S000005563 [Member] Expense Example - Nuveen Real Estate Securities Fund |
Dec. 31, 2025
USD ($)
|
|---|---|
| Class A | |
| Prospectus [Line Items] | |
| Expense Example, with Redemption, 1 Year | $ 688 |
| Expense Example, with Redemption, 3 Years | 937 |
| Expense Example, with Redemption, 5 Years | 1,222 |
| Expense Example, with Redemption, 10 Years | 2,030 |
| Class C | |
| Prospectus [Line Items] | |
| Expense Example, with Redemption, 1 Year | 196 |
| Expense Example, with Redemption, 3 Years | 616 |
| Expense Example, with Redemption, 5 Years | 1,078 |
| Expense Example, with Redemption, 10 Years | 2,357 |
| Class I | |
| Prospectus [Line Items] | |
| Expense Example, with Redemption, 1 Year | 95 |
| Expense Example, with Redemption, 3 Years | 306 |
| Expense Example, with Redemption, 5 Years | 552 |
| Expense Example, with Redemption, 10 Years | 1,257 |
| Class R6 | |
| Prospectus [Line Items] | |
| Expense Example, with Redemption, 1 Year | 74 |
| Expense Example, with Redemption, 3 Years | 240 |
| Expense Example, with Redemption, 5 Years | 439 |
| Expense Example, with Redemption, 10 Years | $ 1,011 |