of portfolio holdings |
|
|
672 |
|
|
|
| Portfolio turnover (%) |
|
|
54% |
|
|
|
| Holdings [Text Block] |
(1) Includes 12.0% of $1,000 Par Preferred and/or Contingent Capital Securities. (2) The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies
|
|
| Credit Ratings Selection [Text Block] |
The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies
|
|
| C000151934 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Nuveen Strategic Income Fund
|
|
| Class Name |
Class R6 Shares
|
|
| Trading Symbol |
FSFRX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Class R6 Shares of the Nuveen Strategic Income Fund for the period of September 1, 2025 to February 28, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information at https://www.nuveen.com/en‑us/mutual‑funds/prospectuses. You can also request this information by contacting us at (800) 257‑8787.
|
|
| Additional Information Phone Number |
(800) 257‑8787
|
|
| Additional Information Website |
https://www.nuveen.com/en‑us/mutual‑funds/prospectuses
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months? (based on a hypothetical $10,000 investment)
|
|
|
|
|
|
|
|
| |
|
Cost of a $10,000 investment |
|
Costs paid as a percentage of
$10,000 investment* |
| |
|
|
| Class R6 Shares |
|
$24 |
|
0.47% | * Annualized for period less than one year.
|
|
| Expenses Paid, Amount |
$ 24
|
|
| Expense Ratio, Percent |
0.47%
|
[6] |
| Net Assets |
$ 1,359,904,229
|
|
| Holdings Count | Holding |
672
|
|
| Investment Company Portfolio Turnover |
54.00%
|
|
| Additional Fund Statistics [Text Block] |
Fund Statistics (as of February 28, 2026)
|
|
|
|
|
|
|
| Fund net assets |
|
|
$1,359,904,229 |
|
|
|
| Total number of portfolio holdings |
|
|
672 |
|
|
|
| Portfolio turnover (%) |
|
|
54% |
|
|
|
| Holdings [Text Block] |
(1) Includes 12.0% of $1,000 Par Preferred and/or Contingent Capital Securities. (2) The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
|
|
| Credit Ratings Selection [Text Block] |
The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
|
|
| C000015189 [Member] |
|
|
| Shareholder Report [Line Items] |
|
|
| Fund Name |
Nuveen Strategic Income Fund
|
|
| Class Name |
Class I Shares
|
|
| Trading Symbol |
FCBYX
|
|
| Annual or Semi-Annual Statement [Text Block] |
This semi-annual shareholder report contains important information about the Class I Shares of the Nuveen Strategic Income Fund for the period of September 1, 2025 to February 28, 2026.
|
|
| Shareholder Report Annual or Semi-Annual |
semi-annual shareholder report
|
|
| Additional Information [Text Block] |
You can find additional information at https://www.nuveen.com/en‑us/mutual‑funds/prospectuses. You can also request this information by contacting us at (800) 257‑8787.
|
|
| Additional Information Phone Number |
(800) 257‑8787
|
|
| Additional Information Website |
https://www.nuveen.com/en‑us/mutual‑funds/prospectuses
|
|
| Expenses [Text Block] |
What were the Fund costs for the last six months? (based on a hypothetical $10,000 investment)
|
|
|
|
|
|
|
|
| |
|
Cost of a $10,000 investment |
|
Costs paid as a percentage of
$10,000 investment* |
| |
|
|
| Class I Shares |
|
$28 |
|
0.55% | * Annualized for period less than one year.
|
|
| Expenses Paid, Amount |
$ 28
|
|
| Expense Ratio, Percent |
0.55%
|
[7] |
| Net Assets |
$ 1,359,904,229
|
|
| Holdings Count | Holding |
672
|
|
| Investment Company Portfolio Turnover |
54.00%
|
|
| Additional Fund Statistics [Text Block] |
Fund Statistics (as of February 28, 2026)
|
|
|
|
|
|
|
| Fund net assets |
|
|
$1,359,904,229 |
|
|
|
| Total number of portfolio holdings |
|
|
672 |
|
|
|
| Portfolio turnover (%) |
|
|
54% |
|
|
|
| Holdings [Text Block] |
(1) Includes 12.0% of $1,000 Par Preferred and/or Contingent Capital Securities. (2) The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
|
|
| Credit Ratings Selection [Text Block] |
The ratings disclosed are the highest rating given by one of the following national rating agencies: Standard & Poor’s (S&P), Moody’s Investors Service, Inc. (Moody’s) or Fitch, Inc (Fitch). This treatment of split-rated securities may differ from that used for other purposes, such as for Fund investment policies. Credit ratings are subject to change. AAA, AA, A, and BBB are investment grade ratings; BB, B, CCC, CC, C and D are below-investment grade ratings. Holdings designated N/R are not rated by these national ratings agencies.
|
|
|
|
