Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	NUVEEN INVESTMENT FUNDS INC
Prospectus Date	rr_ProspectusDate	Feb. 27, 2015
Nuveen Small Cap Index Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	Nuveen Small Cap Index Fund
Objective [Heading]	rr_ObjectiveHeading	Investment Objective
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The investment objective of the Fund is to provide investment results that correspond to the performance of the Russell 2000® Index (Russell 2000 Index).
Expense [Heading]	rr_ExpenseHeading	Fees and Expenses of the Fund
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in the Fund or in other Nuveen Mutual Funds. More information about these and other discounts, as well as eligibility requirements for each share class, is available from your financial advisor and in “What Share Classes We Offer” on page 62 of the Fund’s prospectus and “Purchase and Redemption of Fund Shares” on page S-82 of the Fund’s statement of additional information.
Shareholder Fees Caption [Text]	rr_ShareholderFeesCaption	Shareholder Fees (fees paid directly from your investment)
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	September 30, 2016
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	Portfolio Turnover
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 12% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	12.00%
Expenses Deferred Charges [Text Block]	rr_ExpensesDeferredChargesTextBlock	The contingent deferred sales charge on Class C shares applies only to redemptions within 12 months of purchase.
Expense Breakpoint Discounts [Text]	rr_ExpenseBreakpointDiscounts	You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in the Fund or in other Nuveen Mutual Funds.
Expense Breakpoint, Minimum Investment Required [Amount]	rr_ExpenseBreakpointMinimumInvestmentRequiredAmount	50,000
Expense Example [Heading]	rr_ExpenseExampleHeading	Example
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	The following example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then either redeem or do not redeem your shares at the end of a period. The example also assumes that your investment has a 5% return each year, that the Fund’s operating expenses remain the same and that the contractual fee waivers currently in place are not renewed beyond September 30, 2016. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Expense Example by, Year, Caption [Text]	rr_ExpenseExampleByYearCaption	Redemption
Expense Example, No Redemption, By Year, Caption [Text]	rr_ExpenseExampleNoRedemptionByYearCaption	No Redemption
Strategy [Heading]	rr_StrategyHeading	Principal Investment Strategies
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	Under normal market conditions, the Fund invests at least 90% of the sum of its net assets and the amount of any borrowings for investment purposes in common stocks included in the Russell 2000 Index. This index measures the performance of the 2,000 smallest companies in the Russell 3000 Index (which is made up of the 3,000 largest U.S. companies based on total market capitalization). Reconstitution of the index occurs annually. As of January 31, 2015, market capitalizations of companies in the Russell 2000 Index ranged from approximately $16.0 million to $10.6 billion. The Fund’s sub-adviser believes that the Fund’s objective can best be achieved by investing in common stocks of at least 90% of the issues included in the Russell 2000 Index, depending on the size of the Fund. A computer program is used to identify which stocks should be purchased or sold in order to replicate, as closely as practicable, the composition of the Russell 2000 Index. Because the Fund may not always hold all of the stocks included in the Russell 2000 Index, and because the Fund has expenses and the index does not, the Fund will not duplicate the index’s performance precisely. However, the Fund’s sub-adviser believes there should be a close correlation between the Fund’s performance and that of the Russell 2000 Index in both rising and falling markets. The Fund will attempt to achieve a correlation between the performance of its portfolio and that of the Russell 2000 Index of at least 95%, without taking into account expenses of the Fund. A perfect correlation would be indicated by a figure of 100%, which would be achieved if the Fund’s net asset value, including the value of its dividends and capital gains distributions, increased or decreased in exact proportion to changes in the Russell 2000 Index. If the Fund is unable to achieve a correlation of 95% over time, the Fund’s board of directors will consider alternative strategies for the Fund. The Fund may invest in stock index futures contracts, options on stock indices, and options on stock index futures (“derivatives”) on the Russell 2000 Index. The Fund makes these investments to maintain the liquidity needed to meet redemption requests, to increase the level of Fund assets devoted to replicating the composition of the Russell 2000 Index, and to reduce transaction costs.
Risk [Heading]	rr_RiskHeading	Principal Risks
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	The value of your investment in this Fund will change daily. You could lose money by investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The principal risks of investing in the Fund, listed alphabetically, include: Derivatives Risk—The use of derivatives involves additional risks and transaction costs which could leave the Fund in a worse position than if it had not used these instruments. Derivative instruments can be used to acquire or to transfer the risk and returns of a security or other asset without buying or selling the security or asset. These instruments may entail investment exposures that are greater than their cost would suggest. As a result, a small investment in derivatives can result in losses that greatly exceed the original investment. Derivatives can be highly volatile, illiquid and difficult to value. A derivative transaction also involves the risk that a loss may be sustained as a result of the failure of the counterparty to the contract to make required payments. Equity Security Risk—Equity securities may decline significantly in price over short or extended periods of time, and such declines may occur because of declines in the equity market as a whole, or because of declines in only a particular country, company, industry, or sector of the market. Failure to Match Index Performance—The Fund may not replicate the performance of the Russell 2000 Index. Small-Cap Stock Risk—Small-cap stocks involve substantial risk. Prices of small-cap stocks may be subject to more abrupt or erratic movements, and to wider fluctuations, than stock prices of larger, more established companies or the market averages in general. It may be difficult to sell small-cap stocks at the desired time and price.
Risk Lose Money [Text]	rr_RiskLoseMoney	The value of your investment in this Fund will change daily. You could lose money by investing in the Fund.
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Fund Performance
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The following bar chart and table provide some indication of the potential risks of investing in the Fund. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Updated performance information is available at www.nuveen.com/performance or by calling (800) 257-8787.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The bar chart below shows the variability of the Fund’s performance from year to year for Class A shares.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	(800) 257-8787
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.nuveen.com/performance
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.
Bar Chart [Heading]	rr_BarChartHeading	Class A Annual Total Return
Bar Chart Narrative [Text Block]	rr_BarChartNarrativeTextBlock	The bar chart below shows the variability of the Fund’s performance from year to year for Class A shares.
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	During the ten-year period ended December 31, 2014, the Fund’s highest and lowest quarterly returns were 20.68% and -25.79%, respectively, for the quarters ended June 30, 2009 and December 31, 2008.
Performance Table Heading	rr_PerformanceTableHeading	Average Annual Total Returns for the Periods Ended December 31, 2014
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	All after-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred	rr_PerformanceTableNotRelevantToTaxDeferred	After-tax returns are not relevant to investors who hold Fund shares in tax-deferred accounts such as IRAs or employer-sponsored retirement plans.
Performance Table One Class of after Tax Shown [Text]	rr_PerformanceTableOneClassOfAfterTaxShown	After-tax returns are shown for Class A shares only; after-tax returns for other share classes will vary.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	The table below shows the variability of the Fund’s average annual returns and how they compare over the time periods indicated with those of a broad measure of market performance and an index of funds with similar investment objectives. All after-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. After-tax returns are shown for Class A shares only; after-tax returns for other share classes will vary. Your own actual after-tax returns will depend on your specific tax situation and may differ from what is shown here. After-tax returns are not relevant to investors who hold Fund shares in tax-deferred accounts such as IRAs or employer-sponsored retirement plans. Both the bar chart and the table assume that all distributions have been reinvested. Performance reflects fee waivers, if any, in effect during the periods presented. If any such waivers had not been in place, returns would have been reduced.
Nuveen Small Cap Index Fund | Class A
Risk/Return:	rr_RiskReturnAbstract
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum Deferred Sales Charge (Load) (as a percentage of the lesser of purchase price or redemption proceeds)	rr_MaximumDeferredSalesChargeOverOther	none	[1]
Maximum Sales Charge (Load) Imposed on Reinvested Dividends	rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther	none
Exchange Fee	rr_ExchangeFeeOverRedemption	none
Annual Low Balance Account Fee (for accounts under $1,000)	rr_MaximumAccountFee	15	[2]
Management Fees	rr_ManagementFeesOverAssets	0.33%
Distribution and/or Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other Expenses	rr_OtherExpensesOverAssets	0.45%
Acquired Fund Fees and Expenses	rr_AcquiredFundFeesAndExpensesOverAssets	0.06%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	1.09%
Fee Waivers and/or Expense Reimbursements	rr_FeeWaiverOrReimbursementOverAssets	(0.22%)	[3]
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	rr_NetExpensesOverAssets	0.87%
1 Year	rr_ExpenseExampleYear01	89
3 Years	rr_ExpenseExampleYear03	311
5 Years	rr_ExpenseExampleYear05	567
10 Years	rr_ExpenseExampleYear10	1,297
1 Year	rr_ExpenseExampleNoRedemptionYear01	89
3 Years	rr_ExpenseExampleNoRedemptionYear03	311
5 Years	rr_ExpenseExampleNoRedemptionYear05	567
10 Years	rr_ExpenseExampleNoRedemptionYear10	1,297
2005	rr_AnnualReturn2005	3.49%	[4]
2006	rr_AnnualReturn2006	17.49%	[4]
2007	rr_AnnualReturn2007	(2.08%)	[4]
2008	rr_AnnualReturn2008	(33.78%)	[4]
2009	rr_AnnualReturn2009	26.85%	[4]
2010	rr_AnnualReturn2010	26.20%	[4]
2011	rr_AnnualReturn2011	(4.75%)	[4]
2012	rr_AnnualReturn2012	15.74%	[4]
2013	rr_AnnualReturn2013	38.02%	[4]
2014	rr_AnnualReturn2014	4.30%	[4]
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	highest
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Jun. 30, 2009
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	20.68%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	lowest
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2008
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(25.79%)
1 Year	rr_AverageAnnualReturnYear01	4.30%
5 Years	rr_AverageAnnualReturnYear05	14.90%
10 Years	rr_AverageAnnualReturnYear10	7.19%
Nuveen Small Cap Index Fund | Class C
Risk/Return:	rr_RiskReturnAbstract
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum Deferred Sales Charge (Load) (as a percentage of the lesser of purchase price or redemption proceeds)	rr_MaximumDeferredSalesChargeOverOther	1.00%	[1]
Maximum Sales Charge (Load) Imposed on Reinvested Dividends	rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther	none
Exchange Fee	rr_ExchangeFeeOverRedemption	none
Annual Low Balance Account Fee (for accounts under $1,000)	rr_MaximumAccountFee	15	[2]
Management Fees	rr_ManagementFeesOverAssets	0.33%
Distribution and/or Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	1.00%
Other Expenses	rr_OtherExpensesOverAssets	0.45%
Acquired Fund Fees and Expenses	rr_AcquiredFundFeesAndExpensesOverAssets	0.06%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	1.84%
Fee Waivers and/or Expense Reimbursements	rr_FeeWaiverOrReimbursementOverAssets	(0.22%)	[3]
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	rr_NetExpensesOverAssets	1.62%
1 Year	rr_ExpenseExampleYear01	165
3 Years	rr_ExpenseExampleYear03	544
5 Years	rr_ExpenseExampleYear05	963
10 Years	rr_ExpenseExampleYear10	2,130
1 Year	rr_ExpenseExampleNoRedemptionYear01	165
3 Years	rr_ExpenseExampleNoRedemptionYear03	544
5 Years	rr_ExpenseExampleNoRedemptionYear05	963
10 Years	rr_ExpenseExampleNoRedemptionYear10	2,130
1 Year	rr_AverageAnnualReturnYear01	3.50%
5 Years	rr_AverageAnnualReturnYear05	14.03%
10 Years	rr_AverageAnnualReturnYear10	6.39%
Nuveen Small Cap Index Fund | Class R3
Risk/Return:	rr_RiskReturnAbstract
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum Deferred Sales Charge (Load) (as a percentage of the lesser of purchase price or redemption proceeds)	rr_MaximumDeferredSalesChargeOverOther	none	[1]
Maximum Sales Charge (Load) Imposed on Reinvested Dividends	rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther	none
Exchange Fee	rr_ExchangeFeeOverRedemption	none
Annual Low Balance Account Fee (for accounts under $1,000)	rr_MaximumAccountFee	none	[2]
Management Fees	rr_ManagementFeesOverAssets	0.33%
Distribution and/or Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	0.50%
Other Expenses	rr_OtherExpensesOverAssets	0.45%
Acquired Fund Fees and Expenses	rr_AcquiredFundFeesAndExpensesOverAssets	0.06%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	1.34%
Fee Waivers and/or Expense Reimbursements	rr_FeeWaiverOrReimbursementOverAssets	(0.22%)	[3]
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	rr_NetExpensesOverAssets	1.12%
1 Year	rr_ExpenseExampleYear01	114
3 Years	rr_ExpenseExampleYear03	390
5 Years	rr_ExpenseExampleYear05	700
10 Years	rr_ExpenseExampleYear10	1,582
1 Year	rr_ExpenseExampleNoRedemptionYear01	114
3 Years	rr_ExpenseExampleNoRedemptionYear03	390
5 Years	rr_ExpenseExampleNoRedemptionYear05	700
10 Years	rr_ExpenseExampleNoRedemptionYear10	1,582
1 Year	rr_AverageAnnualReturnYear01	4.07%
5 Years	rr_AverageAnnualReturnYear05	14.61%
10 Years	rr_AverageAnnualReturnYear10	6.93%
Nuveen Small Cap Index Fund | Class I
Risk/Return:	rr_RiskReturnAbstract
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum Deferred Sales Charge (Load) (as a percentage of the lesser of purchase price or redemption proceeds)	rr_MaximumDeferredSalesChargeOverOther	none	[1]
Maximum Sales Charge (Load) Imposed on Reinvested Dividends	rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther	none
Exchange Fee	rr_ExchangeFeeOverRedemption	none
Annual Low Balance Account Fee (for accounts under $1,000)	rr_MaximumAccountFee	15	[2]
Management Fees	rr_ManagementFeesOverAssets	0.33%
Distribution and/or Service (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	0.45%
Acquired Fund Fees and Expenses	rr_AcquiredFundFeesAndExpensesOverAssets	0.06%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.84%
Fee Waivers and/or Expense Reimbursements	rr_FeeWaiverOrReimbursementOverAssets	(0.22%)	[3]
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	rr_NetExpensesOverAssets	0.62%
1 Year	rr_ExpenseExampleYear01	63
3 Years	rr_ExpenseExampleYear03	233
5 Years	rr_ExpenseExampleYear05	431
10 Years	rr_ExpenseExampleYear10	1,004
1 Year	rr_ExpenseExampleNoRedemptionYear01	63
3 Years	rr_ExpenseExampleNoRedemptionYear03	233
5 Years	rr_ExpenseExampleNoRedemptionYear05	431
10 Years	rr_ExpenseExampleNoRedemptionYear10	1,004
1 Year	rr_AverageAnnualReturnYear01	4.54%
5 Years	rr_AverageAnnualReturnYear05	15.17%
10 Years	rr_AverageAnnualReturnYear10	7.46%
Nuveen Small Cap Index Fund | (return after taxes on distributions) | Class A
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	2.51%
5 Years	rr_AverageAnnualReturnYear05	13.94%
10 Years	rr_AverageAnnualReturnYear10	5.95%
Nuveen Small Cap Index Fund | (return after taxes on distributions and sale of Fund shares) | Class A
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	3.41%
5 Years	rr_AverageAnnualReturnYear05	11.89%
10 Years	rr_AverageAnnualReturnYear10	5.68%
Nuveen Small Cap Index Fund | Russell 2000® Index (reflects no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	4.89%	[5]
5 Years	rr_AverageAnnualReturnYear05	15.55%	[5]
10 Years	rr_AverageAnnualReturnYear10	7.77%	[5]
Nuveen Small Cap Index Fund | Lipper Small-Cap Core Funds Classification Average (reflects no deduction for taxes or sales loads)
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	3.85%	[6]
5 Years	rr_AverageAnnualReturnYear05	14.41%	[6]
10 Years	rr_AverageAnnualReturnYear10	7.69%	[6]

[1] The contingent deferred sales charge on Class C shares applies only to redemptions within 12 months of purchase.

[2] Fee applies to the following types of accounts under $1,000 held directly with the Fund: individual retirement accounts (IRAs), Coverdell Education Savings Accounts and accounts established pursuant to the Uniform Transfers to Minors Act (UTMA) or Uniform Gifts to Minors Act (UGMA).

[3] The Fund's investment adviser has agreed to waive fees and/or reimburse other Fund expenses through September 30, 2016 so that total annual fund operating expenses (excluding 12b-1 distribution and/or service fees, interest expenses, taxes, Acquired Fund Fees and Expenses, fees incurred in acquiring and disposing of portfolio securities and extraordinary expenses) do not exceed 0.58% of the average daily net assets of any class of Fund shares. Fee waivers and/or expense reimbursements will not be terminated prior to that time without the approval of the Fund's Board of Directors.

[4] The performance of the other share classes will differ due to their different expense structures.

[5] An index that measures the performance of the small-cap segment of the U.S. equity universe. The Russell 2000® is a subset of the Russell 3000® Index representing approximately 10% of the total market capitalization of that index. It includes approximately 2,000 of the smallest securities based on a combination of their market cap and current index membership.

[6] Represents the average annualized total return for all reporting funds in the Lipper Small-Cap Core Funds Classification.