Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	SIT LARGE CAP GROWTH FUND INC
Prospectus Date	rr_ProspectusDate	Nov. 01, 2013
SIT MUTUAL FUNDS INC | Sit Global Dividend Growth Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	SUMMARY INFORMATION SIT GLOBAL DIVIDEND GROWTH FUND
Objective [Heading]	rr_ObjectiveHeading	INVESTMENT OBJECTIVE
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Fund seeks to provide current income that exceeds the dividend yield of a composite index (comprised of 60% S&P 500 Index and 40% MSCI EAFE Index) and that grows over a period of years.
Objective, Secondary [Text Block]	rr_ObjectiveSecondaryTextBlock	Secondarily the Fund seeks long-term capital appreciation.
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.
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)
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	PORTFOLIO TURNOVER
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The Fund pays transactions 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 in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 26.15% (both classes) of the average value of the portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	26.15%
Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text]	rr_ExpensesNotCorrelatedToRatioDueToAcquiredFundFees	The total annual fund operating expenses do not correlate to the ratio of expenses to average net assets shown in the Fund’s Financial Highlights, which does not include Acquired Fund Fees and Expenses.
Expense Example [Heading]	rr_ExpenseExampleHeading	Example
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. It assumes that you invest $10,000 in the Fund for the time periods indicated, that your investment has a 5% return each year, that the Fund’s operating expenses remain the same, and that you redeem all of your shares at the end of those periods. Although your actual costs and returns may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading]	rr_StrategyHeading	PRINCIPAL INVESTMENT STRATEGIES
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The Fund seeks to achieve its objectives by investing, under normal market conditions, at least 80% of its net assets in dividend-paying common stocks issued by U.S. and foreign companies. The Fund may invest the balance of its assets in preferred stocks, convertible bonds, U.S. Treasury securities, closed-end investment companies, and master limited partnerships. The Fund's diversified portfolio is designed to have lower volatility than that of the MSCI World Index, but with a higher yield and greater prospects for dividend growth. The Adviser invests in dividend paying growth-oriented companies it believes exhibit the potential for growth and growing dividend payments. The Adviser believes that a company's earnings growth is a primary determinant of its potential long-term return, and that a record of increasing dividend payments is a strong indicator of financial health and growth prospects. By investing in dividend paying stocks it is anticipated that the holdings will tend to be in large to medium-sized companies (companies with market capitalization in excess of $2 billion). The Adviser considers several factors in its evaluation of a company's potential for above average long-term earnings, revenue, and dividend growth, including: a record of paying dividends, strong prospects for growing dividend payments indicated in part by growing earnings and cash flow, unique product or service, growing product demand, dominant and growing market share, management experience and capabilities, and strong financial condition. Since stocks that pay dividends tend to be less volatile and may not experience the same capital appreciation as stocks that don't pay dividends, the Fund's diversified portfolio of dividend paying stocks is expected to have lower volatility than that of the MSCI World Index, but with a higher dividend yield and greater prospects for dividend growth. The Fund diversifies its investments among a number of different countries throughout the world, but not fewer than three countries. Under normal market conditions, the Fund will invest significantly (at least 30% of its net assets) in companies outside the U.S. When selling equity securities for the Fund, the Adviser considers several factors, including changes in the company's fundamentals, anticipated earnings, anticipated dividend payments and financial position.
Risk [Heading]	rr_RiskHeading	PRINCIPAL INVESTMENT RISKS
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	You could lose money by investing in the Fund. The principal risks of investing in the Fund are as follows: Dividend Paying Company Risk: The Fund's income objective may limit its ability to appreciate during a broad market advance because dividend paying stocks may not experience the same capital appreciation as non-dividend paying stocks. In addition, stocks held by the Fund may reduce or stop paying dividends which could affect the Fund's ability to generate income. Growth Style Investing Risk: Different types of stocks tend to shift into and out of favor with stock market investors depending on market and economic conditions. The Fund invests in growth style stocks. The Fund's performance may at times be better or worse than the performance of funds that focus on other types of stocks or that have a broader investment style. International Investing Risk: International investing involves risks not typically associated with investing in U.S. securities which may adversely affect the Fund's investment. These risks include currency risk, foreign securities market risk, foreign tax risk, information risk, investment restriction risk, and political and economic risks. Management Risk: A strategy used by the investment management team may not produce the intended results. Market Risk: The market value of securities may fall or fail to rise. Market risk may affect a single issuer, sector of the economy, or the market as a whole. The market value of securities may fluctuate, sometimes rapidly and unpredictably. Mid Cap Stock Risk: Stocks of mid cap stocks may be subject to more abrupt or erratic market movement than stocks of larger, more established companies.
Risk Lose Money [Text]	rr_RiskLoseMoney	You could lose money by investing in the Fund.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	HISTORICAL PERFORMANCE
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The following bar chart and table provide information on the Fund’s volatility and performance. The Fund’s past performance before and after taxes is not necessarily an indication of how the Fund will perform in the future. The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year for Class I shares. The table below compares the Fund’s performance over different time periods to that of the Fund’s benchmark index, which is a broad measure of market performance. Updated performance information is available at the Fund’s website at www.sitfunds.com or by calling 800-332-5580. After-tax returns are calculated using historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns are shown only for Class I shares; after-tax returns for Class S shares will vary.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The bar chart below is intended to provide you with an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year for Class I shares. The table below compares the Fund’s performance over different time periods to that of the Fund’s benchmark index, which is a broad measure of market performance.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	800-332-5580
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.sitfunds.com
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	Annual Total Returns for calendar years ended December 31 (Class I)
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	The Fund's year-to-date return as of 9/30/13 (not annualized) was 13.92% Best Quarter: 16.30% (2Q09); Worst Quarter: -16.65% (3Q11)
Performance Table Heading	rr_PerformanceTableHeading	Average Annual Total Returns for periods ended December 31, 2012
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	After-tax returns are calculated using 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	Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.
Performance Table One Class of after Tax Shown [Text]	rr_PerformanceTableOneClassOfAfterTaxShown	After-tax returns are shown only for Class I shares; after-tax returns for Class S shares will vary.
SIT MUTUAL FUNDS INC | Sit Global Dividend Growth Fund | Sit Global Dividend Growth Fund - Class I
Risk/Return:	rr_RiskReturnAbstract
Redemption Fee (as a percentage of amount redeemed only on shares held for less than 30 days)	rr_RedemptionFeeOverRedemption	2.00%
Management Fees	rr_ManagementFeesOverAssets	1.25%
Distribution (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	none
Acquired Fund Fees and Expenses	rr_AcquiredFundFeesAndExpensesOverAssets	0.30%	[1]
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	1.55%	[1]
1 Year	rr_ExpenseExampleYear01	$ 159
3 Years	rr_ExpenseExampleYear03	493
5 Years	rr_ExpenseExampleYear05	850
10 Years	rr_ExpenseExampleYear10	1,856
2008	rr_AnnualReturn2008	(5.25%)
2009	rr_AnnualReturn2009	24.65%
2010	rr_AnnualReturn2010	11.58%
2011	rr_AnnualReturn2011	(2.58%)
2012	rr_AnnualReturn2012	13.61%
Year to Date Return, Label	rr_YearToDateReturnLabel	Fund's year-to-date return
Bar Chart, Year to Date Return, Date	rr_BarChartYearToDateReturnDate	Sep. 30, 2013
Bar Chart, Year to Date Return	rr_BarChartYearToDateReturn	13.92%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Best Quarter:
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Jun. 30, 2009
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	16.30%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Worst Quarter:
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Sep. 30, 2011
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(16.65%)
1 Year	rr_AverageAnnualReturnYear01	13.61%
Life of Fund	rr_AverageAnnualReturnSinceInception	9.27%
Inception Date	rr_AverageAnnualReturnInceptionDate	Sep. 30, 2008
SIT MUTUAL FUNDS INC | Sit Global Dividend Growth Fund | Sit Global Dividend Growth Fund - Class S
Risk/Return:	rr_RiskReturnAbstract
Redemption Fee (as a percentage of amount redeemed only on shares held for less than 30 days)	rr_RedemptionFeeOverRedemption	2.00%
Management Fees	rr_ManagementFeesOverAssets	1.25%
Distribution (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Acquired Fund Fees and Expenses	rr_AcquiredFundFeesAndExpensesOverAssets	0.30%	[1]
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	1.80%	[1]
1 Year	rr_ExpenseExampleYear01	185
3 Years	rr_ExpenseExampleYear03	571
5 Years	rr_ExpenseExampleYear05	983
10 Years	rr_ExpenseExampleYear10	$ 2,130
1 Year	rr_AverageAnnualReturnYear01	13.35%
Life of Fund	rr_AverageAnnualReturnSinceInception	9.00%
Inception Date	rr_AverageAnnualReturnInceptionDate	Sep. 30, 2008
SIT MUTUAL FUNDS INC | Sit Global Dividend Growth Fund | Return after taxes on distributions | Sit Global Dividend Growth Fund - Class I
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	13.18%
Life of Fund	rr_AverageAnnualReturnSinceInception	8.90%
SIT MUTUAL FUNDS INC | Sit Global Dividend Growth Fund | Return after taxes on distributions and sale of Fund shares | Sit Global Dividend Growth Fund - Class I
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	9.38%
Life of Fund	rr_AverageAnnualReturnSinceInception	7.99%
SIT MUTUAL FUNDS INC | Sit Global Dividend Growth Fund | MSCI World Index (reflects no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	15.83%	[2]
Life of Fund	rr_AverageAnnualReturnSinceInception	5.25%	[2]
SIT MUTUAL FUNDS INC | Sit Global Dividend Growth Fund | Composite Index (reflects no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	16.64%	[2]
Life of Fund	rr_AverageAnnualReturnSinceInception	5.94%	[2]
SIT MUTUAL FUNDS INC | Sit Global Dividend Growth Fund | S&P 500® Index (reflects no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	16.00%
Life of Fund	rr_AverageAnnualReturnSinceInception	7.22%
SIT MUTUAL FUNDS INC | Sit Global Dividend Growth Fund | MSCI EAFE Index (reflects no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
1 Year	rr_AverageAnnualReturnYear01	17.32%
Life of Fund	rr_AverageAnnualReturnSinceInception	3.79%

[1] The total annual fund operating expenses do not correlate to the ratio of expenses to average net assets shown in the Fund's Financial Highlights, which does not include Acquired Fund Fees and Expenses. Acquired Fund Fees and Expenses represent fees and expenses incurred indirectly by the Fund as a result of its investment in shares of investment companies.

[2] The index used to compare the Fund's performance was changed to the MSCI World Index from a composite index (comprised of 60% S&P 500® Index and 40% MSCI EAFE Index) because the Fund's investment adviser believes that the MSCI World Index is a more appropriate and more widely available broad-based securities market index. It will be used to compare the Fund's performance going forward.