| Form N-CSR Cover | 6 Months Ended |
| Jun. 30, 2024 | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSRS |
| Amendment Flag | false |
| Registrant Name | NUVEEN INVESTMENT FUNDS INC |
| Entity Central Index Key | 0000820892 |
| Document Period End Date | Jun. 30, 2024 |
| Shareholder Report | 6 Months Ended | |
| Jun. 30, 2024 USD ($) Holding | ||
| Shareholder Report [Line Items] | ||
| Document Type | N-CSRS | |
| Amendment Flag | false | |
| Registrant Name | NUVEEN INVESTMENT FUNDS INC | |
| Entity Central Index Key | 0000820892 | |
| Document Period End Date | Jun. 30, 2024 | |
| C000015147 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | Nuveen Real Estate Securities Fund | |
| Class Name | Class A Shares | |
| Trading Symbol | FREAX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about the Class A Shares of the Nuveen Real Estate Securities Fund for the period of January 1, 2024 to June 30, 2024. | |
| 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 Class A Shares $61 1.21% * This cost is annualized. | |
| Expenses Paid, Amount | $ 61 | |
| Expense Ratio, Percent | 1.21% | [1] |
| Net Assets | $ 967,891,916 | |
| Holdings Count | Holding | 57 | |
| Investment Company Portfolio Turnover | 32% | |
| Additional Fund Statistics [Text Block] | Fund Statistics (as of June 30, 2024) Fund net assets $ 967,891,916 Total number of portfolio holdings 57 Portfolio turnover (%) 32% | |
| Holdings [Text Block] | ||
| C000015149 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | Nuveen Real Estate Securities Fund | |
| Class Name | Class C Shares | |
| Trading Symbol | FRLCX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about the Class C Shares of the Nuveen Real Estate Securities Fund for the period of January 1, 2024 to June 30, 2024. | |
| 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 Class C Shares $98 1.96% * This cost is annualized. | |
| Expenses Paid, Amount | $ 98 | |
| Expense Ratio, Percent | 1.96% | [2] |
| Net Assets | $ 967,891,916 | |
| Holdings Count | Holding | 57 | |
| Investment Company Portfolio Turnover | 32% | |
| Additional Fund Statistics [Text Block] | Fund Statistics (as of June 30, 2024) Fund net assets $ 967,891,916 Total number of portfolio holdings 57 Portfolio turnover (%) 32% | |
| Holdings [Text Block] | ||
| C000126484 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | Nuveen Real Estate Securities Fund | |
| Class Name | Class R6 Shares | |
| Trading Symbol | FREGX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about the Class R6 Shares of the Nuveen Real Estate Securities Fund for the period of January 1, 2024 to June 30, 2024. | |
| 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 Class R6 Shares $40 0.80% * This cost is annualized. | |
| Expenses Paid, Amount | $ 40 | |
| Expense Ratio, Percent | 0.80% | [3] |
| Net Assets | $ 967,891,916 | |
| Holdings Count | Holding | 57 | |
| Investment Company Portfolio Turnover | 32% | |
| Additional Fund Statistics [Text Block] | Fund Statistics (as of June 30, 2024) Fund net assets $ 967,891,916 Total number of portfolio holdings 57 Portfolio turnover (%) 32% | |
| Holdings [Text Block] | ||
| C000015151 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | Nuveen Real Estate Securities Fund | |
| Class Name | Class I Shares | |
| Trading Symbol | FARCX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about the Class I Shares of the Nuveen Real Estate Securities Fund for the period of January 1, 2024 to June 30, 2024. | |
| 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 Class I Shares $48 0.96% * This cost is annualized. | |
| Expenses Paid, Amount | $ 48 | |
| Expense Ratio, Percent | 0.96% | [4] |
| Net Assets | $ 967,891,916 | |
| Holdings Count | Holding | 57 | |
| Investment Company Portfolio Turnover | 32% | |
| Additional Fund Statistics [Text Block] | Fund Statistics (as of June 30, 2024) Fund net assets $ 967,891,916 Total number of portfolio holdings 57 Portfolio turnover (%) 32% | |
| Holdings [Text Block] | ||
| C000056118 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | Nuveen Global Infrastructure Fund | |
| Class Name | Class A Shares | |
| Trading Symbol | FGIAX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about the Class A Shares of the Nuveen Global Infrastructure Fund for the period of January 1, 2024 to June 30, 2024. | |
| 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 A Shares $62 1.24% * This cost is annualized. | |
| Expenses Paid, Amount | $ 62 | |
| Expense Ratio, Percent | 1.24% | [5] |
| Net Assets | $ 465,097,444 | |
| Holdings Count | Holding | 96 | |
| Investment Company Portfolio Turnover | 38% | |
| Additional Fund Statistics [Text Block] | Fund Statistics (as of June 30, 2024) Fund net assets $ 465,097,444 Total number of portfolio holdings 96 Portfolio turnover (%) 38% | |
| Holdings [Text Block] | ||
| C000070757 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | Nuveen Global Infrastructure Fund | |
| Class Name | Class C Shares | |
| Trading Symbol | FGNCX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about the Class C Shares of the Nuveen Global Infrastructure Fund for the period of January 1, 2024 to June 30, 2024. | |
| 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 Class C Shares $100 1.99% * This cost is annualized. | |
| Expenses Paid, Amount | $ 100 | |
| Expense Ratio, Percent | 1.99% | [6] |
| Net Assets | $ 465,097,444 | |
| Holdings Count | Holding | 96 | |
| Investment Company Portfolio Turnover | 38% | |
| Additional Fund Statistics [Text Block] | Fund Statistics (as of June 30, 2024) Fund net assets $ 465,097,444 Total number of portfolio holdings 96 Portfolio turnover (%) 38% | |
| Holdings [Text Block] | ||
| C000171406 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | Nuveen Global Infrastructure Fund | |
| Class Name | Class R6 Shares | |
| Trading Symbol | FGIWX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about the Class R6 Shares of the Nuveen Global Infrastructure Fund for the period of January 1, 2024 to June 30, 2024. | |
| 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 Class R6 Shares $46 0.92% * This cost is annualized. | |
| Expenses Paid, Amount | $ 46 | |
| Expense Ratio, Percent | 0.92% | [7] |
| Net Assets | $ 465,097,444 | |
| Holdings Count | Holding | 96 | |
| Investment Company Portfolio Turnover | 38% | |
| Additional Fund Statistics [Text Block] | Fund Statistics (as of June 30, 2024) Fund net assets $ 465,097,444 Total number of portfolio holdings 96 Portfolio turnover (%) 38% | |
| Holdings [Text Block] | ||
| C000056119 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | Nuveen Global Infrastructure Fund | |
| Class Name | Class I Shares | |
| Trading Symbol | FGIYX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about the Class I Shares of the Nuveen Global Infrastructure Fund for the period of January 1, 2024 to June 30, 2024. | |
| 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 Class I Shares $49 0.99% * This cost is annualized. | |
| Expenses Paid, Amount | $ 49 | |
| Expense Ratio, Percent | 0.99% | [8] |
| Net Assets | $ 465,097,444 | |
| Holdings Count | Holding | 96 | |
| Investment Company Portfolio Turnover | 38% | |
| Additional Fund Statistics [Text Block] | Fund Statistics (as of June 30, 2024) Fund net assets $ 465,097,444 Total number of portfolio holdings 96 Portfolio turnover (%) 38% | |
| Holdings [Text Block] | ||
| C000104365 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | Nuveen Real Asset Income Fund | |
| Class Name | Class A Shares | |
| Trading Symbol | NRIAX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about the Class A Shares of the Nuveen Real Asset Income Fund for the period of January 1, 2024 to June 30, 2024. | |
| 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 Class A Shares $58 1.16% * This cost is annualized. | |
| Expenses Paid, Amount | $ 58 | |
| Expense Ratio, Percent | 1.16% | [9] |
| Net Assets | $ 1,030,296,666 | |
| Holdings Count | Holding | 397 | |
| Investment Company Portfolio Turnover | 37% | |
| Additional Fund Statistics [Text Block] | Fund Statistics (as of June 30, 2024) Fund net assets $ 1,030,296,666 Total number of portfolio holdings 397 Portfolio turnover (%) 37% | |
| Holdings [Text Block] | ||
| C000104366 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | Nuveen Real Asset Income Fund | |
| Class Name | Class C Shares | |
| Trading Symbol | NRICX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about the Class C Shares of the Nuveen Real Asset Income Fund for the period of January 1, 2024 to June 30, 2024. | |
| 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 $96 1.91% * This cost is annualized. | |
| Expenses Paid, Amount | $ 96 | |
| Expense Ratio, Percent | 1.91% | [10] |
| Net Assets | $ 1,030,296,666 | |
| Holdings Count | Holding | 397 | |
| Investment Company Portfolio Turnover | 37% | |
| Additional Fund Statistics [Text Block] | Fund Statistics (as of June 30, 2024) Fund net assets $ 1,030,296,666 Total number of portfolio holdings 397 Portfolio turnover (%) 37% | |
| Holdings [Text Block] | ||
| C000171407 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | Nuveen Real Asset Income Fund | |
| Class Name | Class R6 Shares | |
| Trading Symbol | NRIFX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about the Class R6 Shares of the Nuveen Real Asset Income Fund for the period of January 1, 2024 to June 30, 2024. | |
| 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 Class R6 Shares $41 0.81% * This cost is annualized. | |
| Expenses Paid, Amount | $ 41 | |
| Expense Ratio, Percent | 0.81% | [11] |
| Net Assets | $ 1,030,296,666 | |
| Holdings Count | Holding | 397 | |
| Investment Company Portfolio Turnover | 37% | |
| Additional Fund Statistics [Text Block] | Fund Statistics (as of June 30, 2024) Fund net assets $ 1,030,296,666 Total number of portfolio holdings 397 Portfolio turnover (%) 37% | |
| Holdings [Text Block] | ||
| C000104368 [Member] | ||
| Shareholder Report [Line Items] | ||
| Fund Name | Nuveen Real Asset Income Fund | |
| Class Name | Class I Shares | |
| Trading Symbol | NRIIX | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about the Class I Shares of the Nuveen Real Asset Income Fund for the period of January 1, 2024 to June 30, 2024. | |
| 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 Class I Shares $46 0.91% * This cost is annualized. | |
| Expenses Paid, Amount | $ 46 | |
| Expense Ratio, Percent | 0.91% | [12] |
| Net Assets | $ 1,030,296,666 | |
| Holdings Count | Holding | 397 | |
| Investment Company Portfolio Turnover | 37% | |
| Additional Fund Statistics [Text Block] | Fund Statistics (as of June 30, 2024) Fund net assets $ 1,030,296,666 Total number of portfolio holdings 397 Portfolio turnover (%) 37% | |
| Holdings [Text Block] | ||
| [1]This cost is annualized.[2]This cost is annualized.[3]This cost is annualized.[4]This cost is annualized.[5]This cost is annualized.[6]This cost is annualized.[7]This cost is annualized.[8]This cost is annualized.[9]This cost is annualized.[10]This cost is annualized.[11]This cost is annualized.[12]This cost is annualized. | ||
| Shareholder Report, Holdings (Details) | Jun. 30, 2024 |
| C000015147 [Member] | Repurchase Agreements [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000015147 [Member] | Real Estate Investment Trust Common Stocks [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 97.80% |
| C000015149 [Member] | Repurchase Agreements [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000015149 [Member] | Real Estate Investment Trust Common Stocks [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 97.80% |
| C000126484 [Member] | Repurchase Agreements [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000126484 [Member] | Real Estate Investment Trust Common Stocks [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 97.80% |
| C000015151 [Member] | Repurchase Agreements [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000015151 [Member] | Real Estate Investment Trust Common Stocks [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 97.80% |
| C000056118 [Member] | Other [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 6.90% |
| C000056118 [Member] | AUSTRALIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.30% |
| C000056118 [Member] | CANADA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 7.20% |
| C000056118 [Member] | SPAIN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 6.90% |
| C000056118 [Member] | FRANCE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.60% |
| C000056118 [Member] | UNITED KINGDOM | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.30% |
| C000056118 [Member] | ITALY | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4% |
| C000056118 [Member] | JAPAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.40% |
| C000056118 [Member] | MEXICO | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.40% |
| C000056118 [Member] | NEW ZEALAND | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.70% |
| C000056118 [Member] | UNITED STATES | |
| Holdings [Line Items] | |
| Percent of Total Investments | 52.30% |
| C000056118 [Member] | Repurchase Agreements [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000056118 [Member] | Real Estate Investment Trust Common Stocks [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.80% |
| C000056118 [Member] | Common Stock [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 93.30% |
| C000056118 [Member] | Investment Companies [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.40% |
| C000070757 [Member] | Other [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 6.90% |
| C000070757 [Member] | AUSTRALIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.30% |
| C000070757 [Member] | CANADA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 7.20% |
| C000070757 [Member] | SPAIN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 6.90% |
| C000070757 [Member] | FRANCE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.60% |
| C000070757 [Member] | UNITED KINGDOM | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.30% |
| C000070757 [Member] | ITALY | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4% |
| C000070757 [Member] | JAPAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.40% |
| C000070757 [Member] | MEXICO | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.40% |
| C000070757 [Member] | NEW ZEALAND | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.70% |
| C000070757 [Member] | UNITED STATES | |
| Holdings [Line Items] | |
| Percent of Total Investments | 52.30% |
| C000070757 [Member] | Repurchase Agreements [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000070757 [Member] | Real Estate Investment Trust Common Stocks [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.80% |
| C000070757 [Member] | Common Stock [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 93.30% |
| C000070757 [Member] | Investment Companies [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.40% |
| C000171406 [Member] | Other [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 6.90% |
| C000171406 [Member] | AUSTRALIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.30% |
| C000171406 [Member] | CANADA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 7.20% |
| C000171406 [Member] | SPAIN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 6.90% |
| C000171406 [Member] | FRANCE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.60% |
| C000171406 [Member] | UNITED KINGDOM | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.30% |
| C000171406 [Member] | ITALY | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4% |
| C000171406 [Member] | JAPAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.40% |
| C000171406 [Member] | MEXICO | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.40% |
| C000171406 [Member] | NEW ZEALAND | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.70% |
| C000171406 [Member] | UNITED STATES | |
| Holdings [Line Items] | |
| Percent of Total Investments | 52.30% |
| C000171406 [Member] | Repurchase Agreements [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000171406 [Member] | Real Estate Investment Trust Common Stocks [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.80% |
| C000171406 [Member] | Common Stock [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 93.30% |
| C000171406 [Member] | Investment Companies [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.40% |
| C000056119 [Member] | Other [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 6.90% |
| C000056119 [Member] | AUSTRALIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.30% |
| C000056119 [Member] | CANADA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 7.20% |
| C000056119 [Member] | SPAIN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 6.90% |
| C000056119 [Member] | FRANCE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 5.60% |
| C000056119 [Member] | UNITED KINGDOM | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.30% |
| C000056119 [Member] | ITALY | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4% |
| C000056119 [Member] | JAPAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.40% |
| C000056119 [Member] | MEXICO | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.40% |
| C000056119 [Member] | NEW ZEALAND | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.70% |
| C000056119 [Member] | UNITED STATES | |
| Holdings [Line Items] | |
| Percent of Total Investments | 52.30% |
| C000056119 [Member] | Repurchase Agreements [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.50% |
| C000056119 [Member] | Real Estate Investment Trust Common Stocks [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4.80% |
| C000056119 [Member] | Common Stock [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 93.30% |
| C000056119 [Member] | Investment Companies [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.40% |
| C000104365 [Member] | Other [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4% |
| C000104365 [Member] | AUSTRALIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.20% |
| C000104365 [Member] | CANADA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 12.30% |
| C000104365 [Member] | SPAIN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.20% |
| C000104365 [Member] | FRANCE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000104365 [Member] | UNITED KINGDOM | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.80% |
| C000104365 [Member] | ITALY | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000104365 [Member] | JAPAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.20% |
| C000104365 [Member] | UNITED STATES | |
| Holdings [Line Items] | |
| Percent of Total Investments | 66.80% |
| C000104365 [Member] | HONG KONG | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000104365 [Member] | SINGAPORE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000104365 [Member] | Repurchase Agreements [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.10% |
| C000104365 [Member] | Real Estate Investment Trust Common Stocks [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 21.10% |
| C000104365 [Member] | Common Stock [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 23.10% |
| C000104365 [Member] | Investment Companies [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.50% |
| C000104365 [Member] | Corporate Bond Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 26% |
| C000104365 [Member] | Collateralized Mortgage-Backed Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.10% |
| C000104365 [Member] | Convertible Preferred Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.80% |
| C000104365 [Member] | Investments Purchased with Collateral from Securities Lending [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.60% |
| C000104365 [Member] | Dollar Thousand Par or similar Institutional Preferred [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 12.60% |
| C000104365 [Member] | Dollar Twenty Five Par or similar Retail Preferred [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 13.10% |
| C000104365 [Member] | Variable Rate Senior Loan Interests [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0% |
| C000104366 [Member] | Other [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4% |
| C000104366 [Member] | AUSTRALIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.20% |
| C000104366 [Member] | CANADA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 12.30% |
| C000104366 [Member] | SPAIN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.20% |
| C000104366 [Member] | FRANCE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000104366 [Member] | UNITED KINGDOM | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.80% |
| C000104366 [Member] | ITALY | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000104366 [Member] | JAPAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.20% |
| C000104366 [Member] | UNITED STATES | |
| Holdings [Line Items] | |
| Percent of Total Investments | 66.80% |
| C000104366 [Member] | HONG KONG | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000104366 [Member] | SINGAPORE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000104366 [Member] | Repurchase Agreements [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.10% |
| C000104366 [Member] | Real Estate Investment Trust Common Stocks [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 21.10% |
| C000104366 [Member] | Common Stock [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 23.10% |
| C000104366 [Member] | Investment Companies [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.50% |
| C000104366 [Member] | Corporate Bond Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 26% |
| C000104366 [Member] | Collateralized Mortgage-Backed Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.10% |
| C000104366 [Member] | Convertible Preferred Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.80% |
| C000104366 [Member] | Investments Purchased with Collateral from Securities Lending [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.60% |
| C000104366 [Member] | Dollar Thousand Par or similar Institutional Preferred [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 12.60% |
| C000104366 [Member] | Dollar Twenty Five Par or similar Retail Preferred [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 13.10% |
| C000104366 [Member] | Variable Rate Senior Loan Interests [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0% |
| C000171407 [Member] | Other [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4% |
| C000171407 [Member] | AUSTRALIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.20% |
| C000171407 [Member] | CANADA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 12.30% |
| C000171407 [Member] | SPAIN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.20% |
| C000171407 [Member] | FRANCE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000171407 [Member] | UNITED KINGDOM | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.80% |
| C000171407 [Member] | ITALY | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000171407 [Member] | JAPAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.20% |
| C000171407 [Member] | UNITED STATES | |
| Holdings [Line Items] | |
| Percent of Total Investments | 66.80% |
| C000171407 [Member] | HONG KONG | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000171407 [Member] | SINGAPORE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000171407 [Member] | Repurchase Agreements [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.10% |
| C000171407 [Member] | Real Estate Investment Trust Common Stocks [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 21.10% |
| C000171407 [Member] | Common Stock [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 23.10% |
| C000171407 [Member] | Investment Companies [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.50% |
| C000171407 [Member] | Corporate Bond Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 26% |
| C000171407 [Member] | Collateralized Mortgage-Backed Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.10% |
| C000171407 [Member] | Convertible Preferred Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.80% |
| C000171407 [Member] | Investments Purchased with Collateral from Securities Lending [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.60% |
| C000171407 [Member] | Dollar Thousand Par or similar Institutional Preferred [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 12.60% |
| C000171407 [Member] | Dollar Twenty Five Par or similar Retail Preferred [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 13.10% |
| C000171407 [Member] | Variable Rate Senior Loan Interests [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0% |
| C000104368 [Member] | Other [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 4% |
| C000104368 [Member] | AUSTRALIA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.20% |
| C000104368 [Member] | CANADA | |
| Holdings [Line Items] | |
| Percent of Total Investments | 12.30% |
| C000104368 [Member] | SPAIN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.20% |
| C000104368 [Member] | FRANCE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000104368 [Member] | UNITED KINGDOM | |
| Holdings [Line Items] | |
| Percent of Total Investments | 3.80% |
| C000104368 [Member] | ITALY | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.10% |
| C000104368 [Member] | JAPAN | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.20% |
| C000104368 [Member] | UNITED STATES | |
| Holdings [Line Items] | |
| Percent of Total Investments | 66.80% |
| C000104368 [Member] | HONG KONG | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.60% |
| C000104368 [Member] | SINGAPORE | |
| Holdings [Line Items] | |
| Percent of Total Investments | 2.20% |
| C000104368 [Member] | Repurchase Agreements [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.10% |
| C000104368 [Member] | Real Estate Investment Trust Common Stocks [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 21.10% |
| C000104368 [Member] | Common Stock [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 23.10% |
| C000104368 [Member] | Investment Companies [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.50% |
| C000104368 [Member] | Corporate Bond Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 26% |
| C000104368 [Member] | Collateralized Mortgage-Backed Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.10% |
| C000104368 [Member] | Convertible Preferred Securities [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 1.80% |
| C000104368 [Member] | Investments Purchased with Collateral from Securities Lending [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0.60% |
| C000104368 [Member] | Dollar Thousand Par or similar Institutional Preferred [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 12.60% |
| C000104368 [Member] | Dollar Twenty Five Par or similar Retail Preferred [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 13.10% |
| C000104368 [Member] | Variable Rate Senior Loan Interests [Member] | |
| Holdings [Line Items] | |
| Percent of Total Investments | 0% |
